Ecologie: Sous les pavés, l’enfer des bonnes intentions ? (Disneyfied Eden: Was Rachel Carson wrong?)

Les joncs de l’étang sont flétris et aucun oiseau ne chante. Keats
Depuis l’interdiction, deux millions de personnes par an, principalement des enfants, meurent du paludisme. Cette interdiction a causé plus de cinquante millions de morts inutiles. Interdire le DDT a tué plus de personnes qu’Hitler. C’était si sûr qu’on pouvait le manger. Ted (State of Fear, Michael Crichton, 2004)
La prophétie de malheur est faite pour éviter qu’elle ne se réalise; et se gausser ultérieurement d’éventuels sonneurs d’alarme en leur rappelant que le pire ne s’est pas réalisé serait le comble de l’injustice: il se peut que leur impair soit leur mérite. Hans Jonas
Hey, farmer, farmer put away your DDT now. Joni Mitchell
No responsible person contends that insect-borne disease should be ignored. The question that has now urgently presented itself is whether it is either wise or responsible to attack the problem by methods that are rapidly making it worse. The world has heard much of the triumphant war against disease through the control of insect vectors of infection, but it has heard little of the other side of the story – the defeats, the short-lived triumphs that now strongly support the alarming view that the insect enemy has been made actually stronger by our efforts. Even worse, we may have destroyed our very means of fighting. … What is the measure of this setback? The list of resistant species now includes practically all of the insect groups of medical importance. … Malaria programmes are threatened by resistance among mosquitoes. … Practical advice should be ‘Spray as little as you possibly can’ rather than ‘Spray to the limit of your capacity’ …, Pressure on the pest population should always be as slight as possible. Rachel Carson
Il est plus judicieux dans certains cas d’accepter de subir une faible quantité de dégâts, plutôt que de n’en subir aucun pendant un moment, mais de le payer sur le long terme en perdant son moyen de lutte [ceci est le conseil donné en Hollande par le Docteur Briejer en tant que directeur du Service de protection des plantes]. Un conseil pratique serait plus “Pulvérisez aussi peu que vous pouvez” que “Pulvérisez autant que possible”. Rachel Carson
Printemps silencieux” [Rachel Carson, 1962) a changé l’équilibre des forces dans le monde. Personne ne peut plus présenter aussi facilement la pollution comme un effet secondaire et nécessaire du progrès sans être critiqué. H. Patricia Hynes
Rachel Carson’s Silent Spring (…) dramatizes in an effective fashion the losses that society has suffered from the use of new pesticides. Her emphasis is upon the danger to human health and the possible irreparable damage to various forms of wildlife. Silent Spring is superbly written and beautifully illustrated with line drawings. The author has made an exhaustive study of the facts bearing on the problem. It is not, however, a judicial review or a balancing of the gains and losses; rather, it is the prosecuting attorney’s impassioned plea for action against the use of these new materials which have received such widespread acceptance, acceptance accorded because of the obvious benefits that their use has conferred. The author has reviewed many of the instances in which unfortunate accidents have occurred. In some cases the accidents were the result of carelessness; in others they were caused by widespread use of materials prior to adequate small-scale testing; in some instances the unfortunate effect on wildlife was a result of the failure of those who used the new pesticide to consider wildlife values. The author’s mode of approach to the use of pesticides will undoubtedly result in wider recognition of the fact that these chemicals are poisons and in a more careful and rigorous control of every step in the pathway that pesticide must travel, from the research laboratory, through the process of obtaining government approval, to use in the field. Perhaps the tremendous improvements in public health and welfare that have resulted from the use of these materials have caused us to become careless in our control and use of them. There are serious hazards involved in the use of pesticides. It has frequently been said: « There are no harmless chemicals, only harmless use of chemicals. » The recent case in which the death of several infants in a hospital was caused by the inadvertent use of salt instead of sugar in their food comes to mind. (…) The author gives no figures for deaths known to be due to pesticides, but her description of certain cases may leave the inlpression with the uninformed reader that such cases of death due to the direct effects of pesticides are numerous. Actually human deaths in the United States known to be caused by pesticides are less than 100 annually. To place this in proper perspective, consider that almost twice that many deaths are known to be caused by aspirin and that almost one-half as manv deaths are known to be caused by bee stings. Another example, in which the author’s choice of language may lead to false impressions, is her reference to the « fall of chemical death rain. » Many may be led to believe that, just as rain falls on all of our land, so is all of our land sprayed with pesticides. Actually less than 5 percent of all the area of the United States is annually treated with insecticides. (…) The author pleads for a return to the balance of nature as the method of controlling our pests. Greater use of biological control of pests would be desirable, but, if it is to be effective enough to meet human needs, it must result in upsetting the balance of nature. Mankind has been engaged in the process of upsetting the balance of nature since the dawn of civilization. Certain species of plant and animal life that serve the economic or esthetic needs of mankind have been nurtured with great care; other species that have interfered with the health, comfort, or welfare of mankind have been attacked with great vigor; the large majority of the species have been ignored by all but a small portion of the population. Fortunately there is a growing concern, coupled with positive action, for the preservation of all forms of plant and animal life. This effort to preserve our wildlife is too late to save some species and too little to save others, but an encouraging start is being made. Undoubtedly mankind’s own self-interests have suffered in the past and are still suffering because of his callous disregard of the damage he does to other species of plant and animal life. But it is equally certain that modern agriculture and modern public health, indeed, modern civilization, could not exist without an unrelenting war against a return of a true balance of nature. Just as it is important for us to be reminded of the dangers inherent in the use of the new pesticides, so must our people also be made aware of the tremendous values to human welfare conferred by the new pesticides. No attempt is made by the author to portray the many positive benefits that society derives from the use of pesticides. No estimates are made of the countless lives that have been saved because of the destruction of insect vectors of disease. No mention is made of the fact that the average length of human life has steadily increased over the last several years. No consideration is given to the important role played by modern pesticides in the production of food and fiber. The author does suggest that, with a surplus of food in the United States, we might well curtail the use of pesticides. Although the United States has a surplus of food, over one half of the people of the world go to bed hungry each night. The greater use of pesticides in most sections of the world would increase food production, alleviate hunger, and improve the health of the people. Modern agriculture, with its high-quality foods and fibers, could not exist without the use of pesticides. Weeds, disease, and insect pests would take an extremely heavy toll if these chemicals were not used. The yields per acre, the yields per man hour, and the quality of the product would all suffer materially if these chemicals were withdrawn from use. One cannot do more than guess about the changes that would be necessary in American society if pesticides were banned. An immediate back-to-the-farm movement would be necessary, and this would involve many millions of people. It is hoped that someone with Rachel Carson’s ability will write a companion volume dramatizing the improvements in human health and welfare derived from the use of pesticides. Such a story would be far more dramatic than the one told by Miss Carson in Silent Spring, which deals with the losses society has sustained or may suffer in the future because of the use of these materials. (…) The story of Silent Spring, so well told by Rachel Carson, even though it presents only one side of a very complex problem, will serve a useful purpose, if research on better methods of pest control is stimulated and if all concerned with the production, control, and use of pesticides are stimulated to exercise greater care in the protection of the public welfare. In the meantime it is my hope that some equally gifted writer will be willing to do the necessary research and to write the even more dramatic story of the values conferred on mankind by the chemical revolution of the last two decades. Ira L. Balwin
The human costs have been horrific in the poor countries where malaria returned after DDT spraying was abandoned. Malariologists have made a little headway recently in restoring this weapon against the disease, but they’ve had to fight against Ms. Carson’s disciples who still divide the world into good and bad chemicals, with DDT in their fearsome “dirty dozen.” Ms. Carson didn’t urge an outright ban on DDT, but she tried to downplay its effectiveness against malaria and refused to acknowledge what it had accomplished. As Dr. Baldwin wrote, “No estimates are made of the countless lives that have been saved because of the destruction of insect vectors of disease.” He predicted correctly that people in poor countries would suffer from hunger and disease if they were denied the pesticides that had enabled wealthy nations to increase food production and eliminate scourges. The NYT (05.06.07)
The book did point to problems that had not been adequately addressed, such as the effects of DDT on some wildlife. And given the state of the science at the time she wrote, one might even make the case that Carson’s concerns about the effects of synthetic chemicals on human health were not completely unwarranted. Along with other researchers, she was simply ignorant of the facts. But after four decades in which tens of billions of dollars have been wasted chasing imaginary risks without measurably improving American health, her intellectual descendants don’t have the same excuse. Ronald Bailey (Reason magazine,  2002)
Carson didn’t seem to take into account the vital role (DDT) played in controlling the transmission of malaria by killing the mosquitoes that carry the parasite (…) It is the single most effective agent ever developed for saving human life (…) Rachel Carson is a warning to us all of the dangers of neglecting the evidence-based approach and the need to weight potential risk against benefit: it can be argued that the anti-DDT campaign she inspired was responsible for almost as many deaths as some of the worst dictators of the last century. Dick Taverne
Millions of people around the world suffer the painful and often deadly effects of malaria because one person sounded a false alarm. That person is Rachel Carson. Rachelwaswrong.org (Competitive Enterprise Institute, 2009)
The truth is that DDT is neither superhero nor supervillain — it’s just a tool. And if entomologists have learned anything in the last half-century of dealing with the million-plus species of insects in the world, it’s that there is no such thing as an all-purpose weapon when it comes to pest management. DDT may be useful in controlling malaria in some places in Africa, but it’s essential to determine whether target populations are resistant; if they are, then no amount of DDT will be effective. We have new means of determining whether populations are genetically prone to developing resistance. DDT advocates are right to suggest that DDT may be useful as a precision instrument under some circumstances, particularly considering that environmental contamination in Africa may be less of a problem than it has been in temperate ecosystems because the chemical can degrade faster due to higher temperatures, moisture levels and microbial activity. Moreover, resistance evolves due to random mutation, so there are, by chance, malaria-carrying mosquito species in Africa that remain susceptible to DDT despite more than two decades of exposure to the chemical. But environmentalists are right to worry that the unwise use of DDT, particularly where it is likely to be ineffective, may cause environmental harm without any benefit. In 2000, I chaired a National Research Council committee that published a study titled « The Future Role of Pesticides in U.S. Agriculture. » Our principal recommendation is germane to discussions of malaria management: « There is no justification for completely abandoning chemicals per se as components in the defensive toolbox used for managing pests. The committee recommends maintaining a diversity of tools for maximizing flexibility, precision, and stability of pest management. » May Berenbaum
We must take a position based on the science and the data. One of the best tools we have against malaria is indoor residual spraying. Of the dozen or so insecticides WHO has approved as safe for house spraying, the most effective is DDT.  Arata Kochi (WHO’s malaria chief, 2006)
In 2006, after 25 years and 50 million preventable deaths, the World Health Organization reversed course and endorsed widespread use of the insecticide DDT to combat malaria. So much for that. Earlier this month, the U.N. agency quietly reverted to promoting less effective methods for attacking the disease. The result is a victory for politics over public health, and millions of the world’s poor will suffer as a result. The U.N. now plans to advocate for drastic reductions in the use of DDT, which kills or repels the mosquitoes that spread malaria. The aim « is to achieve a 30% cut in the application of DDT worldwide by 2014 and its total phase-out by the early 2020s, if not sooner, » said WHO and the U.N. Environment Program in a statement on May 6. Citing a five-year pilot program that reduced malaria cases in Mexico and South America by distributing antimalaria chloroquine pills to uninfected people, U.N. officials are ready to push for a « zero DDT world. » Sounds nice, except for the facts. It’s true that chloroquine has proven effective when used therapeutically, as in Brazil. But it’s also true that scientists have questioned the safety of the drug as an oral prophylactic because it is toxic and has been shown to cause heart problems. Most malarial deaths occur in sub-Saharan Africa, where chloroquine once worked but started failing in the 1970s as the parasite developed resistance. Even if the drugs were still effective in Africa, they’re expensive and thus impractical for one of the world’s poorest regions. That’s not an argument against chloroquine, bed nets or other interventions. But it is an argument for continuing to make DDT spraying a key part of any effort to eradicate malaria, which kills about a million people — mainly children — every year. Nearly all of this spraying is done indoors, by the way, to block mosquito nesting at night. It is not sprayed willy-nilly in jungle habitat. WHO is not saying that DDT shouldn’t be used. But by revoking its stamp of approval, it sends a clear message to donors and afflicted countries that it prefers more politically correct interventions, even if they don’t work as well. In recent years, countries like Uganda, Tanzania and Zambia have started or expanded DDT spraying, often with the help of outside aid groups. But these governments are also eager to remain in the U.N.’s good graces, and donors typically are less interested in funding interventions that WHO discourages. The  WSJ (2007)
La prohibition du DDT, sous la pression des groupes environnementaux des pays riches dans les années 1970, a provoqué une recrudescence du paludisme dans le Sud, c’est-à-dire des millions de morts, même si la controverse sur la nocivité de cet insecticide se poursuit de nos jours. Pascal Bruckner
Il n’est pas exagéré de dire que ceux qui promurent l’interdiction [du DDT] portent une part de responsabilité indirecte dans les dizaines de millions de morts du paludisme qui ont été recensés depuis quarante ans. Bruno Tertrais
L’histoire du DDT est au livre écolophobe ce que la fève est à la galette des Rois : on est sûr de l’y découvrir. Elle est pourtant complètement imaginaire. Au moins les lecteurs du Monde sont-ils désormais informés. Pour ses usages de contrôle des moustiques vecteurs de maladies comme le paludisme, le DDT n’a jamais été interdit en Afrique. Ni, du reste, nulle part ailleurs… Et, en tout état de cause, les mouvements écologistes des pays du Nord n’ont guère le pouvoir de faire interdire quoi que ce soit dans les pays du Sud. Une subtile variante de cette légende urbaine veut que l’Agence américaine pour le développement international (Usaid) ait refusé de financer des programmes de lutte contre le paludisme pour cause d’utilisation du DDT. L’opprobre écologiste sur le fameux insecticide aurait poussé l’agence américaine à une manière de politiquement correct « vert » et meurtrier… Sur Internet, où un lien hypertexte a trop souvent valeur de preuve, cette affirmation est omniprésente. A tel point qu’elle s’impose désormais comme la version officielle de l’histoire. A tel point, aussi, que l’Usaid a publié en 2005, sur son site Internet, une mise au point spécifiant qu’aucun financement de projet n’avait jamais été rejeté au motif de l’utilisation du DDT. Enfin et pour finir, le seul texte international qui réglemente l’usage du fameux DDT est la convention de Stockholm sur les polluants organiques persistants – librement signée et ratifiée par les Etats parties -, dont l’annexe B précise explicitement que tout usage du DDT à des fins de contrôle des vecteurs de maladies est autorisé… C’est d’ailleurs toujours le cas dans certains pays.  Le Monde
 Il est très difficile de savoir qui a inventé cette histoire. Mais ce que nous pouvons dire, c’est qu’on la voit émerger il y a un peu plus d’une dizaine d’années et que l’organisation qui en a fait la plus forte promotion sur Internet est le Competitive Entreprise Institute, un think tank libertarien en lutte contre toute forme de régulation de l’activité économique… (…) Je suis très surprise et aussi attristée que des intellectuels français reprennent cette histoire où tout est faux. L’idée que ce serait une sorte d’hystérie environnementaliste qui aurait poussé à l’interdiction du DDT aux Etats-Unis ne tient simplement pas la route : c’est un comité de chercheurs, par ailleurs tous assez conservateurs, qui a travaillé pendant dix ans pour parvenir en 1972, c’est-à-dire sous la présidence de Richard Nixon – un républicain ! -, à la conclusion qu’il fallait limiter l’usage de cette molécule… Aujourd’hui, il est vrai que le DDT est beaucoup moins utilisé dans le monde, mais c’est principalement parce que des résistances sont apparues dans les populations de moustiques. (…) C’est une révision de l’histoire dont le seul but est de discréditer a priori toute forme de régulation environnementale. Naomi Oreske
Près de trente ans après l’abandon progressif de la pulvérisation à grande échelle de DDT et d’autres insecticides dans les habitations pour lutter contre le paludisme, l’Organisation mondiale de la Santé (OMS) a annoncé aujourd’hui que cette méthode allait de nouveau jouer un rôle important dans son combat contre la maladie. L’OMS recommande désormais la pulvérisation d’insecticide à effet rémanent à l’intérieur des habitations non seulement dans les zones d’épidémie palustre mais aussi dans celles où la transmission de la maladie est constamment élevée, notamment dans toute l’Afrique. Communiqué OMS (2006)
Les données scientifiques et programmatiques justifient sans conteste cette réévaluation (…) la pulvérisation d’insecticide à effet rémanent dans les maisons est utile pour réduire rapidement le nombre de personnes contaminées par les moustiques porteurs de la maladie. Elle s’est révélée d’un aussi bon rapport coût/efficacité que les autres mesures de prévention du paludisme et le DDT ne présente pas de risque pour la santé s’il est correctement utilisé.  (…) Nous devons fonder notre position sur la science et les données objectives. (…) L’une des meilleures armes que nous ayons contre le paludisme est la pulvérisation d’insecticide à effet rémanent dans les habitations. Sur la douzaine d’insecticides que l’OMS juge sans danger pour cet usage, le plus efficace est le DDT. Dr Anarfi Asamoa-Baah, (Sous-Directeur général de l’OMS chargé du VIH/SIDA, de la tuberculose et du paludisme, 2006)
De leur côté, les Etats-Unis ne peuvent qu’être hostiles à la poursuite du protocole de Kyoto. Ce serait un suicide politique pour Barack Obama d’y adhérer alors que la population y est très défavorable – elle se montre même sceptique sur la responsabilité humaine du réchauffement climatique ! Les industries énergétiques ont subventionné le déni pendant des années. Et elles ont très bien réussi. Si Barack Obama va à contre-courant, il sait qu’il perdra la Maison Blanche. Gwynne Dyer
En France, le libéralisme économique n’est pas le principal ressort de la défiance vis-à-vis des sciences de l’environnement. C’est plutôt notre rapport au progrès qui en est le moteur, progrès que nous associons généralement à la technique. Source de bien-être et de désaliénation des hommes, la technologie est aussi devenue source de nuisances et de dangers, alors que « beaucoup tiennent énormément à l’idée qu’elle permet et permettra de régler tous les problèmes. (…)  J’ai personnellement le sentiment que nous n’avons pas eu le bon débat. Pour ce qui est de la question climatique, le débat qui a été mis en avant a été celui de la réalité ou des causes principales du changement climatique, ce sur quoi il n’y a pas vraiment de débats dans la communauté scientifique. En revanche, le débat sur la manière dont nous devons nous adapter et nous préparer au changement climatique qui vient, nous ne l’avons pas eu. Valérie Masson-Delmotte

Sous les pavés, l’enfer des bonnes intentions ?

A l’heure où, du fait de l’opposition tant de pays émergents comme l’Inde que d’une Amérique qui trois ans après Bush n’a toujours pas signé Kyoto, une énième conférence des Nations unies sur le climat s’achève par la décision de reporter toute décision à 2015 …

Et où Le Monde remet dûment à sa place un Pascal Bruckner accusé de propager les pires mensonges contre la doxa écolo …

Pendant qu’en Europe le soja bio tueur fait plus de victimes en quelques jours que l’accident nucléaire de Fukushima (une quarantaine de morts et 4 000 intoxiqués sur 12 pays contaminés contre 0 mort et une vingtaine de faiblement à moyennement irradiés) …

Retour sur la question qui, avec le célèbre livre de l’Américaine Rachel Carson (Printemps silencieux, 1962) lança justement l’écologie moderne.

A savoir celle du DDT, accusé alors d’être « cancérigène et d’empêcher la reproduction des oiseaux en amincissant la coquille de leurs œufs » mais dont Carson elle-même, contrairement à nombre de ses émules, n’excluait pas une utilisation raisonnée …

Pour découvrir, à l’instar d’une OMS ayant pendant 30 ans découragé son utilisation dans la lutte antipaludique (du fait, notamment, de l’apparition de résistances dans les populations de moustiques) puis prôné (non, il est vrai, sans contestation interne) en 2006 sa réutilisation avant, trois ans plus tard, d’annoncer son objectif de sa mise à l’écart définitive pour le début des années 2020 …

Une communauté scientifique apparemment bien plus divisée et une question bien plus controversée et complexe  que ne le laisseraient croire les péremptoires jugements de nos censeurs du Monde.

Pour une condition qui continue à faire, chaque année et notamment en Afrique, quelque 250 millions de nouveaux cas et 800 000 victimes  …

La rhétorique de la dérision en défaut

Nicolas Weill

Le Monde

23.11.11

Mettre les rieurs de son côté, voilà un talent que maîtrise à coup sûr Pascal Bruckner. Ce talent, il le prodigue aujourd’hui pour dénoncer un discours écologique supposé dominant. La thèse du livre au titre emprunté à l’historien Norman Cohn (Les Fanatiques de l’Apocalypse – Julliard, 1962) est simple : le souci de l’environnement aurait tourné en Occident à une manie de la contrition dont le but serait moins le salut de la planète que la satisfaction d’un masochisme postchrétien prônant le châtiment, voire l’extinction de l’homme. Après Le Nouvel Ordre écologique de Luc Ferry (Grasset, 1992), voilà Pascal Bruckner qui reprend le slogan lancé en 1990 par le philosophe Marcel Gauchet dans la revue Le Débat : « Sous l’amour de la nature, la haine de l’homme ».

En concédant la nécessité d’une « écologie d’admiration » (du monde) pour remplacer l’« écologie d’accusation » (de l’homme), Pascal Bruckner décoche ses traits sur les excès, les cocasseries, les exagérations d’un milieu où la prophétie de malheur soutenue par des observations scientifiques ne laisse que peu de place à l’humour. Mais l’absence d’humour justifie-t-elle à elle seule les simplifications bruckneriennes ? Sans parler des contre-vérités comme l’imputation aux écologistes de la recrudescence du paludisme en Afrique (Le Monde du 5 novembre). L’inquiétude pour l’avenir de la Terre est en réalité l’objet d’une discussion savante, technique même. Il est simple voire simpliste de la ravaler à un millénarisme aux ténébreuses racines théologiques.

Certes, les exemples produisent un effet comique : l’enfant incité dans une ferme biologique de Californie à plonger son bras nu dans du fumier pour « mieux sentir les entrailles de Gaïa » (la Terre) ; le conseil d’uriner dans la douche pour économiser les chasses d’eau ; les calculs maniaques de la moindre dépense susceptible d’approfondir notre « empreinte écologique » sur la planète, etc. Mais, quand on prétend par ce procédé damer le pion à certains des plus grands penseurs de l’écologie – le philosophe Hans Jonas (systématiquement qualifié d’« allemand » et d’« heideggérien », en oubliant que, juif et sioniste, il combattit le nazisme sous uniforme britannique), Günther Anders (l’un des premiers à avoir conceptualisé l’effroi nucléaire), André Gorz, etc. -, cette rhétorique de la dérision n’est guère convaincante.

Surtout quand elle se résume à un unique procédé : renverser les positions de l’adversaire en leur contraire. Le catastrophisme écologiste se réduit, pour Bruckner, à un anthropocentrisme délirant où nos moindres faits et gestes (choisir une ampoule à basse consommation, ne plus consommer de viande, limiter ses déplacements en avion) auraient des conséquences cosmiques. Pis, les écologistes seraient les complices objectifs d’un capitalisme où la crise accroît les inégalités, en cherchant par leur ascétisme branché à habituer les pauvres à leur misère…

Sans compter l’injuste et classique assimilation de l’écologie au fascisme (c’est Vichy qui encourage la bicyclette !). Le réductionnisme finit dans l’insignifiance.

 Voir aussi:

Haro sur les écolos !

Les ouvrages qui pourfendent l’«intégrisme vert» fleurissent depuis trois ans, l’essai de Pascal Bruckner en est le dernier exemple. La plupart de ces livres utilisent pourtant des arguments mensongers

Stéphane Foucart

Le Monde

05.11.11

Les écologistes sont des génocidaires. Des meurtriers de masse. Leurs lubies d’enfants gâtés tuent chaque année, indirectement, des millions d’enfants africains. A lire ce petit paragraphe de la page 175 du dernier livre de Pascal Bruckner (Grasset), c’est un peu ce qui vient à l’esprit. « La prohibition du DDT, sous la pression des groupes environnementaux des pays riches dans les années 1970, a provoqué une recrudescence du paludisme dans le Sud, c’est-à-dire des millions de morts, même si la controverse sur la nocivité de cet insecticide se poursuit de nos jours », écrit l’ancien nouveau philosophe.

La puissance de feu rhétorique de l’« argument du DDT » est formidable. Lorsqu’il survient dans les conversations, les écologistes regardent leurs pieds. Ils préfèrent tirer pudiquement le voile de l’oubli sur cette déplorable affaire. Mais pour ceux qui les affrontent, l’histoire de cet insecticide miracle répudié par le « fanatisme vert » est un cadeau du ciel. Ils le gardent précieusement par-devers eux comme l’argument définitif – un de ces traits capables de clore, pour de bon, une conversation enflammée sur la place de l’homme dans la nature.

Dans la blogosphère, l’argument du DDT est partout. Et aussi, sous une forme ou une autre, dans tous les livres dont le titre arbore le mot « apocalypse »… Dans son dernier essai, le politologue Bruno Tertrais (L’apocalypse n’est pas pour demain, Denoël) le dégaine en page 50 : « Il n’est pas exagéré de dire que ceux qui promurent l’interdiction [du DDT] portent une part de responsabilité indirecte dans les dizaines de millions de morts du paludisme qui ont été recensés depuis quarante ans ». L’économiste de la santé Jean de Kervasdoué, dans Les Prêcheurs de l’apocalypse (Plon, 2007), propose à ses lecteurs le même argument – à quelques variations cosmétiques près.

L’histoire du DDT est au livre écolophobe ce que la fève est à la galette des Rois : on est sûr de l’y découvrir. Elle est pourtant complètement imaginaire. Au moins les lecteurs du Monde sont-ils désormais informés. Pour ses usages de contrôle des moustiques vecteurs de maladies comme le paludisme, le DDT n’a jamais été interdit en Afrique. Ni, du reste, nulle part ailleurs… Et, en tout état de cause, les mouvements écologistes des pays du Nord n’ont guère le pouvoir de faire interdire quoi que ce soit dans les pays du Sud.

Une subtile variante de cette légende urbaine veut que l’Agence américaine pour le développement international (Usaid) ait refusé de financer des programmes de lutte contre le paludisme pour cause d’utilisation du DDT. L’opprobre écologiste sur le fameux insecticide aurait poussé l’agence américaine à une manière de politiquement correct « vert » et meurtrier… Sur Internet, où un lien hypertexte a trop souvent valeur de preuve, cette affirmation est omniprésente. A tel point qu’elle s’impose désormais comme la version officielle de l’histoire. A tel point, aussi, que l’Usaid a publié en 2005, sur son site Internet, une mise au point spécifiant qu’aucun financement de projet n’avait jamais été rejeté au motif de l’utilisation du DDT. Enfin et pour finir, le seul texte international qui réglemente l’usage du fameux DDT est la convention de Stockholm sur les polluants organiques persistants – librement signée et ratifiée par les Etats parties -, dont l’annexe B précise explicitement que tout usage du DDT à des fins de contrôle des vecteurs de maladies est autorisé… C’est d’ailleurs toujours le cas dans certains pays.

Dans un livre important à paraître en France au printemps (Les Marchands de doute, Ed. Le Pommier, publié en anglais sous le titre Merchants of Doubt, Bloomsbury), les historiens des sciences américains Naomi Oreskes (université de Californie à San Diego) et Erik Conway (Jet Propulsion Laboratory) ont remonté la piste de cette fable moderne. « Il est très difficile de savoir qui a inventé cette histoire, raconte Naomi Oreskes. Mais ce que nous pouvons dire, c’est qu’on la voit émerger il y a un peu plus d’une dizaine d’années et que l’organisation qui en a fait la plus forte promotion sur Internet est le Competitive Entreprise Institute, un think tank libertarien en lutte contre toute forme de régulation de l’activité économique… »

« Je suis très surprise et aussi attristée que des intellectuels français reprennent cette histoire où tout est faux, ajoute Mme Oreskes. L’idée que ce serait une sorte d’hystérie environnementaliste qui aurait poussé à l’interdiction du DDT aux Etats-Unis ne tient simplement pas la route : c’est un comité de chercheurs, par ailleurs tous assez conservateurs, qui a travaillé pendant dix ans pour parvenir en 1972, c’est-à-dire sous la présidence de Richard Nixon – un républicain ! -, à la conclusion qu’il fallait limiter l’usage de cette molécule… Aujourd’hui, il est vrai que le DDT est beaucoup moins utilisé dans le monde, mais c’est principalement parce que des résistances sont apparues dans les populations de moustiques. »

Dans leur livre, les deux historiens exhument ainsi les rapports officiels de l’Organisation mondiale de la santé (OMS) qui faisaient état, dans les années 1970, des résistances développées par les insectes dans certains pays tropicaux, y justifiant l’abandon de l’insecticide miracle. L’« intégrisme vert » n’y apparaît pas pour grand-chose… Le plus cocasse est que, selon les chiffres du département américain de l’agriculture, l’usage à des fins agricoles du DDT avait déjà commencé à décliner en 1959 aux Etats-Unis, précisément en raison des résistances déjà émergentes.

Du coup, les deux historiens américains s’interrogent sur les motivations des inventeurs de cette fable du DDT. Il y a là un mystère. A la fin des années 1990, quand elle apparaît sur le Net, le DDT n’est plus produit aux Etats-Unis. Il ne représente plus aucun enjeu économique… « C’est une révision de l’histoire dont le seul but est de discréditer a priori toute forme de régulation environnementale », dit Naomi Oreskes, qui note dans son livre que les organisations qui relaient l’« argument du DDT » sont aussi, invariablement, celles qui tentent avec le plus d’âpreté de discréditer les sciences de l’environnement dans leur ensemble.

Des histoires comme celle de l’« argument du DDT », il en existe des centaines. Et il faut bien constater qu’en matière d’écolophobie, les « éléments de langage » des groupes de pressions ultra-conservateurs américains mis en circulation sur le Net sont souvent repris, de bonne foi, par des intellectuels français, publiés par de prestigieuses maisons d’édition. « Internet est passé par là », s’amuse Naomi Oreskes.

Depuis quelques années, et singulièrement depuis l’échec du sommet de Copenhague sur le changement climatique, une abondante littérature est publiée chaque année pour faire pièce à l’« intégrisme vert » ; elle se place dans la lignée d’un prestigieux prédécesseur, L’Ecologiste sceptique (Le Cherche Midi, 2004), le best-seller du statisticien danois Bjorn Lomborg… dont on sait moins qu’il a fait l’objet d’un blâme officiel du Comité d’éthique des sciences du Danemark, qui a dénoncé en 2003 la « malhonnêteté scientifique » de l’ouvrage. Ses héritiers se vendent, eux aussi, très bien. Le dernier livre de Claude Allègre, L’Imposture climatique (Plon, 2010) s’est ainsi écoulé, selon son auteur, à quelque 180 000 exemplaires.

Réduire toute la littérature des pourfendeurs de l’« intégrisme vert » à une succession de contrevérités glanées sur Internet serait trompeur. Parfois, les auteurs frappent juste, démontant les outrances et l’irrationalisme de certains mouvements écologistes. Mais très souvent, les chevilles des argumentaires proposés par les écolophobes sont de grossières torsions de faits bien établis, qui font l’objet de larges consensus chez les scientifiques compétents.

Par exemple, dans L’apocalypse n’est pas pour demain, Bruno Tertrais cite, entre autres choses, une étude montrant que le réchauffement n’est pour rien dans le déclin des ours polaires de la baie de l’Hudson… Mais en fait d’étude, l’article qu’il cite est un « point de vue » aux allures de travail scientifique, rédigé par des chercheurs non spécialistes de la question (géologues et astrophysiciens) et explicitement rémunérés par le pétrolier Exxon et l’American Petroleum Institute.

L’augmentation des gaz à effet de serre dans l’atmosphère réchauffe le climat de la terre et ce réchauffement est, à terme, dangereux pour la stabilité des sociétés ; les chlorofluorocarbures (CFC) détruisent la couche d’ozone stratosphérique ; les effluents agricoles sont les responsables des « marées vertes » ; l’amiante est carcinogène, même à faibles doses, etc. De telles affirmations sont étayées par des centaines d’études publiées après expertise dans des revues scientifiques à comité de lecture. Or, dans une très large mesure, l’écolophobie prospère sur la relativisation ou la réfutation de telles connaissances. Souvent ces affirmations reposent sur des « études » bardées de calculs et de graphiques, mais n’ayant pas le statut de publication scientifique. Plus subtile, une autre technique consiste à citer sur un domaine précis une étude marginale et réfutée de longue date… en omettant bien sûr de préciser qu’elle a finalement été rejetée par les spécialistes de la discipline.

Le domaine le plus maltraité par cette vulgate est celui du climat. Un nombre étourdissant d’ouvrages y est consacré. Le plus célèbre, celui de Claude Allègre, a suscité en avril 2010 une levée de boucliers inédite dans l’histoire de la recherche française. Une lettre de protestation, signée par quelque 600 chercheurs des organismes de recherche (CNRS, CEA, INRA, etc.) et des universités, a été adressée aux grandes instances de la science française.

Connu pour son sens de la provocation, l’ancien ministre socialiste n’est pas le seul à prendre, sur le sujet du climat, d’amples libertés avec la science. L’essayiste Jean-Michel Bélouve (La Servitude climatique, Liber Media, 2009), le mathématicien Benoît Rittaud (Le Mythe climatique, Seuil, 2010) ou encore le patron de l’Automobile club de France, Christian Gérondeau (CO2. Un mythe planétaire, Editions du Toucan, 2009) ne sont pas en reste.

Eux aussi puisent ad libitum dans les arguments mis en circulation sur la Toile, hors de toute validation scientifique, où ils se répliquent à haut débit. Lors d’une conférence donnée voilà quelques mois à l’Assemblée nationale, M. Bélouve l’admettait d’ailleurs sans ambages : « Si cela vous intéresse, allez sur Internet, j’indique dans mon livre beaucoup de sites très intéressants, et vous deviendrez des savants, de véritables climatologues sceptiques de haut niveau. »

Quant au Mythe climatique, « il reprend très fidèlement ce qu’on peut lire dans la blogosphère américaine », estime la climatologue Valérie Masson-Delmotte, du Laboratoire des sciences du climat et de l’environnement (LSCE). De fait, la bibliographie de l’ouvrage arbore une quantité impressionnante de liens hypertextes. « De manière plus générale, les arguments ou les points de vue qu’on peut lire chez les auteurs climato-sceptiques français ne sont pas originaux, la plupart sont repris de ce qui circule sur Internet », dit la chercheuse, qui a consacré un récent ouvrage à démonter cette mythologie climatique moderne (Climat. Le vrai et le faux, Le Pommier, 2011).

Les emprunts à la blogosphère, directs ou indirects, sont parfois subtils, parfois massifs. Dans La Légende de l’effet de serre (Favre, 2011), François Meynard, chargé de l’organisation des cours du Collège des humanités de l’Ecole polytechnique fédérale de Lausanne (EPFL), a carrément copié-collé une vingtaine de pages du site Wikibéral – sorte d’encyclopédie collaborative écrite au prisme de la promotion du libéralisme économique. L’affaire a tout récemment fait scandale en Suisse.

L’activisme en ligne des think tanks américains ultraconservateurs ou libertariens a transformé la Toile en réservoir inépuisable d’arguments repris, traduits, enrichis et repris encore, même quand ils ont été réfutés et démontés par les chercheurs compétents. Le plus puissamment véhiculé est celui selon lequel le Groupe intergouvernemental d’experts sur l’évolution du climat (GIEC) serait infiltré par les écologistes et que ses rapports sur le réchauffement, rendus tous les six ans environ, seraient biaisés par un alarmisme systématique.

Comme l’« argument du DDT », cette idée est constamment reprise dans la littérature écolophobe. Elle est désormais si ancrée dans les esprits qu’elle permet à Luc Ferry de faire cette surprenante déclaration au Figaro : « Le GIEC, c’est un groupement où sont cooptés des patrons d’associations qui sont souvent des idéologues écologistes. » L’ancien ministre de l’éducation prépare justement, avec Claude Allègre, un nouvel ouvrage sur le sujet.

Pourtant, le GIEC est structurellement conçu pour produire les rapports les plus « conservateurs » possibles. Ces derniers représentent une synthèse consensuelle de la littérature scientifique, rédigée par plusieurs centaines de chercheurs et expertisée par des milliers d’autres… En outre, les documents synthétisant ces rapports sont endossés par l’ensemble des délégués des quelque 190 Etats parties à la Convention-cadre des Nations unies sur les changements climatiques – dont l’Arabie saoudite, la Chine, la Russie ou les Etats-Unis, dont l’intérêt d’agiter le chiffon rouge climatique n’est pas absolument évident…

Si les mêmes arguments sont repris des deux côtés de l’Atlantique, les motivations idéologiques sont très différentes. Pour Naomi Oreskes et Erik Conway, l’écolophobie américaine est surtout motivée par la défense de la liberté économique. Les questions environnementales sont vues comme des entraves à la liberté d’entreprendre – un avatar du communisme.

Mais le succès, en France, de cette littérature tient à d’autres ressorts. Le côté écrasant et culpabilisant de la glose écologiste n’y est pas étranger. « En France, le libéralisme économique n’est pas le principal ressort de la défiance vis-à-vis des sciences de l’environnement, dit Valérie Masson-Delmotte. C’est plutôt notre rapport au progrès qui en est le moteur, progrès que nous associons généralement à la technique. » Source de bien-être et de désaliénation des hommes, la technologie est aussi devenue source de nuisances et de dangers, alors que « beaucoup tiennent énormément à l’idée qu’elle permet et permettra de régler tous les problèmes », ajoute la climatologue.

A bien y regarder, la défiance vis-à-vis des sciences de l’environnement s’appuie sur de multiples ressorts idéologiques. « Nombreux sont ceux qui considèrent le diagnostic scientifique à travers la lorgnette de leurs préoccupations, rappelle Olivier Godard, chercheur au CNRS et à l’Ecole polytechnique et auteur de plusieurs contributions sur le climato-scepticisme. Par exemple, Elisabeth Badinter, dont le combat actuel est de lutter contre le retour du naturalisme dans les rapports entre les sexes, minore la question climatique, y voyant une menace naturaliste… »

En France, l’apparent consensus politique autour de ces questions n’est sans doute pas étranger au succès de la littérature écolophobe. « Aux Etats-Unis, ces questions sont politiquement beaucoup plus clivantes, note le philosophe Mathias Girel, maître de conférences à l’Ecole normale supérieure. Des questions scientifiques comme celle du changement climatique ont par exemple été abordées au cours de la primaire républicaine, et elles opposent clairement démocrates et républicains. Ce qui n’est pas le cas en France, où les sciences du climat sont en général acceptées par l’ensemble du spectre politique. »

Absent de la scène politique, le « débat » fait donc florès dans l’édition. Le débat ? « J’ai personnellement le sentiment que nous n’avons pas eu le bon débat, dit Valérie Masson-Delmotte. Pour ce qui est de la question climatique, le débat qui a été mis en avant a été celui de la réalité ou des causes principales du changement climatique, ce sur quoi il n’y a pas vraiment de débats dans la communauté scientifique. En revanche, le débat sur la manière dont nous devons nous adapter et nous préparer au changement climatique qui vient, nous ne l’avons pas eu. »

Voir également:

Haro sur les écolos !

L’écologie, « j’y pense et puis j’oublie »

Eric Collier

Le Monde

 05.11.11

Une petite Danica est née aux Philippines lundi 31 octobre, et la planète a basculé dans une nouvelle dimension : nous voici sept milliards de Terriens, plus que jamais contraints de penser à préserver une planète qu’on dit en danger. Pas d’inquiétude, tout est en place. Les scientifiques balisent la carte des risques, les gouvernements promettent d’en tenir compte, industriels et agriculteurs envisagent même de réorganiser (plus tard) leurs outils de production et, à l’échelon individuel, chacun est concentré sur ses objectifs, plus modestes : tri sélectif des ordures ménagères, douche plutôt que bain, fruits et légumes venus de moins loin, covoiturage, etc.

Jusqu’ici, tout va bien dans le meilleur des mondes (occidental). M. et Mme Tout-le-Monde et leurs enfants semblent convertis à ce que l’écrivain Iegor Gran nomme « la religion du petit geste », « ce petit geste qui vous soulage, l’équivalent du signe de croix qui vous protège si vous êtes chrétien ». Pourtant, in petto, la famille Tout-le-Monde paraît gagnée par le doute : tout cela n’est-il pas légèrement dérisoire ? Ces efforts « pour la planète » dont chacun se félicite, parfois bruyamment, sont-ils bien utiles ? Indispensables ?

En publiant L’Ecologie en bas de chez moi (POL, 2010), récit grinçant dans lequel il s’amuse de voir combien « la moindre fuite de chasse d’eau est vécue comme un drame » par les habitants d’un immeuble parisien au début du XXIe siècle, Iegor Gran a été l’un des premiers à exprimer sa « révolte » contre une certaine hypocrisie ambiante. Avec, derrière l’ironie, une conviction : « Ce geste que vous vous imposez, que vous imposez à vos amis ou à vos voisins ne va pas faire reculer la pollution. » Il aimerait qu’un économiste « se pose la question de la valeur de ces gestes, en tenant compte du temps perdu par l’individu pour les réaliser et par la collectivité pour organiser ces circuits ».

Son texte, « autofiction et parodie » à la fois, Iegor Gran ne l’a pas voulu comme un pamphlet anti-écolo, mais plutôt comme « un livre sur la liberté ». « La liberté d’être con », écrit-il, concept qu’il n’est apparemment pas le seul à revendiquer. Faites le test avec des amis, des collègues de travail : les émules sont nombreux et leurs moyens assez variés.

Ici, au Monde, le premier journaliste venu (pas de nom) reconnaît qu’il prend « un malin plaisir à ne plus trier [ses] détritus ». Sans vergogne. Un autre racontait il y a peu comment il s’est empressé de constituer chez lui une belle réserve d’ampoules traditionnelles après avoir testé, et désapprouvé, la lumière blafarde des premières ampoules basse consommation. Et un directeur de la rédaction (pas de nom) a longtemps supplié les spécialistes de l’environnement du journal de cesser de culpabiliser, entre autres, les amateurs de belles voitures gourmandes en énergie non renouvelable…

La fraude à l’écologie n’est sans doute pas encore le nouveau sport national, mais une petite musique donne à entendre comme une parodie de la célèbre chanson de Jacques Dutronc, l’écologie, « j’y pense et puis j’oublie ». « C’est la vie, c’est la vie », semble même ajouter Pascal Bruckner dans Le Fanatisme de l’apocalypse (Grasset, 2011).

« Nous restons vivants tant que nous sommes capables d’être dans le désir et la convoitise, dit-il. Ce qui ne veut pas dire qu’il ne faut pas essayer de les contrôler. » Or, écrit-il, « tout devient maintenant dramatique, boire un verre d’eau, une tasse de thé, croquer une pomme ». Convaincu que la « parole apocalyptique » de certains défenseurs de l’environnement relève du « vieil instrument de la peur », l’essayiste assure que « l’écologie fait fausse route quand elle fait appel à notre culpabilité plutôt qu’à notre désir ».

Pascal Bruckner ne se range pourtant pas parmi les détracteurs du mouvement écologiste : « On sait bien que le capitalisme du XXIe siècle sera vert », convient-il. Ses ennemis, il les recrute chez « les lugubres, les sinistres, les bigots ».

Lui aussi évoque « une religion », dont « le péché originel » serait « l’empreinte carbone ». Et pour avoir commis pareil « sacrilège », il a d’ailleurs vu sa thèse assimilée au « négationnisme » par un lecteur du Nouvel Observateur et par un auditeur de France Inter. Excès de langage qui confortent, à ses yeux, l’existence d’un « malaise » provoqué par un certain discours écologiste. « Si l’écologie ne peut pas se moquer d’elle-même, quel monde vont-ils nous préparer ? », s’interroge Sergio Emilson, auteur de Comment recycler les oiseaux mazoutés (Plume de carotte, 2010). Un ouvrage « de potache », commis pour pasticher une parole écologiste devenue « obligatoire, moralisatrice, péremptoire et triste », selon cet écrivain toulonnais.

Après la sortie du livre, des témoignages l’ont aidé à comprendre que, comme lui, « des tas de gens sont excédés par ce propos culpabilisant et pesant. Ils se sentent coincés à force de s’entendre dire : «Vous recyclez mal, pas assez, les Allemands font bien mieux…» » Le constat l’afflige, mais il le fait sien : il arrive que le discours écologique soit contre-productif. Ce qui soulève une interrogation : et si la guerre écologique était une affaire trop sérieuse pour être abandonnée aux militants ?

Voir encore:

 Malaria, Politics and DDT

The U.N. bows to the anti-insecticide lobby..

The WSJ

26.05.09

In 2006, after 25 years and 50 million preventable deaths, the World Health Organization reversed course and endorsed widespread use of the insecticide DDT to combat malaria. So much for that. Earlier this month, the U.N. agency quietly reverted to promoting less effective methods for attacking the disease. The result is a victory for politics over public health, and millions of the world’s poor will suffer as a result.

The U.N. now plans to advocate for drastic reductions in the use of DDT, which kills or repels the mosquitoes that spread malaria. The aim « is to achieve a 30% cut in the application of DDT worldwide by 2014 and its total phase-out by the early 2020s, if not sooner, » said WHO and the U.N. Environment Program in a statement on May 6.

Citing a five-year pilot program that reduced malaria cases in Mexico and South America by distributing antimalaria chloroquine pills to uninfected people, U.N. officials are ready to push for a « zero DDT world. » Sounds nice, except for the facts. It’s true that chloroquine has proven effective when used therapeutically, as in Brazil. But it’s also true that scientists have questioned the safety of the drug as an oral prophylactic because it is toxic and has been shown to cause heart problems.

Most malarial deaths occur in sub-Saharan Africa, where chloroquine once worked but started failing in the 1970s as the parasite developed resistance. Even if the drugs were still effective in Africa, they’re expensive and thus impractical for one of the world’s poorest regions. That’s not an argument against chloroquine, bed nets or other interventions. But it is an argument for continuing to make DDT spraying a key part of any effort to eradicate malaria, which kills about a million people — mainly children — every year. Nearly all of this spraying is done indoors, by the way, to block mosquito nesting at night. It is not sprayed willy-nilly in jungle habitat.

WHO is not saying that DDT shouldn’t be used. But by revoking its stamp of approval, it sends a clear message to donors and afflicted countries that it prefers more politically correct interventions, even if they don’t work as well. In recent years, countries like Uganda, Tanzania and Zambia have started or expanded DDT spraying, often with the help of outside aid groups. But these governments are also eager to remain in the U.N.’s good graces, and donors typically are less interested in funding interventions that WHO discourages.

« Sadly, WHO’s about-face has nothing to do with science or health and everything to do with bending to the will of well-placed environmentalists, » says Roger Bate of Africa Fighting Malaria. « Bed net manufacturers and sellers of less-effective insecticides also don’t benefit when DDT is employed and therefore oppose it, often behind the scenes. »

It’s no coincidence that WHO officials were joined by the head of the U.N. Environment Program to announce the new policy. There’s no evidence that spraying DDT in the amounts necessary to kill dangerous mosquitoes imperils crops, animals or human health. But that didn’t stop green groups like the Pesticide Action Network from urging the public to celebrate World Malaria Day last month by telling « the U.S. to protect children and families from malaria without spraying pesticides like DDT inside people’s homes. »

« We must take a position based on the science and the data, » said WHO’s malaria chief, Arata Kochi, in 2006. « One of the best tools we have against malaria is indoor residual spraying. Of the dozen or so insecticides WHO has approved as safe for house spraying, the most effective is DDT. » Mr. Kochi was right then, even if other WHO officials are now bowing to pressure to pretend otherwise.

Voir de même:

Lutte antipaludique: l’OMS estime que l’utilisation de DDT à l’intérieur des habitations est sans danger pour la santé

OMS

15 septembre 2006

L’OMS fait de la pulvérisation d’insecticide à l’intérieur des habitations l’une des trois grandes interventions qu’elle préconise contre le paludisme

Près de trente ans après l’abandon progressif de la pulvérisation à grande échelle de DDT et d’autres insecticides dans les habitations pour lutter contre le paludisme, l’Organisation mondiale de la Santé (OMS) a annoncé aujourd’hui que cette méthode allait de nouveau jouer un rôle important dans son combat contre la maladie. L’OMS recommande désormais la pulvérisation d’insecticide à effet rémanent à l’intérieur des habitations non seulement dans les zones d’épidémie palustre mais aussi dans celles où la transmission de la maladie est constamment élevée, notamment dans toute l’Afrique.

« Les données scientifiques et programmatiques justifient sans conteste cette réévaluation », a déclaré le Dr Anarfi Asamoa-Baah, Sous-Directeur général de l’OMS chargé du VIH/SIDA, de la tuberculose et du paludisme. « La pulvérisation d’insecticide à effet rémanent dans les maisons est utile pour réduire rapidement le nombre de personnes contaminées par les moustiques porteurs de la maladie. Elle s’est révélée d’un aussi bon rapport coût/efficacité que les autres mesures de prévention du paludisme et le DDT ne présente pas de risque pour la santé s’il est correctement utilisé. »

L’OMS a activement encouragé le recours à cette méthode prophylactique jusqu’au début des années 80 quand, ayant de plus en plus de raisons de s’inquiéter des effets du DDT sur la santé et l’environnement, elle lui a préféré d’autres moyens de prévention. Depuis, de nombreux tests et travaux de recherche ont montré que la pulvérisation de DDT à l’intérieur des habitations dans le cadre de programmes bien gérés n’est dangereuse ni pour l’homme ni pour la faune et la flore.

« Nous devons fonder notre position sur la science et les données objectives », a expliqué le Dr Arata Kochi, Directeur du Programme mondial de lutte antipaludique à l’OMS. « L’une des meilleures armes que nous ayons contre le paludisme est la pulvérisation d’insecticide à effet rémanent dans les habitations. Sur la douzaine d’insecticides que l’OMS juge sans danger pour cet usage, le plus efficace est le DDT. »

La pulvérisation d’insecticide à effet rémanent à l’intérieur des habitations consiste à appliquer des insecticides à effet longue durée sur les murs et le toit des maisons et des abris pour animaux domestiques afin de tuer les moustiques porteurs du paludisme qui se posent sur ces surfaces.

« Pulvériser des insecticides dans les habitations, c’est comme tendre une énorme moustiquaire au-dessus d’une maison pour la protéger 24 heures sur 24 », a expliqué le Sénateur américain Tom Coburn, l’un des principaux avocats de la lutte antipaludique dans le monde. « Grâce à la position claire de l’OMS sur la question, nous pouvons enfin couper court aux mythes et prétendues données scientifiques qui n’ont fait qu’aider les vrais ennemis, les moustiques, qui mettent en danger la vie de plus de 300 millions d’enfants chaque année. »

Ces dernières années, l’opinion a changé au sujet de l’utilisation d’insecticides dans les maisons pour prévenir le paludisme. Le Environmental Defense Fund, qui avait lancé la campagne contre le DDT dans les années 60, approuve maintenant son usage à l’intérieur des habitations contre le paludisme, tout comme le Sierra Club et le Endangered Wildlife Trust. Par ailleurs, il a été annoncé l’année dernière que la récente initiative du Président des Etats-Unis contre le paludisme financerait la pulvérisation de DDT sur les murs intérieurs des habitations pour prévenir la maladie.

« Je pense que les 15 programmes de pays au profit desquels le Président Bush s’est engagé à verser US $1,2 milliard pour réduire de moitié les décès par paludisme feront une large place à la pulvérisation d’insecticide rémanent dans les maisons, et principalement de DDT », a présagé l’Amiral R. Timothy Ziemer, qui coordonne l’initiative du Président. « Parce que c’est une méthode relativement bon marché et très efficace, l’AID des Etats-Unis finance la pulvérisation d’insecticide à l’intérieur des habitations dans le cadre d’un programme complet et équilibré de prévention et de traitement. »

Les données de programme montrent qu’effectuée correctement et en temps voulu, la pulvérisation d’insecticide à effet rémanent dans les habitations réduit la transmission du paludisme dans une proportion pouvant atteindre 90 %. L’Inde est parvenue autrefois à diminuer considérablement la morbidité et la mortalité palustres en pulvérisant du DDT dans les habitations. L’Afrique du Sud a réinstauré la pulvérisation de DDT pour maintenir la morbidité et la mortalité aux taux les plus bas jamais enregistrés et progresser vers l’élimination de la maladie. Aujourd’hui 14 pays d’Afrique subsaharienne pratiquent la pulvérisation d’insecticide à effet rémanent dans les habitations et dix d’entre eux utilisent du DDT.

A la conférence de presse tenue aujourd’hui, l’Organisation mondiale de la Santé a également lancé un appel à tous les responsables de programmes de lutte antipaludique dans le monde pour qu’ils énoncent clairement leur position sur la pulvérisation d’insecticides à effet longue durée comme le DDT à l’intérieur des habitations, en indiquant où et quand seront effectuées ces pulvérisations conformément aux directives de l’OMS, et quels moyens ils mettront en oeuvre pour accélérer et bien gérer cette intervention.

« Tous les organismes de développement et tous les pays d’endémie doivent agir conformément à la position de l’OMS sur la pulvérisation de DDT à l’intérieur des habitations », a estimé le Sénateur Coburn. « Les donateurs, en particulier, doivent aider l’OMS à fournir l’appui technique et programmatique nécessaire pour que cette intervention soit correctement appliquée. »

Au même titre que l’utilisation généralisée de moustiquaires imprégnées d’insecticide, la pulvérisation d’insecticide à effet rémanent à l’intérieur des habitations compte désormais parmi les principales interventions que préconise l’OMS pour combattre et éliminer le paludisme dans le monde. L’OMS recommande depuis longtemps l’utilisation de moustiquaires, mais les moustiquaires à imprégnation durable mises au point dernièrement sont beaucoup plus efficaces. Contrairement aux anciennes, il n’est pas nécessaire de les tremper dans des seaux d’insecticide tous les six mois et elles restent efficaces pendant au moins cinq ans sans qu’il soit besoin de les retraiter.

Enfin, pour les malades, il existe maintenant des médicaments plus efficaces, de plus en plus largement distribués. Il s’agit des associations médicamenteuses comportant de l’artémisinine (ACT), qui remplacent les antipaludiques devenus inopérants dans de nombreuses régions à cause de la pharmacorésistance. Ces médicaments salvateurs sont de plus en plus largement distribués dans le monde. En janvier de cette année, l’OMS a pris des mesures strictes pour éviter la résistance aux antipaludiques en interdisant l’utilisation des monothérapies. La pharmacorésistance a notamment pour effet de compromettre le traitement préventif intermittent pendant la grossesse, stratégie cruciale pour protéger les femmes enceintes contre les conséquences de la maladie.

Depuis quelques années, grâce à la création du Fonds mondial de lutte contre le SIDA, la tuberculose et le paludisme, aux projets de la Banque mondiale visant à financer beaucoup plus généreusement la lutte antipaludique et à l’initiative du Président contre le paludisme, on dispose de beaucoup plus de fonds pour appliquer plus largement ces trois interventions stratégiques.

« Vu les sommes importantes enfin débloquées pour la lutte antipaludique, il est plus indispensable que jamais que l’OMS donne des orientations techniques avisées et assiste les programmes pour que ces ressources soient utilisées en temps voulu et à bon escient », a souligné le Dr Kochi.

On recense chaque année plus de 500 millions de cas de paludisme aigu, dont plus d’un million sont mortels. Au moins 86 % de ces décès ont lieu en Afrique subsaharienne. On estime que 3 000 enfants et nourrissons meurent chaque jour du paludisme dans le monde et que, chaque année, 10 000 femmes enceintes succombent à la maladie en Afrique. Le paludisme touche de façon disproportionnée les pauvres, près de 60 % des cas se produisant parmi les 20 % les plus pauvres de la population mondiale.

Voir de même:

Countries move toward more sustainable ways to roll back malaria

4th Meeting of the Conference of the Parties to the UNEP-Linked Stockholm Convention on Persistent Organic Pollutants

Joint news release UNEP/WHO/GEF

06 MAY 2009 | Geneva/Nairobi/Washington DC -The United Nations Environment Programme and the World Health Organization, in partnership with the Global Environment Facility, today announced a rejuvenated international effort to combat malaria with an incremental reduction of reliance on the synthetic pesticide DDT.

Ten projects, all part of the global programme “Demonstrating and Scaling-up of sustainable Alternatives to DDT in Vector Management”, involving some 40 countries in Africa, the Eastern Mediterranean and Central Asia are set to test non-chemical methods ranging from eliminating potential mosquito breeding sites and securing homes with mesh screens to deploying mosquito-repellent trees and fish that eat mosquito larvae.

The new projects follow a successful demonstration of alternatives to DDT in Mexico and Central America. Here pesticide-free techniques and management regimes have helped cut cases of malaria by over 60 per cent.

The success of the five year-long pilot indicates that sustainable alternatives to Dichloro-Diphenyl-Trichloroethane (DDT) are emerging as cost effective solutions that may be applicable regionally and globally.

The Integrated Vector Management (IVM) strategy promoted by the World Health Organization (WHO) provides the framework to include these measures in combinations of interventions adapted to differing local circumstances.

Allied to measures such as improved health care, monitoring and education the findings could set the stage for meeting the twin aims of achieving the health-related and environmental Millennium Development Goals (MDGs) by 2015 while also ridding the world of the persistent organic pollutant DDT.

The initiatives come amid long-standing and growing concern over the use of DDT and evidence that in many countries there is increasing mosquito resistance to the pesticide.

However concern over DDT is matched by concern over the global malaria burden in which close to 250 million cases a year result in over 880 000 deaths. Thus any reduction in the use of DDT or other residual pesticides must ensure the level of transmission interruption is, at least, maintained.

The international community has, under the Stockholm Convention, agreed to ban a ‘dirty dozen’ of persistent organic pollutants including, ultimately, DDT on environmental and health grounds.

However, a specific and limited exemption was made for the use of DDT to control malaria, because it was recognized that in some situations adequate alternative control methods were not currently available.

Aim of new projects

The aim of the new projects, a major initiative of the Global Environment Facility (GEF) with close to $40 million funding, being spearheaded by WHO and the UN Environment Programme (UNEP), is to achieve a 30% cut in the application of DDT world-wide by 2014 and its total phase-out by the early 2020s if not sooner, while staying on track to meet the malaria targets set by WHO.

Achim Steiner, UN Under-Secretary General and UNEP Executive Director which hosts the secretariat of the Stockholm Convention, said: “The new projects underline the determination of the international community to combat malaria while realizing a low, indeed zero DDT world”.

“Today we are calling time on a chemical rooted in the scientific knowledge and simplistic options of a previous age. In doing so, innovative solutions are being catalyzed and sustainable choices brought forward that meet the genuine health and environmental aspirations of a 21st century society”.

“WHO faces a double challenge – a commitment to the goal of drastically and sustainably reducing the burden of vector-borne diseases, in particular malaria, and at the same time a commitment to the goal of reducing reliance on DDT in disease vector control”, said Dr Margaret Chan, WHO Director-General.

WHO sees these projects in the context of IVM which it promotes as the approach of choice to control transmission of malaria and other vector-borne diseases. A key element of IVM is a solid evidence base for the effectiveness of combinations of locally-adapted, cost-effective and sustainable vector-control methods. This approach will facilitate sustainable transition away from DDT.

Monique Barbut, Chief Executive Officer and Chairperson of the Global Environment Facility, the financial arm of the convention and which is funding over half of the initiative, said: “The GEF is investing in these projects to take decisive action toward ridding the world of dangerous chemicals now and forever. The dividends from these investments will mean a cleaner, safer and sustainable environment for future generations. “

Notes to editors

Mexico and Central America

The first of the demonstration projects, which began in 2003, has been coordinated by the Pan American Health Organization of the WHO in partnership with a wide range of bodies including UNEP, the Commission for Environmental Cooperation, and the eight country governments.

It has involved the Ministries of Health of Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua and Panama where DDT has been extensively sprayed in homes and onto water bodies in the region order to combat malaria since the 1950s.

More than 89 million people in Mesoamerica live in areas suitable for malaria transmission of which over a third or 23.5 million live in highly endemic areas.

The work, involving just under $7.5 million from the GEF and co-financing of $6.4 million, has pioneered the demonstration of “integrated vector control” methods working with 202 communities of 50 municipalities in the eight countries.

The work covered close to 160 000 people directly and an estimated 6.8 million indirectly representing nearly 30 per cent of those in the highly effected areas.

Various malaria control strategies and techniques have been tried and evaluated including:

community participation as central axis of the control activities;

equity prioritizing rural areas with mostly indigenous populations in critical poverty and the persistence of malaria;

a multidisciplinary and multisector approach involving the environment and education sectors to the health sector;

combination of control methods according to the Global Strategy in the Fight Against Malaria and the Roll Back Malaria initiative;

destruction of parasites in the population through rapid diagnosis and treatment including improved counseling and supervision of oral treatments;

reduction of contact between mosquitoes and people via treated bed nets; meshes on doors and windows; the planting of repellent trees like neem and oak and the liming of households;

control of breeding sites by clearing vegetation, draining stagnant water ditches and channels and the use of biological controls such as fish and bacteria in some countries;

elimination of places near houses that attract and shelter mosquitoes through, for example the cleaning and tidying up of areas in and around homes alongside the promotion of personal hygiene.

The project achieved a 63 per cent reduction in malaria cases and a more than 86 per cent cut in ones linked with Plasmodium falciparum, the malarial parasite that causes the most severe kind of infection and the highest death rate globally.

The researchers point to other benefits including the strengthening of national and local institutions involved in combating malaria; improved scientific data on DDT contamination of communities and action on stockpiles of persistent organic pollutants.

During the project more than 136 tons of DDT and over 64 tons of chemicals such as toxapehene and chlordane were pin pointed.

These stockpiles are scheduled for export and destruction under a separated but related UNEP treaty, the Basel Convention on transboundary hazardous waste.

Rolling out projects globally

Projects are now going global with several new, five year regional demonstrations of sustainable alternatives to DDT launched, or set to be launched over the next 12 months.

These include one involving Eritrea, Ethiopia and Madagascar and a larger regional initiative with Djibouti; Egypt; Jordan, Morocco; the Islamic Republic of Iran, Sudan, Syria and Yemen.

A third project is involving Georgia, Tajikistan and Kyrgyzstan in the Southern Caucasus and Central Asia with a possibility of including relevant neighboring countries as well.

Another is focusing on Kenya, Tanzania and Uganda in order to develop a Decision Taking Tool for governments allowing them to evaluate health, social and environmental impacts and policy tradeoffs.

Voir aussi:

If Malaria’s the Problem, DDT’s Not the Only Answer

May Berenbaum

June 5, 2005

In the pantheon of poisons, DDT occupies a special place. It’s the only pesticide celebrated with a Nobel Prize: Swiss chemist Paul Mueller won in 1948 for having discovered its insecticidal properties. But it’s also the only pesticide condemned in pop song lyrics — Joni Mitchell’s famous « Hey, farmer, farmer put away your DDT now » — for damaging the environment. Banned in the United States more than 30 years ago, it remains America’s best known toxic substance. Like some sort of rap star, it’s known just by its initials; it’s the Notorious B.I.G. of pesticides.

Now DDT is making headlines again. Many African governments are calling for access to the pesticide, believing that it’s their best hope against malaria, a disease that infects more than 300 million people worldwide a year and kills at least 3 million, a large proportion of them children. And this has raised a controversy of Solomonic dimensions, pitting environmentalists against advocates of DDT use.

The dispute between them centers on whether the potential benefits of reducing malaria transmission outweigh the potential risks to the environment. But the problem isn’t that simple. This is a dispute in which science should play a significant role, but what science tells us is that DDT is neither the ultimate pesticide nor the ultimate poison, and that the lessons of the past are being ignored in today’s discussion.

The United Nations Environment Program has identified DDT as a persistent organic pollutant that can cause environmental harm and lists it as one of a « dirty dozen » whose use is scheduled for worldwide reduction or elimination. But some DDT advocates have resorted to anti-environmentalist drama to make their case for its use in Africa.

They have accused environmental activists of having « blood on their hands » and causing more than 50 million « needless deaths » by enforcing DDT bans in developing nations. In his best-selling anti-environmentalist novel « State of Fear, » Michael Crichton writes that a ban on using DDT to control malaria « has killed more people than Hitler. »

Such statements make good copy, but in reality, chemicals do not wear white hats or black hats, and scientists know that there really are no miracles.

Malaria is caused by a protozoan parasite that is transmitted by mosquitoes. For decades, there have been two major strategies for curbing the disease: killing the infectious agent or killing the carrier. Reliably killing the protozoan has proved difficult; many older drugs are no longer effective, new ones are prohibitively expensive, and delivering and administering drugs to the susceptible populace presents daunting challenges. Killing the carrier has long been an attractive alternative.

And DDT has been an astonishingly effective killer of mosquitoes. DDT (which stands for the far less catchy dichloro-diphenyl-trichloroethane) is a synthetic chemical that didn’t exist anywhere on the planet until it was cooked up for no particular purpose in a German laboratory in 1874. Decades later, in 1939, Mueller pulled it off a shelf and tested it, along with many other synthetic substances, for its ability to kill insects. DDT distinguished itself both by its amazing efficacy and its breadth of action — by interfering with nervous system function, it proved deadly to almost anything with six, or even eight, legs. And it was dirt-cheap compared to other chemicals in use — it could be quickly and easily synthesized in chemical laboratories from inexpensive ingredients.

Soon after its insecticidal properties were discovered, DDT was put to use combating wartime insect-borne diseases that have bedeviled troops mobilized around the world for centuries. It stemmed a louse-borne typhus outbreak in Italy and prevented mosquito-borne diseases in the Pacific theater, including malaria and yellow fever, to almost miraculous effect. This military success emboldened governments around the world to use DDT after World War II to try to eradicate the longtime scourge of malaria. And in many parts of the world, malaria deaths dropped precipitously. This spectacular success is why many people are calling for the use of DDT specifically for malaria control.

At the same time that malaria deaths were dropping in some places, however, the environmental persistence of DDT was creating major problems for wildlife, as famously documented in Rachel Carson’s classic 1962 book, « Silent Spring. » By 1972, the pesticide had become the « poster poison » for fat-soluble chemicals that accumulate in food chains and cause extensive collateral damage to wildlife (including charismatic predators such as songbirds and raptors), and a total ban on the use of DDT went into effect in the United States.

What people aren’t remembering about the history of DDT is that, in many places, it failed to eradicate malaria not because of environmentalist restrictions on its use but because it simply stopped working. Insects have a phenomenal capacity to adapt to new poisons; anything that kills a large proportion of a population ends up changing the insects’ genetic composition so as to favor those few individuals that manage to survive due to random mutation. In the continued presence of the insecticide, susceptible populations can be rapidly replaced by resistant ones. Though widespread use of DDT didn’t begin until WWII, there were resistant houseflies in Europe by 1947, and by 1949, DDT-resistant mosquitoes were documented on two continents.

By 1972, when the U.S. DDT ban went into effect, 19 species of mosquitoes capable of transmitting malaria, including some in Africa, were resistant to DDT. Genes for DDT resistance can persist in populations for decades. Spraying DDT on the interior walls of houses — the form of chemical use advocated as the solution to Africa’s malaria problem — led to the evolution of resistance 40 years ago and will almost certainly lead to it again in many places unless resistance monitoring and management strategies are put into place.

In fact, pockets of resistance to DDT in some mosquito species in Africa are already well documented. There are strains of mosquitoes that can metabolize DDT into harmless byproducts and mosquitoes whose nervous systems are immune to DDT. There are even mosquitoes who avoid the toxic effects of DDT by resting between meals not on the interior walls of houses, where chemicals are sprayed, but on the exterior walls, where they don’t encounter the chemical at all.

The truth is that DDT is neither superhero nor supervillain — it’s just a tool. And if entomologists have learned anything in the last half-century of dealing with the million-plus species of insects in the world, it’s that there is no such thing as an all-purpose weapon when it comes to pest management. DDT may be useful in controlling malaria in some places in Africa, but it’s essential to determine whether target populations are resistant; if they are, then no amount of DDT will be effective.

We have new means of determining whether populations are genetically prone to developing resistance. DDT advocates are right to suggest that DDT may be useful as a precision instrument under some circumstances, particularly considering that environmental contamination in Africa may be less of a problem than it has been in temperate ecosystems because the chemical can degrade faster due to higher temperatures, moisture levels and microbial activity. Moreover, resistance evolves due to random mutation, so there are, by chance, malaria-carrying mosquito species in Africa that remain susceptible to DDT despite more than two decades of exposure to the chemical.

But environmentalists are right to worry that the unwise use of DDT, particularly where it is likely to be ineffective, may cause environmental harm without any benefit. In 2000, I chaired a National Research Council committee that published a study titled « The Future Role of Pesticides in U.S. Agriculture. » Our principal recommendation is germane to discussions of malaria management: « There is no justification for completely abandoning chemicals per se as components in the defensive toolbox used for managing pests. The committee recommends maintaining a diversity of tools for maximizing flexibility, precision, and stability of pest management. »

Overselling a chemical’s capacity to solve a problem can do irretrievable harm not only by raising false hopes but by delaying the use of more effective long-term methods. So let’s drop the hyperbole and overblown rhetoric — it’s not what Africa needs. What’s needed is a recognition of the problem’s complexity and a willingness to use every available weapon to fight disease in an informed and rational way.

May Berenbaum is head of the department of entomology at the University of Illinois, Urbana-Champaign.

Voir encore:

Findings

Fateful Voice of a Generation Still Drowns Out Real Science

John Tierney

The NYT

June 5, 2007

For Rachel Carson admirers, it has not been a silent spring. They’ve been celebrating the centennial of her birthday with paeans to her saintliness. A new generation is reading her book in school — and mostly learning the wrong lesson from it.

If students are going to read “Silent Spring” in science classes, I wish it were paired with another work from that same year, 1962, titled “Chemicals and Pests.” It was a review of “Silent Spring” in the journal Science written by I. L. Baldwin, a professor of agricultural bacteriology at the University of Wisconsin.

He didn’t have Ms. Carson’s literary flair, but his science has held up much better. He didn’t make Ms. Carson’s fundamental mistake, which is evident in the opening sentence of her book:

“There was once a town in the heart of America where all life seemed to live in harmony with its surroundings,” she wrote, extolling the peace that had reigned “since the first settlers raised their houses.” Lately, though, a “strange blight” had cast an “evil spell” that killed the flora and fauna, sickened humans and “silenced the rebirth of new life.”

This “Fable for Tomorrow,” as she called it, set the tone for the hodgepodge of science and junk science in the rest of the book. Nature was good; traditional agriculture was all right; modern pesticides were an unprecedented evil. It was a Disneyfied version of Eden.

Ms. Carson used dubious statistics and anecdotes (like the improbable story of a woman who instantly developed cancer after spraying her basement with DDT) to warn of a cancer epidemic that never came to pass. She rightly noted threats to some birds, like eagles and other raptors, but she wildly imagined a mass “biocide.” She warned that one of the most common American birds, the robin, was “on the verge of extinction” — an especially odd claim given the large numbers of robins recorded in Audubon bird counts before her book.

Ms. Carson’s many defenders, ecologists as well as other scientists, often excuse her errors by pointing to the primitive state of environmental and cancer research in her day. They argue that she got the big picture right: without her passion and pioneering work, people wouldn’t have recognized the perils of pesticides. But those arguments are hard to square with Dr. Baldwin’s review.

Dr. Baldwin led a committee at the National Academy of Sciences studying the impact of pesticides on wildlife. (Yes, scientists were worrying about pesticide dangers long before “Silent Spring.”) In his review, he praised Ms. Carsons’s literary skills and her desire to protect nature. But, he wrote, “Mankind has been engaged in the process of upsetting the balance of nature since the dawn of civilization.”

While Ms. Carson imagined life in harmony before DDT, Dr. Baldwin saw that civilization depended on farmers and doctors fighting “an unrelenting war” against insects, parasites and disease. He complained that “Silent Spring” was not a scientific balancing of costs and benefits but rather a “prosecuting attorney’s impassioned plea for action.”

Ms. Carson presented DDT as a dangerous human carcinogen, but Dr. Baldwin said the question was open and noted that most scientists “feel that the danger of damage is slight.” He acknowledged that pesticides were sometimes badly misused, but he also quoted an adage: “There are no harmless chemicals, only harmless use of chemicals.”

Ms. Carson, though, considered new chemicals to be inherently different. “For the first time in the history of the world,” she wrote, “every human being is now subjected to contact with dangerous chemicals, from the moment of conception until death.”

She briefly acknowledged that nature manufactured its own carcinogens, but she said they were “few in number and they belong to that ancient array of forces to which life has been accustomed from the beginning.” The new pesticides, by contrast, were “elixirs of death,” dangerous even in tiny quantities because humans had evolved “no protection” against them and there was “no ‘safe’ dose.”

She cited scary figures showing a recent rise in deaths from cancer, but she didn’t consider one of the chief causes: fewer people were dying at young ages from other diseases (including the malaria that persisted in the American South until DDT). When that longevity factor as well as the impact of smoking are removed, the cancer death rate was falling in the decade before “Silent Spring,” and it kept falling in the rest of the century.

Why weren’t all of the new poisons killing people? An important clue emerged in the 1980s when the biochemist Bruce Ames tested thousands of chemicals and found that natural compounds were as likely to be carcinogenic as synthetic ones. Dr. Ames found that 99.99 percent of the carcinogens in our diet were natural, which doesn’t mean that we are being poisoned by the natural pesticides in spinach and lettuce. We ingest most carcinogens, natural or synthetic, in such small quantities that they don’t hurt us. Dosage matters, not whether a chemical is natural, just as Dr. Baldwin realized.

But scientists like him were no match for Ms. Carson’s rhetoric. DDT became taboo even though there wasn’t evidence that it was carcinogenic (and subsequent studies repeatedly failed to prove harm to humans).

It’s often asserted that the severe restrictions on DDT and other pesticides were justified in rich countries like America simply to protect wildlife. But even that is debatable (see http://www.tierneylab.com), and in any case, the chemophobia inspired by Ms. Carson’s book has been harmful in various ways. The obsession with eliminating minute risks from synthetic chemicals has wasted vast sums of money: environmental experts complain that the billions spent cleaning up Superfund sites would be better spent on more serious dangers.

The human costs have been horrific in the poor countries where malaria returned after DDT spraying was abandoned. Malariologists have made a little headway recently in restoring this weapon against the disease, but they’ve had to fight against Ms. Carson’s disciples who still divide the world into good and bad chemicals, with DDT in their fearsome “dirty dozen.”

Ms. Carson didn’t urge an outright ban on DDT, but she tried to downplay its effectiveness against malaria and refused to acknowledge what it had accomplished. As Dr. Baldwin wrote, “No estimates are made of the countless lives that have been saved because of the destruction of insect vectors of disease.” He predicted correctly that people in poor countries would suffer from hunger and disease if they were denied the pesticides that had enabled wealthy nations to increase food production and eliminate scourges.

But Dr. Baldwin did make one mistake. After expressing the hope “that someone with Rachel Carson’s ability will write a companion volume dramatizing the improvements in human health and welfare derived from the use of pesticides,” he predicted that “such a story would be far more dramatic than the one told by Miss Carson in ‘Silent Spring.’ ”

That never happened, and I can’t imagine any writer turning such good news into a story more dramatic than Ms. Carson’s apocalypse in Eden. A best-seller titled “Happy Spring”? I don’t think so.

Voir enfin:

BOOK REVIEWS

Chemicals and Pests
Man’s use, misuse, and abuse of the products of science determine whether these valuable assets are also harmful.
I.L. Baldwin
Science
September 28, 1962

Human society, since the time of recorded history, has encountered many difficulties in adapting itself to changes brought on by the advancement of technology. Although we usually think of the Industrial Revolution as the starting point of modern technology, the invention of the wheel must have brought about one of the greatest changes in human society the world has seen. In recent years there has been a rapid expansion of scientific endeav- ors and a consequent rapid increase in the rate of accumulation of knowledge. Technology has quicky translated this new knowledge into materials and procedures for use by society.

The discovery of methods of harnessing nuclear energy, some two decades ago, has so captured public attention that few have given serious attention to the chemical revolution which has oc-curred during the same period. It is the chemical revolution, however, that has most intimately affected every aspect of our daily life. The develop-ment of new fibers, new plastics, new medicinals, and new agricultural chemicals has produced profound changes in our lives. Public health has been im- proved; the span of life has been greatly extended; our clothes are composed of fibers unknown 20 years ago; our ma- chinery and household utensils are made of new and strange materials; and our rate of productivity in agriculture has been greatly expanded.

Benefits, however, have not been achieved without cost. Many of the new materials have been used without adequate testing, or they have been used under improper conditions. Sometimes lives have been lost or health has been destroyed. At other times our economy has suffered when shoddy materials have been used in clothing, equipment, and structures. Often men have lost their means of livelihood. Rachel Carson’s Silent Spring (Houghton Mifflin, Boston, 1962. 368 pp., $5) dramatizes in an effective fashion the losses that society has suffered from the use of new pesticides. Her emphasis is upon the danger to human health and the possible irreparable damage to various forms of wildlife.

Silent Spring is superbly written and beautifully illustrated with line drawings. The author has made an exhaustive study of the facts bearing on the problem. It is not, however, a judicial review or a balancing of the gains and losses; rather, it is the prosecuting attorney’s impassioned plea for action against the use of these new materials which have received such widespread acceptance, acceptance ac-corded because of the obvious bene-fits that their use has conferred. The author has reviewed many of the in-stances in which unfortunate accidents have occurred. In some cases the acci- dents were the result of carelessness; in others they were caused by wide-spread use of materials prior to ade-quate small-scale testing; in some instances the unfortunate effect on wild- life was a result of the failure of those who used the new pesticide to consider wildlife values.

The author’s mode of approach to the use of pesticides will undoubtedly result in wider recognition of the fact that these chemicals are poisons and in a more careful and rigorous control of every step in the pathway that pesticide must travel, from the research laboratory, through the process of obtaining government approval, to use in the field. Perhaps the tremendous improvements in public health and wel- fare that have resulted from the use of these materials have caused us to become careless in our control and use of them. There are serious hazards involved in the use of pesticides. It has frequently been said: « There are no harmless chemicals, only harmless use of chemicals. » The recent case in which the death of several infants in a hospital was caused by the inadvertent use of salt instead of sugar in their food comes to mind.

A Matter of Perspective

The possible indirect harmful effects of pesticides on humans and wildlife are stressed in Silent Spring. It is noted that certain of the pesticides may serve as carcinogens and that some may serve as mutagens. How often all the necessary conditions are met, so that the pesticides do actually serve as carcino- gens or mutagens, is unknown. The author feels that such dangers are very great. Most scientists who are familiar with the field, including government workers charged with the responsibility of safeguarding the public health, feel that the danger of damage is slight. The author gives no figures for deaths known to be due to pesticides, but her description of certain cases may leave the inlpression with the uninformed reader that such cases of death due to the direct effects of pesticides are nu-merous. Actually human deaths in the United States known to be caused by pesticides are less than 100 annually. To place this in proper perspective, consider that almost twice that many deaths are known to be caused by aspirin and that almost one-half as manv deaths are known to be caused by bee stings. Another example, in which the author’s choice of language may lead to false in~pressions, is her reference to the « fall of chemical death rain. » Many may be led to believe that, just as rain falls on all of our land, so is all of our land sprayed with pesticides. Actually less than 5 percent of all the area of the United States is annually treated with insecticides.

I can understand that the author felt it necessary to portray as « bad guys » all those who recommend the use of pesticides and as « good guys » all those who oppose the use of such insecticides. I cannot condone, however, the sarcastic and unjustified attack on the ethics and integrity of many scientific workers. The following quotation is only one of such attacks.

The major chemical companies are pouring money into the universities to support research on insecticides. This creates attractive fellowships for graduate students and attractive staff positions. Biological- control studies, on the other hand, are never so endowed-for the simple reason that they do not promise anyone the fortunes that are to be made in the chemi- cal industry. These are left to state and federal agencies, where the salaries paid are far less.

This situation also explains the otherwise mystifying fact that certain outstanding entomologists are among the leading advocates of chemical control. Inquiry into the background cf some of these men reveals that their entire research program is supported by the chemical industry. Their professional prestige, sometimes their very jobs depend on the perpetuation of chemical methods. Can we then expect them to bite the hand that literally feeds them? But knowing their bias, how much credence can we give to their pro- tests that insecticides are harmless?

The author pleads for a return to the balance of nature as the method of controlling our pests. Greater use of biological control of pests would be desirable, but, if it is to be effective enough to meet human needs, it must result in upsetting the balance of nature. Mankind has been engaged in the process of upsetting the balance of nature since the dawn of civilization. Certain species of plant and animal life that serve the economic or esthetic needs of mankind have been nurtured with great care; other species that have interfered with the health, comfort, or welfare of mankind have been attacked with great vigor; the large majority of the species have been ignored by all but a small portion of the population. Fortunately there is a growing concern, coupled with positive action, for the preservation of all forms of plant and animal life. This effort to preserve our wildlife is too late to save some species and too little to save others, but an en- couraging start is being made. Undoubtedly mankind’s own self-interests have suffered in the past and are still suffering because of his callous disre-gard of the damage he does to other species of plant and animal life. But it is equally certain that modern agricul- ture and modern public health, indeed, modern civilization, could not exist without an unrelenting war against a return of a true balance of nature.

Valuable but Dangerous

Just as it is important for us to be reminded of the dangers inherent in the use of the new pesticides, so must our people also be made aware of the tremendous values to human welfare con- ferred by the new pesticides. No attempt is made by the author to portray the many positive benefits that society derives from the use of pesticides. No estimates are made of the countless lives that have been saved because of the destruction of insect vectors of disease. No mention is made of the fact that the average length of human life has steadily increased over the last severa1 years. No consideration is given to the important role played by modern pesticides in the production of food and fiber. The author does suggest that, with a surplus of food in the United States, we might well curtail the use of pesticides. Although the United States has a surplus of food, over one half of the people of the world go to bed hungry each night. The greater use of pesticides in most sections of the world would increase food production, alle-viate hunger, and improve the health of the people.

Modern agriculture, with its high-quality foods and fibers, could not exist without the use of pesticides. Weeds, disease, and insect pests would take an extremely heavy toll if these chemicals were not used. The yields per acre, the yields per man hour, and the quality of the product would all suffer materially if these chemicals were withdrawn froni use. One cannot do more than guess about the changes that would be necessary in American society if pesticides were banned. An immediate back-to-the-farm movement would be necessary, and this would in- volve many millions of people. It is hoped that someone with Rachel Carson’s ability will write a companion volume dramatizing the improvements in human health and welfare derived froni the use of pesticides. Such a story would be far more dramatic than the one told by Miss Carson in Silent Spring, which deals with the losses society has sustained or may suffer in the future because of the use of these materials.

The problem which Rachel Carson so effectively dramatizes is not a new one. It has long been recognized by workers in government and industrial laboratories and by chemists and biologists wherever they may work. Several years ago the National Academy of Sciences established a committee of out-standing scientists to study the problem of food protection and the influence of pesticides and other chemicals on hu-man health and welfare. Some three years ago a companion committee was established to deal with pesticides and wildlife relationships. These commit-tees and their subcommittees have members from all of the scientific dis- ciplines that might be able to contribute to the problem, including physicians, wildlife specialists, toxicologists en-tomologists, agriculturists, biologists, chemists, and economists. Both the Food Protection Committee and the Pesticides and Wildlife Relationships Committee have made a careful and judicial review of all the evidence avail- able, and they have published a series of reports making appropriate reconi- nlendations. These reports are not dramatically written, and they were not intended to be best sellers. They are, however, the result of careful study by a wide group of scientists, and they represent balanced judgments in areas in which emotional appeals tend to over-balance sound judgment based on facts.

I suggest that those who read Silent Spring include as companion reading the following publications of the National Academy of Sciences (Washington, D.C.). Publications 920-A and 920-B: Pe~t Control and Wildlife Relationshipc., part 1, Evalciation of Pe~ticide-Wildlife Prohlerns; part 2, Policy and Procedures for Pe~t Control (1 962. $1.25 each); Publication 887: Use of Chemicals in Food Production, Processing. Storage, and Distribution (1961. $0.50); Publication 470: Safe Use of Pesticides in Food Production (1956. $0.50).

The story of Silent Spring, so well told by Rachel Carson, even though it presents only one side of a very complex problem, will serve a useful purpose, if research on better methods of pest control is stimulated and if all concerned with the production, control, and use of pesticides are stimulated to exercise greater care in the protection of the public welfare. In the meantime it is my hope that some equally gifted writer will be willing to do the necessary research and to write the even more dramatic story of the values conferred on mankind by the chemical revolution of the last two decades.

The reviewer is professor of agricultural bac-teriology at the University of Wisconsin, and special assistant to the president of the uni-versity. He also serves as chairman of the Committee on Pest Control and Wildlife Rela-tionships of the National Academy of Sciences-National Research Council.

3 Responses to Ecologie: Sous les pavés, l’enfer des bonnes intentions ? (Disneyfied Eden: Was Rachel Carson wrong?)

  1. […] communauté scientifique apparemment bien plus divisée et une question bien plus controversée et complexe que ne le laisseraient croire les péremptoires jugements de nos censeurs du […]

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  2. […] le DDT a tué plus de personnes qu’Hitler. Personnage d’un roman de  Michael Crichton (State of Fear, […]

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  3. jcdurbant dit :

    SONOROUS SPRING (Small-scale rewilding experiment produces a wealth of scientific information and brings back many endangered birds and insects, but could a Disneyfied Eden feed the world ?)

    Giving up intensive farming on our 3,500 acres had been a difficult, but unavoidable, decision; on desperately poor soil — heavy clay — we rarely made a profit and had worked up an eye-watering overdraft. Inspired by a rewilding experiment in Holland, we’d sold our dairy herds and farm machinery, stepped back and allowed nature to take the driving seat — the first project of its kind in Britain. This didn’t go down well with many of our neighbours, who complained that it was an immoral waste of land, an eyesore full of weeds and brambles. And now the great thistle invasion seemed to be proving them right. Had we been hopelessly naive? Was this the end of our vision to establish a patch of self-wilded nature, a messy, rambunctious, mini-wilderness in the heart of West Sussex? Just when all seemed lost, out of a clear blue sky came a very different invasion. That warm, clear Sunday morning in May 2009, we woke to see painted lady butterflies streaming past our bedroom window at the rate of one a minute. Outside, thousands upon thousands of them had descended on the swathes of creeping thistle to lay their eggs. As we approached, our dogs ran into the prickly cover, sending up puffs of orange and brown wings like autumn leaves. We walked for half an hour that morning, parting curtains of butterflies. A few weeks later, spiky black caterpillars were swarming over the thistles, spinning silken webs like tents. The whole area took on the appearance of a chaotic army encampment. By autumn, the caterpillars had wolfed down the leaves, pupated and flown away, leaving our thistle fields in tatters. The following year, our 60 acres of creeping thistle had vanished entirely. Not only had Nature solved the thistle problem, but thanks to sitting on our hands, we’d been given a ringside seat at one of its greatest spectacles. Miles of hedgerows, previously cut back every autumn — thereby depriving birds of winter berries — have exploded into the welcoming earth, billowing out like a dowager liberated from her stays. The first thing that strikes visitors is the noise: the low-level surround-sound thrumming of insects. Then the countless different bird songs: the very air, it seems, is being recolonised with the sounds of the past. We walk knee-deep through ox-eye daisies, bird’s-foot trefoil, ragged robin, knapweed, red clover, lady’s bedstraw, crested dog’s tail and sweet vernal grass, kicking up grasshoppers, hoverflies and all sorts of bumblebees. On a good July day, I can count ten species of butterfly — we have 34 altogether, including the rare purple emperor — without moving from my desk. At night, Knepp hosts an incredible 441 different species of moth. Meanwhile, more and more endangered species turn up every year — such as turtle doves, which are on the brink of extinction, and nightingales, whose numbers fell by 91 per cent between 1967 and 2007.

    Cuckoos, spotted flycatchers, fieldfares, hobbies, woodlarks, skylarks, lapwings, house sparrows, lesser spotted woodpeckers, yellowhammers, woodcock, red kites, sparrowhawks, peregrine falcons, all five types of British owl, the first ravens at Knepp in the past 100 years — the list goes on and on. The speed at which all these species — and many more — have appeared has astonished observers, particularly as our intensively farmed land was, biologically speaking, in dire condition in 2001, at the start of the project. The key to Knepp’s extraordinary success? It’s about surrendering all preconceptions, and simply observing what happens. By contrast, conventional conservation tends to be about targets and control, and often involves micro-managing a habitat for the perceived benefit of several chosen species.

    The rewilding of Knepp has turned out to be far richer than we ever dreamed and is producing a wealth of information new to science, often subverting what ecologists think they know about the natural world. Leave a piece of land to nature for long enough, and it will eventually become a dense wood. Every farmer knows that. In ancient times, before humans had any impact on the land, Britain was covered with closed-canopy forest. A squirrel could have run from John o’ Groats to Land’s End across the tops of trees. Or so the prevailing theory goes. But it’s wrong for several reasons. One is that grazing animals — such as wild ox, horses and bison — were here long before the trees. And if they’d had to live in dense forests, they would have quickly died off. Another is that Britain has had oak trees for millennia, and these require an open landscape. Fossils of beetles and snails, among other species, also indicate that the land was once largely wood pasture (trees dotted across fields) and thorny scrub.

    So what stopped the trees from taking over? There’s only one possible answer: herbivores. Unfortunately, many of the big, grazing animals that once roamed Britain — such as the wild ox, the original wild horse and the truly wild boar — are now extinct. But we have modern equivalents and we decided to introduce some of these to Knepp: red and fallow deer, Exmoor ponies, Tamworth pigs and old English longhorns. We’d chosen the longhorns because they retain enough of their wild ancestor’s genes to survive all year round outside.

    But how would they really behave when they were allowed to run wild? In featureless fields, our old dairy herds had simply kept their heads down chewing the cud, but without fences to contain them the longhorns could give full expression to their innate desires and preferences. They weaved among the trees, rubbing themselves against trunks and low-lying branches, raising their heads to strip off leaves and buds with their long, gluey tongues, foraged in the margins of ponds and streams, waded through the marsh. They seemed to love the sallow trees: when the flies and midges were bothersome, they’d rub their horns against the branches, smearing sap on to their faces as insect repellent.

    At first, not intervening, particularly when the longhorns were calving, felt entirely alien. We’d find ourselves suddenly encountering newborns lying in a ditch or hedge. Shortly after the birth, the cow would often seek out a patch of nettles to eat, presumably to replenish her levels of iron. After suckling her newborn, the new mother returns to the herd, commuting sometimes miles to her fellows and back again until her calf is strong enough to follow her. The calf’s introduction to the herd is momentous. The cattle crowd around, lowing gently, sniffing at the new arrival one by one, imprinting its aroma. While the calves are still young, one or two experienced matrons often guard them in a nursery while the herd moves on to feed. But even after a cow has more offspring, the family bond remains strong. I thought back to the agonising nights, many years before, when I’d hear bellowing calves, newly separated from their mothers. At just three days old, they’d been put into calf units, where they were fed on powdered milk from an automated machine. It took about two years for our longhorns to settle into a recognisable pattern, with an older cow as decision-maker. The herd might be lazing in the sun or holed up in warm leaf litter when suddenly she’d begin to bellow and lead them off into a brisk trot. Seeing the cattle crashing along on some unknown mission is reminiscent of the elephant march in The Jungle Book. In places where a low branch provided a scratching post, for example, the clay compacted by their hooves created saucers that periodically filled with water. These clean-water ‘ephemeral ponds’ are an important habitat for plants like water crowfoot, water starwort and stoneworts, and a whole range of snails and water beetles, as well as the endangered and ethereal fairy shrimp.

    The first March after the longhorns’ arrival, their former owner paid us a visit, anxious to see how they’d weathered the winter without human intervention. He couldn’t believe we hadn’t fed them. Nor had there been any need for the vet; indeed, our calving and health statistics were better than on most conventional cattle farms. Browsing on twigs, bark, herbs and leaves appears to provide cows with nutrients and minerals that grass alone cannot give.
    As they galloped from the trailer, bucking their way back to freedom, we could see we were dealing with an animal way wilder than the longhorn. There’s little doubt about their credentials as an ancient breed: fossil remains dating back to around 50,000BC have been found round Exmoor. Now an endangered species, they’re rarer than tigers.

    A year later, we introduced two Tamworth sows and their eight piglets. Prohibited by law from keeping wild boar, we’d opted for this old breed to stand in as their proxy — rootling and disturbing the soil as their ancestors had on our land in the time of King John. The Exmoors acted as if we’d introduced them to a pack of grizzly bears. One glimpse of the vast, bristly, ginger farmyard sows, and the ponies were running for the hills. Perhaps they had some atavistic memory of wild boar predating on newborn foals.

    The pigs had an extraordinary impact. The instant they were let out, they destroyed Charlie’s manicured verges along the drives with the unstoppable momentum of forklift trucks. Then, two abreast, they unzipped the turf down the public footpaths. We realised they were zeroing in on slivers of the land never ploughed — margins rich in invertebrates and rhizomes. Their ingenuity often got the better of us when it came to public events in our park. Though we electric-fenced a showground for a summer Craft Fair, we didn’t think to fortify the pond on one side of it. The pigs swam over in the middle of the night, broke into the confectionery tent and hoovered down two sacks of Mr Whippy powdered ice cream. At first, we were dismayed to observe their capacity for damage, particularly in the wet, when ten pigs could churn acres into the battlefield of the Somme in a matter of hours. But the land’s ability to regenerate was equally astonishing. Within days, a patchwork of pioneer plants would appear where the sward had been opened. nvertebrates, including rare bees, colonised the exposed ground.

    In winter, wrens, dunnocks and robins trailed in the wake of the Tamworths, picking for insects in the furrows. Ants used clods of earth turned over by the pigs to kick-start anthills that have grown, in some places, over a foot in eight years. Anthills, in turn, attracted mistle thrushes and wheatears — and especially green woodpeckers, whose diet consists of as much as 80 per cent grassland ants.

    To many of our neighbours, the most offensive aspect of Knepp, epitomising our neglectful ways, is the appearance of ‘injurious’ weeds. By far the worst, in their view, is common ragwort. Standing around 3ft tall, it produces dense, flat-topped clusters of bright yellow flowers, and is thought to be a killer of livestock. And it does, indeed, contain toxins that, when eaten in large quantities, cause liver failure and death.

    But grazing animals have lived with it for tens of thousands of years. Our longhorns, Exmoors and Tamworths, as well as roe and red deer, graze among ragwort with no adverse effects They know to avoid it. In fact, the plant itself warns them away with its bitter taste and unpleasant smell. Poisoning arises not in the wild, of course, but where fields and paddocks are over-grazed and the animals have no choice but to eat it — or when ragwort is cut into silage or hay and animals are unable to detect and avoid it. Even then, the animal has to eat an excessive amount for it to be fatal, yet few people nowadays are able to accept common ragwort’s place in nature. To put it in context, there are plenty of other common plants that can kill, including foxglove, cuckoo pint, ivy, black bryony, white bryony, bracken, elder, spindle, and yew — as well as daffodils, one of our most poisonous plants. A few years ago, daffodils almost killed a vicar, after he ate a bunch to enliven his Easter sermon. He had to be rushed to hospital to have his stomach pumped. Yet no one thinks to denigrate these lovely flowers. As for ragwort, it’s one of the most sustaining hosts to insects that we have in Britain: in all, 177 species of insects use it as a source of nectar or pollen.

    The nightingales arrived in such numbers that we began to have nightingale dinners, taking friends out at night to listen to their astonishing arias. Most had never heard one before. Conservationists began taking an interest when it emerged that the nightingales nested deep in the exploding skirts of an overgrown hedge, fringed with brambles, nettles and long grasses Contrary to what naturalists had assumed, a nightingale is not a woodland bird after all. Neither are purple emperors — one of our most spectacular butterflies — a woodland species, as previously thought: ours nest in young sallow scrub. Even more exciting even than the nightingales was the arrival of turtle doves, with their throaty turr-turr-ing. There are estimated to be fewer than 5,000 pairs left in the whole of Britain. The RSPB describes them as feeding on seeds and nothing else. In fact, in the increasing absence of weeds in the countryside, grains may be their food of last resort. Whole grains are indigestible and the sharp edges of cracked grains can tear their throats. Grains can also absorb moisture in the gut and generate fungal disease.

    We don’t yet know exactly what our turtle doves are eating, but we do know that they’re finding it at Knepp. The pigs may yet again be playing a role: their rootling produces exactly the right conditions for the germination of seed-bearing wildflowers that attract these rare birds. One thing is for certain. If we hadn’t allowed a dynamic ecosystem to establish itself here, we’d never have had turtle doves — or any other endangered species — in the first place. And if all these natural miracles can happen here, on our depleted patch of land in the over-developed, densely populated South-East, they can happen anywhere.

    https://www.dailymail.co.uk/news/article-5640191/How-letting-Mother-Nature-reclaim-prime-farmland-produced-breathtaking-results.html

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