Position Statement on Synthetic Pesticides
The large-scale use of synthetic pesticides has been taking place for only two and a half generations.
Beginning with the use of DDT during the Second World War (whose discovery earned entomologist Dr. Paul Mueller a Nobel Prize in 1948), the pesticide industry has grown rapidly, and at times even exponentially, up to the present day. Currently over 2.5 million tons of such chemicals, worth over US $30 billion, are applied to crops in every country in the world. Of this amount, 73% is produced by just ten multinational agrochemical corporations1; five countries – France, the U.S.A., Germany, Britain and Switzerland – are the primary producing nations.2 Encompassing insecticides, herbicides, parasitocides, nematocides, growth regulators, fungicides, defoliants and dessicants among others, this wide-ranging set of approximately 100,000 compounds, 7000 of which are registered for use in Canada,3 have one thing in common; they are all designed to kill one or more often many species of living organisms, usually in a nonspecific manner. Estimates that less than five percent of pesticide formulations by volume reach intended target organisms may well be accurate, considering the inevitability of drift, routine pesticide use as prevention without prior confirmation of infestations, and incautious application. So-called ‘inert’ portions of formulations – composing up to 95% of many products – are often quite toxic in themselves.
Early on in their history, the development of resistance to chemical pesticides became a significant issue. The rapid multiplication rates of single-celled or other simple organisms makes it clear that such a problem is inevitable, but the speed with which resistance occurs has often surprised observers. Resistance to DDT was a major problem only five years after its introduction. Today multiple pesticide resistance is common, and new pesticides, like new antibiotics, are regularly produced by industry to address this problem.
The World Health Organization (WHO) estimates today – in figures that are widely accepted to be underestimates – that 200,000 people are killed worldwide, every year, as a direct result of pesticide poisoning, up from 30,000 in 1990. The WHO further estimates that at least 3 million persons are poisoned annually, many of whom are children. A study in England and Wales demonstrated that 50% of pesticide poisonings involved children under the age of 10.4
Pesticides can be remarkably persistent in biological systems. The US Environmental Protection Agency has conducted the National Human Adipose Tissue Survey since 1976, measuring toxic compounds in human fat. In 1982 this study found DDE, the primary metabolite of DDT, in 93% of samples.5 A 1990 study of adipose tissue levels of toxic compounds in autopsy specimens from elderly Texans found DDE, dieldrin, oxychlordane and heptachlor epoxide in 100% of samples.6 These findings are particularly disturbing because DDT has been banned in the US since 1972.
Pesticides are also found far afield, in ecosystems considered pristine and far from active pesticide use. Osprey eggs in the Queen Charlotte Islands, polar bear fat in the high arctic, and the blubber of whales in all the oceans of the world are contaminated with pesticide residues,7 even though all these creatures live far from point sources of pesticide application. Water and wind, as well as the bodies of animals that serve as prey for others (including humans) higher on the food chain, are the universal vectors for pesticide dispersal. Highest on the food chain, human breast milk is of great concern because of high levels of bio-accumulated pesticides. Breast milk of Inuit women contains much higher pesticide levels than the milk of women in southern Canada, raising concerns about this most intimate and crucial form of human sustenance.8,9
Two other factors make pesticides problematic for human and ecosystem health. First, many pesticides are not persistent in human or other biological systems. Therefore they may be difficult to measure in tissue or other samples collected more than a few hours after exposure, although their biological effects may persist for days, months or even years. Second, many pesticides undoubtedly have additive or synergistic effects with one another, especially when they belong to the same chemical class. Only recently have these two issues been acknowledged by legislators, with the 1996 US Food Quality and Protection Act being the first major enactment anywhere in the world that takes the latter fact into consideration.
A further health issue regarding pesticides has emerged in the last decade. This is the demonstration that many chemical compounds, among them many pesticides, have hormone-like effects in biological systems, effects that were previously unsuspected as occurring on such a wide scale. During the last four years, the US Environmental Protection Agency (EPA) has been designing a first-ever program for analyzing these effects. The work has proceeded so slowly, however, despite a legislative mandate to act speedily, that the EPA itself is now being sued for dragging its feet!10 The Canadian government, lacking legislation for examining any adverse effects of pesticides, relies on manufacturers to supply such evidence.
Rationale for a CAPE Position Statement
As a result of the unquestioning trust that the population at large has placed in the scientific community, the commercial sector and regulatory agencies in the past, pesticides have become dispersed on a massive scale throughout our global ecosystem, without adequate testing for adverse effects in humans. In what has been called a massive, uncontrolled, global biochemical experiment, they are now essentially universal in surface waters, soils and biological systems. Because of their fundamentally toxic nature, pesticides are unlikely to be absolved of their demonstrated negative role in the health of humans and biological systems in general. In fact, it can be logically inferred that their deleterious impact will eventually be shown to be far more extensive than what is known at present, because so much research has yet to be done on the full range of toxicity potentialities.
Physicians are ill-trained to diagnose the adverse effects of pesticide exposures. Because there is no mandatory requirement for reporting actual or suspected pesticide poisonings, little confidence can be placed in many aspects of estimates of the public health effects of pesticide accumulation in local or regional ecosystems.
However there is growing evidence that the health of future generations may be severely harmed by pesticides, alone or in combination with other toxic chemicals now permeating the global ecosphere. The fetus and the newborn child, in particular, appear to be uniquely sensitive to the harmful effects of pesticides and other toxins.11 Children, it has often been said, are not simply small adults. They are beings with uniquely vulnerable physiological processes. They incorporate ingested or inhaled substances into their growing bodies far more avidly than adults; these substances can profoundly influence their unique developmental processes, and induce disproportionately greater acute and chronic toxicity.12
For the above reasons, the Canadian Association of Physicians for the Environment feels it is important for us, as concerned clinicians, to lay out clearly what we believe to be the path for ethical scientists, medical or otherwise, to advocate on behalf of Canadian society. We believe that in such a statement, we must avoid ambiguity. We believe that we should likewise avoid clinging to banal certitudes. Instead, we must speak in a balanced and responsible way about the future direction society must take to avoid a possible looming toxic tragedy.
Reaching the goal of pesticide elimination cannot be accomplished without a dramatically increased support program for farmers and other growers who are prepared to convert to sustainable growing practices, including cessation of pesticide use. We believe that the best means to accomplish the goal of eliminating routine pesticide use is as follows:
Copyright © 2000 Canadian Association of Physicians for the Environment
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