The Myths of Safe Pesticides

review by Jack Kittredge

André Leu, an Australian tropical fruit farmer, is a leader in the organic movement and president of IFOAM, the International Federation of Organic Agricultural Movements. He has occasionally written articles we reprint in The Natural Farmer, and I am glad to have a chance to review his book on the pesticide threat.

Fifty years ago Rachel Carson published “Silent Spring”, the book which first seriously examined the widespread use of pesticides and their impact on human and environmental health. More books followed in the subsequent decades, as more and more novel chemicals have been created and introduced into our agriculture, our food, and our bodies.

The situation now is simply scandalous. Some of the rain falling on Europe contains such high levels of pesticide that it would be illegal to supply it as drinking water. Only 23% of US food samples are pesticide-free (29.5% contain residues of one pesticide, the rest – almost 50% — have residues of two or more).

In this book Leu demolishes five myths that have been put forth by officialdom to lull the public into a false sense of security about our extravagant use of these poisons.

1) They are rigorously tested. According to the 2010 US President’s Cancer Panel (USPCP): “Only a few hundred of the more than 80,000 chemicals in use in the US have been tested for safety.” How can this be? In part, regulators (largely the EPA) rely on testing done by the chemical manufacturers, whose reported results are hardly unbiased. More significantly, however, what testing is done is on isolated ‘active ingredients’. But pesticides are not applied as isolated chemicals. They all contain solvents, adjuvants, surfactants, and other ‘inert’ chemicals which are hardly inert. They are there to greatly enhance the effectiveness of the poisons. Not only that, but pesticides are also applied in situations where other pesticides are also present, leading to toxic mixtures which greatly multiply the impact of any single product.

2) Only a very small amount is used. Most developed nations have programs where food is occasionally tested to see if pesticide residues exceed a maximum residue level (MRL). It is this testing which is used as the basis for most findings of “safety”, not actual toxicity tests on the compounds themselves. But how are these levels set, and are they scientifically sound? Leu says the answers to these questions are not very reassuring. For one, many toxins do not show what one might assume are “normal” properties like effect decreasing with dose. There are hundreds of examples in the epidemiologic literature of low dosage leading to unpredictable effects. Particularly in the endocrine system, hormone levels which are either too high or too low can cause a wide variety of disease. Yet it is exactly this homeostasis that many modern pesticides target with their impact on estrogen, progesterone, and testosterone.

3) Modern pesticides rapidly degrade. In fact, most modern pesticides leave residues in food – thus the high levels found cited above. Many of these products break down into metabolites called oxons, which are even more dangerous than the original compound. Dioxins and other polychlorinated chemicals are often found in pesticides as impurities from the manufacturing process or other sources and maintain their toxic effect for long periods. Glyphosate (Roundup) is another compound which breaks down into a persistent toxin (AMPA) which has been linked to liver disease.

4) The regulatory authorities can be trusted. In many cases in the developing world despite regulations about proper use, pesticides are applied by people who cannot read, have not been trained in their use, and do not have proper equipment for application as prescribed by the authorities. But even in advanced nations, regulatory history shows that authorities cannot be relied upon to prevent contamination by such toxins as lead, mercury, dioxins, PCBs, DDT, dieldrin and many others. For current pesticides, the EPA has ignored a wealth of peer-reviewed studies and risk assessments in favor of data supplied by the chemical companies. In 2013 the EPA increased the allowed MRL of glyphosate in food and crops in response to a petition from Monsanto despite many peer-reviewed studies linking the herbicide with cancer, birth defects, damage to many organs, disruption of the gut microbiome, and diabetes.

5) Pesticides are essential to farming. Many studies have measured and compared organic and conventional yields. A number of these have found organic yields comparable or better (ARS Pecan Study found organic yields surpassed conventional ones by 12 to 18 pounds of nuts per tree; Wisconsin Integrated Cropping Systems Trials found that organic yields beat conventional ones in drought years, equaled them in normal years, and fell behind by about 10% in wet ones; Cornell’s analysis of a 22-year Rodale study found that after five years organic equaled or exceeded conventional yields; Rodale’s Organic Low/No Till study found organic corn production beat the conventional county average by over 20%; Iowa State University’s 12-year trials concluded that organic systems have equal to higher yields than conventional; etc.) One of organic farming’s strengths is in dealing with adverse conditions. Yet these are exactly what we are going to see more of as we experience more and more droughts and heavy rainfall. Over 85% of the world’s farmers are smallholders, and the UN consistently reports that their yields, using organic systems without synthetic chemicals, are higher than conventional farms.

The only people who need pesticides are the chemical companies themselves. Farmers can raise enough food to feed the world as they always have – without toxins poisoning our land and our bodies. If you are not convinced, read André Leu and you will be.