What do Norway, Denmark, Sweden, Sri Lanka, El Salvador, Brazil, and India have in common? They have banned the use of Roundup—the most heavily applied herbicide in the United States. Why have these nations acted against what is the most heavily used herbicide in the world today? This is because of growing reports of serious illness to farmworkers and their families. Thanks to a little known provision in US law governing pesticides (the overarching category defined by the EPA for pesticides, herbicides, fungicides, and rodenticides), industry experts sit side by side with government officials in determining what is and is not toxic. In these other nations, far less cozy arrangements exist and reports of tragic illness have spurred direct and immediate actions.

To understand what inspired these disparate nations to restrict a pesticide widely dispersed in garages, schoolyards, golf courses, and farmland around America today, it’s important to consider the close tie between glyphosate (the main ingredient in Roundup) and the production of corn, cotton, soybeans, alfalfa, canola, sorghum, sugar beets, and wheat. Seeds for these major US commercial crops have been genetically engineered to resist the toxic effect Roundup has on weeds. Physicians report that rates of serious birth defects in one of Argentina’s poorest regions, Chaco, quadrupled the decade after glyphosate was introduced, while that of chronic kidney disease is soaring in young men and women in Central America, India, and other heavily sprayed regions.

This past June, a group of experts advising the World Health Organization (WHO) known as the International Agency for Research on Cancer (IARC) unanimously determined that glyphosate is probably a human carcinogen (“Group 2A” in the IARC Monographs on the Evaluation of Carcinogenic Risks to Humans). Other agents identified as Group 2A include jet fuel, engine exhausts, a number of pesticides, and tars—all of which are subject to stringent controls today. More recently, nearly 100 scientists joined in rejecting the European Food Safety Agency assurance that Roundup was not toxic.

Underlying the WHO evaluations over the past four decades is one simple fact: Every agent known to cause cancer in humans also causes it in animals when adequately studied. Whenever experimental studies indicate a compound causes cancer in animals, it should be regarded as if it causes cancer in humans.

If glyphosate were a drug, it would never have been allowed to market.

Drugs are put into medical practice only after experiments establish that a novel agent might alleviate disease in animals. Monsanto began selling glyphosate in Roundup in 1973. It didn’t complete animal tests until 1981. When those tests produced a rare form of kidney cancer, industry sponsored scientists effectively discredited them.

In the case of glyphosate and cancer, one important animal study stands out. That study used a type of mouse bred to never get the disease. Four animals exposed to glyphosate developed the same very rare cancer in a single study. Not a single case of cancer was expected. The chances of that happening are close to one in a billion. Of course, people are not rodents. But the human genome project has shown that we differ from the mouse by less than one percent of all our genetic material. If studies with mice guide the pharmaceutical industry, how can we deny their relevance to toxic chemicals?

With tobacco, asbestos, vinyl chloride, hormone replacement therapy, diagnostic radiation, some metals, exhaust gases, chlorinated solvents, and a host of other agents, we got it backwards. Reports of their detrimental impacts surfaced decades before steps were finally taken to discourage their widespread use.

We are flying blind when it comes to understanding the risks of glyphosate—along with malathion and diazonon and other pesticides—because we have assumed them to be innocent until proven guilty. To the contrary, pesticides should not be accorded the rights of the accused in a criminal trial. By their very nature pesticides are designed to kill things and indeed there are times, as with epidemics such as equine-encephalitis, that we need to employ them for that purpose.

Studies of people with high exposures to glyphosate or other pesticides, including farmers, pesticide applicators, crop duster pilots, and manufacturers, have found high rates of blood and lymphatic system cancers, cancers of the lip, stomach, lung, brain, and prostate, as well as melanoma and other skin cancers. But what about the rest of us who may be exposed as golfers, lawn applicators, home gardeners, school children, ball players, and the like? We must rely on animal experiments, coupled with studies of those with high exposures, to predict risk in order to prevent harm.

What are we to do now? While industry spokespersons assure us that these other governments are just uninformed and ill-advised, their growing numbers alone should give us pause. There’s been a disturbing pattern in US law of late that places us all at risk. Recent interpretations of the Daubert standard of evidence increasingly mean that only after harm has been demonstrated to have taken place can steps be taken to reduce exposures to a suspect agent. This ignores and undermines the fundamental goal of public health: Preventing harm by reducing risk.

With glyphosate and other toxic agents we cannot and should not wait for additional proof that low levels of exposure affect our health, before taking steps to reduce our exposures. We must rely on animal experiments coupled with studies of those with high exposures in efforts to reduce the burden of cancer and other diseases. To do otherwise treats ourselves and our children as lab rats in an experiment without any controls.

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