GM Roundup Ready (RR) soy is the most widely grown GM crop. It is engineered to tolerate being sprayed with Roundup herbicide, based on the chemical glyphosate. Widespread planting of GM soy in North and South America has led to large increases in the amount of glyphosate herbicide used. Regulators have responded by raising the allowed residue limit of glyphosate in crops eaten by people and animals. So people and animals that eat GM RR crops are eating potentially toxic herbicide residues.
Regulators and industry claim that this is safe because Roundup has low toxicity. But these claims – as well as the supposed “safe” level of glyphosate set by regulators – are based on outdated industry studies, the findings of which have been thrown into question by numerous independent studies. These studies show that Roundup and glyphosate are not safe but pose serious health risks. Effects found in animal studies and test-tube studies on human cells include cell death and damage, damage to DNA, disruption of hormones, birth defects, and cancer. Some of these effects have been found at levels far below those used in agriculture and corresponding to low levels of residues in food and feed. The added ingredients in Roundup (adjuvants) increase the toxicity of glyphosate, and the main breakdown product of glyphosate, AMPA, is also toxic.
Effects of exposure to glyphosate herbicides on humans found in epidemiological studies include DNA damage, premature birth and miscarriage, cancer, and attention deficit disorder in children.
The widespread use of glyphosate herbicides – not just on farms but in gardens, on roadsides, and in parks and school grounds – means that many people are exposed. In addition, glyphosate does not stay where it is applied but moves around the environment. It is frequently found in rain, air, streams, and groundwater, and even in women’s blood.
GM crops have increased the use of glyphosate and thus people’s exposure to it, presenting a risk that has not been adequately considered in regulatory assessments of GM crops.