Journal or Publishing Institution: Journal of Pesticide Reform
Author(s): Cox, C.
Article Type: Report
Record ID: 408
Introduction: Glyphosate is a broad-spectrum herbicide widely used to kill unwanted plants both in agriculture and in nonagricultural landscapes. Estimated use in the U.S. is between 19 and 26 million pounds per year. Most glyphosate-containing products are either made or used with a surfactant, chemicals that help glyphosate to penetrate plant cells. Glyphosate-containing products are acutely toxic to animals, including humans. Symptoms include eye and skin irritation, cardiac depression, gastrointestinal pain, vomiting, and accumulation of excess fluid in the lungs. The surfactant used in a common glyphosate product (Roundup) is more acutely toxic than glyphosate itself; the combination of the two is yet more toxic. In animal studies, feeding of glyphosate for three months caused reduced weight gain, diarrhea, and salivary gland lesions. Lifetime feeding of glyphosate caused excess growth and death of liver cells, cataracts and lens degeneration, and increases in the frequency of thyroid, pancreas, and liver tumors. Glyphosate-containing products have caused genetic damage in human blood cells, fruit flies, and onion cells. Glyphosate causes reduced sperm counts in male rats, a lengthened estrous cycle in female rats, and an increase in fetal loss together with a decrease in birth weights in their offspring. It is striking that laboratory studies have identified adverse effects of glyphosate or glyphosate-containing products in all standard categories of toxicological testing. Two serious cases of fraud have occurred in laboratories conducting toxicology and residue testing for glyphosate and glyphosate-containing products.
Advertised as herbicides that can “eradicate weeds and unwanted grasses effectively with a high level of environmental safety,”1 glyphosate-based herbicides can seem like a silver bullet to those dealing with unwanted vegetation. However, an independent, accurate evaluation of their health and environmental hazards can draw conclusions very different than those presented by these advertisements.
The following summary of glyphosate’s hazards is intended to serve that purpose. It will appear in two parts: Part 1 discusses the toxicology of glyphosate, its metabolites, and the other ingredients of glyphosate products and Part 2 will discuss human exposure to glyphosate and its ecological effects.
Keywords: glyphosate, human exposure, animal studies, ecological effects, toxicity
Citation: Cox, C., 1995. Glyphosate, part 1: toxicology. Journal of Pesticide Reform, 15(3), 14-20.
