Round Up & other glyphosate products

Glyphosate is the active ingredient of the herbicide best known commercially as “Roundup.” It is a non-selective, systemic herbicide for controlling weeds in agriculture, forestry, rights-of-way and aquatic systems. Glyphosate disrupts plant growth and eventually causes death by inhibiting synthesis of amino acids. Isopropylamine salt is the most frequently used form of glyphosate.

Human Health Risk Summary

Acute Effects: Some formulations of glyphosate cause extreme irritation of the skin and eyes, such as blurred vision, burning eyes, rashes and skin blisters. Other symptoms reported following acute exposures include: nausea, sore throat, dizziness, gastrointestinal and respiratory tract injuries.

Chronic Effects/Carcinogenicity: Though evidence that glyphosate causes cancer is yet to be established, several animal and human population studies have indicated that it may increase the risk of non-Hodgkin’s lymphoma, multiply myeloma, pancreatic, thyroid and testicular cancers.

Reproductive & Developmental Toxicity: Glyphosate exposure has been associated with several manifestations of reproductive and developmental impairment. In animal studies, high dose or prolonged exposures have resulted in skeletal malformations, disrupted organ development, and reduced sperm volume and quality. In human population studies, exposure to glyphosate has been connected to an increased rate of miscarriage, reduction in sex hormone production, and disruptions to endocrine system development.

Mutagenicity: Several studies on both animals and humans have suggested that exposure to glyphosate can cause chromosomal aberrations, DNA breaks, and other genetic mutations.

Ecological Hazard Summary

Environmental Fate: Glyphosate has frequently been detected in surface water nation-wide. It tends to bond strongly to soil particles and therefore may be displaced to surface water from movement of soil by wind, erosion, or storm runoff. Drift following arial applications also contributes to the presence of glyphosate in water.

Glyphosate is moderately to highly persistent, with half remaining toxic in soil from 60 days to six months or more, depending on soil conditions. In aquatic environments, half may remain toxic for several weeks to several months.

Risk to Non-Target Flora & Fauna: Because of drift and offsite movement from wind and rain, glyphosate poses a considerable risk to non-target plant and animal species. A significant amount of glyphosate spray applications drift off-site (from 14% to 78%), affecting plants 130 feet away, and residues have been detected up to 1,300 feet downwind.
Glyphosate has been shown to disrupt the immune systems and cause genetic abnormalities in fish. Similarly, it causes genetic, developmental and reproductive mutation in amphibians.

The balance of soil organisms is disrupted by glyphosate, which leaches from the roots of sprayed plants into the surrounding soil. Several studies have indicated that pathogenic fungi and other crop pests increase in numbers or have less competition when glyphosate is present in soil.

Toxicity of Other Ingredients

Commercial products such as Roundup are composed of the active ingredient (approximately 40% of the solution) and other ingredients that improve its effectiveness. These compounds exhibit toxicity at much higher levels than glyphosate alone. One such chemical, polyethoxylated tallowamine (POEA), is three times as acutely toxic to humans as glyphosate alone.

A product commonly mixed with glyphosate formulations to improve performance in the environment was found to be 100 times more toxic to aquatic invertebrates. Other added ingredients have been shown to damage cellular DNA, cause cancer or birth defects, and disrupt reproductive function in both humans and animals.

Summary

Glyphosate and commercially available products containing this compound are of particular concern to human health and the environment, due to: 1) some evidence of carcinogenicity, reproductive/developmental toxicity, endocrine system and genetic toxicity to humans; 2) potential adverse effects to non-target plant and animal species due to overspray, drift, and displacement; and 3) the potentially sever impact of many of its additives such as POEA, which have been identified as extremely hazardous to both humans and animals.