The Hazards of Glyphosate

Toxicity in Animals

• Glyphosate has been tested extensively on animals that have experienced adverse effects. Rats that inhaled even small amounts of products containing glyphosate experienced some signs of toxicity: bloody lung congestion, body weight loss and reduced respiratory activity. Long-term effects in rats included salivary gland lesions and an increase in thyroid, pancreas and liver tumors. Dogs given intravenous injections at the amount of accidental human consumption showed an increase in the heart's ability to contract. One glyphosate product caused canine cardiac depression. Testing on rabbits for eye irritation found that glyposate products caused severe eye irritation and breakdown of eye tissue that required 21 days of healing.

Toxicity in Humans

• Even small amounts of exposure to glyphosate products had adverse effects in humans. For example, farmers that rubbed their eyes after touching glyphosate experienced eye swelling and irritation, elevated blood pressure and rapid heartbeat. Inhalation in humans has caused acute toxic pneumonitis, high fever and general fatigue. Accidentally soaking the skin in glyphosate products led to temporary two-week eczema in the exposed area. Widespread aerial spraying in Colombia caused the poisoning of 4,000 people. In Denmark, 24 people were exposed by inhalation and 42 topically. Approximately 75 percent developed some form of poisoning symptoms.

Environmental Hazards

• Glyphosate products have shown to have adverse effects on both marine and land environments. When the herbicides leaked or ran off into bodies of water there were lethal effects to bluegill sunfish and tadpoles. In 2004, Denmark restricted the use of glyphosate products during fall and winter months because of leaching through the root zone into groundwater. Glyphosate acts nonselectively, so widespread aerial or ground application can cause drift and kill plants in surrounding areas. This includes woody plants, perennials and grasses. The killing of non-target plants affects the surrounding ecosystem by killing herbivore insects, birds and small mammals. Glyphosate products have also been found to increase crop susceptibility to plant diseases by decreasing their ability to fight. Even woody plants such as the lodgepole pine were shown to have a decreased ability to fight blue stain fungus after exposure to a glyphosate herbicide.