Roundup Weed Killer Side Effects

Roundup is perhaps the best-known and most widely used herbicide for home gardens. It is effective at killing a large number of unwanted plants. The active chemical ingredient of Roundup is glyphosate, which has been implicated in causing miscarriages of pregnant farm animals that graze in areas where this product is used. The EPA classifies glyphosate as a class II toxicity chemical (class I are the most toxic).

Adverse Effect on Placental Cells

The journal "Environmental Health Perspectives" reported in March 2005 that glyphosate, the active chemical in Roundup, causes late spontaneous abortions in cattle and other livestock that graze where this product has been used. Professor Gilles-Eric Seralini of France's University of Caen concluded in the study that glyphosate could have adverse effects on human placental cells, meaning that it might cause miscarriages or other reproductive problems in pregnant women who work or live near areas where large quantities of this chemical are used.

Contamination of Surface Water

The U.S. Environmental Protection Agency has found, contrary to popular belief, that Roundup is capable of contaminating surface water because the glyphosate does not break down quickly. In ponds, rivers, lakes and streams, glyphosate remains for as many as 84 days. The International Organization for Biological Control found in a study that Roundup's effects on birds, fish, insects, earthworms, small mammals and amphibians can result in death. The University of Pittsburgh conducted a study in 2005 that implicated Roundup in "extremely lethal" effects on amphibians that live in areas where Roundup is heavily used.

Toxic When Consumed

In Japan, 56 people consumed Roundup between 1984 and 1986, causing adverse effects to their bodies, including the nervous system, respiratory system and cardiovascular system. Nine of these people reportedly died, according to the Chemical Watch Factsheet, published by Although glyphosate was not implicated, the inert ingredient polyoxyethyleneamine (POEA) was. This chemical is a surfactant, which is added to products like Roundup to help the glyphosate penetrate plant tissues. POEA makes up 15 percent of Roundup. In 2009, researchers in France determined that another of Roundup's inert ingredients was responsible for killing human embryonic, umbilical and placental cells. Other inert ingredients in Roundup include ammonium sulfate, benziothiazolone sodium, sulfite, sorbic acid and others, all of which can cause irritation of the skin and problems with the digestive and respiratory systems.

Non-Hodgkin Lymphoma and Other Diseases

The American Cancer Society published the results of a study in 1999 showing that people who have frequent contact with glyphosate are 2.7 times more likely to develop non-Hodgkin lymphoma. In Finland, researchers found in 2000 that glyphosate weakens liver and intestinal enzymes. Roundup was found to switch off an antioxidant in the liver, making harmful substances pass through and be excreted in bile. High doses of glyphosate might also cause thyroid and testicular tumors in laboratory rats, but the EPA is not requiring further studies on this subject.

Roundup Does Not Discriminate

Herbicidal products like Roundup are designed to kill all plants they contact. Label instructions advise avoiding use of the product on windy days because the spray can drift to plants that you don't want to kill.

Keywords: weed killers, Roundup Glyphosate, toxic chemicals, herbicide dangers health

About this Author

Barbara Fahs lives on Hawaii island, where she has created Hi'iaka's Healing Herb Garden. Fahs wrote "Super Simple Guide to Creating Hawaiian Gardens," and has been a professional writer since 1984. She contributes to Big Island Weekly, Ke Ola magazine, GardenGuides and eHow. She earned her B.A. at UCSB and her M.A. from San Jose State University.