October 8, 2009
US to weigh cancer risk from popular corn herbicide
The US Environmental Protection Agency (EPA) announced Wednesday (Oct 7) it is launching an investigation into whether the herbicide atrazine, popular among US corn farmers, causes cancer and birth defects.
"Our examination of atrazine will be based on transparency and sound science, including independent scientific peer review, and will help determine whether a change in EPAa€？s regulatory position on this herbicide is appropriate," said Steve Owens, an EPA assistant administrator.
But agribusiness giant Syngenta AG, maker of atrazine for 50 years, said the chemical has already been proven safe. The company, in a recent statement, said the EPA, the World Health Organisation and others have previously reviewed the drug and pronounced it safe.
Sherry Ford, a spokeswoman for Syngenta, said the EPA re-licensed atrazine for sale in the US in 2006 and said the chemical wasn''t likely to cause cancer.
US corn farmers have come to rely on the herbicide to control weeds in their fields. Ken McCauley, former president of the National Corn Growers Association, said Wednesday that atrazine is used on most corn fields in the US.
Syngenta''s Ford said about 60 percent of the corn, 75 percent of the sorghum and 90 percent of sugarcane grown in the US is done so with the aid of atrazine.
"When EPA re-registered it in 2006...they estimated that atrazine saves corn farmers about US$28 per acre in herbicide costs and yield advantages," Ford said.
McCauley, who farms 4,500 acres in Kansas, said he relies on the herbicide to "enhance" the effects of other chemicals. While he and many farmers rely heavily on atrazine, they use less of it than when the chemical was first sold on the market. Initially, atrazine was used as a primary herbicide and farmers would use about three to five pounds per acre. Now, McCauley said, it''s common practice to use about a pound or less.
Use of the herbicide makes it possible for many corn producers to conduct "no-till" farming, McCauley said, a practice that eliminates plowing to protect against soil erosion.
US farmers are currently in the midst of harvest and they are expected to produce about 13 billion bushels of corn on 80 million acres of land, according to USDA data.
Atrazine is already regulated by the EPA, which warns of human health threats from contamination of drinking water. The EPA said atrazine may cause "congestion of heart, lungs and kidneys; low blood pressure; muscle spasms; weight loss; damage to adrenal glands" if "people are exposed to it at levels above three parts per billion for relatively short periods of time."
