Atrazine Controversy Swirls

Forrest Laws, Farm Press Editorial Staff
May 26, 2010

As U.S. growers wrap up planting an estimated 90 million acres of corn this spring, there’s a good chance many of those acres have something in common besides seed corn – an application of atrazine.

Discovered more than 50 years ago, 2-chloro-4-(ethylamine)-6-isopropylamine)-s-triazine or atrazine has become one of the most commonly used herbicides in the world. According to some counts, U.S. farmers apply around 76 million pounds a year.

But those applications could be in jeopardy if environmental groups such as the Natural Resources Defense Council succeed in their efforts to persuade EPA to phase out all uses of the product in the United States, including gardens and golf courses.

In a recent report entitled, “Still Poisoning the Well,” the NRDC repeated its claims that atrazine is responsible for pervasive contamination of watersheds and drinking water systems across the Midwest and Southern United States. The NRDC claims “thousands of drinking water systems may be unknowingly contaminated with atrazine.”

Representatives of Syngenta, the basic manufacturer of atrazine, have heard it all before. Some of them seem resigned to the fact they will have spent much of their careers defending the safety of atrazine.

“I’m proud to say atrazine is a tried and true herbicide that’s been used by American growers for over 50 years now,” says Chuck Foresman, technical brand manager for Syngenta. “And the reason why people use it is because it works and is safe.”

Foresman, who was interviewed following a Syngenta presentation at the Commodity Classic earlier this year, acknowledged that atrazine is well on its way to becoming one of the most studied herbicides in crop protection chemical history.

Despite its having been given a clean bill of health by EPA four years ago, the agency has announced it is taking yet another look at the herbicide’s safety record. Besides the NRDC’s April critique of atrazine, the National Academy of Sciences has also released a report echoing some of the NRDC’s claims.

“There are over 6,000 studies that have been looked at by the EPA over the last several years,” said Foresman. “In fact, in 2006, EPA decided to re-register, in other words, re-license the use of atrazine, and so it has come under close scrutiny.”

Syngenta toxicologists have looked at the National Academy of Sciences report, which refers to a study that claims atrazine appears to inhibit the reproductive development of a certain species of frogs. The study contains several flaws, according to Syngenta scientists.

“No. 1, we wonder if the results are really reproducible,” says Foresman. “In fact, the author of the article suggests these findings are not similar to previous test findings. No. 2, when you do toxicological studies you really should be looking at more than a single dose, and that’s what they did in this study, a single dose of atrazine that was used to expose these frogs.”

The scientists also question the lack of an internal positive control among the population. (An independent Scientific Advisory Panel set up by EPA has reviewed the findings and said there is not enough data to determine if atrazine affects amphibian development.)

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