Minnesota Reviews Atrazine -- And Drops the Ball

Photo of dye being used in a study of atrazine degradation on Roberts Creek, IA, to determine the transport time of water as it moves through the study reach of the stream.  (USDA photo)

For those of you who have been following the growing concerns over the widespread use of the pesticide atrazine in the United States, you probably know that EPA recently announced it was going to conduct a top-to-bottom review of the chemical’s safety (for NRDC’s comments on the EPA review, click here).*

What you may not know, however, is that states can also initiate their own reviews—federal environmental law allows states to set standards that are more restrictive than those mandated by the EPA.

Minnesota recently took this much needed step when it decided to open its own review of atrazine to determine whether tighter standards were needed.  So far so good.  Two months ago, Minnesota released the results of its review and invited comment.  On Wednesday, NRDC submitted its comments on the review, which starts with our recent report on atrazine contamination in the Midwest, Poisoning the Well.  Unfortunately, the conclusions in Minnesota’s review fall far short of the mark.  Here’s the top line results of our analysis:

  • Minnesota minimizes much of the recent science on atrazine’s effects.  This includes studies that indicate that prenatal atrazine exposure may increase risk of poor birth outcomes and birth defects in infants, as well as studies that links atrazine urine levels in farm workers and rural men to reproductive effects, such as low sperm count and motility.
  • The report also ignores much of the experimental literature on atrazine’s endocrine disrupting effects, including a recent study reporting that 10 percent of male frogs that were born and raised in water contaminated with 2.5 parts per billion (ppb) of atrazine grew up with female sex characteristics, had reduced levels of male testosterone hormone, reduced sperm levels, and decreased fertility.
  • The report mischaracterizes the economic benefits of atrazine use.  Minnesota fails to discuss (or mischaracterizes) studies that predict very small crop yield losses from phasing out atrazine, as well as one study that found that, despite a ban on the use of atrazine in Italy and Germany (both corn-producing nations) since 1991, neither country has recorded any economic effects.
  • The report relies on inadequate and probably faulty water monitoring data to reach its conclusions.   Minnesota’s review relies on the results of 2,782 samples taken from the 544 community water systems.  While that might sound like a lot, it averages to only about 5 samples taken per system. Moreover, these samples were taken over a period of 9 years. This averages out to fewer than one sample per system per year. Simply put: samples taken a few times a year, or once a year, or as little as once every three years (as was the case for some systems) should not be relied on. Dangerously high spikes of atrazine can occur in drinking water for just a few weeks out of the year. If a system samples only once a year or a few times a year, it is very likely that that sample will miss the spike entirely and give the false impression that there is little to no atrazine in the water.

Hopefully, Minnesota will take these comments to heart and revise its assessment.  The North Star state could sure use it.

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*Quick atrazine primer: Atrazine is used mostly on corn, sugarcane and other crops to suppress weed growth. United States farmers apply an estimated 60 to 80 million pounds of atrazine active ingredient annually. Because it is typically used in the spring before crops are planted and when rains are frequent, atrazine is often transported in runoff from fields to nearby surface waters. As a result, atrazine is the most commonly detected pesticide in U.S. waters, present in more than 75% of stream samples and 40% of shallow groundwater samples in agriculture areas across the United States.  It is an endocrine disrupting chemical, meaning that it can disrupt normal hormone function in a wide variety of organisms, including people.

About the Authors

Andrew Wetzler

Deputy Chief Program Officer

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