NRDC Report: Widespread Atrazine Contamination in Drinking Water and Streams

In NRDC's new atrazine report we analyzed a mountain of data showing widespread water contamination from atrazine, a toxic herbicide. The data was mostly, but not all, generated by Syngenta, the main manufacturer of atrazine. Are you drinking atrazine in your tap water? Possibly. Fishing, swimming, or boating in it? Probably. Check out the report to look up specific information for your state.

Atrazine is sold under kick-butt trade names like Bicep II Magnum. The website boasts that it's "how fields get clean, and stay clean". That's ag-speak for kills every green thing in the field before you plant the crop...even the good stuff like beneficial nutrient-rich plants and bacteria in the soil.

Atrazine has a half-life of several years (longer in colder climates), and can be detected in most streams and rivers of the U.S. Eventually, much of it gets to the Gulf of Mexico, where it continues its plant-killing spree of algae and other beneficial water plants that provide food and oxygen for aquatic life.

In addition, there is strong evidence that atrazine is an endocrine disrupting chemical (EDC), interfering with critical reproductive hormones even at extremely low levels. This is because hormones in our bodies are active at very low levels, parts-per-billion or lower. Higher doses of an EDC may knock the whole hormone system out, whereas low doses can interfere with the normal system in more subtle ways, sending things in strange directions. For example, lab studies in frogs indicates that low levels of atrazine may turn males into females. Ewwww.

The big problem is that atrazine in drinking water is regulated as an annual average; the spikes get averaged out. Similarly, in streams and rivers the seasonal fluctuations are averaged out by the regulatory agencies. Unfortunately, reproductive development happens a lot faster than that, so spikes matter!

What can we learn from the 2009 studies? Spikes matter!

• Even a single dose of atrazine (200 mg/kg) given to male Wistar rats caused and increase in steroid hormone release within 15 minutes after dosing. (Laws et al, 2009. Tox Sci)


• Rats fed atrazine-contaminated feed for 1 or 2 weeks (120 mg/kg, 200 mg/kg) had a dose-dependent reduction in sperm number and impaired daily sperm production. (Abarikwu et al, 2009. Arch Environ Contam Toxicol)


• Rats fed atrazine-contaminated feed (50 mg/kg, 200 mg/kg) for 25 days had a significant dos-dependent reduction in steroid production in the Leydig cells of the testes (Pogrmic et al, 2009. Toxicol Sci)


• When tiger salamander larvae were raised for 2 weeks in water containing atrazine (20, 200 ppb) or chlorpyrifos (2, 20, 200 ppb) no increase in deaths was observed. When the larvae were exposed to the combination of atrazine and chlorpyrifos together, however, there was a significant increase in larval deaths from increased viral infection and disease, suggesting that the treatment critically impaired immune function (Kerby and Storfer, 2009. Ecohealth)


• Rats treated for 5 months with atrazine-laced drinking water (30 or 300 µg/kg [ppb]) had associated insulin-resistance leading to obesity (Lim et al, 2009. PLoS One)

And, what are Syngenta-supported scientists saying?

• "Based on a weight of evidence analysis of all the data" the hypothesis that atrazine is associated with reproductive abnormalities "is not supported by the vast majority of observations". Same for other reported effects such as impaired immune function, stress, or population-level effects (Solomon et al, 2008. Crit Rev Toxicol)

Happily, many future-thinking farms, including many in atrazine-abundant regions like Illinois, are already getting ahead of the toxic curve with effective and affordable agricultural practices that avoid toxic chemicals. Yay!

Say no to the unnecessary use of toxic agriculture chemicals, where safer alternative methods or materials exist. Do it for the future gonads of America! You can help NRDC learn more about water treatment in your area by calling your utility and submitting this online form.

This post originally appeared on NRDC's Switchboard blog.