Where atrazine comes from
- pre-emergent herbicide widely applied to corn and sorghum crops
- soil leaching during spring application and heavy rainfall
- runoff from agricultural fields into shallow aquifers
- seasonal spikes in spring and early summer following application
Health considerations
- endocrine disruption — IARC Group 2B (possible human carcinogen). Studies show atrazine disrupts endocrine function in amphibians at low concentrations; human epidemiological evidence is mixed but includes associations with disrupted menstrual cycles and increased risk of small-for-gestational-age births (Chevrier et al., 2011).
- cardiovascular and reproductive effects — EPA MCL set at 3 μg/L based on chronic exposure data showing heart congestion, muscle degeneration, and retinal degeneration in animal studies at higher doses.
EPA MCL = MCLG = 3 μg/L (set in 1991). The MCL and MCLG are equal, indicating EPA determined the MCL was technically and economically achievable at the health-based level. The EU drinking water standard is 0.1 μg/L — far more stringent. Atrazine was banned in the EU in 2004.
Who is most at risk
- private well owners in corn-belt states (OH, IL, IA, IN, KS, WI)
- pregnant women (potential developmental effects)
- infants (formula prepared with contaminated water)
- households above glacial outwash aquifers recharged by agricultural land
Testing
EPA Method 507/525.2/525.3 (GC/MS or GC-ECD); LC-MS/MS for confirmation; certified lab required; collect in 40 mL amber glass vials with HCl preservative; test in spring/early summer for highest sensitivity
Find a certified lab and learn how to collect a sample
Treatment
- granular activated carbon (GAC) — most effective, NSF/ANSI 53 certified
- activated carbon block point-of-use filter
- reverse osmosis (removes atrazine with GAC pre-filter)
- no effective treatment via aeration or water softening