Where It Comes From
Forms as alachlor degrades in soil and water; it is more mobile and persistent than alachlor itself [3].
How You Are Exposed
Mainly by drinking contaminated private-well or small-system water in agricultural regions; food and air are minor sources [1][3].
Why It Matters
Data on ESA are limited; as a marker of alachlor contamination, it signals potential health concerns. Alachlor can irritate eyes/skin and affect the liver/kidneys; EPA’s drinking-water limit for alachlor is 0.002 mg/L, and IARC classifies alachlor as possibly carcinogenic (Group 2B) [1][2][6].
Who Is at Risk
People using untreated private wells near cropland; infants and pregnant people; farm communities [1][3][5].
How to Lower Your Exposure
Test private wells for pesticides (including alachlor/ESA); consider certified activated carbon or reverse osmosis treatment; use alternative water if levels exceed standards; maintain wells and reduce runoff near wellheads [2][4][5].