A DRINKING WATER EXPOSURE ASSESSMENT FOR ATRAZINE,SIMAZINE AND METOLACHLOR IN 32 STATES, 1993-2000

摘要

A drinking water exposure assessment of atrazine, simazine and metolachlor was conducted forCommunity Water Systems (CWS) in 32 states using Safe Drinking Water Act (SDWA) monitoring data collected over 8years (1993 – 2000). These states represent 95 to 99% of the herbicides annual use. A population linked exposure database(PLEX) was constructed. Most samples (92% atrazine, 98% metolachlor and 99% simazine) were non-detections. Themajority of the CWS population had no detectable exposure to atrazine (78%), simazine (86%) and metolachlor (88%).Period mean concentrations (8 years) for CWS did not exceed the Maximum Contaminant Level (MCL) of 4 ppb forsimazine or the Health Advisory Level of 100 ppb for metolachlor. Three of the 28,280 CWS had atrazine period meanconcentrations (3.30 to 3.41 ppb) slightly above the MCL of 3 ppb. Overall, CWS populations in the 32 states have little orno exposure to atrazine, simazine or metolachlor in drinking water.