Assessment of human exposure and human health effects after indoor application of methyl parathion in Lorain County, Ohio, 1995-1996.

In January 1995 the U.S. Environmental Protection Agency declared methyl parathion-contaminated homes in Lorain County, Ohio, as a Superfund cleanup site. During the 2-year cleanup, the Centers for Disease Control and Prevention in collaboration with county and city health officials conducted a study of exposure and health effects among residents. We administered 254 household and 747 individual questionnaires; urine analysis for p-nitrophenol (PNP, a metabolite of methyl parathion) was available for 626 participants. We also reviewed medical records of 49 people who were hospitalized or died after their homes were sprayed. People living in homes sprayed <180 days previously were most likely to have the highest PNP levels (22.9% > 100 ppb PNP), but even people living in homes sprayed more than a year previously appeared to be highly exposed (8.5% > 100 ppb PNP). The National Health and Nutrition Examination Survey reference range is 0-63 ppb. Median detectable PNP levels among children younger than 3 years of age were 93.9 ppb compared with 41.6 ppb among people older than 3 years. Younger children appeared to be at greatest risk of exposure. In none of the medical records that we reviewed did a health care provider consider pesticide poisoning as a potential etiology.