Introduction--the methyl parathion story: a chronicle of misuse and preventable human exposure.

In the fall of 1994, Lorain County, Ohio, became the site of the first investigation of several large-scale incidences in which the organophosphate pesticide methyl parathion was illegally applied to private residences. The extent of potential human exposure to this pesticide led the Ohio Department of Health to formally request technical assistance from the Centers for Disease Control and Prevention (CDC). This article describes the initial investigation of 64 homes in Ohio and introduces the method of using both biological markers of exposure (p-nitrophenol levels in human urine samples) and environmental markers of contamination in dust and air samples when making public health decisions about the cleanup of homes sprayed with methyl parathion. The results of the CDC rapid investigation led the U.S. Environmental Protection Agency to declare the contaminated homes in Lorain County a Superfund cleanup site. Seven years after the Lorain incident, and after subsequent Superfund actions had been implemented in Illinois and Mississippi, researchers participated in an expanded session devoted to methyl parathion at the 11th Annual Meeting of the International Society of Exposure Analysis held in Charleston, South Carolina, in the fall of 2001. The articles included in this monograph are based on presentations at that meeting. They report previously unpublished data that tell the methyl parathion story from different perspectives, each providing in-depth information about separate aspects of this multistate, multiagency, and multimillion dollar chemical exposure. This monograph is the methyl parathion story.