The only legal uses of methyl parathion are for agricultural crops under restricted conditions. When applied in accordance with label instructions, the pesticide kills certain agricultural pests quickly, then breaks down to harmless materials in a short period of time. The toxicity ends as the compound degrades in the field through exposure to sunlight and soil microbes. If used indoors, however, the pesticide can cause nausea, vomiting, headaches and diarrhea.
High exposures can lead to convulsions, cardiac arrest and death.
Approximately 95 percent of the estimated 4.5 million pounds of MP used annually in the United States is applied to cotton, soybeans, field corn, peaches, wheat, barley and rice. Most of the use occurs in Alabama, Arkansas, Louisiana, Mississippi, Nebraska, and Texas. In 1994, methyl parathion contamination was discovered in homes and businesses in Lorain County, Ohio, largely due to the unlicensed pest control operations of a single applicator, Lutellis Kilgore. In April 1995, a similar incident was discovered in Detroit, Michigan. Working in concert with state agencies, the civil investigative team gathered enough evidence to support the execution of two search warrants, nine state arrest warrants and, after providing over 70 civil case files to a team consisting of the Assistant U.S. Attorney for the Southern District of Mississippi, the Justice Department's Environmental Crimes Section and EPA's Region 4 CID, two federal arrest warrants.