Methyl Parathion is used on a wide variety of fruits and vegetable crops, tree crops, grains, cotton, and ornamentals.
Methyl parathion is a restricted use pesticide applied aerially and by ground methods.
On average, four million pounds of methyl parathion are applied annually. In other tissues such as blood, though the concentration may be much higher than in nerve tissues, there is no known function. Although a relatively slight inhibition of this enzyme can be chemically detected in toxicology studies, it requires a relatively severe level of inhibition before actual clinical effects can be detected with specific neurological testing of the animals in the study. It is known that cholinesterase is regenerated in the body, so any inhibition of the enzyme disappears with time. EPA has not finalized a number of critical policies relative to risk assessments by requires registrants to mitigate product use.