A previously healthy 51 year old farmer presented to the hospital emergency room with symptoms of seating, headache, impaired vision, abdominal cramping, extreme weakness and shortness of breath. Within a few minutes, he became confused lapsed into a coma, convulsed and died. The mechanism of death appeared to be respiratory failure.
According to a co-worker, approximately 45 minutes preceding onset of symptoms, the man had sprayed an orchard with an insecticide. The subject had read the warning label and was aware of the dangers of the insecticide but declined to use protective clothing or a mask during the mixing and application. He had never used the insecticide before. Samples of the insecticide were submitted for toxicology studies and they were found to be Methyl Parathion.
The Coroner signed the death certificate as cause being Respiratory Failure due to Methyl Parathion. Manner of death is Accident.
What is Methyl Parathion?
According to the EPA, Methyl parathion is a man-made pesticide that may only be used lawfully on certain agricultural crops in open fields to control insects. It is most commonly used on cotton. Other major uses include field corn, peaches, wheat, barley, soybeans and rice fields. Together these uses account for about 95 % of methyl parathion used in the U.S. It is also registered for numerous other economically important minor uses.
Methyl parathion is a highly toxic organophosphate insecticide first registered in 1954. It has been classified as a "Restricted Use Pesticide (RUP)" since 1978 based upon its potential acute toxicity to humans and birds. Methyl parathion is a brownish liquid that turns milky white when mixed with water; smells like rotten eggs; and can leave a yellow stain on indoor surfaces where it has been sprayed. It is illegal to use methyl parathion inside residences or other buildings.
Methyl parathion formulations subject to the EPA-Registrants agreement have been marketed under the following product names: Nitrox; Dithon 63; Ketokil 52; Seis-Tres 6-3; Metaspray 5E; and Paraspray 6-3.
What are the health effects?
Short-term exposure to high levels of methyl parathion, an organophosphate, may affect the nervous system by inhibiting the activity of an enzyme called cholinesterase. At normal levels, cholinesterase breaks down a chemical called acetylcholine, which helps transmit signals in the nervous system. When cholinesterase is inhibited, an excess of acetylcholine builds up and impairs the proper functioning of the nervous system.
Signs and symptoms of direct exposure to high levels of the more concentrated forms of methyl parathion may include headache, dizziness, loss of coordination, muscle twitching, tremor, nausea, vomiting, abdominal cramps, diarrhea and general weakness, blurred vision, excessive perspiration and salivation. These symptoms may result from a single exposure or from repeated exposures occurring over several days. Exposure may occur through inhaling the pesticide, absorbing it through the skin, or swallowing it. At higher levels of exposure, methyl parathion poisoning can lead to respiratory failure and death. Even diluted methyl parathion used indoors can lead to serious poisoning, especially in children and household pets.
What does “Restricted Use” mean?
Restricted use pesticides are those pesticides that can only be sold or distributed to, and used by, or under the direct supervision of, Certified Pesticide Applicators. Certified applicators must be trained and certified by their State, and recertified periodically.