Malathion

Malathion is an organophosphate insecticide used to control agricultural and public-health pests and, in some formulations, to treat head lice. It disrupts nerve signaling by inhibiting acetylcholinesterase.

Acetylcholinesterase: An enzyme that breaks down the neurotransmitter acetylcholine at nerve synapses. Malathion’s active metabolite inhibits this enzyme, causing acetylcholine to accumulate.
Integrated pest management: An approach that combines biological, cultural, physical, and chemical methods to manage pests. Malathion may be one chemical option within a broader pest-control program.
Parathion: A highly toxic organophosphate insecticide that is more acutely hazardous to mammals than malathion. Both are organophosphates, but parathion’s mammalian toxicity is substantially greater.
Cholinergic syndrome: A set of symptoms caused by excessive acetylcholine activity at nerve synapses and neuromuscular junctions. Acetylcholinesterase inhibition from substantial malathion exposure can trigger this syndrome.
Organophosphate: An organic compound containing phosphorus, often with bonds to carbon and oxygen or sulfur. Malathion belongs to this chemical family, many members of which affect nervous systems.
Malaoxon: The oxidized metabolite of malathion that strongly inhibits acetylcholinesterase. This metabolite accounts for much of malathion’s insecticidal action.
Aerial spraying: The application of pesticides from aircraft over agricultural land or populated areas. Public-health programs have used aerially applied malathion against adult mosquitoes.
Chlorpyrifos: An organophosphate insecticide formerly used widely in agriculture and residential pest control. It shares acetylcholinesterase inhibition with malathion but has different uses and exposure concerns.
Pesticide drift: The movement of pesticide droplets or vapors away from their intended application site. Drift can expose people, animals, and habitats beyond a malathion treatment area.
American Cyanamid: A United States chemical and manufacturing company founded in 1907. The company developed malathion in the 1950s.

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