The organophosphate malathion bind irreversbly to cholinesterase, which is responsible for the hydrolysis of the neurotransmitter acetylcholine in the synaptic cleft. Primarily used as an insecticide in agriculture, it also has uses as medical treatment in low doses for head lice and scabies. Absorption or ingestion into the human body results in its conversion into malaoxon which is substantially more toxic than malathion itself. Acute exposure to extremely high levels of malathion produce symptoms of cramps, skin and eye irritation, nausea,seizures and even death. Elevated levels have also been linked to attention deficit hyperactivity disorder.