Aldrin

Aldrin is a synthetic organochlorine insecticide that belongs to the cyclodiene class. It is a highly chlorinated bicyclic compound and is closely related to dieldrin, which is formed by epoxidation of aldrin during metabolism. Aldrin was developed for agricultural use as a broad-spectrum insecticide and for termite control, becoming widely used in the mid-20th century.

Aldrin acts by disrupting inhibitory neurotransmission in the nervous system. It is a noncompetitive antagonist of GABA receptor–gated chloride channels, which leads to uncontrolled neural firing, hyperexcitability, and, in severe cases, seizures. This mechanism affects a range of organisms, contributing to its broad toxicity profile beyond target pests.

Environmental fate and health considerations are major reasons for its regulation. Aldrin is highly lipophilic and persistent in soil and sediments, where it degrades very slowly. It bioaccumulates in fatty tissues of wildlife and humans and can magnify through food chains. Long-term exposure has been associated with neurotoxic effects and possible carcinogenic risk. Because of these concerns, aldrin is listed under international and national regulations, and its production and use have been restricted or banned in many countries. It is also included in global lists of persistent organic pollutants, prompting efforts to manage legacy contamination and prevent ongoing environmental exposure.

Regulatory status and legacy: Many jurisdictions have prohibited or tightly controlled aldrin use, with emphasis on monitoring, remediation of contaminated sites, and substitution with safer alternatives. Related compounds such as dieldrin and endrin are also subject to strict controls due to similar persistence and toxicity.