Used as contact insecticides; formerly widely used in agriculture and for domestic purposes, their use is now restricted in some countries due to recognition of their extreme persistence in the environment and potential for chronic toxicity.

[affected.gif] Animals most affected
All species.

[etiology.gif] Etiology

Note: possibility of iatrogenic incidents where some organochlorines (e.g. lindane) are used on domestic pets for the treatment of ectoparasites.

Compounds in this category
AIdrin, chlordane, chlordecone, DDT, dicofol, dieldrin, dienochlor, endosulfan, endrin, lindane, perthrane, toxaphene. Lindane is also widely known as gamma hexachlorocyclohexane (gamma-HCH) or gamma benzene hexachloride (gammaBHC).
Many of the above, along with organochlorine compounds in general, are either banned from use (in both the UK and France) or are permitted for only severely restricted usages.

[toxic.gif] Toxicity
Persistent liposoluble compounds which concentrate in body fat and nervous tissue.
Toxic to the nervous system. For toxicity, see entries for individual compounds.

[clinical.gif] Clinical features
Acute poisoning
Occasionally immediate onset of clinical signs with death occurring in a few minutes, accompanied by hyperaesthesia, trembling, convulsions, or depression (particularly following inhalation exposure). Characteristic clinical signs include:

Death may occur during the convulsive stage within a few hours, or after several days. In particular species (e.g. cats), or in some individual animals, the dominant features of poisoning are depression, weakness, prostration, coma and death.

Chronic poisoning
(Difficult to diagnose and relatively nonspecific):

[lesions.gif] Lesions

In acute poisoning

In chronic poisoning

[treatm~1.gif] Treatment
No antidote. Symptomatic care only:

Organochlorines have two fundamental characteristics: liposolubility and chemical persistence. In addition, they are powerful enzyme inducers. These factors explain the extent and the degree of contamination of ecosystems by organochlorines, justifying their restriction or even prohibition in use.
Organochiorines accumulate in the food chain, with highly significant concentration factors of 10000 or more. Due to their ability to induce mono-oxygenase enzymes, specific toxic effects can be observed which are clearly evident in animals at the top of food chains. In raptors (birds of prey), eggshell fragility and lowered fecundity have been well documented.
The inherent properties of the organochlorines also explain their transfer as residues into fats used for foods, such as dairy products (milk, butter, etc.), which have had important consequences for public health and a significant economic impact.