ENDOSULFAN: A PROFILE
An organochlorine insecticide. Effective against a wide range of pests of crops including cereals, coffee, cotton, fruit, oilseeds, potato, tea and vegetables. Highly toxic substance .
The US Environmental Protection Agency classifies it as a Category 1b (highly hazardous). Easily absorbed by the stomach, lungs and through the skin. All routes of exposure can pose a hazard . Exposure may result from:
• breathing air near where it has been sprayed;
• drinking water contaminated with it;
• eating contaminated food;
• touching contaminated soil;
• smoking cigarettes made from tobacco with endosulfan residues;
• working in an industry where it is used.
ACUTE TOXICITY
Stimulation of the central nervous system is the main characteristic of endosulfan poisoning . Acute exposure leads to: hyperactivity, tremors, decreased respiration, salivation, anaemia, lack of coordination, loss of ability to stand, gagging, vomiting, diarrhoea, agitation, convulsions and loss of consciousness. Blindness has been observed in animals that grazed in sprayed fields. People with diets low in protein may be more sensitive .
CHRONIC EFFECTS
Studies on animals show that long-term exposure to low levels of endosulfan affects the kidneys, the developing foetus, and the liver. The ability to fight infections ebbs away. Organochlorine compounds are suspected to play a part in the decrease in the quality of semen, in the increase in testicular and prostate cancer, an increase in the defects in male sex organs , and increased incidence of breast cancer. Endosulfan can cause mutations. It has been shown to be toxic to genes in human cells.*
ENVIRONMENTAL FATE
Highly toxic to fish, birds, fowl, bees and wildlife. Breaks down faster than the other organochlorines, leaving the body fairly quickly. Despite rapid degradation in water, it can bind to soil particles and persist for a relatively long period . Doesn't leach into groundwater, but is particularly prone to runoff immediately after spraying. Its half-life (the time it takes to dissolve into the body or the environment, becoming half the original mass) in water and in most fruits/vegetables is three to seven days. In sandy loam, its half-life is 60-800 days. Endosulfan in soil inhibits the degradation of other organochlorines .
BREAKDOWN PRODUCT
Endosulfan sulphate is more persistent than its parent compound , accounting for 90 per cent of the residue in 11 weeks. Sulphate formation increases with rise in temperatures .
REGULATORY STATUS
A lot of countries have regulations against endosulfan or have severely restricted its use. Those who have banned it include: Denmark, Germany, the Netherlands, Sweden, Belize, Singapore, and the Brazilian state of Rondonia. Colombia and Indonesia have been preparing for a ban. Its use is disallowed in rice fields in: Bangladesh, Indonesia, Korea and Thailand . Use is restricted or severely restricted in: Canada, Finland, Great Britain, Kuwait, the Philippines, Russia, Sri Lanka, Thailand and Madagascar . Campaigns have been going on worldwide for several years to ban endosulfan.
Source: Anon 2000, Endosulfan