Endosulfan, a highly toxic organochlorine pesticide was sprayed in the cashew plantations in Kasargod District since 1978, till 2001 regularly three times every year. The aerial spraying of Endosulfan was undertaken to contain the menace of the tea mosquito bug. Endosulfan is a harmful insecticide. It causes several health hazards in human beings. The terrain was unsuitable for aerial spraying considering the relatively high rainfall and its geological structure. Unusual diseases and even deaths were observed in and around the region. Children were found to be the worst affected with congenital anomalies, mental retardation, physical deformities, cerebral palsy, epilepsy, hydrocephalus etc. From the mid of 1990’s, the community living near plantations had been complaining against the spraying of Endosulfan. Today villages in Kasaragod District are complaining from peculiar and complex variety of diseases unprecedented in this part of the country. All these villages lie in the mid-lands and laterite hill area of Kasaragod District, the northernmost district of the Kerala State. None of these diseases were known to the people of the area about two decades ago.
WHAT IS ENDOSULFAN?
Endosulfan is a chlorinated hydrocarbon insecticide of the cyclodiene subgroup which acts as a contact poison in a wide variety of insects and mites. It can also be used as wood preservative. It is used primarily on food crops like tea, fruits, and vegetables on grains.
Endosulfan is sold as a mixture of two different forms of the same chemical and is cream to brown in color and has the smell of turpentine. It is a highly toxic substance and the WHO classifies Endosulfan in Category II (moderately hazardous) based mainly on the LD 50 value taken from the manufacturer, whereas the US Environmental Protection Agency classifies it as Category 1b (highly hazardous) pesticide. Endosulfan is easily absorbed in the stomach, by the lungs and through the skin meaning that any of these routes can pose hazard to humans. Thus exposure can occur when breathed through air, drinking water contaminated with it, eating contaminated food, touching contaminated soil, smoking cigarettes made from tobacco with Endosulfan residue or working in an industry where Endosulfan is used. Stimulation of Central Nervous system is the most important acute toxic feature of the pesticide. People with low protein diets are more sensitive to the effects.
Long-term toxicity of the chemical is also somewhat well documented. Toxicity on kidneys, on intrauterine fetuses, on liver and suppression of immunity are well documented. Organochlorine compounds including DDT and Endosulfan are also implicated in the causation of decrease in quality of semen, increase in the incidence of testicular and prostatic cancer, increase in defects of male sex organs and increase in incidence of breast cancer.
The compound has adverse effects on the environment and is highly toxic to fish, birds, fowls, wildlife and bees. It is established that Endosulfan may run off immediately after spraying to surface water and may not reach the ground water. Despite rapid degradation in water, it can bind to soil particles and persist for a relatively long period. While its half life in water and most fruits / vegetables is 3 to 7 days, in sandy loam its half life is 60 to 800 days. The breakdown product Endosulfan Sulphate is also toxic and more persistent than the parent compound and accounts for 90% of residue in 11 weeks. Sulphate formation increases as temperature increases and this has to be borne in mind while using the chemical in the tropics. The degree of pollution it causes as Persistent Organic Pollutant is still vague and that is the grounds under which the chemical is widely being used as pesticide.
At least ten countries have completely banned the use of Endosulfan, including Germany, Netherlands, Sweden,...