Endosulfan, 6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-
6,9-methano-2,4,3-benzodioxathiepine-3-oxide, is an organochlorine compound. Almost all organochlorine compounds are poisons. Endosulfan is mostly used as an insecticide and acaricide. It can also be used as a wood preservative. It is uses mostly on food crops like grains, tea, fruits and on vegetables. It acts as a contact poison. It can accumulate in the body and can create health problems. It is banned in more than 65 countries and is unfortunately used in countries like India and Brazil. Because of its threats to human health and the environment, a global ban on the manufacture and use of endosulfan is being considered under the Stockholm Convention.

I have seen many patients with organochlorine chemical poisoning as a clinical toxicologist. If we come in contact with small amount of Endosulfan, the body has no problem to excrete them with its genes and enzymes. Since these pesticides are fat soluble they are deposited in our fat tissues. If a person has problems with his detoxification genes or enzymes he is going to suffer a lot or even it can be fatal to him. During the detoxification uncontrolled amount of free radicals are produced and so the free radical scavenging system must be well functioning. The antioxidants from the food are very important as well as the minerals, copper, zinc, manganese and selenium. These minerals are part of the free radical scavenging enzymes.

How toxic is endosulfan? Undiluted endosulfan is slowly absorbed into the body. The absorption is rapid if it is dissolved in alcohols, oils and emulsifiers.

Endosulfan poisoning affects the Central Nervous System. The symptoms include:

• Incoordination including a loss of the ability to stand
• Gagging
• Vomiting
• Agitation
• Diarrhea
• Convulsions
• Loss of conscience
• Blindness is noted in animals, cow, sheep and pigs, grazing the grass sprayed with endosulfan

Lot of research is done to find the lethal dose of endosulfan and the oral LD50 in different animals include:

• Rat 18 to 220 mg/kg
• Mice 7.36 mg/kg
• Hamster 118 mg/kg
• Cat 2 mg/kg
• Dog 76.7 mg/kg
• Young ducks 33 mg/kg

The dermal LD50 include:

• Rat 74 mg/kg
• Rabbit 200 to 359 mg/kg

The solvents used to dissolve endosulfan influence its toxicity. Many chronic effects have been noted in animals exposed to endosulfan. Kidneys, liver, parathyroid gland and blood chemistry are mostly affected. In rats skeletal deformities in the fetus are noted. Although there are no evidences, chronic exposure to humans may cause reproductive and/or developmental problems in humans.

It has mutagenic effects at least in two mammalian spices and this means it can also change human DNA.

In the environment the surface water is mostly contaminated with endosulfan. The half-life of alpha-endosulfan is 35 days and the beta-endosulfan is 150 days under neutral conditions. If the soil is acidic the half-life is long for both the isomers.

Endosulfan is also toxic for birds and fishes.

The breakdown product of endosulfan is the endosulfan sulfate. It is as poisonous as endosulfan and is present longer in the environment.

Endosulfan and its breakdown products are detected in vegetables, milk, sea foods and in tobacco. The right decision is to ban all the organochlorine pesticides for the whole world. This is healthy for all living beings and to our environment too.

India is the largest user of endosulfan and the problems in Kerala is well known. We must have the courage to ban this.