"SUMMARY
Background
Endosulfan, commonly known by its trade name Thiodan, is an insecticide. It was first introduced in the 1950s. It is now out-of-patent, but AgrEvo (formerly Hoescht) is still the most important producer world-wide. Endosulfan is widely used, and is an important cause of pesticide poisoning in many countries. It is also extremely toxic to fish and other aquatic life.
Endosulfan is one of the class of compounds called organochlorines. This class of chemicals is the most important of the persistent organic pollutants or POPs. There is now a move for a world-wide ban on POPs because of their link to cancer and long-term subtle effects on hormones, the immune system, and reproduction. Unlike other POPS which travel across the globe, endosulfan tends to remain in the region of its use. Yet it has been found in high concentrations in many areas around the world because it is so widely used. The information below describes the environmental and health properties of endosulfan, and shows why it should be banned world-wide.
Short term toxicity
There is concern over the acute toxicity of endosulfan. The World Health Organization (WHO) classifies endosulfan in Category 2 (moderately hazardous). The U.S. Environmental Protection Agency (US EPA) classifies it as Category Ib (highly hazardous) pesticide. It is readily absorbed by the stomach, by the lungs, and through the skin, meaning that all routes of exposure can pose a hazard.
Numerous cases of both suicidal and occupational poisonings have been reported. Proper protective clothing (safety goggles, gloves, long sleeves, long pants, respirator) is needed to prevent poisoning when handling endosulfan. (IPCS,1988) Before it was banned in the Philippines in the early 1990s, endosulfan had become the number one cause of pesticide poisonings. (NPCIC,1991) Another concern, especially in developing countries, is that people with diets low in protein may be more sensitive to the effects of this pesticide. (ATSDR,1993)
Long-term toxicity
Although the short-term toxicity of endosulfan is of immediate concern, there are also long-term effects to consider. There is some indication that endosulfan can have adverse effects on the immune system at low levels of exposure. (ATSDR,1993) There is mounting evidence that organochlorine compounds can act as hormones. These compounds, including DDT, PCBs, and endosulfan, may also be part of the cause for the decrease in the quality of semen, an increase in testicular and prostate cancer, an increase in defects in male sex organs, and increased incidence of breast cancer which has been observed in the last fifty years. (Hileman,1994; Soto,1993) Endosulfan has also been found to cause mutations. (ATSDR,1993)
Environmental Effects
Endosulfan is also a concern for environmental reasons: it is highly toxic to fish. Safe levels of endosulfan in water are measured in parts per trillion, e.g. European Union maximum acceptable level is 0.001 ug/l. (PRC,1994) Endosulfan can cause fish kills even when used at recommended application rates. Because of this, endosulfan should not be sprayed over marshlands or bodies of water. Caution should also be observed when spraying near ditches, canals, rivers, streams, ponds, and lakes. (IPCS,1988) Endosulfan is persistent in soil, and its major degradation product, endosulfan sulfate, is as toxic as endosulfan.(ASTDR,1993)
