Endosulfan may finally have a destroyer
endosulfan, the deadly pesticide, now has a destroyer. Scientists at iit Madras have found a bacterial mixture that can break it down to environment friendly inorganic chemicals.
Ligy Philip and Mathava Kumar studied the action of a bacterial culture consisting of Staphylococcus Sp, Bacillus circulans-i and ii on endosulfan-contaminated soil. Their paper, posted on-line on the website of the Journal of Hazardous Materials on May 30, 2006, states that the bacterial mixture converts endosulfan into mineral form in both aerobic and anaerobic conditions. The paper also said that addition of external carbon increased degradation efficiency. "This enriched bacterial consortium can detoxify endosulfan and completely degrade it in the presence and absence of other food.They first remove the chlorine atoms, slowly degrade it and convert into co2 and other environment friendly inorganics,' says Philip. "These bugs can be applied in contaminated soils. By providing proper nutrients, moisture content and other conditions conducive for their growth, within weeks the pesticides can be degraded.' he adds.
Highly toxic With a half-life, which can range up to 800 days, endosulfan is toxic in nature. It is also an endocrine disruptor and causes severe disturbance in the female reproductive cycle, resulting in birth defects. According to the Atlanta-based Agency for Toxic Substances and Disease Registry (atsdr), endosulfan affects the central nervous system. Hyperactivity, nausea, dizziness, headache or convulsions have also been observed. High doses may even be fatal. It also damages testes of animals.
Endosulfan enters the air, water and soil during its manufacture and use. When sprayed on crops, it breaks down partially in a few weeks but sticks to soil particles. It may take years for it to break down completely. Human beings are usually exposed by eating food contaminated with it, working in industries involved in making endosulfan or as pesticide applicators. It can be easily absorbed by stomach, lungs and skin. In 2001, in Kerala, endosulfan spraying became suspect when linked to a series of abnormalities noted in local children. It was banned and the ban was revoked (see