Monday, November 05, 2007

Sunderbans polluted: Persistent organic pollutants found

Rising sea level and erosion aside, the Sundarbans now face a new threat. An international research team has detected polybrominated diphenyl ethers (pbde), a persistent organic pollutant, in the core sediment from seven sites in the wetland. pbdes are used as flame-retardants in electrical equipments, plastics, textiles, building materials, vehicles and aircraft industries. Earlier research has established that pbdes can be persistent, bioaccumulative and toxic. They can cause liver and neuro-developmental toxicity and affect thyroid hormone levels.

“The huge discharge of municipal wastewater along with local industries’ waste may have contributed to elevated levels of pbdes. The presence of several textile plants along the upper stretch of Hooghly estuary indicates local use of pbde formulates for textile production,” says Santosh Kumar Sarkar, a co-researcher at the department of marine sciences in the Calcutta University, in a study published in the recent issue of Marine Pollution Bulletin (Vol 54, No 8).

Sarkar says, among the 12 kinds of pbdes found, the penta-bde mixture is most dangerous. “We will give due emphasis on the risks of exposure to wildlife species and humans now,” he adds. He feels the results will help monitor the wetland for more persistent organic pollutants.

The above article was originally written by this blogger and published in the 15th October 2007 issue of Down To Earth, a science and environment fortnightly published from New Delhi