Spilled oil may not move beyond Tamil Nadu coast: Experts

CHENNAI: Even as oil that leaked from

Dawn Kanchipuram

near Ennore drifted south till Thiruvanmiyur, covering more than 24km in three days, a change in wind direction may move the oil slick toward the northern coast of Chennai from Wednesday.

With a measured 1.1 metric tonnes of oil beached, scientists have found dangerous levels of hydrocarbon deposits along the coast. Though oil spills are known to affect marine life in faraway coasts, experts say the slick may not move beyond the Tamil Nadu coast due to its low quantity. However, its high viscosity may pose a big challenge to the clean-up process.

Oil spill trajectory models run by a team at INCOIS, Hyderabad, have forecast a change in wind direction towards northwest in the next 24 hours. "Since the quantity of oil is less and the cleanup process is on, the slick may disperse in the next two weeks and may not move beyond the TN coast," said

Balakrishnan Nair

T M, head, Ocean Science and Information Services Group.

Another team from ICMAM, Chennai has analysed water samples collected near Kasikoil kuppam, north of Kasimedu, and found total petroleum hydrocarbon (TPH) levels at 2,000 microgram per litre in it. The high levels were found from samples taken about 500m from the coast at a depth of 7m to 8m. As the slick drifted southwards, the hydrocarbon levels reduced to 700microgram per litre from similar samples collected from Marina.

"The samples showed safer levels of oxygen. We will test samples collected from the same location in the coming days and compare it with those from other locations to see if the oil is dispersing," said Pravakar Mishra, scientist, ICMAM.

A team from IIT-Madras that tested water samples found the oil in it to be a grade four fuel oil with high viscosity. "It may not be very toxic to human beings. But dermal contact is not recommended," said associate professor Indumathi M Nambi, environmental and water resources engineering division, civil engineering, IIT-M.