Tamil Nadu

Study indicates high level of mercury in fish at Kodai lake

Relying on findings from an expert team from IIT-Hyderabad, environmental activists and CPI (ML) functionaries have alleged that Hindustan Unilever’s (HUL) presence from the mid-80s to the beginning of the millennium had polluted the Kodaikanal lake and the surrounding Periyakulam pond.

Claiming that the mercury levels in fish in the region were high, activists under the banner ‘Campaign to Cleanup Kodaikanal Mercury Pollution,’ including members of the People’s Union for Civil Liberties (PUCL) and CPI (ML), urged the government on Monday to share vital information with the people and prevent spread of diseases. The fish were tested in December 2016.

The activists displayed a few photographs to show how people in the hilly region had been at the receiving end due to pollution and contamination of the environment beyond permissible levels.

Accusing the government and the Tamil Nadu Pollution Control Board (TNPCB) of being dormant in the past, activist Nityanand Jayaraman said that the study had found high levels of mercury in fish from Kodai lake and ponds fed by the Pambar stream in Periyakulam plains.

He said that, in a letter written to Theni and Dindigul District Collectors and Kodaikanal Municipal Commissioner on August 2, 2017, IIT-Hyderabad scientist Asif Qureshihe had urged the administration to advise people, particularly, pregnant women, to limit their consumption of fish from these water bodies.

Potency of mercury

Mercury is a potent neurotoxin. It can damage the brain and also lead to kidney failure. Methyl mercury, the form that is found in fish, is even more poisonous.

The U.S. environmental Protection Agency has prescribed a safe level of 30 microgram/kg of mercury in fish. However, four out of eight fish caught from Kodai lake contained between 31.1 and 41.9 microgram/kg. Fish caught from a pond fed by the Pambar stream, less than 5 km from Kumbakarai falls, contained far higher levels – between 94 and 165 micrograms/kg.

Unilver’s proposed clean-up standard for soil in Kodaikanal was 20 times weaker than the soil guideline value for mercury in the UK, Unilever’s headquarters, Mr. Nityanand said. He urged the State government and the TNPCB to tighten the clean-up standards for Unilever’s contaminated site remediation.

Meanwhile, responding to the allegations, a spokersperson for HUL said that over the last 15 years, independent studies carried out by IIT-Delhi, the National Botanical Research Institute, Lucknow, and the Indian Institute of Soil and Water Conservation Research Centre, Ooty, have confirmed that there has been no adverse impact on the environment outside the factory premises.

The only exception is a small area on the perimeter of the factory, which HUL has already committed to remediate through soil remediation trials which commenced in August 2017 as per approval given by the TNPCB.

With regard to the proposed clean-up standard for soil in Kodaikanal, he said that the TNPCB, in consultation with the Scientific Experts Committee (constituted by the Supreme Court Monitoring Committee), set the remediation standard of 20 mg/kg based on a site-specific risk assessment study in line with international best practices.

The standard has been confirmed by the Central Pollution Control Board (CPCB), to which the TNPCB had referred the matter. The Ministry of Environment, Forest & Climate Change has also endorsed the 20 mg/kg soil remediation standard.

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Printable version | Jul 4, 2020 8:23:27 PM | https://www.thehindu.com/news/national/tamil-nadu/study-indicates-high-level-of-mercury-in-fish-at-kodai-lake/article20406597.ece

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