'Mercury-level tops among fish-eaters near coal-fired units'

: People living in a city with active coal-fired power plants and consuming local aquatic produce may have higher body levels of mercury, a study by the Indian Institute of Technology-Hyderabad has revealed.

Researchers of the institute said they arrived at this finding after analysing the amount of mercury in the hair of over 600 people in three cities- Hyderabad, Nellore and Vasco da Gama, a press release said here Tuesday.

The study has recently been reported in the Journal of Exposure Science and Environmental Epidemiology, a peer-reviewed public health journal, the release said.

Mercury, a neurotoxin, is distributed in the environment and present in many products encountered in daily life. With wide circulation within and between ecosystems, the non-degradable liquid metal is used in industry and consumer products and exists as a natural impurity in ores, it said.

The IIT-Hyderabad research team chose the three cities for their analysis Hyderabad, a city in the interior of the country with no specific local mercury source, Vasco da Gama, a city along the west coast, with again, no specific mercury source but probably more fish-eaters, and Nellore, a coastal city in Andhra Pradesh with several coal-fired power plants, it said.

In modern times, the non-occupational exposure of humans to mercury comes from food, especially fish, and rice grown in contaminated fields, said associate professor, Department of Civil Engineering, IIT-Hyderabad, Asif Qureshi, who heads the team of researchers.

Coal-fired power plants are estimated to be the largest emitters of mercury to the atmosphere. The total mercury emissions in the country is estimated to be around 540 tonnes in 2020.

In addition to neurotoxicity, mercury has also been implicated in adverse effects on lungs and kidneys, and heart diseases.

"So, how much of mercury are Indians exposed to? This is a question we attempt to answer," he said.

Hair is an excellent indicator of mercury in the body, Qureshi said adding that hair concentrates mercury and its sampling is non-invasive, making it easy to both measure and correlate to the amount of mercury in the body.

Qureshis survey showed that nearly 5.5 per cent of the people tested had mercury levels above the current US-EPA (environmental protection agency) reference.

It was found that the women of child-bearing age surveyed in this study had generally lower hair mercury than the women of child-bearing age in the US or EU.

The general understanding gleaned from Qureshis work is that people must take care of how much fish and which fish they eat.

The researchers also opined that as, fish is also a good source of nutrition.

Power plants themselves must take more stringent measures to contain mercury release into the atmosphere, they said.