Research Highlight

Higher mercury in hair points to coal-fed power plant emissions

doi:10.1038/nindia.2019.75 Published online 11 June 2019

People living in cities with coal-fed power plants and consuming aquatic produce were found to have higher levels of mercury.

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Researchers have found higher levels of  mercury in the bodies of people living in cities with coal-fired power plants, and consuming local aquatic produce, as compared to those living in cities with no major source of mercury1

A research team from the Indian Institute of Technology in Hyderabad, India arrived at this finding after analyzing the amounts of mercury in the hair of over 600 people in three cities in India.

Mercury is a harmful chemical that quickly migrates to the brain and destroys nerve cells there. Despite such threats, it is used in industrial and consumer products, and exists as a natural impurity in ores. Compounds of mercury don’t degrade easily and the metal circulates widely within and between ecosystems.

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.  After collating information on demography, body mass index, dietary patterns, professions and other variables of more than 600 residents in Hyderabad, Vasco da Gama and Nellore, the researchers measured the levels of mercury in the hair of these people. 

The researchers, led by Asif Qureshi, found that nearly 5.5% of the people tested had mercury levels above the current permissible limit determined by the US Environmental Protection Agency.

Non-occupational exposure of humans to mercury comes from food, especially fish, and rice grown in contaminated fields. Coal-fired power plants are the largest emitters of mercury with the total mercury emission in India expected to reach around 540 tons in 2020, the researchers estimate.

The researchers suggest caution in the intake of fish varieties and urge power plants to contain the release of mercury into the atmosphere.


1. Subhavana, K. L. et al.  Mercury levels in human hair in South India: baseline, artisanal goldsmiths and coal-fired power plants. J. Expo. Sci. Env. Epid. (2019) doi:10.1038/s41370-018-0107-0