Impact of mercurial pollutants on human health in India with special reference to Sonanchal region: A review

Abstract

Mercury, also known as quicksilver, is a heavy, odourless, lustrous liquid metal mainly found in bright red crystalline solid Cinnabar ore. It can be found in its elemental form, both as inorganic mercury or as organic mercury. It has toxicological effects on the health of human beings and the environment. It is well documented in a few pieces of evidence such as the Mad Hatter disease, Minamata episodes, methyl mercury poisoning in Iraq, the Kodaikanal incident, etc. India is a signatory to the Minamata Convention (2013) and one of the major mercury emitters in the world. According to the Central Pollution Control Board (CPCB), coal burning is the primary source of mercury emissions in India. Although the CPCB listed only a few mercury-contaminated sites but there are numerous mercury polluted sites that continue to pose a threat to human health and the environment of India. So, it is necessary to find out the contaminated sites and their impact on human health for controlling this health hazard. Various biomarker studies on the micro level have been conducted in different locations in India and a few remarkable studies were organised in the Sonanchal coalmine region of the Eastern Vindhyan Range. The outcome of studies outlined that adverse health conditions have been identified in the local population due to mercurial toxicity. The Coal-fired power plants are likely to cause mercury pollution in the region. The common diseases caused by these pollutants include tremors, joint pain, skin discoloration, etc. These symptoms align with acute to chronic indicators of mercury toxicity as recognized by the United States Environment Protection Agency (USEPA) and World Health Organisation (WHO) in 2021. This study aims to review the various studies that have been carried out on this crucial health issue to identify the affected areas, its impact on human health, and its causes.