Coal-Fired Thermal Power Plants and Mercury Risks: Status and Impacts to Realize Minamata Convention Promises

Abstract

Coal is widely used as a thermal energy source and also as fuel for thermal power plants producing electricity. Thermal power plants (TPPs) have emerged as a major source of air, water, and soil pollution because of the presence of many toxic metals (As, Pb, Hg, Cr, etc.). Coal-fired power plants are major emitters of mercury to the atmosphere. Approximately, 30–80% of the total Hg content in coal is found in fly ash (FA) after the combustion process. Mercury (Hg), a potentially toxic element, has raised concerns for worldwide public health as it has the property to get bioaccumulated and biomagnified in the food chain. Aquatic ecosystems are an essential component of the global biogeochemical cycle of mercury, as inorganic mercury can be converted into toxic methylmercury. The biogeochemical cycle of mercury is complex, making it difficult to accurately assess the hazards to the environment and to human health. Importantly, several developing nations, like India and China, make large contributions to the supply, commerce, and anthropogenic emissions of mercury globally. India is one of the major emitters of anthropogenic mercury into the atmosphere due to its recent rapid economic growth, and forecasts indicate that it will continue to make a large contribution to global mercury emissions in the future. Considering the severity of the issue and growing risk of mercury pollution, this study attempts to understand, provide a synthesis of the mercury risk posed to India, and actions taken in accordance with the Minamata Convention to reduce mercury pollution.