Occurrence, Spatial Distribution and Ecological Impact of Heavy Metals in Rivers, Lakes and Marine Environments of Tamil Nadu, India

Abstract

The importance of a clean environment is recognized as a “pillar” of sustainable development. There is, however, a serious public health threat associated with heavy metal releases into the environment. Aquatic environments in Tamil Nadu state of India lack heavy metals monitoring data. From year 2008 to 2022, research articles were assessed that focused at heavy metal concentrations in freshwater and marine ecosystems. It has been shown that elevated levels of heavy metals in sediments of aquatic ecosystems contribute to an increase in their abundance, which may further enter the food chain through bioaccumulation. In addition, intensifying human exploitation of the South East Coastal region (SEC) in Tamil Nadu state of India through industries, tourism, aquaculture and recreation further complicates the situation by providing ever-changing sources of contamination. As a result of analyzing all heavy metals, the levels of Cd in biota collected from ocean environments were higher. Rivers and lakes have shown increased levels of heavy metals such as Zn, Cu and Pb as a result of localized anthropogenic activities. In accordance with sediment guidelines and human health risk assessments, most of the heavy metals concentrations in sediments and aquatic biota exceeded the permissible limits. It is highly recommended that more monitoring studies are conducted to monitor the levels of heavy metals in organisms and in urban rivers, lakes and marine environments in the future, with extreme importance both for environmental health and economics. By identifying the sources of pollutants and implementing strict policies to abate pollution, local governments can implement better control measures to decrease pollution levels.