Managing Emerging Contaminants: Status, Impacts, and Watershed-Wide Strategies

Abstract

Widespread occurrence of emerging contaminants (ECs) in water bodies is a major health concern worldwide, both in developing and developed countries. Contaminants from pharmaceutical, personal care products, pest control, and animal operations enter water bodies and can exceed acceptable levels. ECs can cause harmful impacts on aquatic and terrestrial wildlife and human communities. Endocrine disrupting chemicals cause a number of reproductive and sexual abnormalities in wildlife and humans. During prenatal and/or early postnatal life, exposure to these chemicals can impair the development of the endocrine system and of the organs that respond to endocrine signals in organisms. The effects during development are permanent and sometimes irreversible. Managing ECs in water resources is a critical issue that requires attention especially in sensitive ecosystems and in rapidly developing areas. There is a need for a comprehensive framework that aims at system-wide abatement (source-transfer-fate levels) using both structural and non-structural approaches. In this study, we review the state of this problem in developing and developed countries, nature of their impacts on aquatic organisms, terrestrial animals, and on public health. A comprehensive, innovative, and novel approach with multi-level strategies at source, transfer, and sink level is proposed for effective removal of ECs. Some structural approaches at source level for abatement of ECs include the use of best management practices like buffer strips, riparian management, natural, and constructed wetlands. Since these strategies have multi-level applicability, they are cost-effective alternatives to include in wastewater treatment. Among structural approaches at sink level, powdered activated carbon, nanofiltration, and reverse osmosis can remove most of the emerging organic. However, the cost of treatment by these methods is high and it is inevitable for treating drinking water. Besides structural approaches, non-structural approaches play a major role and need to use targeted strategies in dissemination of information, outreach to modify human behavior, incentives for controlling contaminant loads, and improved and updated policy mechanism for compliance to pollutant standards.