A critical review of occurrence, sources, fate, ecological risk, and health effect of emerging contaminants in water and wastewater

Emerging contaminants (ECs) are a diverse group of chemicals that have recently been identified as potential threats to human health and the environment. ECs are typically found at low concentrations (ng/L to ug/L) in water and wastewater, but they can bioaccumulate and biomagnified in the food chain, posing a risk to aquatic life and humans. Sources of these contaminants are diverse, with pharmaceuticals and personal care products entering the environment through human excretion, while industrial chemicals and pesticides are introduced through manufacturing processes and agricultural runoff. Wastewater treatment plants (WWTPs) are often unable to remove ECs effectively so that they can increase in surface water, groundwater, and drinking water. The fate of ECs in the environment is complex. It depends on various factors, including the chemical properties of the EC, the environmental conditions, and the presence of other chemicals. ECs can be transported long distances in water and persist in the environment for years or even decades.

Developing countries like India have limited information about most of the ECs. The ecological risks of ECs are not fully understood, but there is growing concern that they can have a negative impact on aquatic life and human health. Furthermore, the EC has undergone a detailed risk assessment examination, and the risk quotient (RQ) for different aquatic species with respect to corresponding contaminants is also calculated. Results imply that Paracetamol and Bisphenol-A have high RQ values for algae, fish and daphnia. Algae have shown substantially greater resilience to the action of ECs among the selected aquatic species.