Pollutants of Emerging Concern in Urban Wastewater Impacted Aquatic Environments and Management Recommendations

Abstract

Contamination of aquatic environments by pollutants of emerging concern (PEC) creates new public health and environmental threats. Over the years, Africa has struggled to adequately treat wastewater before discharged into the environment. The situation is expected to be worsened by the more challenging to treat PEC like pharmaceuticals, endocrine disrupters, microplastics, surfactants, cyanotoxins, radioactive and flame retardants. Generally, the pollution of aquatic environments will have serious negative impacts on organisms that depend on the affected sources. Elsewhere, a number of research studies have reported the occurrence of these pollutants and in some cases exceeding the recommended levels. However, in Africa and other developing countries, a few studies have focused on PEC in aquatic resources. In this review, discussions are centered on the: (i) occurrence of PEC in African aquatic environments, (ii) potential risks to aquatic ecosystems and human health, and (iii) current chemical and biological monitoring techniques. There is need to include PEC in the research studies and routine environmental monitoring programmes particularly before the urban wastewater is discharged into the environment. Passive biomonitoring through using biomarkers like oxidative stress proteins and gonadal histopathology may be more informative and cheaper way of monitoring PEC than chemical analysis.