Occurrence of pharmaceuticals in aquatic environments: A review and potential impacts in South Africa

Abstract

The carbon footprint of pharmaceuticals through manufacturing, distribution, the incineration of unwanted pharmaceuticals as well as the packaging of pharmaceutical waste is an emerging and enormous challenge. Pharmaceuticals are major contributors to water pollution in aquatic environments that include surface water and groundwater. These pollutants arise not only from waste products but also from pharmaceutical products that have not been properly disposed of. The continuous exposure to unspecified sub-therapeutic doses of antibiotics presents risks to humans and other animals. Due to their extensive use and incomplete elimination, antibiotics have been detected in various environmental waters. The persistence of antibiotics in the environment and chronic exposure of organisms to these chemical stressors has also proven to have ecotoxicological effects. The prevailing emergence of antimicrobial resistance amongst bacteria is an area of primary concern, especially with regard to the release of antibiotics into the environment. Resistance is the acquired ability of bacterial populations to render an antibiotic ineffective as a result of a change in bacterial DNA which occurs when bacteria are subjected to an antibiotic concentration that will not kill them. A sub-lethal concentration possibly exerts a selective pressure that can result in the development of antimicrobial resistance in bacteria. It is clear that there is a need for extensive research to improve regulations and guidance on pharmaceutical waste management, pharmaceutical take-back programmes and consumer awareness.