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.

Antiretroviral Drugs in African Surface Waters: Prevalence, Analysis, and Potential Remediation

“…Nevirapine (0.3 -6.7 ng L -1), efavirenz (0.3 -3.5 ng L -1 ) and didanosine (0.4 -3.3 ng L -1 ) have been detected in drinking water in South Africa Accepted Article (Swanepoel et al 2015). The most prevalent antiretroviral drugs detected in South African aquatic environments has been efavirenz with a concentration as high as 140 μg L -1 (Durban WWTP influent sample), whilst lower concentrations ranging from 0.002 to 2.45 μg L -1 have been detected in surface water samples (Rimayi et al 2018;Mtolo et al 2019;Ngqwala and Muchesa 2020).…”

Sulfidogenic fluidized-bed bioreactor kinetics for co-treatment of hospital wastewater and acid mine drainage

“…Without a doubt, ineffective removal efficiency of pharmaceuticals in WWTP leads to the degradation of surface water, ground water and drinking water quality [57] . In well-developed economies like the United State of America, Canada and other European countries, there are strict regulations that control the disposal of pharmaceuticals into the sewage [58] . However, in the context of South Africa, there are still no legislative measures in place regulating the discharge of pharmaceutical residues in water bodies.…”

Occurrence and Effects of Antimicrobials Drugs in Aquatic Ecosystems

“…It is difficult to determine the global figures of antimicrobial use in aquaculture, as it is subject to variations in each country, authorized compounds, diversity of species and their mode of farming [48]. For example, Vietnam is the country with the highest number of authorized antibacterials (30), followed by Chile (19) and South Korea (17). The antimicrobials used in aquaculture are mostly antibacterial compounds (Table 1).…”

“…The high consumption of antimicrobials together with their low absorption by humans and animals [13] has caused them to be continuously discharged into wastewater treatment plants (WWTP) [14] or directly into surface waters. Conventional treatments applied in WWTPs are ineffective in removing many of these antimicrobial compounds [15], allowing their entry into multiple aquatic ecosystems at concentrations in the range of ng to mg L −1 [16,17].…”