Applied Water Science

Systematic studies investigating human toxicology and epidemiology of pharmaceuticals in aquatic systems are still lacking. Thus, there is need for comprehensive studies based on established research protocols such as case-control experiments to better understand the human toxicology and epidemiology of pharmaceuticals and their metabolites.

Literature investigating the removal of pharmaceuticals in aquatic systems is dominated by water treatment processes used in large-scale centralized systems common in developed countries. The capacity of several low-cost methods (e.g., biosand filtration, solar disinfection, and boiling) commonly used in developing countries to remove pharmaceuticals and their metabolites remains unknown. This calls for further research using field samples such as surface and groundwater contaminated with pharmaceuticals and their metabolites as reported in literature (e.g., Sorensen et al., 2015).

The current chapter presented an overview of the occurrence, behaviour, human health risks, and removal of pharmaceuticals in aquatic systems. The major classes of pharmaceuticals detected in aquatic systems were antibiotics, beta-blockers, analgesics, cancer therapeutics, antiinflammatory drugs, lipid regulators, endocrine disruptors, and illicit drugs. Hotspot sources include medical facilities, pharmaceutical industries, veterinary facilities, and municipal wastewater treatment systems which act as reservoirs of pharmaceuticals and their metabolites. Hydrological processes disseminated pharmaceuticals into various aquatic systems, where they undergo sorption, biochemical degradation, phase partitioning, and uptake and bioaccumulation by aquatic organisms. Ingestion of contaminated water and aquatic foods, inhalation, and dermal contact contribute to human exposure. Barring the risk for antimicrobial resistance caused by pharmaceuticals, the evidence linking pharmaceuticals to human health outcomes remain poor. However, human health risks could be significant in Africa and other developing regions due to several risk factors. These exposure risk factors include: (1) the high prevalence of consumption of raw drinking water and aquatic foods from polluted sources, (2) a putative high pharmaceutical pollution associated with intensive use of pharmaceuticals to control the high animal and human disease burden in the tropics, (3) high abuse and misuse of pharmaceuticals caused by the existence of informal markets and weak and poorly enforced environmental, public health, and medicines regulations. The capacity of conventional and advanced water treatment processes to remove pharmaceutics in aqueous systems was discussed. Finally, future research directions were highlighted to address the lack of comprehensive data on the ecotoxicology, epidemiology, and behaviour and fate of pharmaceuticals in aquatic systems especially in the tropics.

WG conceptualized the idea and finalized the manuscript. WG, AK, CD, NM-Z, and NC contributed equally to research design, data acquisition and analysis, and manuscript compilation.

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