Читать книгу Applied Water Science - Группа авторов - Страница 29

The potential human health risks could be higher in developing countries including those in Africa than in developed countries due to several risk factors. These risk factors are discussed in earlier reviews focusing on organic and emerging contaminants (Gwenzi and Chaukura, 2018; Gwenzi et al., 2019). These risk factors are underpinned by weak and poorly enforced regulations on environment, public health and medicines control prevalent in developing countries. Consequently, there is a thriving informal or black market for pharmaceuticals, including those long banned in developed countries, a scenario that promotes misuse and abuse of pharmaceuticals (Schwarzenbach et al., 2006).

The food safety and hygiene standards tend to be poor. Thus, the consumption of untreated drinking water and aquatic foods obtained from polluted aquatic systems is prevalent (Gwenzi and Chaukura, 2018). Even in cases where drinking water is treated, the capacity of conventional low-cost methods (e.g., biosand filtration, chlorination, solar disinfection, and boiling) to remove dissolved contaminants such as pharmaceuticals could be low (Gwenzi et al., 2017). In the case of chlorination, formation of carcinogenic disinfection by-products formed when chlorine reacts with organic materials may even increase the human health risks (Sorensen et al., 2015).

Poor solid waste and wastewater management practices, including direct discharge of raw wastewater promotes the contamination of aquatic systems with pharmaceuticals (Gwenzi and Chaukura, 2018). Moreover, the overuse and misuse of pharmaceuticals driven by the high burden of livestock and human diseases in tropical environments in developing countries could lead to increased release of pharmaceuticals into aquatic systems (Badejo, 2000). Yet, environmental and public health systems and health risk assessment of pharmaceuticals are non-existent in most developing countries. Taken together, the human health risks could be significant in these developing countries, highlighting the need for caution when extrapolating findings on human health risks based on evidence from developed countries. Thus, comprehensive research on human health risks, including toxicological and epidemiological studies are needed in developing countries especially those in Africa.