Poor sanitation leads to untreated wastewater entering river systems in many countries where industrialisation and urbanisation is not supported by appropriate infrastructure. The lack of regulation and enforcement means toxic chemicals can damage the ecology of the natural environment and pose a risk to human health.
Responsible producers of active pharmaceutical ingredients (APIs) are growing increasingly concerned that current environmental risk assessment methods do not adequately reflect the sources and pathways of APIs to the rivers of developing countries.
Now, new research led by the University of Plymouth suggests that failure to ensure the environmental sustainability of growing patient access to medicines in developing economies could increase the risk of adverse environmental impacts.
Scientists took a series of samples from the Nairobi/Athi river basin in Kenya to assess the source, occurrence, magnitude and risk associated with a range of APIs and other chemicals.
They found elevated levels of drugs including paracetamol, caffeine, sulfamethoxazole and trimethoprim, up to 75km downstream from the urban centre of the city of Nairobi.
The primary sources were the direct discharge of untreated domestic wastewater from informal settlements, the industrial area of Nairobi where drug formulation is known to occur, a major landfill site and veterinary medicines from upstream agricultural use.
Scientists say the chemicals could pose a number of risks, the most prominent being the potential threat of anti-microbial resistance (AMR) with the river being used by communities as a source of drinking water and for the irrigation of crops.
And, while this research focused on the Nairobi area, they say its findings could be applied to anywhere in the world where the development of an urban area has outpaced the development of basic sanitation and the environmental infrastructure required to support its population.
The study, published in Science of The Total Environment, was led Dr Simone Bagnis (as part of his PhD studies) and Dr Sean Comber from the University of Plymouth.
Samples were collected in 27 locations along the river catchment and were analysed by collaborators at the University of York for the occurrence of 55 APIs, with 45 compounds under scrutiny being detected in at least one sampling location. The APIs with the highest frequency of detection were caffeine (stimulant), carbamazepine (antiepileptic), trimethoprim, sulfamethoxazole ciprofloxacin (antibiotics), fluconazole (antifungal) and amitriptyline (antidepressant).