A Comprehensive Review of the Occurrence, Distribution, Characteristics and Fate of Per- and Polyfluoroalkyl Substances in the African Continent

Abstract

Abstract Per- and polyfluoroalkyl substances (PFAS) represent synthetic organic compounds extensively utilized in a variety of domestic and industrial products due to their distinctive characteristics. Designated as persistent organic pollutants (POPs) by the Stockholm Convention, PFAS are recognized for their long-lasting presence, widespread prevalence, and adverse impacts on both the environment and human health. Recently, the United States Environmental Protection Agency (US EPA) revised the guideline limits for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in drinking water, setting them at 0.02 and 0.004 ng/L, respectively. Despite the global emphasis on the necessity for monitoring and treating PFAS in environmental media, there is a scarcity of information on PFAS studies in Africa. This gap may be attributed to a lack of modern laboratory facilities, weak governance, and the enforcement of environmental regulations. This study comprehensively reviews PFAS, focusing on key areas such as global guidelines and regulations, sources and distribution in the environmental matrix in Africa, characteristics, environmental fate, reported methods for sampling and analysis in Africa, and the role of government in the National Implementation Plan (NIP) on the continent. Additionally, the study offers recommendations and identifies knowledge gaps. In Africa, PFAS have been detected in various environmental compartments, including drinking water ranging from 0.03 to 200 ng/L, surface water ranging from 0.0254 to 788 ng/L, sediment ranging from 0.50 to 248.14 ng/g, wastewater ranging from 0.9 to 507 ± 257.6 ng/L, seafood ranging from 0.12 to 179.2 ng/g, sludge ranging from 0.01 to 0.098 ng/g, plants ranging from 0.160 to 29.33 ng/g, and indoor dust ranging from 1.3 to 69 ng/g. Notably, perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are prevalent in samples from various environmental matrices across Africa. Reported sources of PFAS in African countries include municipal waste, hospital waste from medical equipment, discharge from industries, and wastewater treatment plants. Urgent attention is required from decision-makers and researchers in Africa to address PFAS monitoring, regulation, and treatment within the continent. Graphical abstract