Profile distribution and health risk assessment of per- and polyfluoroalkyl substances in indoor dust from urban households in Uganda, East Africa

and polyfluoroalkyl substances (PFAS) contamination of various environmental compartments continues to attract scrutiny due to their persistence, bioaccumulation and toxicity, following their widespread application over the years as surfactants and stain repellents. Studies have indicated that PFAS in the indoor environments, including dust, may serve as sources of human exposure. However, little is known about the prevalence of PFAS and their associated health risks in indoor environments from the sub-Saharan African countries, including Uganda. Herein, we collected samples of indoor household dust from the floors of residential houses (n=43) in Kampala, Uganda, to assess the levels and associated health risks of PFAS to the exposed humans. Of the 11 targeted PFAS, only 8 were detected in the collected samples. The mean level of ∑ 8 PFAS in household dust was 427 ng/g, with a maximum concentration of 2,850 ng/g. 10:2 fluorotelomer alcohol (10:2 FTOH), and perfluorobutanoic acid (PFBA) predominated among the neutral and ionic PFAS, respectively. Source apportionment revealed food packaging, semiconductor materials and textiles as the major sources. The calculated hazard quotients (HQs) due to exposure to PFAS, and their sums (∑HQs) in our study for both adults and toddlers, were all less than 1, suggesting negligible non-carcinogenic risk. Despite the low estimated exposure via dust ingestion and dermal contact, compound-specific toxicological profiles of PFAS, their potential for interactive effects, and the presence of additional exposure routes underscore the urgency of regularly investigating indoor PFAS-related health risks. • First study to analyze legacy and emerging PFAS in indoor dust from Uganda. • 10:2 FTOH and PFBA dominated the neutral and ionic PFAS profiles, respectively. • Major sources of PFAS were food packaging, semiconductor materials, and textiles. • Non-carcinogenic risks to exposed adults and toddlers were negligible.