Water quality and human health risk assessment of phthalate esters: A comparison of treated and raw water from Ogbomosho Waterworks, Nigeria

Abstract

In this study, we assessed the occurrence, level, and health risk of phthalic acid esters (PAEs) in water samples collected from Ogbomosho waterworks, including the physicochemical properties of raw and treated water. Water samples were collected from the treated and untreated water tanks at the waterworks. Treatment efficiencies recorded for PAEs showed an insufficiency of methods employed by the waterworks in the removal of dimethyl, dibutyl, and di-n-octyl phthalates (DMP, DBP, and DnOP, respectively). Although 28 % of diethylhexyl phthalate (DEHP) was removed after treatment, the remaining level was still above US EPA regulations. The estimated total carcinogenic risk and hazard quotient values for adults and children were 4.05 × 10⁻³, 1.9 × 10⁻³, 1.62, and 1.44, respectively, all of which are within the high-risk category. It can be concluded that the health risks of PAEs exposures were not within a safe range, meaning that more than 1 in 10,000 people are likely to contract cancer of any type from using this water. This research is of global relevance to achieving the United Nations Sustainable development goals 6 (clean water and sanitation) as it highlights the importance of ensuring safe drinking water quality and informing water treatment strategies and policy globally. It also contributes to development of guidelines and standards for PAEs in drinking water and support public health initiatives to protect public health.