Swimming pools quality risk assessment for heavy metal deposition and intake via oral and dermal exposure

The deplorable environmental conditions coupled to poor management practices employed by public swimming pool owners have led to suspicions over the safety of these recreational sites. This study was carried out to determine the physicochemical properties, heavy metal contents and accumulation, and associated risks of six swimming pools in Owerri, Capital of Imo State, Nigeria. Physicochemical analysis was conducted using standard methods while determination of heavy metals was carried out using an atomic absorption spectrophotometer. Results obtained showed that the turbidities and total dissolved solutes exceeded the Nigeria standard for water quality. Iron (Fe), cadmium (Cd), mercury (Hg), arsenic (As), nickel (Ni), and lead (Pb) exceeded the drinking safety values from United States Environmental Protection Agency, National Standards for Drinking Water Quality, and World Health Organization, while selenium (Se), chromium (Cr), and zinc (Zn) values fell within the permissible limits. From the bioaccumulation models applied, the enrichment factors showed anthropogenic source of deposition of the metals in all swimming pool while the heavy metal index were in a range of 27.30-70.19. For the risk assessment results, the chronic daily intake showed that Hg, and As levels for all the swimming pools, and Cu for some swimming pools exceeded the oral reference doses, while the hazard quotient for Hg (5.65-16.95), As (2.26-3.77), and Cu (1.13-4.11) indicated potentials of causing related toxicities. This study has shown that the aesthetic quality of the swimming pools were compromised, and contained elevated levels of Hg, As, and Cu significant enough to threaten the health safety of users of these swimming pools, which should instigate tough measures from Nigerian water regulatory bodies to ensure compliance from public swimming pool owners.