Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans in Kuala Lumpur urban environment and their potential risk to human health

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are persistent organic pollutants that affect human health. This study aimed to quantify the concentrations of 17 PCDDs/PCDFs congeners in ambient air in the urban environment of Kuala Lumpur and their potential risk to humans. PM_2.5 and TSP were collected on quartz microfibre using separate high-volume samplers, whereas the gaseous phase and passive samples were captured on polyurethane between December 2021 and October 2022. The results show the Ʃ17PCDD/PCDF concentration in ambient air is 736 ± 375 fg WHO-TEQ m^-3, whereas PM_2.5, TSP, and gaseous phase concentrations are 223 ± 161 fg WHO-TEQ m^-3, 337 ± 213 fg WHO-TEQ m^-3 and 507 ± 273 fg WHO-TEQ m^-3, respectively. The hepta- and octa-group congeners dominated up to 80% of the Ʃ17PCDDs/PCDFs and are more likely to bind with the particle phase than the gaseous phase. The Ʃ17PCDDs/PCDFs displayed a significant difference between gaseous and particle concentrations (p <0.001). Exposure to the gaseous phase of Ʃ17PCDDs/PCDFs resulted in a greater inhalation lifetime cancer risk (1.58E06-5.28E-06). This study found that the toxic equivalent (TEQ) concentrations are dominant in the gaseous phase, while cancer risks from exposure to PCDDs/PCDFs in the air are tolerable in children and adults.