The Atmospheric Pollution Characteristics and Health Risk Assessment of Perfluorohexane Sulfonic Acid in Beijing

Perfluorohexane sulfonic acid (PFHxS), one of the substitutes for perfluorooctane sulfonic acid (PFOS), has been widely discussed around the world. In this study, the atmospheric concentra-tions of PFHxS in Beijing in the summer and autumn of 2021 were monitored, and the gas-particle partitioning and wet and dry deposition characteristics were analyzed. The results show that the average total concentrations of PFHxS in Beijing in the summer and autumn were 1.61 pg/m(3 )and 1.41 pg/m(3), respectively. The particulate fraction ? of PFHxS was about 48% during the research period, and there was a significant positive correlation between ? and air temperatures. The linear fitting relationship between log Kp(gas-particle partition coefficient) and log PL (compound vapor pressure) showed that the absorption between the PFHxS molecule and particulate matter dominated the process of gas-particle partitioning. The total deposition flux of PFHxS was the largest in July and the smallest in October, with values of 55.2 and 23.7 ng/m(2), respectively. During the study period, PFHxS in the atmosphere had no obvious health impacts on humans. However, with their extensive use, the possible harmful effects on children should be continuously investigated.