Predicting human exposure and risk from chlorinated indoor swimming pool: a case study

This study predicted human exposure to disinfection by-products (DBPs) in a chlorinated indoor swimming pool. Human exposure was predicted through ingestion, inhalation, and dermal routes while ingestion exposure was accidental with water intake of 18–34 mL/h. The number of pool attendants and duration and frequency of swimming were in the ranges of 14–62 persons/day, 40–85 min/event, and 26–48 times/year, respectively. Trihalomethanes (THMs) in pool water and air were 28.7–95.5 μg/L and 44.1–133.6 μg/m³, respectively, while haloacetic acids (HAAs) in pool water were 68.9–158.9 μg/L. The brominated THMs in water and air were 95.4 and 94.3 % of total THMs, respectively, while brominated HAAs were 94.4 % of total HAAs. Chronic daily intakes of THMs and HAAs were 2.16 × 10⁻⁵–3.14 × 10⁻³ and 8.4 × 10⁻⁸–4.6 × 10⁻⁶ mg/kg-day, respectively. The cancer risk from three THMs and two HAAs was 2.46 × 10⁻⁵ with a range of 8.1 × 10⁻⁶–5.7 × 10⁻⁵, in which THMs contributed 99.6 % of total risks. Approximately 99.3 % of risks were through inhalation and dermal routes, indicating that the ingestion route may be insignificant. The cancer risks from THMs in swimming pool were 4.06–6.64 times to the cancer risks from THMs in drinking water.