Predicting health risk from exposure to trihalomethanes in an Olympic-size indoor swimming pool among elite swimmers and coaches.

Disinfection by-products (DBP) such as trihalomethanes (THM) are formed when chlorine and bromine interact with natural organic materials in chlorine-treated swimming pools. Epidemiological evidence demonstrated an association between exposure to swimming pool environment and adverse health effects. Therefore, this study aimed to assess carcinogenic and non-carcinogenic risk of long-term exposure of elite swimmers and their coaches. In an Olympic-size indoor chlorinated swimming pool, THM levels were determined in water (21-69 µg/L), in the boundary layer above the water surface (59-397 µg/m3), and in the air surrounding the pool (28-390 µg/m3). These values were used to predict multi-pathway chronic daily intake (CDI), cancer risk (CR) and hazard index (HI). Oral and dermal CDI for swimmers were 2.4 × 10-6 and 2.0 × 10-8, respectively. The swimmers' inhalation CDI (1.9 × 10-3 mg/kg/day) was estimated to be sixfold higher than levels obtained for coaches (3.3 × 10-4 mg/kg/day). According to guidelines, the HI was acceptable, but CR exceeded the recommended limit for both, coaches (CR: 5.5 × 10-7-8.5 × 10-5; HI: 6.5 × 10-4-1 × 10-1) and swimmers (CR: 1.4 × 10-5-3.6 × 10-4 HI: 1.6 × 10-2-4.3 × 10-1). Our findings provide further support to the need to develop comprehensive guidelines to safeguard the health of individuals involved in elite swimming.