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

ABSTRACT

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.

KEYWORDS:

• Trihalomethane exposure
• indoor swimming pool
• competitive swimming
• multi-pathway risk assessment

Conflict of interest

The authors declare no conflict of interest.

Additional information

Funding

Authors gratefully acknowledge the funding of Project NORTE-01-0145-FEDER-000010, Health, Comfort and Energy in the Built Environment (HEBE), cofinanced by Programa Operacional Regional do Norte (NORTE2020), through the European Regional Development Fund (ERDF).