93 Chloroform exposure in air and water in Swedish indoor swimming pools - urine as a biomarker of occupational exposure

Introduction Chloroform is found in swimming pool air and can be absorbed by inhalation, ingestion and dermal absorption, and is classified as possibly carcinogenic. The study aimed to investigate if chloroform concentrations in air and water affect the chloroform concentration in urine samples of exposed swimming pool workers. Methods Workers from five adventure indoor swimming pools carried personal chloroform air samplers and provided up to four urine samples during one workday. Chloroform concentrations were analysed with a linear mixed model analysis to investigate a possible correlation between air and urine concentrations. Results The geometric mean chloroform concentration was 11 μg/m3 in air and 0.009 µg/g creatinine in urine among individuals with ≤2 hours at work, 0.023 µg/g creatinine with >2–5 working hours and 0.026 µg/g creatinine with >5–10 working hours. Higher levels of chloroform in urine was associated with longer hours at work (≤2 h vs >5–10 h, OR 2.04, 95% CI 1.25–3.34), personal chloroform concentrations in air (≤17.00 µg/m3 vs >28.00 µg/m3, OR 9.23, 95% CI 3.68–23.13) and working at least half the working day near the swimming pools (OR 3.16, 95% CI 1.33–7.55). Work tasks in the swimming pool water was not associated with higher chloroform concentrations in urine compared to only working on land (OR 0.82, 95% CI 0.27–2.45). Conclusion There is an accumulation of chloroform concentrations in urine during a workday and a correlation between personal air and urine concentrations of chloroform among workers in Swedish indoor swimming pools.