Alveolar air and urine analyses as biomarkers of exposure to trihalomethanes in an indoor swimming pool.

The exposure of workers and swimmers at an indoor swimming pool to trihalomethanes (THMs) as a consequence of water chlorination was evaluated by analyzing alveolar air and urine samples. Environmental monitoring of THMs in water and ambient air was also performed in order to assess the possible correlation between environmental and biological samples. The sampling was done concurrently, taking the urine and alveolar air samples before and after the work shift for 15 workers and the swimming activity for 12 swimmers. A high THM uptake was observed in alveolar air and urine of subjects exposed, with chloroform being the most abundant THM. Mean chloroform levels in alveolar air and urine before exposure were 4 microg/ m3 and 475 ng/L, respectively. After 2 h of exposure, concentration increases of ca. 8 times in alveolar air and 2 times in urine were observed in workers. After 1 h swimming, the increases found in swimmers were ca. 20 and 3 times in alveolar air and urine, respectively. High increases have also been observed in bromodichloromethane levels. We have obtained excellent correlations between the chloroform concentrations found in the swimming pool ambient air/alveolar air, and between the urine/ alveolar air of the participants after exposure (r > 0.9). In conclusion, alveolar air provides better response sensitivity and shorter reaction time to external exposure than urine, being therefore the most sensitive biomarker.