BLOOD AND BREATH ANALYSES AS BIOLOGICAL INDICATORS OF EXPOSURE TO TRIHALOMETHANES IN INDOOR SWIMMING POOLS

In this article, exposure to trihalomethanes (THMs) in indoor swimming pools as a consequence of water chlorination is reported. Environment al and biological monitoring of THMs was performed in order to assess the uptake of these substances after a defined period in five competit ive swimmers, regularly attending an indoor swimming pool to train for competition during four sampling sessions. Analyses were performed by gas-chromatography and the following THMs were detected: chloroform ( CHCl3), bromodichloromethane (CHBrCl2), dibromochloromethane (CHBr2Cl) and bromoform (CHBr3). CHCl3 appeared the most represented compound b oth in water and in environmental air before and after swimming. CHBrC l2 and CHBr2Cl were always present, even though at lower levels than C HCl3, CHBr3 was rarely present. In relation to biological monitoring, CHCl3, CHBrCl2 and CHBr2Cl were detected in all alveolar air samples c ollected inside the swimming pool. Before swimming, after 1 h at rest at the pool edge, the mean values were 29.4 +/- 13.3, 2.7 +/- 1.2 and 0.8 +/- 0.8 mu g/m(3), respectively, while after spending Ih swimming, higher levels were detected (76.5 +/- 18.6, 6.5 +/- 1.3 and 1.4 +/- 0 .9 mu g/m(3), respectively). Only CHCl3 was detected in all plasma sam ples (mean: 1.4 +/- 0.5 mu g/l) while CHBrCl2 and CHBr2Cl were observe d only in few samples at a detection limit of 0.1 mu g/l. After 1 h at rest, at an average environmental exposure of approx. 100 mu g/m(3), the THM uptake was approx, 30 mu g/h (26 mu g/h for CHCl3, 3 mu g/h fo r CHBrCl2 and 1.5 mu g/h for CHBr2Cl). After 1 h swimming, the THM upt ake is approx, seven times higher than at rest: a THM mean uptake of 2 21 mu g/h (177 mu g/h, 26 mu g/h and 18 mu g/h for CHCl3, CHBrCl2 and CHBr2Cl, respectively) was evaluated at an environmental concentration of approx. 200 mu g/m(3). (C) 1998 Elsevier Science B.V. All rights r eserved.