 chloroform is a known contaminant of chlorinated drinking water and of swimming pool water disinfected with chlorine or one of its derivatives . 
 few data exist regarding the importance of dermal and inhalation exposure routes to the chloroform body burden resulting from domestic and recreational use of chlorinated water . in our experimental study involving 11 male swimmers 
 , we quantified the body burden resulting from exposure to various concentrations of chloroform in water and air of an indoor swimming pool , during a daily 55-min exercise period . from the first to the sixth exercise period , chcl3 mean concentration in water was increased from 159 
 micrograms / l to 553 micrograms / l . corresponding mean air chcl3 level ranged from 597 ppb to 1630 ppb . to dissociate the dermal exposure route from that of inhalation 
 , swimmers used scuba tanks during an additional exercise period . 
 chloroform concentrations were measured in alveolar air before and after each exercise period , as well as after 35 min of physical activity . 
 chloroform levels in water and air were measured every 10 min . 
 we examined the relationship between alveolar air concentration ( a measure of body burden ) at 35 and 55 min and environmental chloroform concentrations by using multiple regression models . 
 the natural logarithm of alveolar air concentration was strongly correlated with aqueous chloroform concentration both at 35 ( p2 < 0.001 , r2 = 0.75 ) and 55 min 
 ( p < 0.001 , r2 = 0.86 ) . 
 the relationship with air concentrations was also statistically significant ( 35 min : p < 0.001 , r2 = 0.58 , 55 min : p < 0.001 , r2 = 0.63).(abstract truncated at 250 words)imagesfigure 1.figure 2 . 
 afigure 2 . 
 bfigure 3 . 
 afigure 3 . 
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