Indoor swimming pool facilities often use chlorine for pool water disinfection. Chlorine can also contribute to the formation of unwanted disinfection byproducts (DBPs). Trichloramine and trihalomethanes (THMs) are DBPs formed in swimming pool water and swimming pool air causing occupational exposure. Trichloramine can cause ocular and airway irritation, while some THMs are potentially carcinogenic. Bacterial endotoxins may also cause adverse respiratory effects among swimming pool workers. 

The overall aim of the study was to measure levels of trichloramine, THMs and endotoxins in the air at conventional, habilitation and rehabilitation, and adventure swimming pool facilities, and to investigate adverse ocular and respiratory effects among indoor swimming pool workers.

Trichloramine and THM levels in air were comparable to previous studies. Endotoxin levels in air were low compared to the reference value. Trichloramine concentrations in personal samples were approximately half as high as those measured in stationary samples - an important consideration for a future Swedish occupational exposure limit. The adventure facilities had the highest trichloramine levels while the conventional facilities had the highest THM levels. The adventure workers also reported more ocular and respiratory symptoms compared to referents (office workers) and had a lower FEV1/FVC ratio indicating airway obstruction. Workers both in conventional, and in habilitation and rehabilitation facilities exhibited a difference in FeNO levels compared to referents, implying airway inflammation.

The occupational exposure and adverse health effects found in indoor swimming pool environments emphasizes the importance of a personal based Swedish occupational exposure limit for trichloramine in air.