Introduction: Chlorination is a method commonly used to keep indoor swimming pool water free from pathogens. However, chlorination of swimming pools produces several potentially hazardous by-products as the chlorine reacts with nitrogen containing organic matter. Up till now, exposure assessments in indoor swimming pools have relied on stationary measurements at the poolside, used as a proxy for personal exposure. However, measurements at fixed locations are known to differ from personal exposure.

Methods: Eight public swimming pool facilities in four Swedish cities were included in this survey. Personal and stationary sampling was performed during day or evening shift. Samplers were placed at different fixed positions around the pool facilities, at similar to 1.5 m above the floor level and 0-1 m from the poolside. In total, 52 personal and 110 stationary samples of trichloramine and 51 personal and 109 stationary samples of trihalomethanes, were collected.

Results: The average concentration of trichloramine for personal sampling was 71 mu g m(-3), ranging from 1 to 240 mu g m(-3) and for stationary samples 179 mu g m(-3), ranging from 1 to 640 mu g m(-3). The air concentrations of chloroform were well below the occupational exposure limit (OEL). For the linear regression analysis and prediction of personal exposure to trichloramine from stationary sampling, only data from personal that spent > 50% of their workday in the pool area were included. The linear regression analysis showed a correlation coefficient (r (2)) of 0.693 and a significant regression coefficient beta of 0.621; (95% CI = 0.329-0.912, P = 0.001).

Conclusion: The trichloramine exposure levels determined in this study were well below the recommended air concentration level of 500 mu g m(-3); a WHO reference value based on stationary sampling. Our regression data suggest a relation between personal exposure and area sampling of 1:2, implying an OEL of 250 mu g m(-3) based on personal sampling.

Background: This study investigated trichloramine exposure and prevalence of respiratory and ocular symptoms among Swedish indoor swimming pool workers.

Methods: Questionnaires were distributed to pool workers and referents. Lung function and fraction of exhaled nitric oxide (FeNO) were measured before and after work. Exposure to trichloramine and trihalomethanes was measured over work shifts.

Results: The mean personal trichloramine exposure was 36g/m(3). Significantly more exposed workers reported ocular and nasal symptoms. There were significant differences between groups in FeNO change following work, with exposed showing increased FeNO, which grew when analyses included only nonsmokers.

Conclusions: The findings indicate that indoor swimming pool environments may have irritating effects on mucous membranes. FeNO data also indicate an inflammatory effect on central airways, but the clinical relevance is unclear. Low trichloramine levels found in this study were not associated with health effects.

Personnel in swimming pool facilities typically experience ocular, nasal, and respiratory symptoms due to water chlorination and consequent exposure to disinfection by-products in the air. The aim of the study was to investigate exposure to trichloramine and trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) from the perspective of adverse health effects on the personnel at Swedish habilitation and rehabilitation swimming pools. The study included ten habilitation and rehabilitation swimming pool facilities in nine Swedish cities. The study population comprised 24 exposed swimming pool workers and 50 unexposed office workers. Personal and stationary measurements of trichloramine and trihalomethanes in air were performed at all the facilities. Questionnaires were distributed to exposed workers and referents. Spirometry, fraction of exhaled nitric oxide (FE_NO) and peak expiratory flow (PEF) were measured. Personal and stationary measurements yielded trichloramine levels of 1-76 µg/m³ (average: 19 µg/m³) and 1-140 µg/m³ (average: 23 µg/m³), respectively. A slightly higher, but not significant, prevalence of reported eye- and throat-related symptoms occurred among the exposed workers than among the referents. A significantly increased risk of at least one ocular symptom was attributed to trichloramine exposure above the median (20 µg/m³). Lung function (FVC and FEV1) was in the normal range according to the Swedish reference materials, and no significant change in lung function before and after shift could be established between the groups. Average FE_NO values were in the normal range in both groups, but the difference in the values between the exposed workers and referents showed a significant increase after shift. Hourly registered PEF values during the day of the investigation did not show any unusual individual variability. In conclusion, the increased risk of developing at least one ocular symptom at personal trichloramine concentrations over 20 µg/m³ combined with an increase in the difference in FE_NO during the work shift of the exposed workers should not be neglected as an increased risk of respiratory inflammation in the habilitation and rehabilitation swimming pool environment.