Occupational exposure to trichloramine and trihalomethanes: adverse health effects among personnel in habilitation and rehabilitation swimming pools

Abstract

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 10 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 mg/m 3 (average: 19 mg/m 3 ) and 1-140 mg/m 3 (average: 23 mg/m 3 ), 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 mg/m 3 ). 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 mg/m 3 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.

Inorganic chloramines: a critical review of the toxicological and epidemiological evidence as a basis for occupational exposure limit setting

“…Linear regression analysis based on data from 12 parallel 8-h samplings of trichloramine in pool air suggested a relation between personal and stationary sampling of 1:1.6 (Westerlund et al 2015). In a similar study by the same group, a linear regression based on 8 personal and 14 stationary 8-h samplings showed a corresponding relation of 1:2.2 between personal and stationary sampling (Westerlund et al 2019). Only data from personnel who spent >50% of their workday in the pool area were included in the analyses.…”

“…Marginal effects on lung function were demonstrated in one study with personal trichloramine exposure levels of 0.15 mg/m 3 and 0.23 mg/m 3 (Nordberg et al 2012). In contrast, no effects on lung function were demonstrated in studies with exposure levels of 0.023 mg/m 3 (Westerlund et al 2019), 0.18 mg/ m 3 (personal exposure 0.071 mg/m 3 ) (L€ ofstedt et al 2016), 0.16-0.28 mg/m 3 (Carbonnelle et al 2008), 0.29 mg/m 3 (Font-Ribera et al 2010), and 0.36 and 0.49 mg/m 3 (Carbonnelle et al 2002). FENO has been measured in some studies as a possible marker of airway inflammation, with mostly negative results.…”

“…The results may deviate from results obtained by personal sampling. Linear regression analyses based on data from parallel 8-h samplings of trichloramine in pool air suggested a relation between personal and stationary sampling of approximately 1:2 (Westerlund et al 2015(Westerlund et al , 2019.…”

“…In two studies in indoor swimming pool facilities, personal sampling was used in parallel with stationary sampling. Overall, the personal exposure was approximately 50% of the levels obtained by stationary sampling (Section 5.1.2) (Westerlund et al 2015(Westerlund et al , 2019. King et al (2006) -: missing data; AM: arithmetic mean; GM: geometric mean; LOQ: limit of quantification; ND: non-detectable; SD: standard deviation; UV: ultraviolet.…”

“…Mean FENO values differed between groups before shift (18 ppb versus 16.1 ppb in referents) and decreased over work shift in both groups (17.9 ppb versus 14.3 ppb), but significantly more in referents than in pool workers. Personal trichloramine concentrations were not associated with lung function or FENO (Westerlund et al 2019). Nordberg et al (2012) investigated lung function [forced expiratory volume in the first second (FEV 1 ) and FEV % (FEV 1 / forced vital capacity  100) as well as biomarkers of pulmonary epithelial integrity (CC16 and SP-D) in volunteers before and after exposure to indoor pool air.…”