The presence of trichloramine in the air in different indoor swimming pools has
been studied in several countries. In almost all studies, the results show a
possible health impact due to trichloramine among pool attendants. The main
objectives of this study were to evaluate, for the first time in Switzerland,
occupational and public trichloramine exposure in a representative panel of
indoor pools and to propose an occupational exposure limit for trichloramine.

Measurements were done in 30 indoor swimming pools located in three regions of
Switzerland: Jura, Neuchâtel, and Fribourg. All investigations were performed
during the 2007-2008 winter season in order to assure closed windows and
standard ventilation conditions.

The results indicate that in all the studied facilities except one, the
trichloramine concentrations were below the French reference value of 0.5 mg
m-3, and only three were equal to or slightly over 0.3 mg m-3.

The results demonstrate an increasing risk of irritative symptoms up to a level
of 0.2-0.3 mg m-3 of trichloramine. The health data in our study, as well as
the review of the literature, strongly suggest fixing the trichloramine
occupational exposure limit at 0.3 mg m-3. Severe technical standards (on
flocculation, filters, water flow, and ventilation systems) and regulations on
water quality (free and combined chlorine, urea, and amount of fresh water)
contribute to reducing trichloramine formation and, consequently, occupational
and public trichloramine exposure. In addition, to ensure good public hygiene
(showering before swimming), correct and regular public awareness campaigns
should be undertaken.

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AplusA-online.de - Source: The Annals of Occupational Hygiene