Health effects of exposure to chlorination by-products in swimming pools

Concerns have been raised regarding the potential negative effects on human health of water disinfectants used in swimming pools. Among the disinfection options, the approaches using chlorine-based products have been typically preferred. Chlorine readily reacts with natural organic matter that are introduced in the water mainly through the bathers, leading to the formation of potentially harmful chlorination by-products (CBPs). The formation of CBPs is of particular concern since some have been epidemiologically associated with the development of various clinical manifestations. The higher the concentration of volatile CBPs in the water, the higher their concentration in the air above the pool, and different routes of exposure to chemicals in swimming pools (water ingestion, skin absorption, and inhalation) contribute to the individual exposome. Some CBPs may affect the respiratory and skin health of those who stay indoor for long periods, such as swimming instructors, pool staff, and competitive swimmers. Whether those who use chlorinated pools as customers, particularly children, may also be affected has been a matter of debate. In this article, we discuss the current evidence regarding the health effects of both acute and chronic exposures in different populations (work-related exposures, intensive sports, and recreational attendance) and identify the main recommendations and unmet needs for research in this area.

Automated summary

Concerns have been raised on the potential negative health effects of water disinfectants in swimming pools, particularly chlorine-based products. Formation of chlorination by-products (CBPs) in pools, which react with natural organic matter introduced by bathers, is a particular concern due to epidemiological associations with clinical manifestations. Exposure routes (ingestion, absorption, inhalation) contribute to individual exposome, with potential effects on respiratory and skin health for indoor individuals like swimming instructors and competitive swimmers. Debate persists on whether chlorinated pool users, especially children, may be affected. More research is needed in this area.