Pool Chlorination By-Products and Airway Hyperresponsiveness in Swimmers: Pathomechanism, Pulmonary Diagnostics and Preventive Management — A Narrative Synthesis of Evidence Published Since 2020
DOI:
https://doi.org/10.12775/QS.2026.75.75256Keywords
trichloramine, disinfection by-products, swimmers, airway hyperresponsiveness, exercise-induced bronchoconstriction, club cell protein 16, anti-doping, narrative reviewAbstract
Background: Competitive swimmers train in indoor facilities where chlorine-based disinfection generates volatile by-products like trichloramine. Aquatic disciplines report the highest prevalence of lower airway dysfunction of any sporting group. The clinical picture, often labelled ‘swimmer’s asthma’, sits between classical exercise-induced bronchoconstriction and chemically mediated airway disorder.
Aim: To synthesise evidence (2020 onwards) on mechanisms by which chlorination by-products and sustained hyperpnoea injure airway epithelium in swimmers, appraise diagnostic strategies, and set out preventive and pharmacological options within anti-doping constraints.
Material and methods: This narrative synthesis retrieved PubMed/MEDLINE records (Jan 2020–Jul 2026), combining exposure, respiratory, and anti-doping terms. Priority was given to consensus statements, meta-analyses, and clinical trials.
Results: Meta-analyses place lower airway dysfunction prevalence at 21.8% across athletes and 39.9% in aquatic disciplines. The dominant mechanism combines osmotic/mechanical stress from hyperpnoea with chemical irritation, disrupting the epithelial barrier. Club cell protein 16 marks this disruption, though interpretation is complicated by acute vs. chronic changes. Symptom-based diagnosis performs poorly; objective bronchoprovocation is required (eucapnic voluntary hyperpnoea shows 46% sensitivity, 74% specificity). Inhaled beta-2 agonists are permitted below daily thresholds, but the therapeutic-to-reportable margin is narrow.
Conclusions: Swimmers' airway hyperresponsiveness is an occupational disorder of mixed osmotic and chemical origin, not classical asthma. Objective testing must precede prescription, treatment must align with anti-doping limits, and environmental control of by-products requires greater clinical emphasis.
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Copyright (c) 2026 Aleksandra Pacek, Jakub Bryl, Wioleta Pluta, Aleksandra Plewa-Kijak, Roksana Milaniuk, Aleksandra Drzewiecka, Beata Surówka, Szymon Daniszewski, Izabela Czerny, Krzysztof Talarowski, Piotr Tylec, Arkadiusz Ściubak, Kinga Ostojska
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