Exercise induced bronchospasm and chlorine in swimming pools

Background: Swimming is often the preferred exercise prescription for asthmatics. However, there is also concern because increased sensitisation to allergens and a high rate of bronchial responsiveness to methacholine has been reported in swimmers (Drobnic, 1992). It has recently been hypothesized that chronic exposure to chlorine compounds in swimming pool water might sensitize the airways and cause exercise induce bronchospasm (EIB) in swimmers. Objective: The purpc:>se of this thesis was firstly to review the possible relationship between chlorine in swimming pool water and exercise induced bronchospasm, and secondly to assess whether chlorine exposure during swimming provokes EIB in well-trained swimmers with and without a history of EIB. Review Methods: The relationship between asthma, EIB, swimming and chlorine was reviewed. The internet-based medical literature search engine, PUBMED, was used to obtain the related articles. Copies of the original articles were collected at and through the University of Cape Town Medical Library. The possible relationship between exposure to chlorine in swimming pool water and the prevalence of EIB in swimmers is reviewed. Results: A review of the literature confirms a relationship between chlorine and EIB in swimmers. Furthermore, the effect of chlorine on EIB must be carefully investigated because swimming per se can influence the diagnosis of EIB compared with running. Lastly, there is some evidence that the exposure to chlorine and by-products of water chlorination may have a negative effect on respiratory function in swimmers.