Swimming Pool Disinfectants Linked to Disease


When you and your children head for the swimming pool this summer, you may be getting more than a cool, refreshing break from the heat. A University of Illinois study finds that disinfectants used in swimming pools may be associated with serious health consequences, including asthma and cancer.

Health guidelines make it mandatory to treat recreational swimming pools with certain chemicals, including disinfectants, to prevent the outbreak of infectious disease. When you and your family enter a swimming pool, you introduce a wealth of other organisms that can then mingle with the numerous other substances already in the water, some of which have been added intentionally, and others, such as organic matter carried by the wind from plants and other sources.

According to Michael Plewa, University of Illinois professor of genetics, health consequences can arise when disinfectant byproducts react with organic matter in swimming pool water. Along with nature’s organic matter, people bring other ingredients to pool water, including hair, sweat, dead skin cells, urine, cosmetics, and medications.


Many of the substances people bring to pool water are nitrogen-rich, which, when they meet up with disinfectants, may be chemically changed and be transformed into more toxic agents. These toxic elements, according to Plewa, can cause gene mutation, induce birth defects, speed up the aging process, initiate respiratory ailments, and even trigger cancer if exposure is long-term.

In the current study, which was conducted by Plewa and several colleagues from various institutions, samples of water were collected from public pools and compared with a control sample of tap water. Genotoxicity analysis was used to evaluate the samples, which allowed the investigators to examine cell damage at the level of the nucleus.

Results of the analyses showed that all disinfected pool samples had more genomic DNA damage than tap water. Based on these findings, Plewa advised “that brominating agents should be avoided as disinfectants of recreational pool water. The best method to treat pool water is a combination of UV [ultraviolet] treatment with chlorine as compared to chlorination alone.” He also recommended that organic carbon be removed from pool water before disinfection takes place when the pool water is recycled.

What can you do to protect yourself and your family? Plewa noted that people should shower before entering a swimming pool and that everyone should avoid urinating in pools. These same safety measures should be followed when using hot tubs. Adoption of UV treatment of pool water by pool owners will help eliminate the problem.

Liviac D et al. Environ Sci Technol 2010 May 1; 44(9): 3527-32
University of Illinois College of Agricultural, Consumer and Environmental Sciences