You are here:
Chlorinated Chromosomes: The Impact of Human Use on the Levels of Disinfection By-products and Mutagenicity of Swimming Pools and Hot Tubs
Citation:
DeMarini, D. Chlorinated Chromosomes: The Impact of Human Use on the Levels of Disinfection By-products and Mutagenicity of Swimming Pools and Hot Tubs. Invited Talk at Baylor Univ., Waco, TX, Waco, TX, February 28 - March 02, 2017.
Impact/Purpose:
U.S. EPA scientists and their collaborators have demonstrated that dermal exposure to chlorination disinfection by-products (DBPs) by showering, swimming, or bathing is associated with an increased risk for systemic mutagenicity and bladder cancer. This work helps to protect public health by identifying which classes of DBPs are most associated with those risks. The dissemination of these EPA research results to a group of current and future environmental scientists and educators supports education regarding risks for DBPs in particular and protection of health and the environment in general.
Description:
Pools and spas are enjoyed throughout the world for exercise and relaxation. However, there are no previous studies on mutagenicity of disinfected spa (hot tub) waters or comprehensive identification of disinfection byproducts (DBPs) formed in spas. Using 28 water samples from 7 sites, we report the first integrated mutagenicity and comprehensive analytical chemistry of spas treated with chlorine, bromine, or ozone, along with pools treated with these same disinfectants. Gas chromatography with high-resolution mass spectrometry and membrane-introduction mass spectrometry were used to comprehensively identify and quantify DBPs and other contaminants. Mutagenicity was assessed by the Salmonella mutagenicity assay. More than 100 DBPs were identified, including a new class of DBPs, bromoimidazoles. XAD/ethyl acetate extracts of brominated pool/spa waters were 1.8X more mutagenic than chlorinated ones; spa waters were 1.7X more mutagenic than pools. Pool and spa samples were 2.4 and 4.1X more mutagenic, respectively, than corresponding tap waters. The concentration of the sum of 21 DBPs measured quantitatively increased from finished to tap to pool to spa; and mutagenic potency increased from finished/tap to pools to spas. Mutagenic potencies of samples from a chlorinated site correlated best with brominated haloacetic acid concentrations (Br-HAAs) (r = 0.98) and nitrogen-containing DBPs (N-DBPs) (r = 0.97) and the least with Br-trihalomethanes (r = 0.29) and Br-N-DBPs (r = 0.04). The mutagenic potencies of samples from a brominated site correlated best (r = 0.82) with the concentrations of the 9 HAAs, Br-HAAs, and Br-DBPs. Human use increased significantly the DBP concentrations and mutagenic potencies for most pools and spas. These data provide evidence that human precursors can increase mutagenic potencies of pools and spas and that this increase is associated with increased DBP concentrations. [Abstract does not necessarily reflect the policy of the US EPA.]