Iodo containing disinfection byproducts (DBPs), e.g., iodoacetic acids, iodoacetamides, and iodonitriles, have been reported to be among the most genotoxic of all identified DBPs. Moreover, chlorinated and brominated haloaldehydes are the 3rd largest class of DBPs by weight. Within this context, this study investigated occurrence of iodoacetaldehyde in source and disinfected waters, compared its levels with those measured for chloro- and bromo-acetaldehydes, and evaluated the in vitro genotoxicity and cytotoxicity of the complete class of haloacetaldehydes (HALs) in mammalian Chinese hamster ovary (CHO) cells. Two analytical methodologies based on gas chromatography coupled to mass spectrometry were developed to investigate occurrence of HALs in water. Application of these methodologies to analysis of source and drinking water samples revealed: (1) the presence of all target HALs, except bromoacetaldehyde, in drinking waters at ppb levels; (2) the absence of HALs in source waters, except in one case where tribromoacetaldehyde was detected; (3) the formation of iodoacetaldehyde after water chloramination but not chlorination; and (4) the occurrence of iodoacetaldehyde in chloraminated water at levels between 1.6 and 1.9 ppb, concentrations which are similar to di-HALs, and slightly lower than tri-HALs. Cytotoxicity (decreased cell density) and genotoxicity (single cell gel electrophoresis) results showed that: 1) cytotoxicity and genotoxicity of HALs were not statistically correlated with chemical structure; 2) toxicity was not associated with halogen type or number; 3) iodo-, dibromo-, tribromo-, bromochloro-, and dibromochloroacetaldehyde were more cytotoxic (based on LC50 values) than regulated trihalomethanes and haloacetic acids; and 4) chloro-, dibromo-, and dibromochloroacetaldehyde were more potent genotoxicants than most regulated DBPs.Acknowledgments: Supported by a Marie Curie International Outgoing Fellowship (PIOF-GA-2010-274379) and EPA Grant R834867. It reflects only the author's views; the EU is not liable for any use that may be made of the information contained therein. This abstract does not reflect EPA policy.

Occurrence and toxicity of haloaldehydes in drinking waters: Iodoacetaldehyde as an emerging disinfection byproduct

248th National Meeting (2014)

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