Haloacetonitriles vs. regulated haloacetic acids: Are nitrogen-containing DBFs more toxic?

Mark G. Muellner, Elizabeth D. Wagner, Kristin Mccalla, Susan D. Richardson, Yin Tak Woo, Michael J. Plewa

Research output: Contribution to journalArticlepeer-review


Haloacetonitriles (HANs) are toxic nitrogenous drinking water disinfection byproducts (N-DBPs) and are observed with chlorine, chloramine, or chlorine dioxide disinfection. Using microplate-based Chinese hamster ovary (CHO) cell assays for chronic cytotoxicity and acute genotoxicity, we analyzed 7 HANs: iodoacetonitrile (IAN), bromoacetonitrile (BAN), dibromoacetonitrile (DBAN), bromochloroacetonitrile (BCAN), chloroacetonitrile (CAN), dichloroacetonitrile (DCAN), and trichloroacetonitrile (TCAN). The cytotoxic potency (%C1/2 values) ranged from 2.8 μM (DBAN) to 0.16 mM (TCAN), with a descending rank order of DBAN > IAN ≈ BAN > BCAN > DCAN > CAN > TCAN. HANs induced acute genomic DNA damage; the single cell gel electrophoresis (SCGE) genotoxicity potency ranged from 37 μM (IAN) to 2.7 mM (DCAN). The rank order of declining genotoxicity was IAN > BAN ≈ DBAN > BCAN > CAN > TCAN > DCAN. The accompanying structure-activity analysis of these HANs was in general agreement with the genotoxicity rank order. These data were incorporated into our growing quantitative comparative DBP cytotoxicity and genotoxicity databases. As a chemical class, the HANs are more toxic than regulated carbon-based DBPs, such as the haloacetic acids. The toxicity of N-DBPs may become a health concern because of the increased use of alternative disinfectants, such as chloramines, which may enhance the formation of N-DBPs, including HANs.

Original languageEnglish (US)
Pages (from-to)645-651
Number of pages7
JournalEnvironmental Science and Technology
Issue number2
StatePublished - Jan 15 2007
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry


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