Development of a 4-NQO toxic equivalency factor (TEF) approach to enable a preliminary risk assessment of unknown genotoxic compounds detected by the Ames II test in UV/H₂O₂ water treatment samples.

Autor: Martijn BJ; Wageningen University, Division of Toxicology, P.O. Box 8000, 6700 EA Wageningen, The Netherlands; Wetsus European Centre of Excellence for Sustainable Water Technology, P.O. Box 1113; 8900 CC Leeuwarden, The Netherlands; PWN Water Supply Company North Holland, P.O. Box 2113, 1990 AC Velserbroek, The Netherlands. Electronic address: bmartijn@pwntechnologies.nl., Van Rompay AR; VITO - Environmental Risk & Health - Team ABS, Industriezone Vlasmeer 7, 2400 Mol, Belgium., Penders EJ; Het Waterlaboratorium, P.O Box 734, 2300 RS Haarlem, The Netherlands., Alharbi Y; Wageningen University, Division of Toxicology, P.O. Box 8000, 6700 EA Wageningen, The Netherlands., Baggelaar PK; Icastat, Niagara 18, 1186 JP Amstelveen, The Netherlands., Kruithof JC; Wetsus European Centre of Excellence for Sustainable Water Technology, P.O. Box 1113; 8900 CC Leeuwarden, The Netherlands., Rietjens IM; Wageningen University, Division of Toxicology, P.O. Box 8000, 6700 EA Wageningen, The Netherlands.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2016 Feb; Vol. 144, pp. 338-45. Date of Electronic Publication: 2015 Sep 14.
DOI: 10.1016/j.chemosphere.2015.08.070
Abstrakt: An approach to enable a preliminary risk assessment of unknown genotoxic compounds formed by MP UV/H2O2 treatment of nitrate rich water, is described. Since the identity and concentration of specific genotoxic compounds is not established yet, a compound specific risk assessment cannot be performed. This limitation is circumvented by introducing a toxic equivalency factor, converting the concentration of unknown genotoxic compounds expressed by an Ames II test response into equivalent concentrations of 4-nitroquinoline oxide (4-NQO), to enable a preliminary risk assessment. Based on the obtained 4-NQO equivalent concentrations for the tested water samples and 4-NQO carcinogenicity data, an indication of the associated risk of the by MP UV/H2O2 treatment produced nitrated genotoxic compounds is obtained via the margin of exposure (MOE) approach. Based on a carcinogen study by Tang et al. (2004), a body weight of 70 kg and a drinking water consumption of 2 L per day, the 4-NQO equivalent concentration should not exceed 80 ng/L associated with a negligible risk. Application of this approach on samples from MP UV/H2O2 treated water of a full scale drinking water production facility, a 4-NQO equivalent concentration of 107 ng/L was established. These results indicate a safety concern in case this water would be distributed as drinking water without further post treatment.
(Copyright © 2015 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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