Differential toxicity of drinking water disinfected with combinations of ultraviolet radiation and chlorine.
Alternative technologies to disinfect drinking water such as ultraviolet (UV) disinfection are becoming more widespread. The benefits of UV disinfection include reduced risk of microbial pathogens such as  Cryptosporidium  and reduced production of regulated drinking water disinfection byproducts (DBPs). The objective of this research was to determine if mammalian cell cytotoxicity and genotoxicity varied in response to different chlorination protocols with and without polychromatic medium pressure UV (MPUV) and monochromatic low pressure UV (LPUV) disinfection technologies. The specific aims were to analyze the mammalian cell cytotoxicity and genotoxicity of concentrated organic fractions from source water before and after chlorination and to determine the cytotoxicity and genotoxicity of the concentrated organic fractions from water samples treated with UV alone or UV before or after chlorination. Exposure of granular activated carbon-filtered Ohio River water to UV alone resulted in the lowest levels of mammalian cell cytotoxicity and genotoxicity. With combinations of UV and chlorine, the lowest levels of cytotoxicity and genotoxicity were observed with MPUV radiation. The best combined UV plus chlorine methodology that generated the lowest cytotoxicity and genotoxicity employed chlorination first followed by MPUV radiation. These data may prove important in the development of multibarrier methods of pathogen inactivation of drinking water, while limiting unintended toxic consequences.
College of Agricultural, Consumer, and Environmental Sciences, Department of Crop Sciences, and the NSF WaterCAMPWS Center, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States. mplewa@illinois.edu
Michael J
MJ
Plewa
Elizabeth D
ED
Wagner
Deborah H
DH
Metz
Ramesh
R
Kashinkunti
Katherine J
KJ
Jamriska
Maria
M
Meyer
D000818:Animals; D016466:CHO Cells; D016923:Cell Death / Q000187:drug effects; D002713:Chlorine / Q000633:toxicity*; D020552:Comet Assay; D006224:Cricetinae; D004202:Disinfectants / Q000633:toxicity*; D004203:Disinfection / Q000379:methods*; D060766:Drinking Water / Q000737:chemistry*; D007475:Ion Exchange Resins / Q000737:chemistry; D009153:Mutagens / Q000633:toxicity; D009820:Ohio; D010865:Pilot Projects; D045483:Rivers / Q000737:chemistry; D018675:Toxicity Tests / Q000379:methods*; D014466:Ultraviolet Rays; D060753:Water Quality
D004202:Disinfectants; D060766:Drinking Water; D007475:Ion Exchange Resins; D009153:Mutagens; D002713:Chlorine