Genotoxicity Detection in Drinking Water by Ames Test, Zimmermann Test and Comet
AssayBarbara Lah,a Brigita Žinko,a Tatjana
Tišler,b and Romana Marinšek Logara*
a Biotechnical Faculty,
Zootechnical Department, University of Ljubljana, Groblje 3, 1230 Domžale.
E-mail: romana.marinsek@bfro.uni-lj.si
b National Institute of
Chemistry, Hajdrihova 19, 1001 Ljubljana
Abstract
Drinking water of good quality is the primary requirement from public health
point of view. Over past two decades, many studies have reported the presence of
various hazardous compounds in drinking water that may cause long-term health
effects, e.g. gastrointestinal and urinary tract cancers. Sources of drinking
water contamination are industrial and agricultural activities, disinfection by-products
and transportation. Monitoring of drinking water in Slovenia is based on regular
physico-chemical and microbiological assays according to European Community
legislation. Since physico-chemical analyses do not provide enough information
about biological effects of pollutants, we are studying the possibilities of
including biological tests into drinking water monitoring. In the present work
we tested three genotoxicity assays with water collected at three different
sampling points in Ljubljana drinking water region. The Ames test was performed
with and without metabolic activation using bacterium Salmonella typhimurium
TA97a, TA100 and TA1535 strains. The same samples were tested with the yeast
Saccharomyces cerevisiae strain D7, with and without metabolic activation in
Zimmermann test. Parallel genotoxicity evaluation on the samples was carried out
as alkaline version of the comet assay performed with human HepG2 cell line.
Original and concentrated water samples were tested in all bioassays following
the chemical analyses for pesticides and nitrate. There was no indication of
genotoxic activity in any of drinking water samples according to Ames and
Zimmermann test. On the contrary, the results of the comet assay revealed low
genotoxicity in most of the drinking water samples. As only the Comet assay
proved to be sensitive enough to detect genotoxicity, we propose to include it
in regular biomonitoring of drinking water.
Key words: drinking water, physico-chemical analyses, in vitro
genotoxicity bioassays