DAIRY-CATTLE AS A BIOINDICATOR OF EXPOSURE TO GENOTOXIC SUBSTANCES INA HEAVILY POLLUTED AREA IN NORTHERN BOHEMIA

The exposure of dairy cattle to genotoxic agents in two districts with different levels of environmental pollution was estimated using cytog enetic analysis of bovine peripheral lymphocytes. The Teplice district represented an industrialized area where the air pollution rate is ex tremely high mainly in the winter, and the Prachatice district - an ag ricultural area with a relatively low level of pollution, The Ames tes t was used to examine feed samples for the content of mutagenic substa nces, Cows in the Teplice district showed a significantly higher count of aberrant cells (4.83 +/- 2.36) than cows in the Prachatice distric t (3.63 +/- 2.12). The sum of revertants induced by rinsings or extrac ts of feeds in both of the two test strains (Salmonella typhimurium TA 98 and TA 100) was significantly higher in the district of Teplice th an in the district of Prachatice. The percentages of findings with mut agenic responses were 56.3 and 34.8% for the districts of Teplice and Prachatice, respectively. No mutagenic activity was found in milk samp les collected in any of the districts. Apparently, the cows kept in th e Teplice district were more exposed to genotoxic substances than the cows in the Prachatice district. The major source of this exposure was probably fresh fodder contaminated by industrial emissions. (C) 1997 Elsevier Science B.V.