Environmental genotoxicity evaluation using a micronucleus test and frequency of chromosome aberrations in free-living small rodents

An in vivo micronucleus (MN) test in peripheral erythrocytes and frequency of bone marrow cells with chromosome aberrations in free-living small rodents, chronically exposed to heavy metal pollution were used for detection the genome response to genotoxic agents in the environment. Yellow-necked mice (Apodemus flavicollis), common vole (Microtus arvalis) and East-Mediterranean (Macedonian) mice (Mus macedonicus) were collected in a polluted region near lead-zinc smelting factory – Asenovgrad (South Bulgaria, near Plovdiv) and in the background region of the Strandzha National Park (Southeastern Bulgaria). Mean frequencies of MN and aberrant cells in the individuals from the impact region were significantly higher compared to the mean frequencies from the same species in the background region. The comparative analysis of results confirmed that the species Apodemus flavicollis and Microtus arvalis may be suitable bioindicators for biomonitoring studies using MN test and chromosome aberrations. Obtained results demonstrated that the in vivo MN test may be a sensitive end-point for the detection of genotoxity that may result from the simultaneous action of several metals and may be useful as a biomarker of environmental stress in situ.