Incidence of chromosomal aberrations and micronuclei in cave tour guides

An analysis of structural chromosomal aberrations (SCA) and micronucleus te sts (MN) were performed in 38 subjects, cave tour guides and in appropriate control group. The dominant type of chromosomal aberrations in tourist guides were chromos omal breaks (0.013 per cell) and acentric fragments (0.011 per cell). In th e control group, these aberrations were present up to 0.008 on cells. Considering the analysed cells of the guides in total (33,556), the inciden ce of dicentric and rings range is below 0.0008 on cells, even though three dicentric and ring chromosoms were found already in the first 1000 in vitr o metaphases of some guides. Only 0.0003 dicentrics and neither other trans locations were found in control group (ambiental exposure). The incidence of micronuclei in cytokinesis blocked lymphocytes ranged from 12-32 per 500 CB cells in the cave tour guides and from 4-11 per 500 CB ce lls in control group. Measurements of radon and its daughters were performed at different locatio ns in the cave. Annual doses from 40-60 mSv were estimated per 2000 work ho urs for cave guides. The changes found in the genome of somatic cells may be related to the expo sure doses of radon and its daughters, although smoking should not be ignor ed.