Our study is focused on the extent of any such chromosomal aberrations with respect to chromium levels in the blood of welders as well as on the tentative modulating role of polymorphisms in DNA repair genes XPD Lys751Gln, XPG Asn114His, XPC Lys939Gln, hOGG1Ser326Cys and XRCC1 Arg399Gln on chromosomal damage.