CYTOGENETIC STUDIES OF STAINLESS-STEEL WELDERS USING THE TUNGSTEN INERT-GAS AND METAL INERT-GAS METHODS FOR WELDING

Cytogenetic damage was studied in lymphocytes from 23 welders using th e Tungsten Inert Gas (TIG), and 21 welders using the Metal Inert Gas ( MIG) and/or Metal Active Gas (MAG) methods on stainless steel (SS). A matched reference group I, and a larger reference group II of 94 subje cts studied during the same time period, was established for compariso n. Whole blood conventional cultures (CC), cultures in which DNA synth esis and repair were inhibited (IC), and the sister chromatid exchange (SCE) assay were applied in the study. For the CC a statistically sig nificant decrease in chromosome breaks and cells with aberrations was found far both TIG/SS and MIG/MAG/SS welders when compared with refere nce group II. A non-significant decrease was found for the correspondi ng parameters for the two groups of welders when compared with their m atched referents. A statistically significant negative association was found between measurements of total chromium (Cr) in inhaled air and SCE, and a weaker negative correlation with hexavalent Cr (Cr(VI)) in air. In conclusion, no cytogenetic damage was found in welders exposed to the TIG/SS and MIG/MAG/SS welding fumes with low content of Cr and Ni. On the contrary, a decline in the prevalence of chromosomal aberr ations was indicated in the TIG/SS and MIG/MAG/SS welders, possibly re lated to the suggested enhancement of DNA repair capacity at slightly elevated exposures.