Mortality among Welders Exposed to High and to Low Levels of Hexavalent Chromium and Followed for More Than 20 Years.

Hexavalent chromium particles are generated in the welding of stainless steel. A cohort consisting of 233 welders working on stainless steel and exposed to high levels of chromium was selected. According to an earlier survey, the hexavalent chromium exposures of such welders are often above 20 µg/m(3). Another cohort consisting of 208 railway track welders exposed to low levels of chromium was also selected. The participants of both cohorts had welded for at least five years between 1950 and 1965 and were followed for mortality until December 1992. Among the welders exposed to high levels of chromium, six deaths due to pulmonary tumors occurred. This number is higher than the two deaths that occurred among the welders exposed to low levels of chromium and the corresponding mortality of the general population, but not significantly higher. Thus, exposure to stainless steel welding fumes might increase the incidence of pulmonary tumors.