Monitoring of chromium and nickel in biological fluids of stainless steel welders using the flux-cored-wire (FCW) welding method

Abstract

Objective: This study was undertaken to investigate the exposure to chromium (Cr) and nickel (Ni) in flux-cored wire (FCW) welders welding on stainless steel (SS). Method/design: Seven FCW welders were monitored for 3 days to 1 workweek, measuring Cr and Ni in air, blood, and urine. The welders were questioned about exposure to Cr and Ni during their whole working careers, with emphasis on the week of monitoring, about the use of personal protective equipment and their smoking habits. Results: The air concentrations were mean 200 μg/m³ (range 2.4–2,744) for total Cr, 11.3 μg/m³ (<0.2–151.3) for Cr^VI, and 50.4 μg/m³ (<2.0–416.7) for Ni during the workdays for the five welders who were monitored with air measurements. The levels of Cr and Ni in biological fluids varied between different workplaces. For Cr in whole blood, plasma, and erythrocytes, the mean levels after work were 1.25 (<0.4–8.3) and 1.68 (<0.2–8.0) and 0.9 (<0.4–7.2) μg/l, respectively. For Ni most of the measurements in whole blood and plasma were below the detection limits, the mean levels after work being 0.84 (<0.8–3.3) and 0.57 μg/l (<0.4–1.7), respectively. Mean levels for Cr and Ni in the urine after work were 3.96 (0.34–40.7) and 2.50 (0.56–5.0) μg/g creatinine, respectively. Conclusion: Correlations between the Cr^VI levels measured in air and the levels of total Cr in the measured biological fluids were found. The results seem to support the view that monitoring of Cr in the urine may be versatile for indirect monitoring of the Cr^VI air level in FCW welders. The results seem to suggest that external and internal exposure to Cr and Ni in FCW welders welding SS is low in general.