Air exposure assessment and biological monitoring of manganese and other major welding fume components in welders

Abstract

In a cross-sectional study, 96 welders were compared with 96 control subjects. Also 27 former welders, all diagnosed as having manganism, were examined. Exposure to welding fumes was determined in the 96 welders, while the concentration of elements in whole blood and urine was determined in all subjects. The geometric mean (GM) concentrations of manganese (Mn) and iron in the workroom air were 97 microg m(-3) (range 3-4620 microg m(-3); n=188) and 894 microg m(-3) (range 106-20 300 microg m(-3); n=188), respectively. Thus the Mn concentration in the workroom air was on average 10.6% (GM) of that of the Fe concentration. No substantial difference was observed in the air Mn concentrations when welding mild steel as compared to welding stainless steel. The arithmetic mean (AM) concentration of Mn in whole blood (B-Mn) was about 25% higher in the welders compared to the controls (8.6 vs. 6.9 microg l(-1); p < 0.001), while the difference in the urinary Mn concentrations did not attain statistical significance. A Pearson's correlation coefficient of 0.31 (p < 0.01) was calculated between B-Mn and Mn in the workroom air that was collected the day before blood sampling. Although the exposure to welding fumes in the patients had ceased on average 5.8 years prior to the study (range 4 years-7 years), their AM B-Mn concentration was still higher than in referents of similar age (8.7 microg l(-1) vs. 7.0 microg l(-1)). However, their urinary concentrations of cobolt, iron and Mn were all statistically significantly lower.

Levels and predictors of airborne and internal exposure to manganese and iron among welders

“…28 A lower average concentration of 8.6 mg/l in Russian welders might be explained by a longer time lag between shift exposure and blood sampling. 21 Higher means were reported in alloy-production workers (12 mg/l). 26,29,30 A receiver operating characteristic analysis determined 10 mg/l as 95 th % percentile in a group of unexposed South African workers in comparison to smelters.…”

“…10 The median concentrations of respirable Mn (62 mg/m 3 ) and inhalable Mn (73 mg/m 3 ) were comparable to a median of 60 mg/m 3 from 114 Mn measurements of the database of The Welding Institute (accessible from http://www.twi.co.uk) and to a geometric mean of 97 mg/m 3 in 96 Russian welders. 21 Due to the skewed data distribution, the arithmetic mean of respirable Mn was 258 mg/m 3 in our data set and corresponds to 270 mg/m 3 reported as mean Mn from the welding database of the Occupational Safety and Health Administration (OSHA). 10 Although large collections of welding-fume measurements have been assembled, we could not identify results on comprehensive side-by-side measurements of particle size-specific Mn concentrations among welders in the literature.…”

“…We found significant associations of the post-shift concentrations of MnB and SF with the airborne concentrations of the parent metal in the respirable particle fraction of the welding fumes measured during the shift. Increased concentrations of MnB have been frequently observed in exposed vs non-exposed workers, for example in welders 21 and in smelter workers. 25,26 We determined about 10 mg/l as median MnB in German welders that was similar to the average concentration reported for US welders in bridge building 27 but lower than in Korean welders (15.5 mg/l).…”

Personal Exposure to Metal Fume, NO2, and O3 among Production Welders and Non-welders

“…The high variability may be attributed to large sample sizes 25,26) or to the fact that one study was on flux-cored welders 23) , as the fluxcored process is known to create generally higher and more variable exposures than processes using shielding gas. The high concentrations of Cr and Ni reported may also have been related to process parameters or may have been related to welding on high Cr and Ni containing stainless steel.…”

Using Ionizing Radiation to Determine Trace Element Content in Living Human Subjects

“…Prolonged high level to respirable Mn has been associated with a movement disorder somewhat like Parkinson's disease 58) . Lower levels of exposure have been associated with some loss of the ability to perform neurocognitive tasks.…”