Evaluation of Workers Exposure to Hexavalent Chromium Compounds in a Cement Industry

Background & objectives: Airborne particulate matters in the cement plant contain hexavalent chromium (HVCr) that, as an important harmful agent, would adversely affect worker’s health. This study was conducted to assess workers exposure to hexavalent chromium through monitoring of ambient air and workers blood samples in 2011. Methods: In a cross sectional study occupational exposure of 56 non-smoker workers was investigated. Inhalation exposure of subjects was monitored using personal pumps according to National Institute of Occupational Safety and Health method No 7600. After receiving subjects consent for blood donation, total chromium in packed red blood cells, serum and total blood were determined using Induced Coupled Plasma (ICP) method. Results: Personal exposure of workers to HVCr in the groups 1 (low exposure), 2(medium exposure) and 3 (high exposure) were measured respectively at the concentrations of 0.34±0.18, 17.47±22.18, and 86.59±269 µg/m3. Workers exposure in group 1 (grinding, crashing, and preheater) was significantly lower than the groups 2 (loading) and 3 (furnace maintenance) (p=0.001). Inhalation exposure of group 2 was also significantly lower than the group 3 (p=0.001). Chromium concentrations of blood samples in different groups were mostly below the detection limit of ICP method (1µg/L) utilized for analysis. Conclusion: Occupational exposures of 30 percent of group 2 and 50 percent of group 3 were higher than the corresponding Threshold Limit Value (50µg/m3)