Journal of School of Public Health and

Background and Aim: Exposure to hexavalent chromium in plating operations is associated with skin ulceration, contact dermatitis, respiratory tract irritation, cancer, and kidney damage. We investigated the possibility of using biological monitoring to assess exposure to hexavalent chromium in chrome-plating workers. We compared mean Cr6 concentrations in the breathing zone plus urine chromium, β2 microglobulin (B2M), and N-acetyl-B-D- glucosaminidase (NAG) at the end of the working shift. Then we assessed the correlation between exposure to hexavalent chromium and biological indicators.

Materials and Methods: This study involved 45 chrome platers (Cases) and 40 zinc platers (Controls) in Isfahan. Air and urine samples were collected at the end of the work shift. Measurement of Cr6 concentrations in the workers' breathing zone was performed using the NIOSH Methods 7600. Urine Cr levels were determined by atomic absorption spectrophotometry, with a graphite furnace (Shimadsu, AA680). B2M and NAG were measured by Kits.

Results: Overall, geometric mean of hexavalent chromium concentrations in the breathing zone was significantly higher among chrome platers (14.577 μg/m3) compared to zinc platers (0.862 μg/m3, p<0.001). Moreover, the mean urine Cr concentrations were higher in chrome platers (9.198 vs. 1.811 μg / g creatinine, p<0.001). Similarly, there were significant differences between mean NAG in chrome platers (12.608IU/gr creatinine) and zinc platers (6.824 IU/g creatinine, p<0.001). Differences in B2M concentrations were not significant (p>0.05). A significant correlation was found between Cr6 concentrations in the chrome platers' breathing zone and their urinary chromium levels (r= 0.838, p<0.001). A similar association was found between concentrations of Cr6 and NAG in the breathing zone (r= 0.304, p<0.05).

Conclusion: As urinary B2M concentration did not change significantly, it may not be a sensitive indicator in evaluating exposure to hexavalent chromium. There were significant differences between mean urinary Cr and NAG concentrations in the two groups. The significant correlations between Cr and NAG concentrations indicate that these markers may be suitable indicators of exposure to hexavalent chromium. Our results indicate that NAG is an early indicator of renal dysfunction in chrome platers.

  Background and Aim: Exposure to heavy metals always causes serious health problems in people working in the industry. Heavy metals may interfere with enzyme functioning or accumulate in specific body organs, leading to various health problems. Cadmium is a toxic heavy metal widely used in various industries and, therefore, workers in metal industries are at risk of exposure to it.

  Materials and Methods: A solid-phase sorbent was synthesized and factors influencing its sorption and elution steps were optimized (R>95%). The validated sorbent (chemically, physically and as regards reproducibility) was used to determine the cadmium content of the worker`s urines.

  Results: Optimized conditions for sorption and elution step were found to be as follows: pH= 7 sorption and elution time (both)= 5 min elution volume= 6 mL, and elution concentration= 2 mol L^-1. The great selectivity and the nano-particle size of the sorbent resulted in its highly precise performance (0.6ppb) and high validity and accuracy (CV<3%).

  Conclusion: Using the nano-magnetic sorbent technique and some such laboratory methods as flame atomic absorption spectroscopy, one can easily measure trace amounts of heavy metals in urine. This technique is relatively less expensive and rapid since, when using it, one can omit the filtration and centrifugation steps.