Correlation of Chromium (VI) Concentration in Workers Breathing Zones and Total Chromium in Urine Samples of Electroplating Workers

Abstract

Majid Shahi*, Ali Asghar Farshad, Shahnaz Bakand and Fereshteh Eshaghzadeh

The aim of this research was to investigate the correlation between chromium (VI) concentration in the breathing zone of workers and total chromium in urine specimens as a biomarker of exposure in chromium electroplating workers. In chromium plating, different airborne concentrations of chromium (VI) can be released into the breathing zone of workers. For measurement of chromium (VI) concentration 69 air samples were collected by filtration technique and collected samples were analyzed using NIOSH method 7600. Air sampling from breathing zones was conducted by personal sampling method and further personal exposures to chromium VI was calculated as Time-Weighted Average (TWA) values. For biological monitoring total chromium in urine was measured using WHO method, also this method has been recommended by ATSDR. For this purpose 92 urine samples were collected and analyzed by atomic absorption method equipped with graphite furnace. Data analysis was performed using SPSS version 18 software. The average of chromium VI in worker’s breathing zones was obtained (16.90 ± 23.11 μg/m³). The average of increasing chromium concentration in end of workweek urine samples (8.67 ± 3.97 μg/L) was significantly higher than the average of end of shift samples (4.11 ± 2.57 μg/L). After regression analysis statistically significant correlation was obtained between airborne chromium VI in worker’s breathing zones and chromium in urine samples (e.g. R2=0.83, end of shift samples). The obtained results indicated that the determination of urine chromium content can be considered as an appropriate biomarker for biological monitoring of workers particularly for recent chromium exposure assessment.