Evaluation of Occupational Exposure and Biological Monitoring of Sand Washing Workers Exposed to Silica Dusts

The health of sand washing workers could be threatened by the crystalline silica dust exposure. The aim of this study was the evaluation of occupational and biological monitoring with crystalline silica dusts in the sand washing workers.
This was an analytical and cross-sectional study of 44 sand washing workers exposed to crystalline silica and also 63 municipality gardeners as a control group in the city of Dorood. Occupational exposure monitoring to respirable total dust and silica dust was performed according to the National Institute for Occupational Safety and Health (NIOSH) methods 0600 and 7602-respectively. Biological monitoring of worker's was carried out according to the Karatas method for the analysis of Malondialdehyde in the blood serum of exposed and control subjects. The informed consents were taken for obtaining blood samples of workers, according to the Helsinki Declaration. Statistical analysis of data was done using SPSS version 16. The statistical test of Pearson, t-tests and linear regression was applied.
The occupational exposure of 54.55% was exceeded the occupational exposure limit of Iran at the level of 3 mg/m3. The mean exposure of sand miners and control group to respirable silica dust was evaluated at 0.219 ± 0.177 and 0.010 ± 0.002 as mg/m3respectively. Occupational exposure of all sand washing workers was higher than the occupational exposure limit of Iran at the level of 0.025 mg/m3.The concentration of serum Malondialdehyde (MDA) exposed group and the control group were 36.64 ± 10.75 and 19.40 ± 4.68 as µM respectively.
Due to the positive correlation between exposure of sand washing workers to silica dust sand serum MDA among exposed group(P-value