Evaluation of Workers' Exposure to Crystaline Silica Particles in Some Factories of Mazandaran Province.

Background and purpose: Workers' exposure to respirable silica particles especially free crystalline silica in workplace could result in some dangerous diseases such as silicosis or lung fibrosis. This study was carried out to evaluate the workers' exposure to free crystalline silica particles in some industries using the infrared spectrophotometery method. Materials and methods: In this cross sectional study respirable silica dust was collected from workers' breathing zone using personal sampling device and a cyclone separator with a PVC filter. Then samples containing silica were analyzed by infrared spectrophotometery method based on NIOSH method 7602. Results: The mean of exposure to respirable silica particles within the workers' breathing zone in four industries was considerably higher than the threshold limit value recommended by ACGIH. Workers' exposure to crystalline silica particles ranged from 0.03 mgm-3 to 0.57 mgm-3 and there was a significant difference between the mean of respirable particle concentrations within the workers' breathing zone. Conclusion: Individuals working in asphalt production, foundry, sand and gravel mining and brick manufacturing are exposed to crystalline silica particle more than the standard level. Hence, in order to prevent silica related diseases more emphasize on health and safety issues are of great importance. [ABSTRACT FROM AUTHOR]