Evaluation of Worker's Exposure to Crystaline Silica Particles in Factories Which are Using sand and Gravel Mazandaran Province

Background and Worker's exposure to respirable silica particles and in particular free crystalline silica in the workplace causes some disorders such as silicosis or lung fibrosis. This study was carried out to evaluate the worker's exposure to free crystalline silica particles using the infrared spectrophotometery method in some industries. In this cross sectional study respirable silica dust was collected from worker's breathing zone using a personal sampling device and a cyclone separator with a PVC filter. Silica samples then were analyzed using a infrared spectrophotometery recommended by NIOSH in method number 7602. Mean personal exposure to respirable silica particles within the worker's breathing zone in 4 industries were considerably higher than the threshold limit value recommended by ACGIH. Worker's exposure to crystalline silica particles ranged from 0.03 mgm-3 to 0.57 mgm-3 and there was a significant difference between mean respirable particle concentrations within the worker's breathing zone in these industries. Individuals who are working in asphalt production, foundry work, and sand and gravel mining and brick manufacturing are exposed to crystalline silica particle concentration higher than the standard level. Therefore, engineering and hygiene methods of dust control should be applied for the reduction of exposure and prevention of silica related disorders.