Assessment of Occupational Exposure to Silica Dust and Respiratory Effects in Exposed Workers in one of the Ceramic Products Industry

Abstract

Abstract. Occupational exposure to respirable crystalline silica can increase the incidence of irreversible pulmonary complications. Ceramic and tile production is one of the industries in which workers are exposed to crystalline silica. This study aimed to evaluate the exposure level of respirable dust and silica and its association with pulmonary complications in the ceramic production industry. In this cross - sectional analytic study, all of 39 employees of the manufacturing ceramic products were introduced at the study. Required information were gathered by questionnaire, spirometry testing for evaluation of pulmonary function and air sampling and analysis in accordance with standard procedure, NIOSH 7601, were done. The data analysis was performed by using SPSS, version 16.The average concentration of respirable dust and crystalline silica were 1.53 mg/m3and 0.003 mg/m3, respectively. Pulmonary function of subjects showed that 77.8% of subjects had the normal pattern, 3.7%, restrictive pattern and 18.5 percent had obstructive pattern. The prevalence of respiratory symptoms in workers exposed to silica showed the results as follow: the prevalence of phlegm (37%), shortness of breath during activity (25.9%), frequent cough (18.5%), chest tightness and shortness of breath (14.8%) and wheezing (7.4%). Between silica exposure and respiratory symptoms was significant relationship (P < 0.05). Mean values of FVC and FEV1 in exposed subjects were significantly lower than non-exposed individuals (P < 0.05). Also the correlation between respiratory symptoms and parameters of age and experience was significant (P < 0.05).Exposure to silica-containing respirable dust in the studied industry led to changes in some lung functions, respiratory symptoms and complications. So, the preventive measures to prevent long-term and serious complications are necessary.