22 Evaluation of Occupational Exposure to Respirable Crystalline Silica in Processing of Artificial Stone

Abstract Introduction Clusters of silicosis cases related to the fabrication of quartz conglomerate products and accessories for the furnishing of kitchens and bathrooms are recently reported. The aim of this study was to evaluate the exposure to airborne respirable dust and crystalline silica (RCS) in a company specialized in the production of quartz conglomerates countertops and to investigate the effectiveness of introduced preventive measures (wet finishing, increasing of exhaust ventilation, closing in cabins some of the sanding and finishing operations). Materials and Methods The study was carried out on 51 workers involved in cutting and finishing operations in four facilities. Exposure to respirable dust was evaluated using GS3 cyclones positioned at the breathing zone level for the entire duration of the work shift. RCS content was measured by X-ray diffractometric analysis. Results and Discussion Respirable dust levels were in the range 0.046-1.154 mg/m3 (mean 0.160 mg/m3) with RCS levels within the range <0.003-0.098 mg/m3 (mean 0.022 mg/m3). All RCS levels were lower than the Italian OEL of 0.100 mg/m3 and the 22% above the more restrictive ACGIH-TLV of 0.025 mg/m3. Statistically higher levels were found in correspondence with finishing operations than in cut operations (p<0.05) and during dry operations than in wet (p=0.02). RCS levels were lower than those found in the past before the introduction of preventive technical measures where RCS levels were up to 0.744 mg/m3. Although there was a decisive reduction in exposure levels compared to what was observed in the past, the data still showed a risk condition for some activities. Board of the Italian Association of Industrial Hygienists (AIDII). Her scientific activity is documented by over 80 printed publications both as articles in Journals and contributions to National Congresses.