Evaluation of health and safety risks in municipal solid waste recycling plants

Designers and managers of recycling processing plants need to be informed a bout the inherent occupational health and safety risks; however, there are few studies in the literature describing these risks. Therefore, the object ives of this project were to document the biological, chemical, physical, a nd ergonomic risks in three household-waste recycling plants. Bioaerosols ( molds and bacteria) were measured using the methodology recommended by the American Society for Testing and Materials (ASTM). Chemical contaminants an d physical agents suspected of being present in this type of environment we re measured using the standard methods of the Quebec Occupational Health an d Safety Research Institute (IRSST). The ergonomic part of the study identi fied the work requirements and risk factors causing the workers' physical s ymptoms. In summer, the average concentrations of total bacteria were greater than t he Scandinavian guideline of 10,000 colony forming units per cubic meter of air (CFU/m(3)) in the receiving areas in plants 1 and 3, in the sorting ar eas of the three plants, and in shipping in plants 1 and 3. When the averag e concentrations of Gram-negative bacteria were compared to the Scandinavia n guideline of 1000 CFU/m(3) of air, only the sorting department in plant 2 in summer exceeded this value. Average indoor concentrations of molds that were statistically significantly greater than those measured in the upwind outdoor air were measured in all departments in plants 1 and 3, regardless of the season, and only in sorting in plant 2 during the summer. The only chemical contaminant measured at average concentrations greater than 50% of the Threshold Limit Values (TLVs) proposed by the American Conference of G overnmental Industrial Hygienists (ACGIH) was CO in the sorting departments in plants 1 and 2 during the winter. Noise exceeded the ACGIH TLV in plant 2. The workers' physical symptoms seem to be caused by the posture and eff ort required while remaining in a stationary position. Action must be focus ed on improving aspects such as work organization and personal protection a nd on informing citizens of the need for cleanliness of the material to be recycled.