Evaluation of factors affecting the performance of vacuums used to control respirable crystalline silica in the British Columbia construction industry

Workers in the construction industry are known to be at risk of high exposures to respirable crystalline silica (RCS). Local exhaust ventilation (LEV) has been proposed by regulators as a primary method to control RCS exposure to construction workers. However, real-world data on the effectiveness of LEV in controlling RCS exposure is limited with available studies providing varying results. This study looks at the use and performance of vacuums, a common type of LEV available, used in conjunction with different hand tools on real-world constructions sites. A combination of study methods including field sampling, worker survey and simulated tests were used. During the field sampling, information regarding the vacuums, work environment conditions and dust exposure measurements were collected. These data were later used in regressions models to determine the determinants that strongly influenced the performance of the vacuums. The worker surveys provided information on the knowledge and attitude of workers. The simulated tests were used to corroborate information from the field sampling or to test specific scenarios where there is potential secondary dust exposure due to the use of vacuums. The study results show that the age and maintenance of the vacuums had the strongest effect on the airflow of the vacuum. However, while maintaining a sufficient airflow is important to ensure dust capture, the correlation of airflow with respirable dust exposure was weak. Both age and maintenance of the vacuums as well as environmental factors play a large part in determining the respirable dust exposure to the worker. It is recommended that all vacuum users are trained in both basic principles of ventilation as well as the standard operating procedure of the specific vacuum model being used. This is as each vacuum operates differently and may require different maintenance processes.Medicine, Faculty ofPopulation and Public Health (SPPH), School ofGraduat