Association between manipulation activities of asbestos containing brake products and respiratory abnormalities among brake mechanics

摘要

Introduction In Colombia, asbestos containing brake products (ACBP), which include brake linings and pads, are still distributed separated from the support. Riveters are a specific group of brake mechanics responsible for attaching ACBP to the supports, which require different manipulation activities including drilling, countersinking, riveting, beveling, grinding, and cutting, which release asbestos fibers. Thus, riveters can be exposed to high asbestos concentrations. A cohort of 56 riveters from Bogota, Colombia have been studied to determine variables from this group of workers that could be associated with respiratory health abnormalities. Methods A cohort of 56 riveters has been created. All workers had a comprehensive respiratory health evaluation. Workers answered a standardized occupational questionnaire. Daily asbestos exposure of each worker was estimated applying models previously validated models that only require as input variable the number of ACBP manipulated in a work shift. Cumulative asbestos exposure was calculated from work shift asbestos exposure estimations. Logistic regressions models were used to determine the association between respiratory health abnormalities and different variables related with labor history and smoking status of brake mechanics. Results Sixteen mechanics (28.57%) had pulmonary abnormalities that can result from asbestos exposure. Cumulative lifetime asbestos exposure for the 56 riveters ranged between 0.122-19.064 f/cc-year. Logistic regression models showed a marginal significant association between respiratory abnormalities and cumulative asbestos exposure (OR=1.139,p= 0.078), adjusted for the number of shops where the worker was employed (OR=0.509, p= 0.108), if the riveter had been continuously working in this occupation (OR=1.363, p= 0.698), and if the riveter was a smoker (OR = 0.478, p=0.276). Conclusion The results suggest that each additional f/cc-year cumulative fiber asbestos exposure was associated with a marginal significant increase in the odds of respiratory abnormalities. Each additional shop where the mechanic worked had a marginal protective effect on respiratory abnormalities.