Cumulative Occupational Exposure To Asbestos And Respiratory Health Of Brake Mechanics In Colombia

Abstract

Introduction Asbestos exposure causes several respiratory diseases including asbestosis, mesothelioma, and cancer of the lung, larynx, and ovaries. Asbestos containing brake linings and pads are still distributed in Colombia. Since 2010, asbestos exposure levels for different brake repair tasks have been determined conducting sampling campaigns in shops located in Bogotá. This study analyzed respiratory health and cumulative asbestos exposure of 35 brake mechanics from Bogotá, Colombia. Methods Using a standardized questionnaire, occupational histories from 35 brake mechanics were collected. Based on previous air sampling results, cumulative asbestos exposure was calculated for each mechanic. Respiratory health of each mechanic was evaluated with pulmonary function tests (flow-volume curve with bronchodilator and carbon monoxide diffusing capacity [DLCO]), chest X-rays, and CT Scans. Results All mechanics were males, 26-80 years old. Using chest CT Scans, 18 types of abnormalities were identified. Nineteen mechanics (54%) showed no abnormalities. Nine mechanics (26%) had abnormalities that are suggestive of asbestos exposure, including parenchymal bands (20%), reticular abnormalities (9%), and calcified pleural plaques (3%). Four mechanics had spirometry with obstructive pattern and one decreased DLCO. Cumulative asbestos exposure for the entire occupational history of each mechanic ranged between 65 - 8095 f/cc (average f/cc-year * total # of years of work). A marginal significant association was identified between asbestos- abnormalities and the number of years of work, adjusted for smoking and age when job started (OR=1.12, p=0.053). No significant association between asbestos-abnormalities and cumulative asbestos exposure was observed (OR=1, p=0.18). Conclusions The results of this study suggest that these workers could be at excess risk of developing asbestos related diseases. New methods for retrospectively quantifying asbestos cumulative exposure are needed.