Increased risk of obstructive pulmonary disease in tunnel workers

Background - Tunnel workers are exposed to gases and particles from blastin g and diesel exhausts. The aim of this study was to assess the occurrence o f respiratory symptoms and airflow limitation in tunnel workers and to rela te these findings to years of exposure. Methods - Two hundred and twelve tunnel workers and a reference group of 20 5 other heavy construction workers participated in a cross sectional invest igation. Exposure measurements were carried out to demonstrate the differen ce in exposure between the two occupational groups. Spirometric tests and a questionnaire on respiratory symptoms and smoking habits were applied. Ato py was determined by a multiple radioallergosorbent test (RAST). Radiologic al signs of silicosis were evaluated. Respiratory symptoms and lung functio n were studied in relation to years of exposure and adjusted for smoking ha bits and atopy. Results - Compared with the reference subjects the tunnel workers had a sig nificant decrease in forced vital capacity (FVC) % predicted and forced exp iratory volume in one second (FEV1) % predicted when related to years of ex posure. Adjusted FEV1 decreased by 17 mi for each year of tunnel work expos ure compared with 0.5 mi in outdoor heavy construction workers. The tunnel workers also reported significantly higher occurrence of respiratory sympto ms. The prevalence of chronic obstructive pulmonary disease: (COPD) was 14% in the tunnel workers compared with 8% in the reference subjects. Conclusion - Exposure to dust and gases from diesel exhaust, blasting, dril ling and rock transport in tunnel work enhances the risk for accelerated de cline in FEV1, respiratory symptoms, and COPD in tunnel workers compared wi th Other heavy construction workers.