The Effect of Exposure to Rubber Production Emissions and Physical Activity on Pulmonary Function Indices among Tyre Manufacturing Employees in Iran

BACKGROUND: Exposure to rubber production emissions can cause respiratory problems. There is some evidence that physical activity might have protective effects against respiratory obstruction. AIMS: This study, was investigated the effect of physical activity on potential respiratory damages induced by the exposure to rubber production chemicals. METHODS: This cross-sectional study was carried out during 2019 on the staff of a rubber manufacturing company in Khorasan, Iran. Employees of a rubber manufacturing company were recruited in this cross-sectional study (n = 385), and were classified into exposed (n = 266) and unexposed (n = 119) groups. Baecke Physical Activity Questionnaire (BPAQ) was used to assess the level of physical activity. Logistic regression was used to evaluate the effects of exposure, physical activity and confounding variables on pulmonary function test (PFT) results. RESULTS: Work, leisure time and total physical activity scores were significantly higher in exposure group compared with control group subjects. Although no significant differences were observed between the exposure and control groups in most spirometric parameters, FEF25-75 was significantly lower in the exposure group (P = 0.035). Abnormal PFT was observed in 93 participants (24.2%) and in the multivariate model was significantly associated with exposure (OR = 1.80, CI95: 1.01-3.22) and age (OR = 1.08, CI95: 1.02-1.14) but not physical activity score. CONCLUSION: Exposure to rubber manufacturing chemicals nearly doubles the odds of abnormal PFT, and the self-reported level of physical activity had no protective effect against these occupational hazards.