Effects of Chlorine Gas Exposure and Associated Factors on Spirometric Parameters in Detergent Industry Workers: a Four-Year Cross-Sectional Study

Background: This study aimed to determine the effects of chlorine gas exposure and the associated factors on spirometric parameters among detergent industry workers in Semnan, Iran. Materials and Methods: This four-year cross-sectional study was concocted on 100 workers of two detergent factories in Semnan, Iran. Two questionnaires were used for data collection. The first questionnaire included demographic and occupational information, and the second questionnaire included spirometric parameters, such as forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio, peak expiratory flow (PEF), and PEF 25-75%. The spirometric parameters were measured over four consecutive years by a trained technician. Next, to determine the effects of chlorine gas exposure and its associated factors on spirometric parameters, a generalized estimating equation (GEE) model was used. The correlation structure of GEE was considered to be autoregressive 1 (AR-1). Analyses were performed in STATA version 14. Results: All spirometric parameters showed a decreasing trend during 2012- 2015. The GEE model showed a significant association between chlorine gas exposure and all spirometric parameters; the beta-coefficients for the effect of exposure (year) on FVC, FEV1, FEV1/FVC ratio, PEF, and PEF 25-75% were - 4.51, -6.46, -4.27, -6.09, and -10.29, respectively. Also, this model demonstrated a significant association between smoking and FEV1, PEF, and PEF 25-75%; the beta-coefficients for the effect of smoking on these parameters were -5.64, -8.88, and -5.75, respectively. Additionally, the GGE model showed a significant association between the body mass index (BMI) and FVC and FEV1 (P<0.05); the beta-coefficients for the effect of BMI on these two parameters were - 0.59 and -0.48, respectively. Conclusion: The spirometric parameters showed a decreasing trend over time among detergent industry workers; this decline was more remarkable among individuals with a history of smoking. Therefore, it seems necessary to implement screening programs and periodic active examinations for these workers.