RESUMO
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.
RESUMO
OBJECTIVES: This study was conducted to assess changes in spirometric parameters after protective interventions among workers at a chlorine production plant in Semnan, Iran during 2012-2016. METHODS: This quasi-experimental study included 100 workers at a chlorine production plant in Semnan during 2012-2016. Spirometric parameters (forced vital capacity [FVC], forced expiratory volume in 1 second [FEV1], FEV1/FVC, peak expiratory flow [PEF], and PEF occurring in the middle 50% of the patient's exhaled volume [PEF 25-75%]) were measured in all workers before the initial intervention in 2012. Protective interventions were then implemented for 4 consecutive years and the parameters were measured annually. A multivariable linear regression model was used to assess the factors affecting spirometric parameters before and after the protective interventions in SPSS version 24. RESULTS: The mean values of all spirometric parameters significantly increased after the protective interventions (p<0.05). Multivariable linear regression showed that age (ß=-0.40), body mass index (BMI) (ß=0.71; 95% confidence interval [CI], 0.11 to 1.31), and type of mask (ß=-7.88; 95% CI, -15.96 to -0.46) had significant effects on the mean difference in FVC. Similarly, age (ß=-0.35; 95% CI, -0.70 to -0.01), BMI (ß=0.80; 95% CI, 0.20 to 1.41) and type of mask (ß=-8.88; 95% CI, -16.98 to -0.79) had significant associations with the mean difference in FEV1. The type of mask (ß=-12.81; 95% CI, -25.01 to -0.60) had a significant effect on the mean difference in PEF. CONCLUSIONS: All spirometric parameters significantly increased in workers after protective interventions were implemented. Therefore, protective interventions to prevent respiratory disorders in workers exposed to chlorine gas are suggested.
