The Dose-Effect and Risk Assessment on Lung Function Decline of Long-Term Co-Exposure to BTEXS in Petrochemical Workers in Southern China

Background: Lung is one of the primary target organs of benzene, toluene, ethylbenzene, xylene, and styrene(BTEXS). However, information on potential dose-effect and risk assessment on lung function decline of exposures to BTEXS are limited. We determined the association between BTEXS individuals and mixtures with lung function decline and identified the key pollutants. Methods: 635 petrochemical workers from a petrochemical plant in southern China with valid lung function tests were included. We employed generalized line regression models and generalized weighted quantile sum (gWQS) regression models to estimate associations of BTEXS individual homologs and mixtures with lung function parameters and ventilation dysfunction risk. The wqs index was a sum of weighted quartiles for BTEXS homologs. The modification effect of smoking status, gender, and body mass index(BMI) were also explored. Results: We found a significant association between BTEXS individuals and decline in forced vital capacity percent predicted(FVC% of predicted) and increase in the risk of lung ventilation dysfunction(LVD). The wqs index was inversely associated with the FVC% of predicted (β=-1.136; 95% CI-2.202, -0.070; for one quartile increase), vital capacity percent predicted(VC% of predicted) (β=-1.298; 95%CI: -2.313, -0.282), and forced expiratory volume in 1 second percent predicted (FEV1% predicted) (β=-1.230; 95%CI: -2.265, -0.195). The wqs index was also significantly associated with LVD overall [odds ratio(OR)=1.362; 95% CI: 1.129, 1.594] and in the subtypes: mixed ventilation dysfunction (MVD) (OR=1.323; 95% CI: 1.084, 1.562) and restrictive ventilation dysfunction(RVD)(OR=1.394; 95% CI: 1.096, 1.692). Generally, the most heavily weighted homologs in lung function impairment were xylene, benzene, and toluene. We also observed a significant negative interaction effect between smoking with RVD risk. Conclusion: BTEXS individuals and mixtures both were significantly associated with lung function damage and smoking exacerbates the impairment. Results from gWQS models indicated xylene, benzene and toluene played more crucial roles in the progress. Funding Information: This work was supported by the National Science Foundation of China (81973006, 81973076) and the National Science Foundation of Guangdong province (2021A1515011669). Declaration of Interests: All authors declare no conflicts of interest. Ethics Approval Statement: The Ethics Committee of Medical Research, School of Public Health, Sun Yat-sen University approved the study protocol (No.2020118). And all the participates signed the informed consent in the questionnaire interview.