Objective To investigate the influence and interaction of mixed air pollution exposure and relative telomere length (TL) on the risk of non-smoking female lung cancer (NFLC).

Methods From August 2017 to August 2021, non-smoking women, aged 18-79 years, who were newly diagnosed with lung cancer were enrolled as case group, and a control group was also established. A structured questionnaire was used to collect the general demographic features, exposure factors, and family history of the subjects, and air pollution exposure (including passive smoking, soot and oil smoke exposure, incense burning exposure, occupational exposure, and outdoor work) was calculated based on the information collected through the questionnaire. Real-time quantitative polymerase chain reaction and the relative quantitative method were used to measure TL. Weighted quantile sum (WQS) regression was used to evaluate the impact of mixed air pollution exposure on the risk of NFLC, and a logistic regression analysis was used to investigate the interaction between air pollution and TL on the risk of NFLC.

Results A total of 1 315 subjects were finally included, with 634 in the control group and 681 in the case group. There were statistically significant differences in area, body mass index, number of pregnancies, family history of cancer, and passive smoking between the case group and the control group (P<0.05). There were no statistically significant differences in age, ethnicity, highest level of education, and TL between the case group and the control group (P>0.10). Compared with the control group, the difference in TL was marginally statistically significant in both squamous lung cancer group and small cell lung cancer group (P<0.10). WQS regression showed statistically significant effects of mixed air pollution exposure on the risk of NFLC, lung adenocarcinoma, and non-small cell lung cancer (P<0.001). For every 1 decile increase in mixed air pollution exposure the risk of NFLC, lung adenocarcinoma and non-small cell lung cancer increased by 60% (adjusted OR=1.60, 95%CI: 1.17-2.22), 82% (adjusted OR=1.82, 95%CI: 1.21-2.75) and 121% (adjusted OR=2.21, 95%CI: 1.39-3.56), respectively. The multiple logistic regression analysis showed no multiplicative and additive interaction between mixed air pollution exposure and TL on the risk of NFLC.

Conclusion Both mixed air pollution exposure and TL are associated with the risk of NFLC, and this study does not find the interaction between air pollution and TL on the risk of NFLC.