PM 2.5 and risk of lung cancer and associated mortality: An umbrella meta-analysis.

e20012 Background: PM 2.5, particulate matter with a diameter of 2.5 micrometers or less, is a major contributor to lung cancer and associated mortality. Epidemiological studies reveal a concerning trend, with each 10 micrograms per cubic meter increase in PM 2.5 associated with a 15% higher risk of lung cancer and a 13% increase in mortality rates, underscoring the significant burden it imposes on public health systems globally. We aimed to evaluate the odds of association between environmental exposure to PM 2.5 and the risk of lung cancer and associated mortality. Methods: We performed a systematic review and umbrella meta-analysis using studies containing quantitative data on PM 2.5 and lung cancer. We used PRISMA guidelines and the MOOSE protocol using PubMed and MeSH terms like PM 2.5, non-small cell cancer, lung cancer, pollutants, particulate matter 2.5, and environmental factors. We had excluded non-full-length articles, non-meta-analysis studies, and non-human studies. RavMan 5.4 was used, and generic inverse variance methods with mixed effect models were applied to identify a pooled risk ratio with a 95% confidence interval. Forest plots were obtained, and sensitivity analysis was performed based on funnel plots and I 2 (heterogeneity) values. Results: Of the 245,529 articles evaluated for the quality of the data, 99 met the inclusion and exclusion criteria. Out of 99, we used six articles to derive the quantitative data. In umbrella meta-analysis, PM 2.5 exposure was associated with a 1.16 times higher risk (95%CI: 1.1-1.22, p<0.00001, I 2 =0%) of lung cancer and a 1.22 times higher risk of non-lung cancers (95%CI: 1.15-1.30, p<0.00001, I 2 =0%). PM 2.5 was associated with non-significant higher mortality (RR: 1.06, 95%CI: 0.99-1.13, p=0.09, I 2 =97%) with leave-on-out analysis (excluding Chen et al.) significant association between mortality and PM 2.5 (RR: 1.08, 95%CI: 1.06-1.10, p<0.00001, I 2 =0%). Conclusions: Our umbrella meta-analysis shows a significant risk of lung cancer and mortality from PM 2.5 exposure. Further investigation and increased consciousness are necessary to mitigate the risk of lung cancer associated with this pollutant.