Page 113 - Ebook-Book JCMS 2025

Effect of long-term Exposure to Particulate Matter to Risks
of Lung Cancer in Non-smokers: A Systematic Review and
Meta-analysis
Nutwara Kijthammarat1, Krittin Prechachaisurat1
, Sasatorn Sirikunsathit1, Krittitee Tangthai1
,
Sakditat Ittiphisit2, Nitipatana Chierakul3, Tanawan Kongmalai3, Roongnapa Khampang2
,
Juthamas Prawjaeng2, Varalak Srinonprasert3*
1 Faculty of Medicine, Siriraj Hospital, Mahidol University
2 Siriraj Health Policy Unit, Faculty of Medicine, Siriraj Hospital, Mahidol University
3 Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University
*Corresponding Author E-mail: varalaksi@gmail.com
Background: Abstract
Particulate matter (PM) has emerged as a global health urgency. Previous meta-analyses
revealed that exposure to particulate matter correlated with lung cancer. However, there is
still a lack of studies specifically in non-smokers. This meta-analysis aims to evaluate the
impact of long-term exposure to particulate matter on the incidence and mortality of lung
cancer in non-smokers.
Methods: We systematically searched PubMed, Embase, CINAHL, OVID and Scopus for cohort
studies reporting hazard ratio (HRs) or risk ratio (RRs) of lung cancer incidence or mortality
in non-smokers, associated with 10 µg/m3 increment in PM 2.5 or PM 10 (or convertible).
Risk of bias (RoB) was assessed with the Newcastle-Ottawa Scale. Meta-analyses were
conducted using a random-effects model to calculate pooled risk estimates. We also
attempted to conduct corresponding meta-analyses for lung cancer subtypes.
Results : A total of 25 studies (24 low RoB, 1 moderate RoB) with a non-smoker population size
of 7,041,264 were included. The pooled HRs for lung cancer incidence and mortality
associated with a 10 µg/m3 increment of PM 2.5 were 1.21 (95% CI: 1.07-1.37) and 1.32
(95% CI: 1.15-1.50). For PM 10, the pooled HRs for lung cancer incidence and mortality
were 1.10 (95% CI: 0.91-1.33) and 1.41 (95% CI: 1.29-1.53). The association between PM
2.5 and lung adenocarcinoma was not statistically significant, albeit a limited number of
studies. No differences in risk between subgroup analysis in terms of WHO regions and
exposure assessment methods were observed.
Conclusion: Risk of long-term exposure to PM 2.5 and PM 10 on lung cancer mortality in non-smokers
was affirmed in this meta-analysis. For a common subtype of lung adenocarcinoma, the
association seemed to be not obvious. This limitation could be addressed through improved
accuracy of pollutant measurement, cancer diagnosis, and residential migration patterns.
Harmony in health: Innovation for Sustainable Medicine
111