Long-term exposure to ambient NO2 increase oral cancer prevalence in Southern China: a 3-year time-series analysis.

Abstract

Background: While the correlation between cancer and air pollutants is well-established, research on the delayed effects of NO₂ on oral cancer remains limited.

Methods: We collected data on nitrogen dioxide (NO₂) along with diagnosed cases of oral cancer in Guangxi, China, and analyzed the correlation between exposure to NO₂ and the prevalence of oral cancer.

Results: The study included 1,841 participants diagnosed with oral malignancies, consisting of 1,179 males (64.0%) and 662 females (36.0%), with a mean age of 55.9 ± 14.0 years. The NO₂ concentration is 20.2 ± 10.4 μg/m³. The highest cumulative effects of NO₂ exposure were observed at a 3-year cumulative lag, with a relative risk (RR) of 1.115 (95% CI: 1.102-1.128). For males, the most pronounced effect of NO₂ also occurred at a 3-year lag (RR = 1.110, 95% CI: 1.094-1.127). Similarly, among females, the significant cumulative impact of NO₂ was found at a 3-year lag (RR = 1.123, 95% CI: 1.101-1.145). For individuals under 60 years of age, the cumulative impact of NO₂ peaked at the same 3-year lag (RR = 1.102, 95% CI: 1.085-1.120). For individuals aged 60 and above, the highest cumulative impact of NO₂ was also detected at a 3-year lag (RR = 1.132, 95% CI: 1.112-1.152). For the group with normal BMI, the highest cumulative effect of NO₂ exposure was also observed at the 3-year lag period (RR = 1.289, 95% CI: 1.217-1.365), consistent with the findings for other groups.

Conclusion: These findings suggest a significant lagged effect of long-term NO₂ exposure on oral cancer, with varying associations between NO₂ and oral cancer across different ages and genders.