The association between exposure to air pollutants and latent tuberculosis infection prevalence in the elderly population: a population-based cross-sectional study from China

Background Globally, research on the direct correlation between air pollutants and latent tuberculosis (TB) infection (LTBI) is still relatively scarce. We aimed to conduct a cross-sectional study of LTBI across regions with varying air quality to assess whether air pollution affects the burden of TB infection. Methods We selected the cities of Liaocheng and Weihai in Shandong Province, China, as the research sites from 13-30 April 2025. We used the γ-interferon release assay to detect LTBI. We assessed the concentrations of particulate matter (PM) 2.5 , PM 10 , carbon monoxide (CO), nitrogen dioxide (NO 2 ), sulphur dioxide, and ozone across various time periods by integrating satellite remote sensing data with ground-based monitoring data. We used logistic regression and weighted pollution models to assess the relationship between air pollutants and the prevalence of LTBI. Results A total of 2504 participants were included in the study, and 271 latent infected individuals were identified. The LTBI prevalence in Liaocheng city and Weihai city were 11.8% and 9.7%, respectively. During the three-year exposure window, for every 10 μg/m 3 increase in PM 2.5 , the odds of LTBI were 35.0% higher in Liaocheng city (odds ratio (OR) = 1.35; 95% confidence interval (CI) = 1.04-1.78) and 6.0% higher in Weihai city (OR = 1.06; 95% CI = 1.03-1.09). For every 10μg/m 3 increase in NO 2 concentration, the odds of LTBI in Liaocheng city was 35% higher than in Weihai city (OR = 1.50 vs. OR = 1.15). The results of the weighted pollution model indicated that the comprehensive exposure index was positively correlated with the LTBI prevalence. The subgroup analysis results indicated that the association between exposure to PM 2.5 , PM 10 , CO, and NO 2 and the prevalence of LTBI was more pronounced in populations with a household per capita income Conclusions The research indicates that prolonged exposure to air pollutants substantially elevates the odds of LTBI in Chinese cities, exhibiting regional disparities. This underscores the significance of managing air pollution to prevent and control TB.