Abstract:

Objective: To explore the effect of exposure to air pollutants and greenness on mortality during the treatment of newly treated tuberculosis patients, and to provide a scientific basis for the health management of tuberculosis patients at the environmental level. Methods: Data were collected from 29519 newly treated tuberculosis patients from January 1, 2015 to December 31, 2020 in Hefei City, Huainan City, and Huangshan City, Anhui Province. Data on atmospheric pollutants fine particulate matter (particulate matter with an aerodynamic diameter ≤2.5 μm, PM_2.5), inhalable particulate matter (particulate matter with an aerodynamic diameter ≤10 μm, PM₁₀), carbon monoxide (CO), and nitrogen dioxide (NO₂) were collected through environmental monitoring stations. Cox proportional risk model was applied to calculate the risk ratios (HR) and the 95% confidence intervals (95%CI) for all-cause mortality of air pollutant exposures and newly treated tuberculosis patients, and subgroup analyses were also performed combining with greenness exposure. Results: Of the 29519 tuberculosis patients, 369 (1.25%) died during treatment. The results of multifactorial Cox regression analyses showed that the risk of death increased by 15.6% with every 10 μg/m³ increasement in PM_2.5 (HR=1.156, 95%CI: 1.146-1.165), 18.3% with every 10 μg/m³ increasement in PM₁₀ (HR=1.183, 95%CI: 1.176-1.190); with every 0.10 mg/m³ increase in CO, the risk of death increased by 6.7% (HR=1.067, 95%CI: 1.060-1.074), and with every 10 μg/m³ increase in NO₂, the risk of death increased by 2.8% (HR=1.028, 95%CI: 1.019-1.037). After being divided into different groups based on greenness exposure from low to high by quartiles (Q₁ to Q₄), the effect of air pollutants on mortality rate gradually decreased with elevated greenness exposures (PM_2.5, for example, the HR values of normalized vegetation index on disease mortality rate in the 250 m and 500 m buffer zones were 1.218 (95%CI: 1.197-1.240) and 1.231 (95%CI: 1.210-1.253) for Q₁, respectively, and decreased to 1.125 (95%CI: 1.106-1.146) and 1.138 (95%CI: 1.118-1.159) for Q₄, respectively). Conclusion: Exposure to atmospheric pollutants is a risk factor during the treatment of newly treated tuberculosis patients, and higher levels of greenness can reduce the risk of mortality due to exposure to atmospheric pollutants.

Key words: Tuberculosis, Air pollutants, Environmental exposure, Retrospective studies, Factor analysis, statistical