Ambient air pollution and risk of active tuberculosis: a population-based cohort study in Taiwan

Available evidence on the relationship between long-term exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM2.5) and tuberculosis has been limited and inconsistent.

We conducted a longitudinal cohort study on individuals aged ≥12 years who participated in four rounds of the National Health Interview Survey. PM2.5 exposure was estimated by using data from air-quality monitoring stations and microsensors. Incident tuberculosis was identified based on International Classification of Diseases codes and the prescription of anti-tuberculosis drugs in the National Health Insurance Database. Time-dependent Cox regression analyses were conducted to estimate the linear and nonlinear associations between PM2.5 level and tuberculosis risk.

Among 55 316 individuals with a median follow-up time of 12 years, 429 cases of incident tuberculosis were identified. The annual mean baseline PM2.5 concentration was 34.5 μg/m3 (interquartile range: 28.7-39.2 μg/m3). After adjustment for age, sex, body mass index, cigarette smoking, alcohol use, education level, income, and tuberculosis history, the adjusted hazard ratio was 1.16 (95% confidence interval: 1.00-1.34) for every 10-μg/m3 increase in the PM2.5 level. The results of the restricted cubic spline Cox regression analysis revealed a potential nonlinear relationship (P for nonlinearity: .04), with the risk of tuberculosis increasing more rapidly when the annual mean concentration of PM2.5 exceeded 30 μg/m3.

In this large population-based cohort study, a positive association between PM2.5 and tuberculosis was observed, particularly at moderately high concentrations of PM2.5 exposure. These findings highlight the need for air-pollution control strategies to mitigate tuberculosis risk.