Heterogeneous impact of fine particulate matter constituents on pulmonary tuberculosis onset: a multicenter time series study in Beijing

Abstract

Background: Epidemiological studies have implicated exposure to PM₂.₅ in the development of pulmonary tuberculosis (PTB); however, the key constituents driving this effect have not been clearly identified. Methods: A time-series analysis spanning 2019 to 2023 was performed across several centers in Beijing to assess the links between major PM2.5 constituents and PTB risk. The effects of five specific components—namely organic matter, black carbon, nitrate, sulfate, and ammonium—were evaluated to pinpoint the most influential factors. Results: All five examined components demonstrated significant relationships with an elevated risk of PTB. Associations were not statistically significant on the same day (lag 0) or the next day (lag 1) after exposure. A clear risk increase was detected starting at a 2-day lag, which was no longer observable by lag 3. Per interquartile range (IQR) rise in the 3-day moving average (lag 0–2) of black carbon and organic matter, the relative risks (RRs) for PTB were 1.11 [95% confidence interval (CI): 1.03, 1.19] and 1.11 (95% CI: 1.03, 1.21), correspondingly. Together, these two components were the dominant drivers of the overall PM₂.₅ effect, contributing 41% and 39% of the joint risk, respectively. Conclusions: The results yield novel evidence that exposure to certain PM2.5 constituents is demonstrated to elevate PTB risk, wherein black carbon and organic matter are established as the principal factors.