A little researched topic on the association of tuberculosis incidence and exposure to air pollution was recently published as an article in Nature.

The authors investigated the associations of ambient air pollutants (particulate matter with aerodynamic diameter <2.5 μm (PM2.5), sulfur dioxide (SO2),nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO)) in relation to the risk of pulmonary TB in a cohort of Chinese TB patients in Jinan city from 2011 to 2015. A total of 9344 newly diagnosed pulmonary TB cases were included. Four different air pollution exposure windows (3, 6, 9, and 12 months) before TB diagnoses were calculated from the daily concentration of air pollution. In categorical analysis, the authors observed statistically significant overall associations between pulmonary TB risk and PM2.5 (3 month exposure window: RR = 1.228, 95%CI: 1.091-1.381) as well as CO (3 month exposure window: RR = 1.169, 95%CI: 1.028-1.329; 9 month exposure window: RR = 1.442, 95%CI: 1.028-2.024) exposures. Moreover, subgroup analyses suggested that most of the air pollutants (PM2.5, SO2, O3, and CO) were significantly associated with increased risk of TB among the males, the females, the <60 years, and the smear negative cases. The dominant statistically significant associations were detected at 3-month exposure window of air pollution before the diagnosis of TB. The suggestive evidence is that the 3 month air pollution exposure window was associated with increased TB risk and warrants further investigation.