Ambient PM(2.5) exposures could increase risk of tuberculosis recurrence

BACKGROUND: The effect of ambient PM(2.5) on the incidence of tuberculosis (TB) has been investigated in epidemiological studies. However, they did not separately study new and relapsed TB infection and focused on relatively short-term effects of PM(2.5). In this regard, we examined the associations of long-term PM(2.5) exposures with both new and relapsed TB incidences in South Korea, where the disease burden of TB is greatest among high-income countries. METHODS: An area-level ecological study of 250 districts was conducted from 2015 to 2019. Age- and sex-standardized TB incidence ratios for each district and year were used as outcome variables, and their associations with PM(2.5) concentrations for one to five-year average were examined. Negative binomial regression models incorporating spatiotemporal autocorrelation were employed using integrated nested Laplace approximations. Stratified analyses were conducted by type of TB (total, new, and relapsed cases). RESULTS: Districts with higher PM(2.5) concentrations tended to have significantly higher TB recurrence rate. The relative risks per 10 µg/m(3) PM(2.5) increase were 1.218 (95% credible interval 1.051–1.411), 1.260 (1.039–1.527) and 1.473 (1.015–2.137) using the two, three and five-year average PM(2.5) exposures, respectively. CONCLUSIONS: The results imply that interventions for reducing air pollution might help prevent TB recurrence. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at https://doi.org/10.1265/ehpm.23-00131.