Effects of particulate air pollution on tuberculosis development in seven major cities of Korea from 2010 to 2016: methodological considerations involving long-term exposure and time lag

摘要

OBJECTIVES Epidemiological evidence of associations between ambient particulate matter (PM) and tuberculosis (TB) risk is accumulating. Two previous studies in Korea found associations between air pollution—especially sulfur dioxide (SOsub2/sub)—and TB. In this study, we conducted an annual time-series cross-sectional study to assess the effect of PM with an aerodynamic diameter less than 10 μm (PMsub10/sub) on TB risk in seven major cities of Korea from 2010 to 2016, taking into account time lag and long-term cumulative exposure. METHODS Age-standardized TB notification rates were derived using the Korea National TB Surveillance System. Annual average PMsub10/sub concentrations were obtained from annual Korean air quality reports. We applied a generalized linear mixed model with unconstrained distributed lags of exposure to PMsub10/sub. We adjusted for potential confounders such as age, health behaviors, and area-level characteristics. RESULTS Both average annual PMsub10/sub concentrations and age-standardized TB notification rates decreased over time. The association between cumulative exposure to PMsub10/sub and TB incidence became stronger as a longer exposure duration was considered. An increase of one standard deviation (5.63 μg/msup3/sup) in PMsub10/sub exposure for six years was associated with a 1.20 (95% confidence interval, 1.17 to 1.22) times higher TB notification rate. The marginal association of exposure duration with the TB notification rate was highest at four and five years prior to TB notification. This association remained consistent even after adjusting it for exposure to SOsub2/sub. CONCLUSIONS The findings of this study suggest that cumulative exposure to PMsub10/sub may affect TB risk, with a potential lag effect.