Air pollution linked to pulmonary tuberculosis
13 Jul 2022
In 2012, an estimated 6.5 million deaths were associated with indoor and outdoor air pollution, said WHO.High ambient levels of the air pollutants PM2.5, PM10, and sulphur dioxide (SO2) appear to increase the incidence of pulmonary tuberculosis (PTB), reports a recent meta-analysis.
A total of 24 studies were retrieved from the databases of Scopus, Embase, Medline, and the Cochrane Library, resulting in a cumulative sample of 437,255 tuberculosis patients. Exposures were levels of air pollutants while outcomes were PTB incidence, related hospital admission, or death. According to the Grading of Recommendations Assessment, Development, and Evaluation criteria, overall quality of evidence was low.
Pooled analysis revealed that for every 10-µg/m3 jump in ambient PM2.5 levels, the risk of PTB increased by 12 percent (adjusted risk ratio [RR], 1.12, 95 percent confidence interval [CI], 1.06–1.19; p<0.001). A similar effect was reported for PM10 (adjusted RR, 1.06, 95 percent CI, 1.01–1.12; p=0.022) and SO2 (adjusted RR, 1.08, 95 percent CI, 1.04–1.12; p<0.001), which aggravated such risk by 6 percent and 8 percent, respectively.
In contrast, carbon monoxide (adjusted RR, 1.04, 95 percent CI, 0.98–1.11; p=0.211), nitrogen dioxide (adjusted RR, 1.08, 95 percent CI, 0.99–1.17; p=0.057), and ozone (adjusted RR, 1.00, 95 percent CI, 0.99–1.02; p=0.910) were not associated with PTB.
Meanwhile, none of the tested air pollutants correlated significantly with outcomes. Exposure to PM2.5, PM10, and SO2, for instance, did not increase the likelihood of hospitalization for and death due to PTB.
“Public health strategies aimed at ending the tuberculosis epidemic would therefore have to work alongside interventions aimed at improving overall air quality and addressing air pollution,” the researchers said, adding that future high-quality studies are also needed to verify these findings.