[A Meta analysis on the associations between air pollution and respiratory mortality in China]

To analyze the associations between air pollution and adverse health outcomes on respiratory diseases and to estimate the short-term effects of air pollutions [Particulate matter with particle size below 10 microns (PM(10)), PM(10) particulate matter with particle size below 2.5 microns (PM(2.5)), nitrogen dioxide (NO₂), sulphur dioxide (SO₂) and ozone (O₃)] on respiratory mortality in China.

Data related to the epidemiological studies on the associations between air pollution and adverse health outcomes of respiratory diseases that published from 1989 through 2014 in China, were collected by systematically searching databases of PubMed, SpringerLink, Embase, Medline, CNKI, CBM and VIP in different provinces of China. Short-term effects between (PM(10), PM(2.5), NO₂, SO₂, O₃) and respiratory mortality were analyzed by Meta-analysis method, and estimations were pooled by random or fixed effect models, using the Stata 12.0 software.

A total of 157 papers related to the associations between air pollution and adverse health outcomes of respiratory diseases in China were published, which covered 79.4% of all the provinces in China. Results from the Meta-analysis showed that a 10 µg/m³ increase in PM10, PM(2.5), NO₂, SO₂, and O₃was associated with mortality rates as 0.50% (95% CI: 0-0.90%), 0.50% (95% CI: 0.30%-0.70%), 1.39% (95% CI: 0.90%-1.78%), 1.00% (95% CI: 0.40%-1.59%) and 0.10% (95% CI: -1.21%-1.39%) in respiratory tracts, respectively. No publication bias was found among these studies.

There seemed positive associations existed between PM(10)/PM(2.5)/NO₂/SO₂and respiratory mortality in China that the relationship called for further attention on air pollution and adverse health outcomes of the respiratory diseases.