Peng Yin, Guojun He, Maoyong Fan, Kowk Yan Chiu, Maorong Fan, Chang Liu, An Xue, Tong Liu, Yuhang Pan, Quan Mu, Maigeng Zhou. Particulate air pollution and mortality in 38 of China’s largest cities: time series analysis. BMJ 2017;356:j667 doi: https://doi.org/10.1136/bmj.j667
The findings of this particular study (click here) and been seriously questioned (click here). If not considered, cigarette smoking is a huge confounding factor in any study involving the respiratory system. Confidence limits on the analysis must be considered when evaluating data.