The group around Ting ZHU at Tsinghua University has sequenced metagenomic samples of microorganisms contained in Beijing smog samples. They have traced about 1300 microorganisms, mostly eukaryotes, including Aspergillus fumigatus (1 – 8 % abundance) with pathogenic potential. The relevance of this finding is debated in the media.
China Bio news release, April 23, 2015