To complement the dust-derived metabolomics/exposomics, the microbial communities of the dust samples were analyzed at different taxonomic ranks (from kingdom to species). A total of 1,782 metagenomic operational taxonomic units (mOTUs) were initially characterized ( Table ). This initial list was reduced to 163 mOTUs for subsequent analysis (Table ), after filtering to remove low quality or uninformative features, as indicated in the Material and Methods section. Notably, Actinobacteria, Proteobacteria, and Firmicutes emerged as the three most abundant phyla (Figure ).