Associations between bacteriome and chemical pollutants in indoor dust from Czech households. DustChem

Biological and chemical pollutants in indoor environments are widely studied in relation to human health, yet the complex relationships between chemical substances and bacteria in indoor dust remain underexplored. This study investigated the bacteriome and a broad spectrum of chemical substances in 89 Czech households, analyzing indoor dust samples from 54 flats and 35 houses. The bacteriome was assessed through 16S rRNA amplicon sequencing, while bacterial DNA content was measured by qPCR. The study found that dust from houses had higher concentrations of polyaromatic hydrocarbons (PAHs) and a greater relative abundance of the genera Methylobacterium-Methylorubrum and Sphingomonas, whereas synthetic musks and bacteriome α-diversity were lower compared to flats. Notably, the relative abundance of Methylobacterium-Methylorubrum correlated positively with Sphingomonas and PAH concentrations, while nitrated-PAHs (NOPAHs) were inversely related to bacteriome α-diversity. A regression model revealed that household type, along with NOPAHs and polybrominated diphenyl ethers (PBDEs), explained 25% of the variability in Methylobacterium-Methylorubrum abundance. Synthetic musks, positively associated with bacteriome α-diversity, were significant predictors of this parameter's variability alongside household type and NOPAH concentrations. In conclusion, Methylobacterium-Methylorubrum, known for degrading organic compounds, is linked to indoor dust environments with elevated PAHs, posing potential health risks to inhabitants.