Relationships between airborne microbial community diversity, heating supply patterns and particulate matter properties

Abstract

Airborne microbes play critical roles in atmospheric ecology and human health, while the connections of microbial community with anthropic activity, such as heating supply patterns and chemical compositions of particulate matter (PM), remain unclear. The present study demonstrated that district heating supply regions exhibited higher microbial richness than non-district heating supply regions, and microbial richness in PM1 (aerodynamic diameter ≤ 1 µm) was significantly lower than that in PM10 (aerodynamic diameter ≤ 10 µm). Gram-positive bacteria were dominant, and Bacilli accounts for 85% of the noted bacteria. The total concentrations of heavy metals, polycyclic aromatic hydrocarbons (PAHs) and water-soluble ions increased with PM sizes. Heavy metals and PAHs in non-district heating supply regions showed significantly higher concentrations than that in district heating supply regions. Most of tested chemical compositions negatively contributed to microbial community diversity, except for Zn, Cr, Pyrene (Pyr), and Benzo[a]pyrene (Bap). The above results were also affected by heating supply patterns (district heating supply and non-district heating supply). There was a positive correlation between microbial community richness and •OH concentration, and microbial community richness decreased as PM specific surface area increased. This work reveals connections between the properties of PMs and the microbial community diversity with heating supply patterns, and gives novel insights to atmospheric health and carbon neutrality.