High Abundance of Fluorescent Biological Aerosol Particles in Winter in Beijing, China

Primary
biological aerosol particles (PBAP) such as pollen, fungal
spores, bacteria, and viruses represent a major subset of particulate
matter for both coarse and fine aerosols. Although PBAP affect climate
and human health, there still remains a large uncertainty regarding
their sources and characteristics, especially in urban atmospheres.
Here we combined online fluorescent biological aerosol particle measurements
and offline fluorescent and biomarker analysis in winter in Beijing,
a city suffering from severe air pollution. Our results show that
the abundance of fluorescent biological particles was higher than
that of many other natural environments. Bioaerosol loadings were
greatly enhanced during mealtime, indicating local emissions of bioaerosols
from human activities. The contributions of fungal spores to total
organic carbon (OC) from fluorescent bioaerosol analyses were estimated
to be around 10% both in clean and polluted periods. This study highlights
the importance of human activities to emit bioaerosols into the atmosphere
and the potential uncertainties of modeling bioaerosol effects in
climate systems.