Articles | Volume 12, issue 23
Research article
08 Dec 2015
Research article |  | 08 Dec 2015

Hydroxy fatty acids in fresh snow samples from northern Japan: long-range atmospheric transport of Gram-negative bacteria by Asian winter monsoon

P. Tyagi, S. Yamamoto, and K. Kawamura

Abstract. Hydroxy fatty acids (FAs) in fresh snow from Sapporo, one of the heaviest snowfall regions in the world, have been studied to ascertain the airborne bacterial endotoxin concentrations and their biomass. The presence of β-hydroxy FAs (C9–C28), constituents of the Gram-negative bacterium (GNB), suggests long-range transport of soil microbes. Likewise, the occurrence of α- and ω-hydroxy FAs (C9–C30 and C9–C28, respectively) in snow reveals their contribution from epicuticular waxes and soil microorganisms. Estimated endotoxin and GNB mass can aid in assessing their possible impacts on the diversity and functioning of aquatic and terrestrial ecosystems, as well as lethal effects on pedestrians through dispersal of microbes. Air mass back trajectories together with hydroxy FAs reveal their sources from Siberia, the Russian Far East and northern China by the Asian monsoon. This study highlights the role of fresh snow that reduces the human health risk of GNB and endotoxin by the scavenging from air.

Short summary
Our manuscript represents the first field-based data set on the abundances of hydroxy fatty acids (FAs) in fresh snow and its filtering capacity to reduce hydroxy FA burden on the atmosphere. •Hydroxy fatty acids (FAs) in snow indicate a contribution from soil microbes and higher plants. •Air mass back trajectories reveal their transport from Russia, Siberia and China. We conducted the present study to better understand the impact of aeolian transport on bacteria & their filtering by snow.
Final-revised paper