Bioaerosol generation by raindrops on soil

Young Soo Joung,Zhifei Ge,Cullen R Buie

doi:10.1038/ncomms14668

Young Soo Joung, Zhifei Ge + Show 1 more

Open Access

https://doi.org/10.1038/ncomms14668

Copy DOI

Abstract

Aerosolized microorganisms may play an important role in climate change, disease transmission, water and soil contaminants, and geographic migration of microbes. While it is known that bioaerosols are generated when bubbles break on the surface of water containing microbes, it is largely unclear how viable soil-based microbes are transferred to the atmosphere. Here we report a previously unknown mechanism by which rain disperses soil bacteria into the air. Bubbles, tens of micrometres in size, formed inside the raindrops disperse micro-droplets containing soil bacteria during raindrop impingement. A single raindrop can transfer 0.01% of bacteria on the soil surface and the bacteria can survive more than one hour after the aerosol generation process. This work further reveals that bacteria transfer by rain is highly dependent on the regional soil profile and climate conditions.

Highlights

Aerosolized microorganisms may play an important role in climate change, disease transmission, water and soil contaminants, and geographic migration of microbes
Bioaerosols play an important role in climate change, human health and agricultural productivity[1,2,3,4,5]
We demonstrated that when a raindrop hits soils, small bubbles are formed inside the raindrop and small droplets eject when the bubbles burst at the air/raindrop interface

Summary

Introduction

Aerosolized microorganisms may play an important role in climate change, disease transmission, water and soil contaminants, and geographic migration of microbes. While it is known that bioaerosols are generated when bubbles break on the surface of water containing microbes, it is largely unclear how viable soil-based microbes are transferred to the atmosphere. Aerosols generated at water/air interfaces are considered one of the main mechanisms for transferring microbes to the environment[17,18,19,20]. Aerosols represent small water droplets suspended in the air; in particular, bioaerosols are defined as aerosols containing microbes. We quantitatively examine the effects of bacterial surface concentration, soil composition, raindrop impact speed, and surface temperature to identify trends in bacteria transfer from soil to air. We estimate the global transfer rate of soil bacteria by rainfall

Methods

Results

Conclusion