Airborne biological particles, such as fungal spores and pollen, are ubiquitous in the Earth’s atmosphere and play an important role in the atmospheric environment and climate, impacting
air quality, cloud formation, and the Earth’s radiation budget. The atmospheric transformations
of airborne biological spores at elevated relative humidity remain poorly understood and their
climatic role is uncertain. Using an environmental scanning electron microscope (ESEM), we
observed rupturing of Amazonian fungal spores and subsequent release of nanometer to
submicron size fragments after exposure to high humidity. We find that fungal fragments contain
elements of inorganic salts (e.g., Na and Cl). They are hygroscopic in nature with a growth factor
up to 2.3 at 96% relative humidity, thus they may potentially influence cloud formation. Due to
their hygroscopic growth, light scattering cross sections of the fragments are enhanced by up to a
factor of 10. Furthermore, rupturing of fungal spores at high humidity may explain the bursting events of nanoparticles and may provide insight into new particle formation in Amazonia.
Revised: February 21, 2020 |
Published: October 17, 2016
Citation
China S., B. Wang, J. Weis, L.V. Rizzo, J. Brito, G. Cirino, and L. Kovarik, et al. 2016.Rupturing of biological spores as a source of secondary particles in Amazonia.Environmental Science & Technology 50, no. 22:12179 - 12186.PNNL-SA-118675.doi:10.1021/acs.est.6b02896