Fungal nanoparticles detected in air over Oklahoma field

Abstract:

Primary biological particles are present at low concentrations in the atmosphere, but some can nonetheless play a role in respiratory health by triggering allergies and in weather and climate by acting as ice nucleating particles. During summertime observations conducted near ground level over a rural U.S. agricultural area, we identified several events during which nano-scale fungal particles (~20-50 nm mobility diameter) were detected. The apparent fungal fragments were identified by the presence of chitin and sugar alcohols measured with roughly 1-hr time resolution using the Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS). A comparison of fungal nanoparticle event and non-event periods yielded an estimate of an average of hundreds of these particles per cubic centimeter of air during events. These observations represent a much larger number source of fungal particles to the atmosphere than has been demonstrated previously, and at much smaller sizes. No identification of fungal species was possible during this study. If fungal spores containing allergens or efficient ice nucleating structures burst in this way, this pathway likely influences the spores' impacts on health and cloud formation.