title: Rupturing of Biological Spores As a Source of Secondary Particles in Amazonia.
abstract: Airborne biological particles, such as fungal spores and pollen, are ubiquitous in the Earth's atmosphere and may influence 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 submicrometer 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 new particle formation in Amazonia.
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Swarup
authors.initials: S
authors.lastname: China
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Wang
authors.affiliation: Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Johannes
authors.initials: J
authors.lastname: Weis
authors.affiliation: Federal University of São Paulo , São Paulo - SP, 04021-001, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Rizzo
authors.affiliation: Institute of Physics, University of São Paulo , São Paulo - SP, 05508-900, Brazil.
authors.forename: Joel
authors.initials: J
authors.lastname: Brito
authors.affiliation: National Institute of Research in Amazonia , Manaus - AM, 69067-375, Brazil.
authors.forename: Glauber G
authors.initials: GG
authors.lastname: Cirino
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Libor
authors.initials: L
authors.lastname: Kovarik
authors.affiliation: Institute of Physics, University of São Paulo , São Paulo - SP, 05508-900, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Artaxo
authors.affiliation: Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Gilles
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Alexander
authors.initials: A
authors.lastname: Laskin
mesh_terms: D000485:Allergens; D001272:Atmosphere; D005658:Fungi; D011058:Pollen; D013172:Spores, Fungal
chemical_list: D000485:Allergens