Submicronic fungal bioaerosols: high-resolution microscopic characterization and quantification

Details

• Personal Author:
  Afanou KA ; Eduard W ; Green, Brett J. ; Hjeljord L ; Nilsen T ; Skaar I ; Skogstad A ; Straumfors A ; Synnes O ; Tronsmo A
• Description:
  Submicronic particles released from fungal cultures have been suggested to be additional sources of personal exposure in mold-contaminated buildings. In vitro generation of these particles has been studied with particle counters, eventually supplemented by autofluorescence, that recognize fragments by size and discriminate biotic from abiotic particles. However, the fungal origin of submicronic particles remains unclear. In this study, submicronic fungal particles derived from Aspergillus fumigatus, A. versicolor, and Penicillium chrysogenum cultures grown on agar and gypsum board were aerosolized and enumerated using field emission scanning electron microscopy (FESEM). A novel bioaerosol generator and a fungal spores source strength tester were compared at 12 and 20 liters min(-1) airflow. The overall median numbers of aerosolized submicronic particles were 2x10(5) cm(-2), 2.6 x 10(3) cm(-2), and 0.9 x 10(3) cm(-2) for A. fumigatus, A. versicolor, and P. chrysogenum, respectively. A. fumigatus released significantly (P < 0.001) more particles than A. versicolor and P. chrysogenum. The ratios of submicronic fragments to larger particles, regardless of media type, were 1:3, 5:1, and 1:2 for A. fumigatus, A. versicolor, and P. chrysogenum, respectively. Spore fragments identified by the presence of rodlets amounted to 13%, 2%, and 0% of the submicronic particles released from A. fumigatus, A. versicolor, and P. chrysogenum, respectively. Submicronic particles with and without rodlets were also aerosolized from cultures grown on cellophane-covered media, indirectly confirming their fungal origin. Both hyphae and conidia could fragment into submicronic particles and aerosolize in vitro. These findings further highlight the potential contribution of fungal fragments to personal fungal exposure. [Description provided by NIOSH]
• Subjects:
  Aerosols Environmental Exposure Environmental Pollution Fungi Laboratories Microbiology Occupational Health Particulate Matter Safety Workplace
• Keywords:
  Aerosol-generators Environmental-contamination Environmental-exposure In-vitro-study Laboratory-techniques Microorganisms Microscopic-analysis Microscopy Molds Particle-counters Quantitative-analysis Work-environment

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• ISSN:
  0099-2240
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  80
• Issue:
  22
• NIOSHTIC Number:
  nn:20045276
• Citation:
  Appl Environ Microbiol 2014 Nov; 80(22):7122-7130
• Contact Point Address:
  Wijnand Eduard, National Institute of Occupational Health, Oslo, Norway
• Email:
  wijnand.eduard@stami.no
• Federal Fiscal Year:
  2015
• NORA Priority Area:
  Services
• Peer Reviewed:
  True
• Source Full Name:
  Applied and Environmental Microbiology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:73ef8a3fc748df8f516308c4e0bafeb0927cbea7cccb7ce7b532e4d70fd6785a65ae8bc6cbcc9fbd9548597253651108ee100876f749ab3ef4c73817e12b8760
• Download URL:
  https://stacks.cdc.gov/view/cdc/200744/cdc_200744_DS1.pdf
• File Type:
  [PDF - 1.01 MB ]