Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Airborne fungi, bacteria, actinomycetes, endotoxin, and (1-->3)--D-glucan in Midwest greenhouses and respiratory symptoms among workers.

Adhikari-A; Olds-RL; Gupta-J; Wilkins-JR III; Reponen-T; Grinshpun-SA; Indugula-R; Cho-KJ; Li-C; Yermakov-M
ASM 2010: Proceedings of the 110th American Society for Microbiology General Meeting, May 23 - 27, 2010, San Diego, CA, 2010 May; :853
Background: Greenhouse operation is an important sector of the horticulture industry, also known as the Green Industry, which accounts for nearly 2 million US jobs and $147 billion in output. There is a lack of quantitative information on the workers' exposure to microbial bioaerosols and relevant respiratory symptoms. Methods: Air samples were collected using Button Inhalable Aerosol Samplers from 3 Midwest greenhouses in winter and summer during one work shift in the 4 corners and at the center of a greenhouse compartment. Control samples were collected from offices and nearby outdoor locations. Extracts from the sampler filters were cultivated to examine airborne culturable fungi, bacteria, and actinomycetes. Endotoxin and (1-->3)--D-glucan in filter extracts were analyzed by specific kinetic chromogenic LAL assays. The prevalence of respiratory symptoms among the greenhouse workers (n = 35) and controls (n = 13) was estimated by using a standardized questionnaire. The symptoms were recorded only in summer and related to overall exposure and work status in greenhouses. Results: Mean concentrations of culturable fungi and bacteria were: 429 - 3,584 CFU/m3 and 1,269 - 8,200 CFU/m3 respectively in winter, and 3,939 - 9,947 CFU/m3 and 210 - 666 CFU/m3 respectively in summer. Mean concentrations of endotoxin and (1-->3)--D-glucan were: 14 - 855 EU/m3 and 8 - 71 ng/m3 respectively in winter, and 8 - 39 EU/m3 and 17 - 26 ng/m3 respectively in summer. The mean culturable actinomycetes concentrations were 14 - 127 CFU/m3 in winter and mostly zero in summer. The indoor-to-outdoor ratio exceeded 1 in most cases for all biocontaminants. The prevalence of asthma, wheezing, cough and phlegm was higher in workers (8.6, 42.9, 15.2, and 32.4%, respectively) compared to controls (7.7, 23.0, 7.7, and 7.7%, respectively); however, the differences were not statistically significant in a logistic regression model adjusted for age and gender. Conclusions: Midwest greenhouses are a significant source of workers' exposures to airborne microbial contaminants. Fungi and (1-->3)--D-glucan dominate in summer whereas bacteria and endotoxin dominate in winter.
Agricultural-workers; Agriculture; Air-sampling; Airborne-particles; Aerosol-particles; Aerosols; Environmental-contamination; Microorganisms; Fungi; Bacteria; Endotoxins; Allergens; Humans; Respiratory-system-disorders; Pulmonary-system-disorders; Employee-exposure; Exposure-levels; Bioassays; Questionnaires; Health-surveys; Air-contamination; Indoor-air-pollution; Outdoors; Seasonal-factors; Allergies; Author Keywords: bioaerosols; air microbiology; respiratory symptoms
Atin Adhikari, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267
Publication Date
Document Type
Email Address
Funding Type
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
Source Name
ASM 2010: Proceedings of the 110th American Society for Microbiology General Meeting, May 23 - 27, 2010, San Diego, CA
Performing Organization
University of Cincinnati