Dairy Bioaerosols

Dairy farming is dusty work, and the airborne organic particles in dairy farm environments are complex. Biological materials – like bacteria, fungi, viruses – are likely to attach to these dusts and create biological aerosols (bioaerosols for short). Dairy farm workers are particularly at risk for exposure to these dusts and thus are also at high risk for associated negative respiratory outcomes like inflammation and asthma. The goal of this study was to better characterize the size and composition of bioaerosols on dairy farms and increase our understanding of the impacts of these biological aerosols on the upper respiratory system of workers. Improved characterization of agricultural aerosols is needed to explain the causes of respiratory diseases in the agricultural work environment and to develop interventions that effectively reduce exposures.

Through this study, Stephen Reynolds and collaborators demonstrated that the size-distribution of bioaerosols on dairy farms extends well above 10 µm in diameter and that these dusts contain a diverse mixture of potentially hazardous constituents and opportunistic pathogens. The results of laboratory experiments suggest that both PM10 and PM>10 size fractions elicit a pro-inflammatory response in airway epithelial cells and that the inhalable dusts of all sizes should be considered when assessing potential risks from exposure to agricultural dusts, specifically on dairy farms.


Funding By: National Institute for Occupational Safety and Health (NIOSH)
Funding Period: 2011-2016



Size, Composition, and Source Profiles of Inhalable Bioaerosols from Colorado Dairies.
JW Schaeffer, S Reynolds, S Magzamen, A VanDyke, NR Gottel, JA Gilbert, SM Owens, JT Hampton-Marcell, J Volckens. Environmental Science & Technology, 2017, 51(11), 6430-6440.

Differential Response of Human Nasal and Bronchial Epithelial Cells upon Exposure to Size-fractionated Dairy Dust.
B Hawley, J Schaeffer, JA Poole, GP Dooley, S Reynolds, J Volckens.  J Toxicol Environ Health Sci, 2015, 78:583-594.

Project Investigators

Stephen Reynolds, PhD, CIH

Principal Investigator

Environmental and Radiological Health Sciences
Colorado State University