| Symptomatic Effects of Exposure to Diluted Air Sampled from a Swine Confinement Atmosphere on Healthy Human Subjects Susan S. Schiffman,1 Clare E. Studwell,1 Lawrence
R. Landerman,1 Katherine Berman,2 and John S. Sundy2 1Department of Psychiatry and 2Department of Medicine,
Duke University Medical Center, Durham, North Carolina, USA Abstract
Aerial emissions from a swine house at North Carolina State University’s field laboratory were diluted to a level that could occur at varying distances downwind from a confined animal feeding operation (CAFO) both within and beyond the property line, and these emissions were delivered to an environmental exposure chamber. The study design consisted of two 1-hr sessions, one in which 48 healthy human adult volunteers were exposed to diluted swine air and another in which they were exposed to clean air (control) . Objective measures of blood pressure, temperature, heart rate, respiratory rate, lung function, nasal inflammation, secretory immunity, mood, attention, and memory were correlated with objective measures of air quality. Ratings of perceived (self-reported) health symptoms were also obtained. The mean levels of airborne constituents in the swine air condition were hydrogen sulfide (24 ppb) , ammonia (817 ppb) , total suspended particulates (0.0241 mg/m3) , endotoxin (7.40 endotoxin units/m3) , and odor (57 times above odor threshold) . No statistical differences on objective measures of physical symptoms, mood, or attention resulted from the 1-hr exposure to swine emissions in the environmental chamber when compared with clean air for healthy human volunteers. However, subjects were 4.1 (p = 0.001) times more likely to report headaches, 6.1 (p = 0.004) times more likely to report eye irritation, and 7.8 (p = 0.014) times more likely to report nausea in the swine air (experimental) condition than in the control condition. These results indicate that short-term exposure in an environmental chamber to malodorous emissions from a swine house at levels expected downwind can induce clinically important symptoms in healthy human volunteers. Key words: airborne emissions, attention, environmental chamber, memory, mood, nasal inflammation, pulmonary function, secretory immunity, spirometry, swine. Environ Health Perspect 113: 567-576 (2005) . doi:10.1289/ehp.6814 available via http://dx.doi.org/ [Online 9 February 2005]
Address correspondence to S.S. Schiffman, Department of Psychiatry, 54212 Woodhall Building, Box 3259, Duke University Medical Center, Durham, NC 27710-3259 USA. Telephone: (919) 660-5657. Fax: (919) 684-8449. E-mail: sss@duke.edu and schif003@mc.duke.edu We thank D.A. Schwartz for his assistance on this project. This project was supported by the Z. Smith Reynolds Foundation, the National Pork Board, Duke University Medical Center, and K23-ES11185 from the National Institute of Environmental Health Sciences/National Institutes of Health. The authors declare they have no competing financial interests. Received 23 October 2003 ; accepted 9 February 2005. The full version of this article is available for free in HTML or PDF formats. |
