Bioaerosols in University Animal Care Facilities
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Bioaerosols in University Animal Care Facilities Heather Lorenz Medical College of Ohio 2004 DEDICATION I would like to dedicate this work to my husband for his continued love and support; my parents for always encouraging and believing in me; Dr. Brian Harrington for his love of microbiology; and my major advisor, Dr. Michael Bisesi, for sharing his knowledge and guidance. ii ACKNOWLEDGEMENTS I would like to acknowledge the following for their willingness to contribute and make this work possible: my major advisor, Dr. Michael Bisesi; committee members Dr. Brian Harrington and Dr. Sheryl Milz; April Ames and Sara Fuenger for their guidance and many hours of work they put into the lab; and Dr. Jeffrey Jablonski for giving me the tools to prepare myself. iii TABLE OF CONTENTS DEDICATION................................................................................................................... i. ACKNOWLEDGEMENTS ............................................................................................ ii. TABLE OF CONTENTS ...............................................................................................iii. INTRODUCTION............................................................................................................. 1 LITERATURE REVIEW ................................................................................................ 5 METHODS ...................................................................................................................... 23 RESULTS ........................................................................................................................ 33 DISCUSSION .................................................................................................................. 47 CONCLUSIONS ............................................................................................................. 54 REFERENCES................................................................................................................ 56 APPENDICES................................................................................................................. 66 ABSTRACT................................................................................................................... 100 iv INTRODUCTION Overview Air quality concerns have been a prominent health issue in the indoor environment. According to the American Conference of Governmental Industrial Hygienists (ACGIH’s) Bioaerosols: Assessment and Control Book (Macher, [Ed.] 1999a), sick building syndrome has been used to describe symptoms that appear to be associated with building occupation, however, a specific cause for the symptoms cannot be identified. Another designation defined by the book, building related illness, is a term that is often used to describe symptoms that appear to be associated with building occupation where a specific physical, chemical, or biological agent has been identified as the contributing factor to a diagnosable disease. Biologicals have become the indoor air quality agent of interest to many researchers, medical, public and occupational health professionals because of their known association with a variety of adverse health effects (Douwes et al., 2003). A common route of exposure and the one of most interest is inhalation. According to Hirst (1995), “A bioaerosol is an aerosol comprising particles of biological origin or activity which may affect living things through infectivity, allergenicity, toxicity, pharmacological or other processes.” Health effects cover allergic response, infectious disease and even toxic responses. Bioaerosols encompass a wide range of biologic material; however, bacteria and fungi are of great importance in relation to human health and have been the focus of many indoor air quality studies. 1 Bioaerosols originate from both indoor and outdoor reservoirs. One major biological sources is animals. Therefore, it is reasonable to believe that animal care settings such as animal laboratories housing mice, rabbits, birds, and other small animals, provide the conditions to support biological growth and promote the generation of bioaerosols. Accordingly, this study was designed to determine a profile and characterization of viable bacteria and fungi during different animal activities throughout the work-shift at two university animal care facilities. Rooms studied in the animal care facilities included rooms where the animals were housed, rooms where cage cleaning occurred, office areas, and outdoors. The identification of specific tasks performed throughout the day that produce an increased level of exposure, may be used by occupational and public health professionals to determine adequate control measures. Statement of Problem Scientific research has supported the fact that animal settings present a potential inhalation occupational health concern for animal caretakers. The major potential indoor air quality contaminants in animal houses include viruses, bacteria, fungi, and other organic dust (Wathes, 1995). Wathes further pointed out that animals themselves generate bioaerosols, specifically bacteria and fungi, through secretions, excretions, feed, and bedding material. Health effects, in relation to both bacteria and fungi, include allergenic responses, infectious disease, and toxic responses. Although many studies have been published on bioaerosols in various animal settings in the agricultural industry, there is a paucity of published data on bioaerosol levels in other animal care settings. This study was designed to collect air samples to determine bacterial and fungal levels before 2 and during cleaning activities throughout the work shift to determine if certain tasks created an increased risk for employee fungal and bacterial exposure via inhalation. Purpose and Significance The purpose of this study was to research and conduct an industrial hygiene air sampling investigation in two university animal care facilities to determine if there were statistically significant different levels of fungi and bacteria between outdoors, rooms housing animals, cage cleaning rooms, and rooms not housing animals during different activities throughout the work shift. The significance of the study was to provide assistance to occupational health professionals in order to anticipate, recognize, evaluate, and control bacterial and fungi concentrations in non-agricultural animal care facilities. Hypothesis Hypotheses The hypotheses tested were: 1a. There is no significant difference in measured mean airborne bacteria levels before and during cleaning activities throughout the work shift. 1b. There is no significant difference in measured mean airborne fungi levels before and during cleaning activities throughout the work shift. 2a. There is no significant difference in measured mean airborne bacteria levels between rooms housing animals, cage cleaning rooms, outdoors, and rooms not housing animals. 3 2b. There is no significant difference in measured mean airborne fungi levels between rooms housing animals, cage cleaning rooms, outdoors, and rooms not housing animals. Objectives The objectives of this study were to: Conduct an industrial hygiene air sampling investigation for viable bacteria and fungi in two university animal care facilities and determine concentrations. Compare viable bacteria and fungi results, between areas within each location, to determine if specific area concentrations were statistically significantly higher. Compare viable bacteria and fungi results, between areas within each location, to determine if specific activities were statistically significantly higher. Compare viable bacteria and fungi results to background samples (outdoors and office areas). Classify bacteria into gram-positive or negative, rod or cocci, and determine the genus of fungi. 4 LITERATURE REVIEW Overview Many studies have been published on bioaerosols in various animal care settings such as swine houses, dairy farms and cow barns, poultry housing and other farming environments indicating high concentrations of bacteria, fungi, endotoxin, organic dust, and ammonia among other species specific air contaminants (Chang et al., 2001; Kullman et al., 1998; Debey et al., 1995). These indoor contaminants may affect the respiratory system creating various human health concerns for building occupants (Kaliste et al., 2002). Although a few studies have investigated bioaerosols in other animal housing environments, there is a lack of research on bioaerosol levels in non-agricultural animal care settings. Conceptual Framework Association between employee complaints and a causative agent are often difficult to determine, resulting in the frequent use of a less specific term, sick building syndrome. Research in the area of bioaerosols is helpful in identifying and narrowing down the etiology of symptoms often associated with sick building syndrome in order to anticipate, recognize, evaluate and control the causative agent. Because of the nature of animal care environments, it is reasonable to anticipate that elevated bioaerosol exposure exists, presenting a potential occupational heath concern for the animal caretakers. An industrial hygiene air sampling investigation for bioaerosol concentrations, specifically bacteria and 5 fungi, was warrented to determine potential exposure risks for animal caretakers in order to determine proper control measures. Sources and Generation of Bioaerosols Bioaerosols are airborne organic substances or organisms consisting of and/or originating