It Really Stinks! The Assessment and Control of Airborne Endotoxins During the Processing of Fecal Matter in the Wildlife Endocrinology Laboratory
Abstract No:
1653
Abstract Type:
Professional Poster
Authors:
M Hunt1
Institutions:
1Smithsonian Institution, Washington, DC
Presenter:
Mr. Michael Hunt, M.S., CIH
Smithsonian Institution
Smithsonian Institution
Description:
As part of zoological efforts to propagate endangered/threatened species, many wildlife endocrinology laboratories conduct non-invasive hormonal monitoring. This process may involve collecting animal feces in the field, freeze-drying the fecal matter, crushing and sifting the fecal matter to remove unusable material (e.g., grass), and then collecting the resultant product for hormonal analysis. At one laboratory, where the crushing and sifting was conducted over several hours without the benefit of dedicated engineering controls, the process could be qualitatively described as odiferous. In the vernacular, "It really stunk!" Laboratory staff were wiping up pulverized fecal matter off the laboratory benches at the end of their work shift. This case study (1) assessed personal exposures to airborne endotoxins (respirable and total) during the crushing/sifting/containerization of fecal matter, and (2) evaluated the effectiveness of engineering controls and improved work practices at reducing personal exposures to airborne endotoxin during these tasks.
Situation / Problem:
The authors were concerned that personal airborne endotoxin exposures could exceed levels associated with adverse health effects (e.g., acute airflow obstruction) during the laboratory crushing and siting of fecal matter. The authors suspected that airborne endotoxin exposure levels would exceed the ACGIH® Relative Limit Value (RLV). After the initial survey revealed endotoxin levels exceeding the ACGIH® RLV, a dedicated filtration hood was installed in the laboratory. Follow-up air monitoring was completed to evaluate the effectiveness of the filtration hood at reducing endotoxin exposures. Additional personal endotoxin air monitoring will be completed at a second laboratory where non-invasive hormonal monitoring is completed within a biosafety cabinet. [These results should be available by the presentation date.]
Methods:
Personal and area endotoxin air monitoring (respirable and total) was completed using calibrated sampling pumps connected by tygon® tubing to endotoxin-free 4 micrometer (µm) polycarbonate filter sampling cassettes. During personal monitoring, filter cassettes were affixed within the employee's breathing zone. During respirable monitoring, an SKC aluminum cyclone was used to select the respirable fraction of airborne endotoxin. Samples were refrigerated and shipped cold, overnight, to Indoor Biotechnologies Incorporated, Charlottesville, VA, for analysis using the United States Pharmacopeial Convention (USP) 85 limulus amebocyte lysate (LAL) method.
Results / Conclusions:
During our initial study, average personal exposures to airborne endotoxin were 1060 Endotoxin Units (EU) m−3 (total, n = 3) and 78.4 EU m−3 (respirable, n = 3). Area endotoxin levels in the processing room were 386 EU m−3 (total, n = 3) and 44.6 EU m−3 (respirable, n = 3). The highest levels of airborne endotoxins were observed during the processing of cheetah and painted wild dog feces: 2280 EU m−3 (total). When the results were compared to background levels of airborne endotoxin (adjacent room with air supplied by the same air handling unit), on average, personal endotoxin exposures were 544 times greater than the background total endotoxin level and 72 times greater than the background respirable endotoxin level. Because the comparative results exceeded the ACGIH® maximum RLV, the decision was made to implement engineering controls.
A HEPA filtration hood was subsequently installed in the laboratory. Follow-up air monitoring conducted during fecal processing within the hood revealed a reduction in personal endotoxin exposures levels: 147 EU m−3 (total, n = 2) and 15.2 EU m−3 (respirable, n = 2); levels of exposure which were 74.1 times background (total) and 16.5 times background (respirable).
At the time of writing, the presenter is coordinating with laboratory staff to implement administrative controls and (hopefully) achieve further reduction in endotoxin exposure levels through better laundering of lab coats, and improved containerization of fecal-contaminated supplies. A second endocrinology laboratory was located where crushing and sifting of animal feces is completed within a biological safety cabinet. The presenter is coordinating to assess the inhalation hazards posed to staff from endotoxin in this location. The results of this study reveal the importance of implementing engineering controls to reduce endotoxin exposures during the laboratory processing of fecal matter. Because this study was limited by a small sample size, further exposure studies are desirable to characterize the inhalation hazards associated with the laboratory processing of fecal matter.
A HEPA filtration hood was subsequently installed in the laboratory. Follow-up air monitoring conducted during fecal processing within the hood revealed a reduction in personal endotoxin exposures levels: 147 EU m−3 (total, n = 2) and 15.2 EU m−3 (respirable, n = 2); levels of exposure which were 74.1 times background (total) and 16.5 times background (respirable).
At the time of writing, the presenter is coordinating with laboratory staff to implement administrative controls and (hopefully) achieve further reduction in endotoxin exposure levels through better laundering of lab coats, and improved containerization of fecal-contaminated supplies. A second endocrinology laboratory was located where crushing and sifting of animal feces is completed within a biological safety cabinet. The presenter is coordinating to assess the inhalation hazards posed to staff from endotoxin in this location. The results of this study reveal the importance of implementing engineering controls to reduce endotoxin exposures during the laboratory processing of fecal matter. Because this study was limited by a small sample size, further exposure studies are desirable to characterize the inhalation hazards associated with the laboratory processing of fecal matter.
Primary Topic:
Laboratory Health and Safety
Secondary Topics:
Aerosols
Indoor Environmental Quality/Indoor Air Quality
Co-Authors
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Acknowledgements and References
List any additional people who worked on the project or provided guidance and support along with details on the role they played in the research. (Please include first name, last name, organization, city, state and country).
a. Alicen Heinrich, and Chuck Fry. Role: Assistance in sampling airborne endotoxins.
b. Hayes C. Robinson III and Richard Wright, CIH. Role: Funding and overall project support.
2. National Zoological Park - Smithsonian Conservation Biology Institute, Front Royal, VA, USA: Nicole Boisseau, Natalia Prado-Oviedo, Stephen Paris, and Keith Braesicke. Role: Customers who had an interest in the study, provided logistical support, and procured and implemented controls [NB and SP].)
3. Indoor Biotechnologies Inc., Charlottesville, VA, USA: Stephanie Filep. Role: Laboratory analysis of endotoxins.
4. John Hopkins University, Baltimore, MD, USA: Kirsten Kohler, PhD and Gurumurthy Ramachandran, PhD, CIH. Guidance to coauthor, Erik Heithaus, during his graduate study.