ARS | Publication request: Animal Emissions Analyzed by both Chemical and Odor Panel Methods

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 1, 2008
Publication Date: June 27, 2008
Citation: Trabue, S.L., Kerr, B.J., Ziemer, C.J., Bearson, B.L. 2008. Animal Emissions Analyzed by both Chemical and Odor Panel Methods. Proceedings of the Air & Waste Management Association Annual Meeting, June 24-27, 2008, Portland, OR. 2008 CDROM.

Technical Abstract: The National Research Council identified odors as the most significant animal emission at the local level and highlighted the need for the development of standardized protocols for sampling and analysis of odors. In this study, odorous air from a swine facility was analyzed by both human panels and analytical techniques. Odor analysis was performed by whole air analysis using dynamic dilution olfactometry (DDO), while analytical analysis used thermal desorption GC-MS-O (olfactometry) technique. Samples were collected simultaneously for both DDO and GC-MS-O analysis. Odor samples using DDO analysis were collected in 10 L Tedlar bags and analyzed within 24 hr using a dynamic dilution forced-choice olfactometer. Odor samples from Tedlar bags were also analyzed by GC-MS-O by transferring air from bags to sorbent tubes. The GC-O technique used for determining key odorants was GC-SNIFF. Samples for GC-O analysis were collected on sorbent tubes containing graphitized carbon sorbent material or molecular sieve sorbent material. Odor results for DDO show there were significant differences and variability within and between odor panels in determining odor threshold values. Several key odorants were lost or reduced in concentration by storage in Tedlar bags and include phenol and indole compounds. Key odorants determined by GC-MS-O from Tedlar bags included volatile fatty acids, or oxy compounds, while key odorants detected in sorbent tubes taken directly from manure storage tanks included volatile fatty acids, phenols, indoles, and sulfur compounds. This study shows that there is a significant sampling bias when evaluating odor from animal agriculture using DDO.