Evaluation of Field-based Odor Assessment Methods

This study investigates the differences between field-based odor assessment methods that may be used to discriminate odors from livestock and food processing facilities. Field olfactometers have been praised for their low cost (500 - 1200) and portability but criticized for their lack of control of inhalation rates by different panelists, the discomfort of glass inhalation tubes and the odor fatigue caused by poor nasal sealing or removing the scentometer between samples as compared to laboratory dynamic, triangular forcedchoice olfactometers (30,000). This study evaluated the variability of responses using these three field olfactometers compared to laboratory olfactometry, as well as field and lab odor intensity. Panel responses using laboratory dynamic, triangular force-choice olfactometry and Nasal Ranger field olfactometers were found to exhibit the least amount of variability across odor sources. Significant differences with poor correlation were found between field and laboratory odor intensity methods. Findings of this study should caution regulators, policy makers and investigators about establishing regulatory thresholds or reporting scientific data based on single odor analysis methods or techniques due to the variability in the performance of odor determination methods across the odorous sites investigated.