Improved, GC-Olfactometry Based, Malodor Assessment of Swine CAFOs Utilizing Novel Air Sampling Technologies

Odor profiling efforts were directed at applying to high-density swine CAFOs, some of the experience gained through recent GC-Olfactometry based odorant prioritization studies relative to high-density cattle CAFOs. Preliminary GC-O odor profile work indicates that with increasing distance from either high-density cattle or swine feeder operations the residual odor is increasingly defined by a limited number of high priority odorants. These ‘character defining ’ odorants appear to be dominated by compounds of relatively low volatility and high polarity. This work suggests that, as previously shown for cattle CAFOs, p-cresol alone appears to carry much of the overall odor impact. This is particularly true for the case of increasing distance from the swine CAFO source. If confirmed, such prioritization questions the validity of air sampling protocols which are based on plastic sample bags. Several studies have shown that p-cresol and other high-impact semi-volatile odorants are rapidly lost from the captured air samples through ‘scalping ’ effects; resulting from adsorption onto and absorption into the wall of the bag