The obtained odor thresholds of sETS expressed in terms of measured particle numbers, pPAH, and tVOC concentrations are depicted in Figure 3.
The average concentrations at the lowest sETS were 468 particles per [cm.sup.3], 7.3 ng/[m.sup.3] pPAH, and 19 ppb tVOC.
Based on a Pearson's linear regression model, the log-transformed ETS indicators such as particle numbers, pPAH, and tVOC concentrations show a linear trend with odor strength, eye irritation, arousal, annoyance, odor perception, acceptability of indoor air quality, wanting to open the window, wanting to leave the room, and complaining at work.
We then calculated the average dilution volumes based on volumes obtained from particle number, pPAH, and tVOC concentrations.
The absolute values of these thresholds in terms of particle numbers, tVOC, and pPAH concentrations point out that, for field settings, an odor sensation would lie in the noise of the background concentrations.
Particle numbers concentrations averaged 1.7 x [10.sup.4]/[cm.sup.3]; pPAH concentrations averaged 218 ng/[m.sup.3].