An Algorithm for 353 Odor Detection Thresholds in Humans

Abstract

One hundred and ninety three odor detection thresholds, ODTs, obtained by Nagata using the Japanese triangular bag method can be correlated as log (1/ODT) by a linear equation with R(2) = 0.748 and a standard deviation, SD, of 0.830 log units; the latter may be compared with our estimate of 0.66 log units for the self-consistency of Nagata's data. Aldehydes, acids, unsaturated esters, and mercaptans were included in the equation through indicator variables that took into account the higher potency of these compounds. The ODTs obtained by Cometto-Muñiz and Cain, by Cometto-Muñiz and Abraham, and by Hellman and Small could be put on the same scale as those of Nagata to yield a linear equation for 353 ODTs with R(2) = 0.759 and SD = 0.819 log units. The compound descriptors are available for several thousand compounds, and can be calculated from structure, so that further ODT values on the Nagata scale can be predicted for a host of volatile or semivolatile compounds.

Compilation and analysis of types and concentrations of airborne chemicals measured in various indoor and outdoor human environments

“…Acute awareness of such exposures often arises from chemosensory sensations, principally odor, nasal chemesthesis (i.e., nasal pungency or irritation), and ocular chemesthesis (i.e., eye irritation). These human chemosensations are the focus of our research interest (Cometto-Muniz and Abraham, 2008Abraham, , 2010aCometto-Muñiz et al, 2010), with special emphasis on the search for quantitative structure-activity relationships in terms of detection thresholds (Abraham et al, 2003(Abraham et al, , 2007(Abraham et al, , 2012Cometto-Muniz and Abraham, 2010b;Cometto-Muniz et al, 2005). In general, no matter what the particular focus might be for the study of environmental chemical exposures, previous knowledge of the kind and levels of airborne compounds that have been found in different types of broad environments constitute an Table 1 Comparison of vapor concentration levels for indoor volatile compounds common to home/school and commercial environments (ratios based on geometric means).…”

An assessment of air quality reflecting the chemosensory irritation impact of mixtures of volatile organic compounds

“…(5) are available (Abraham et al, 2010b(Abraham et al, , 2012Absolv, 2014), and the indicator variables that act through specific effects, g in Eq. (5) The data that we have used is summarized in Table 5, which gives the various locations, the number of VOCs analyzed, and references to the source of the data.…”

“…We showed in the case of ODT values (Abraham et al, 2012) that when log ODT for a homologous series of compounds in one data set were compared to corresponding values of log ODT in another dataset, there was a constant difference between the two sets, and this is the reason why the method of indicator variables works reasonably well. However, it would be useful if exceptions to this 'rule' were identified and treated in a more sophisticated way.…”

“…Although Eq. (2) has been applied to eye irritation thresholds and nasal pungency thresholds (Abraham et al, 2001), the number of variables has been given (Abraham et al, 2012). N is the number of data points; this is not the same as the number of VOCs, because many VOCs are in more than one data set.…”

Receptor arrays optimized for natural odor statistics

“…The range of concentrations that can be detected by the receptor array is given by the ratio of the largest concentration c max at which concentration differences can be detected to the lowest detectable concentration c min , the odor detection threshold (30). In terms of η, the logarithm of the concentration range ζ = c max =c min reads (see Supporting Information)…”