Amelioration of odorous components in spent mushroom compost.

Volatile sulfur compounds, as well as other volatiles found in the headspace above spent mushroom compost (SMC), were analyzed by gas chromatography and mass spectrometry. Data from these techniques as well as organoleptic evaluation of both the SMC and the chromatographic eluant indicated that the volatile sulfur compounds and cresol were important odorous components in SMC; cresol was reported as a musty, cattle-feces aroma. Samples consisted of headspaces from untreated SMC as well as SMC stirred with 1% (by weight) powered activated carbon (PAC). SMC stirred with and without PAC reduced headspace volatile concentrations, but the stirred with added PAC further decreased concentrations of important malodorants such as volatile sulfur compounds and cresol.

Acetone odor and irritation thresholds obtained from acetone-exposed factory workers and from control (occupationally unexposed) subjects.

Sensitivity of olfaction (smell) and chemesthesis (irritation) was evaluated for 2-propanone (acetone) and 1-butanol in acetone-exposed workers (AEW; N = 32) during a workday and unexposed subjects (microES; N = 32). Irritation sensitivity was assessed using a method that relies on the ability of individuals to localize irritants on the body. When a volatile compound is inhaled into one nostril and air into the other, the stimulated side can be determined (lateralized) only after the concentration reaches a level that stimulates the trigeminal nerve (irritation); compounds stimulating olfaction alone cannot be lateralized. Intranasal lateralization thresholds offer an objective measure of sensory irritation elicited by volatile compounds. Test results indicated that neither olfactory nor lateralization thresholds for butanol differed between AEW and microES. Olfactory thresholds to acetone in AEW (855 ppm) were elevated relative to those of microES (41 ppm), as were lateralization thresholds (36,669 ppm and 15,758 ppm, respectively). Within AEW, level of occupational exposure was not correlated with thresholds. Other measures revealed that microES used more irritation descriptors than did AEW on trials where the acetone concentration was below the lateralization threshold. This is noteworthy because microES received lower concentrations of acetone to evaluate than did AEW. These results suggest that exposures to acetone induce changes in acetone sensitivity that are specific to acetone. The acetone concentrations eliciting sensory irritation using the lateralization technique were all well above current occupational exposure standards. The current study indicates that acetone is a weak sensory irritant and that sensory adaptation is an important factor affecting its overall irritancy.

Perceived odor, irritation, and health symptoms following short-term exposure to acetone.

The subjectivity of irritancy judgments can bias attempts to establish exposure guidelines that protect individuals from the sensory irritation produced by volatile chemicals. At low to moderate chemical concentrations, naive and occupationally exposed individuals often show considerable variation in the reported levels of perceived irritation. Such variation could result from differences in exposure history, differences in the perceived odor of a chemical, or differences in generalized response tendencies to report irritation, or response bias. Thus, experimental evaluation of sensory irritancy must dissociate sensory irritation from response bias. To this end, judgments of perceived irritation from 800 ppm acetone were obtained from acetone-exposed workers and age- and gender-matched naive controls. To assess the role of response bias during exposure to odorants, subjects were also exposed to phenylethyl alcohol (PEA), an odorant that does not produce sensory irritation. Following exposure, subjects completed a subjective symptom survey that included symptoms that have been associated with long-term solvent exposures and symptoms that have not. Acetone-exposed workers and naive controls reported large differences in the perceived intensity of odor and irritation from acetone, yet no differences in the perception of PEA. However, for both groups, the most significant factors mediating reported irritancy and health symptoms from acetone were the perceived intensity of its odor and an individual's bias to report irritation from PEA. The perception of odor intensity and degree of response bias will differ between and within groups of exposed and naive individuals; hence, an assessment of the influence of these factors in experimental and workplace studies of chemical irritancy is warranted.

The influence of cognitive bias on the perceived odor, irritation and health symptoms from chemical exposure.

OBJECTIVE: Responses to volatile chemicals are often subjective and variable, both over time and across individuals. Although variability can derive from differences in individual olfactory sensitivity, the response to a chemical stimulus is also influenced by the complex environment surrounding the exposure, which can include the perceiver's cognitive state. To explore the role of cognitive bias in chemical exposures, we evaluated whether information about the consequences of exposure to acetone could influence ratings of odor and irritation during exposure and/or the frequency or intensity of reported health symptoms following exposure. METHODS: Ninety adults (mean age 33.7, range 25-64) with no history of occupational exposure to solvents, were exposed to 800 ppm acetone in a chamber for 20 min. To control for non-specific responses to the odor of acetone, the subjects were also exposed for 20 min to 200 ppm phenylethyl alcohol (PEA), a non-irritant volatile chemical that produces a distinct odor but does not elicit irritation in the vapor phase. Subjects were assigned to one of three groups (n = 30/group); each group was given either a positive, negative or neutral bias towards the consequences of exposure to the chemicals in the study. During exposure, subjects rated the intensity of odor and irritation; following exposure, they completed symptom questionnaires. RESULTS: During the 20-min exposure to acetone, the positive bias group exhibited the most adaptation to its odor and the lowest perceived irritation; following exposure they reported the fewest health symptoms. In contrast, the negative bias group rated higher levels of odor intensity and, on average, reported the most over-all irritation; following exposure they reported significantly more health symptoms than the other groups, None of the demographic variables studied (e.g., age, gender, race, smoking status) were predictive of the response to odor or irritation. The perceived irritancy of acetone was well predicted by a linear combination of the perceived odor of acetone and perceived irritation for PEA (the nonirritant), r2 = 0.73. CONCLUSIONS: The results provide strong evidence that both the perceived odor and cognitive expectations about a chemical can significantly affect how individuals respond to it. Moreover, because naive control subjects appear to exhibit extreme variation in their cognitive evaluations of chemical effects, there may be limited value in using non-exposed controls to assess the irritancy of chemicals for worker populations.

Analysis of characteristic odors from human male axillae.

A number of studies concerning the analysis of axillary odors have assumed that the characteristic odor produced in the axillae is due to volatile steroids and isovaleric acid. Organoleptic evaluation of Chromatographic eluants from axillary extracts was employed to isolate the region in the chromatogram where the characteristic odor eluted. The odor of the dissolved eluant was eliminated when it was treated with base, suggesting that acids make up the characteristic axillary odor. Subsequent extraction of the pH-adjusted axillary extract in conjunction with organoleptic evaluation of the Chromatographic eluant, preparative gas chromatography, and analysis by GC-MS as well as GC-FTIR showed the presence of a number of C6 to C11 straight-chain, branched, and unsaturated acids as important contributors to the axillary odor. The major odor component is (E)-3-methyl-2-hexenoic acid. Three homologous series of minor components are also important odor contributors; these consist of the terminally unsaturated acids, the 2-methyl-C6 to -C10 acids and the 4-ethyl-C5 to -C11 acids. These types of acids have not been reported previously as components of the human axillary secretions and have not been proposed previously as part of the principal odor components in this area.

Human axillary secretions influence women's menstrual cycles: the role of donor extract from men.

Menstrual cycle lengths of 29.5 +/- 3 days ("normal cycles") are more frequent in women who have weekly coital activity than in women who do not. In order to investigate potential mechanisms controlling the association between heterosexual activity and menstrual cycle length, and in light of the nonhuman literature suggesting that a chemical signal from males could be involved, menstrual cycle lengths of nulliparous women were evaluated following regular application of axillary extract from donor males. Compared to controls receiving only blank/ethanol applications, women receiving axillary extracts for 12.5 to 14.5 weeks showed the following changes: a reduced incidence in variability of cycle lengths; and a reduced proportion of aberrant length cycles.

Human axillary secretions influence women's menstrual cycles: the role of donor extract of females.

Menstrual synchrony in human females has previously been demonstrated among women attending a predominantly female university as well as among women attending coeducational universities. In each of these studies, women who spent the most time together were most likely to show the menstrual synchrony. In this experiment, the possibility that substances in axillary secretions might mediate this effect was tested using a prospective, double-blind research design and a combined axillary extract from a group of female donors. Female subjects who reported themselves to have normal (29.5 +/- 3 day) cycles were exposed to the axillary extracts or blank/ethanol for 10 to 13 weeks. Recipients of the axillary extracts showed a significant reduction in "days' difference in menses onset" relative to the donor cycle, no change was evident for recipients of blank/ethanol. These results demonstrate that constituents from the axillary region of donor females can shift the time of menstrual onset of another group to conform with the donors' cycle and that this effect can occur even in the absence of social contact.