Annoyance and performance during the experimental chemical challenge of subjects with multiple chemical sensitivity

Multiple chemical sensitivities: A systematic review of provocation studies

“…20 Studies were categorized by the quality of blinding used: double-or single-blind studies that also included an odorous masking agent to prevent identification of the stimuli (Table I), [21][22][23][24][25][26] double-blind studies without masking (Table II), 11,12,[15][16][17][18][19][27][28][29][30][31][32] single-blind studies without masking (Table III), 13,14,[33][34][35][36][37][38][39][40][41][42][43][44] and open-label studies or studies with unclear blinding (see Table E1 in the Online Repository at www.jacionline.org). 10,[45][46][47] Studies using olfactory masking agents or nose clips Three studies testing 70 chemically sensitive participants incorporated blinding and an olfactory mask and failed to show any significant effects on subjects with MCS after provocation with chemicals.…”

Is multiple chemical sensitivity a learned response? A critical evaluation of provocation studies

“…There was no effect on eye blinking frequency, but the scores on two cognitive tests decreased during exposure. The issue of expectancy was addressed by Ö sterberg et al [24], who used a design which included measures of annoyance and irritation, as well as symptoms and cognitive function. Ten women with complaints 'compatible with' MCS for which they were being investigated at a clinic and 20 healthy controls were exposed on 2 days to increasing concentrations of n-butyl-acetate and toluene, both of which have neurotoxic properties.…”

“…In terms of the design, many of the studies tested the effects of chemicals which were not selected on the basis of the person's history or shown in the laboratory to be a problem [5,16,20,24]. Few of the reports gave details of the severity of the symptoms, either in real life or in the laboratory, although one study found significant differences between people with mild complaints and those with symptoms which had resulted in a change of lifestyle [26].…”

Neurobehavioral testing in human risk assessment

“…This lack of information covers both the general environment and the work environment where hazardous chemicals are handled. No epidemiological data from the working environment is available and there are just a few experimental studies reporting impaired task performance during controlled exposures to workplace chemicals (Osterberg, et al, 2004;Osterberg, et al, 2003;van Thriel, et al, 2003;van Thriel, et al, 2007). Without going into details, these studies showed that during exposure to malodorous chemicals (e.g.…”

“…toluene, 1-octanol), a sub-group of subjects that consider themselves chemically sensitive, performed poorer on some neuropsychological tests of attention than those volunteers not reporting chemical sensitivity. In three studies (Osterberg, et al, 2004;Osterberg, et al, 2003;van Thriel, et al, 2003) the sensitive subjects also reported stronger odor annoyance and their "impaired performance" might be a behavioral reflection of reduced well-being (McMillan, 1998). Since not all volunteers of these studies responded behaviorally to the odors the general impact on behavioral parameters of neuropsychological tests (e.g.…”