Psychophysiological functions of subjects with self-reported multiple chemical sensitivity (sMCS) during experimental solvent exposure

Abstract

AbstractThe study examined the assumption of a higher sensitivity of autonomic functions of subjects with self-reported multiple chemical sensitivity (sMCS) during environmental exposure. The hypothesis was tested in a laboratory study with standardized exposures.Twelve healthy male subjects (26.4±5.4y) with and 12 male control subjects (25.7±3.8y) without self-reported multiple chemical sensitivity (sMCS), selected by a questionnaire, were included in the experimental study. At four different days the subjects were exposed in a random order to solvents for four hours: 10ppm or 98ppm ethyl benzene, 10ppm or 189ppm 2-butanone. Heart rate and breathing rate were analysed for two 30-minutes periods of vigilance testing at the beginning and end of exposure.In sMCS-subjects both functions were elevated at the beginning of the testing periods with a tendency to decrease over the 30-minutes periods. Control subjects revealed a relatively constant level (breathing rate) and a small increase (heart rate) during the periods. These group differences were obvious for all experimental conditions across substances and levels of exposures. Furthermore, the mean of the breathing rate of sMCS-subjects was generally higher compared to the control subjects. While the assumption of a generally altered sensitivity of autonomic functions of sMCS-subjects to environmental changes seems to be supported, no specific reactions to the type or level of the chemical exposure were found.