Exposure of humans to a volatile organic mixture. II. Sensory.

Time-course functions for symptoms of the sick building syndrome were derived from 66 healthy males who, during separate sessions, were exposed to clean air and to a volatile organic compound (VOC) mixture. The mixture contained 22 VOCs (25 mg/m3 total concentration) commonly found airborne in new or recently renovated buildings. Subjects rated the intensity of perceived irritation, odor, and other variables before, and twice during, 2.75-h exposure periods. Eye and throat irritation, headache, and drowsiness increased or showed no evidence of adaptation during exposure, whereas odor intensity decreased by 30%. These results indicate that irritation intensity and other symptoms are not related in any simple way to odor intensity, which suggests that the symptoms may not be a psychosomatic response to the detection of an aversive odor. Instead, subthreshold levels of VOCs may interact additively or hyperadditively and stimulate trigeminal nerve receptors. Also, air quality ratings improved by 18% during exposure, which suggests that both odor and irritation intensity may influence assessments of air quality.