Author(s)

H. Nakaoka, H. Seto, E. Todaka, N. Suzuki, C. Mori

Abstract

This paper reports a case study about the relationship between the symptoms of multiple chemical sensitivity (MCS) and indoor air chemicals. In April 2014, a 40-year-old man visited the Environmental Medical Clinic, Chiba University, claiming repeated symptoms of MCS after purchasing an electronic piano. Samples of indoor air from the living room of the patient’s house were collected and chemicals were analysed eight times – when an electronic piano and toys for children were either present or absent, and the floor heating system was on and off. Indoor air in a university office, and outdoor air were used as controls. As a result, it was found that the concentrations of 13 VOCs, for which the Ministry of Health Labour and Welfare of Japan (MHLW) set guideline values, were lower than the guideline values in all the samples. The total volatile organic compounds (TVOC) in three indoor air samples collected from the patient’s house were 550, 520, and 460 μg/m³; slightly higher than the target value (400 μg/m³) of TVOC set by the MHLW. The patient claimed to have the symptoms in all three cases. Furthermore, symptoms were reduced or eliminated when ventilation was conducted, or the patient was exposed to the outdoor air. A tendency was found that symptoms were strengthened as TVOC increased. In conclusion, MCS symptoms in this case were related to indoor air quality, and symptoms appeared even when the 13 VOCs for which the guideline values are set were lower than the guideline values. Therefore, it can be said that TVOC could be used as an indicator of the effects of indoor air quality on human health.

Keywords

indoor air chemical exposure, adverse health effects, indoor air quality, multiple chemical sensitivity, total of volatile organic compounds