In-situ real-time monitoring of volatile organic compound (VOC) exposure and heart rate variability (HRV) were conducted for eight multiple chemical sensitivity (MCS) patients using a VOC monitor, a Holter monitor, and a time-activity questionnaire for 24 h to identify the relationship between VOC exposure, biological effects, and subjective symptoms in actual life. The results revealed no significantly different parameters for averaged values such as VOC concentration, HF (high frequency), and LF (low frequency) to HF ratio compared with previous data from healthy subjects (Int. J. Environ. Res. Public Health 2010, 7, 4127–4138). Significant negative correlations for four subjects were observed between HF and amounts of VOC change. These results suggest that some patients show inhibition of parasympathetic activities along with VOC exposure as observed in healthy subjects. Comparing the parameters during subjective symptoms and normal condition, VOC concentration and/or VOC change were high except for one subject. HF values were low for five subjects during subjective symptoms. Examining the time-series data for VOC exposure and HF of each subject showed that the subjective symptoms, VOC exposure, and HF seemed well related in some symptoms. Based on these characteristics, prevention measures of symptoms for each subject may be proposed.

This paper reports on the measurement results of ventilation rates in existing occupied houses in the northern region of Japan. A total of 61 measurements were made over a period of 4 years on 39 houses. Some houses were measured once a year over the four years investigation period. The ventilation systems equipped in some of the investigated houses were improved during the course of this investigation period. The effect of the improvement on ventilation airflow volume was reported. The ventilation rates were measured by three different methods, namely constant concentration method, measurement of airflow rate at inlets/outlets and passive homogeneous emission method. Through this investigation, the measurement results indicated that the ventilation rate was insufficient in many houses and some of the ventilation systems were not operated properly. In addition, the amount of air leakage in the house envelope and the amount of air change due to occupant behaviour were also determined.