Correlation of symptoms of sick-building syndrome to chemical and odor concentration levels

摘要

[Background] Sick-building syndrome (SBS) is a range of symptoms such as eye irritation, sore throat and headaches that occur when entering a newly constructed or remodelled building.Volatile organic compounds (VOCs) are suspected to be one of the major causes of SBS. In addition, there are reports that when people complain of symptoms of SBS, most of them also claim to smell an odour. [Aims] The aims of this study were (1) to quantify the odour in indoor air, (2) to examine the correlation between the concentration levels of total VOCs (TVOC) and SBS symptoms, and (3) to examine the correlation between odour and SBS symptoms. [Methods] The concentration levels of chemicals in indoor air of the 13 study sites in Chiba University were measured and analyzed.The odour threshold ratio (OTR) was developed to quantify odour by using odour threshold and concentration values for each VOC in indoor air.Next, for the evaluation of indoor air quality by human sensory perception, 218 healthy volunteers stayed for 15 minutes at the 13 study sites and answered questionnaires which inquired about the odour and symptoms. Then correlations of SBS symptoms to TVOC andtotal odour threshold ratio (TOTR) values were examinedstatistically among sensitive and insensitive groups. [Results] There were 218 subjects,of which 134 were female and 84 were male. 35.8% of females and 34.5% of males were classified as being sensitive to chemicals. The percentage of participants who complained of symptoms was 36.7%. It was found that TVOC and TOTR values were significantly correlated with SBS symptoms, especially among the sensitive group when the concentration level of TVOCs was greater than about 400 μg/m3 (95%CI 1.06-14.33) and the level of TOTR was greater than about 40 (95%CI 1.03-20.35). [Conclusion] This study revealed the baseline level of TVOC that may cause SBS symptoms to be about 400 μg/m3and a TOTR value of about 40.lt also suggests that TOTR could be used asa new indicator forevaluating the effects ofindoor air quality on human health.