Effects of Emissions From Cedar Timber on Psychological and Physiological Factors in Indoor Environment

Abstract

PP-29-130 Background/Aims: Improvements in health conditions or symptoms of occupants have been observed after installing indoors the natural wood timber not laminated or composited. However, the scientific evidence has not been almost cleared. Effects of cedar timber as a material for controlling humidity and contamination in indoor environment have been reported. Effects of components extracted from cedar timber on reducing human stress have also been reported. Hence, if positive influence due to cedar timber in indoor environment could be scientifically available, indoor environment that contributes to health improvement or promotion could be proposed. Our purpose of this study is to evaluate the effects of emissions from cedar timber on psychological and physiological factors in indoor environment. Methods: A case control study was conducted in which 10 subjects on crossover design occupied in 2 rooms controlled on interior materials, indoor climate, and room size. Cedar timber was installed in one of the rooms and covered by curtain so that the subjects could not notice it. Salivary amylase, salivary cortisol, blood pressure, and heart rate variability were measured, and a questionnaire survey on psychological factors was conducted. Indoor volatile organic compounds were also measured. Results: We found higher mean concentrations of cedrol and β-eudesmol in indoor air among cases than among controls (4.5 vs. 0.08 μg/m3 and 6.3 vs. 0.02 μg/m3, respectively). No significant differences were found in amylase activity, cortisol concentration, blood pressure, and heart rate variability between both subjects. In a questionnaire survey on psychological factors, no significant differences were also found in tension, depression, anger, vigor, fatigue, and confusion. A significant decrease in vigor was found in the control subjects between before and after entering the room but such decrease was not found in the case subjects. Conclusion: Our result showed a slight change on vigor in short-term exposure to cedar timber.