Nevertheless, the studies above have investigated the effects of a forest environment on human physiological and psychological activities compared with an urban environment in experiments of short-term forest bathing trips. A-1331852 Therefore, studies regarding the long-term health effects for workers living in a forest environment compared with those living in an urban environment are still limited. The objectives of this study were to compare the measurements of cardiovascular parameters and health-related quality of life in people working in forest and urban environments and to demonstrate the forest environment has superior air quality compared with that in an urban environment. Carotid atherosclerosis in the common carotid artery was assessed by measuring carotid IMT, using a high-resolution Bmode, GE Vivid i ultrasound system, equipped with a 3.5�C10 MHz real-time B-mode scanner. Details concerning the methods of carotid IMT measurements have been reported previously. In addition, a software package for vascular ultrasound was used. In general, duplex scanning ML-18 refers to an ultrasound scanning procedure, recording both B-mode images of gray scale from the arteries of interest, and Doppler information about velocity and resistance in the relevant segments. The maximum and mean carotid IMT proximal to the carotid bifurcation, bulb, and internal carotid artery were measured bilaterally. CCA1 and CCA2 are points located at 0�C1 cm and 1�C 2 cm, respectively, on CCA, distal to the carotid bifurcation. All scans were recorded on a digitalized memory system in DICOM format for subsequent off-line analysis. The carotid IMT measurement had excellent intraobserver coefficients of correlation reliability for maximum and mean carotid IMT with 0.976 and 0.988 at LCCA, and 0.970 and 0.973 at RCCA, respectively. This is the first study to demonstrate the health effects of forest environment by comparing traditional cardiovascular risk factors, noninvasive cardiovascular assessments, and detailed environmental monitoring simultaneously in middle-aged workers living in forest and urban environments. Studies have demonstrated that psychosocial and environmental factors play an important role in predicting cardiovascular health.