Journal of the Human-Environment System
Online ISSN : 1349-7723
Print ISSN : 1345-1324
ISSN-L : 1345-1324
Volume 13 , Issue 1
Showing 1-3 articles out of 3 articles from the selected issue
  • Takafumi MAEDA, Mitsuhiro OHTA, Shin-Ya KANEKO, Hideyuki KANDA, Tetsuh ...
    2010 Volume 13 Issue 1 Pages 1-6
    Published: 2010
    Released: July 07, 2011
    JOURNAL FREE ACCESS
    Several risk factors for heatstroke among forestry workers were previously reported, but the effects of lifestyles of the workers on heatstroke symptoms remain unknown. This study examines the effects of lifestyles on heatstroke symptoms among Japanese forestry workers during the summer. We distributed a questionnaire to 97 forestry workers about heatstroke symptoms, hydration, hotness in workplace, lifestyles including food consumption, sleep duration, exercise, alcohol consumption, and smoking, age, and years of forestry service, and measured physical characteristics. The total health score was used as an index of healthy habits. Thirty-seven workers (38.1%) experienced heatstroke symptoms. Heatstroke and asymptomatic groups significantly differed in terms of age, years of forestry service, frequency and volume of hydration, frequency of urination, and perceived hotness. Logistic regression analysis selected the following key variables associated with the development of heatstroke symptoms: years of forestry service, frequency of hydration adjusted by frequency of urination, and total health score. In conclusion, the present study revealed that one third of forestry workers develop some early symptoms of heatstroke during work, and healthy habits reduce the risk of heatstroke in forestry workers.
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  • Joo-Young LEE, Kouhei NAKAO, Yutaka TOCHIHARA
    2010 Volume 13 Issue 1 Pages 7-14
    Published: 2010
    Released: July 07, 2011
    JOURNAL FREE ACCESS
    The purpose of the present study was to examine the extent of the variations in mean skin temperatures by Hardy and DuBois 7-point formula when different single trunk sites were assigned (T sk-chest, T sk- abdomen, and T sk-upper back for the chest, abdomen and back, respectively). The average of the three trunk sites (T sk-all) was considered as a reference value. Eight male subjects underwent twelve experimental conditions: activities (rest and exercise) × clothing (Control, Tyvek and Vinyl condition) × air temperatures (25°C and 32°C). The results showed that 1) for rest conditions, there was no difference among T sk-chest, T sk- abdomen, T sk-upper back, and T sk-all; 2) for exercising conditions at 25°C, T sk-upper back tended to be greater than T sk-chest, and T sk-abdomen. The differences were statistically significant for Control and Tyvek conditions (p<0.05); 3) for Control during exercise, T sk-abdomen was significantly lower than T sk-upper back (p<0.05); 4) T sk-all were not statistically distinguished from T sk-chest, T sk-abdomen, and T sk-upper back; 5) for Control during exercise, T sk- upper back overestimated T sk-chest and T sk-abdomen at T a 25°C, while T sk-abdomen underestimated T sk-upper back at T a 32°C. The variations were attributable to the differences in thermal dynamics of the abdomen and upper back tissues during exercise. For estimating the T sk of lightly clothed male subjects during exercise using Hardy and DuBois 7-point formula, reliance on the abdomen or the upper back as a site representative of the trunk is not recommended, but the average of the chest, abdomen, and back temperatures is recommended as the trunk temperature. In the case that the minimum number of skin sites is required due to dynamic exercise, a preferred single site on the trunk was the chest for male subjects.
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  • Su-Young SON, Yu XIA, Yutaka TOCHIHARA
    2010 Volume 13 Issue 1 Pages 15-24
    Published: 2010
    Released: July 07, 2011
    JOURNAL FREE ACCESS
    The purpose of the present study was to compare the mobility of firefighters wearing different combinations of protective clothing and evaluate the validity of three-dimensional (3D) motion analysis, subjective evaluation and electromyography (EMG) for such analyses. Both comfort and mobility were subjectively evaluated. The 3D motion analysis program used in the study examines seven experimental movements. Experimental ensembles were prepared for four experimental conditions: CO, standard inner uniform + firefighter clothing and gear; ST, inner uniform comprising short pants and a short-sleeved T-shirt + firefighter clothing and gear; SC, standard inner uniform + firefighter clothing and gear + self contained breathing apparatus (SCBA); MO, wet standard inner uniform + firefighter clothing and gear. The short pants uniform did not increase range of motion (ROM). However, participants felt comfortable and mobile in ST. The ROM results of SC showed that SCBA restricted whole body movements by almost 13.7%. Mobility of the lower body was decreased more than that of the upper body while wearing the wet inner uniform with firefighter clothing (17.4% vs. 11.1%). Whole body ROM was decreased by 9.5% while wearing MO. The EMG results did not significantly differ among all conditions. The weight of the SCBA and the friction of wet clothing significantly influenced mobility. Measuring ROM using 3D motion analysis was more effective than subjective evaluation and EMG.
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