本研究主要目的在於探討熱作業環境各環境物理變項對勞工容許暴露時間之影響程度，以研擬有效的改善策略及熱控制技術。研究內容包括一、收集熱作業環境現場勞工生理代謝資料及各環境變項之量測，並依生理觀點之熱作業熱危害評估模式 (ISO 7933) 推估容許暴露時間；二、研擬適當的分析方法，以求取熱作業環境之改善策略，並依據最小焓值之工程控制技術以獲得最省能之環境條件；三、運用熱暴露腔就改善前、後之熱環境條件加以驗證。本研究嘗試以本省一家鋼鐵廠及一家染整廠為例，利用熱作業環境之實測資料，針對前述內容加以探討。研究結果發現，鋼鐵廠與染整廠之乾球溫度 (平均值±標準差) 分別為35.4±1.4℃及33.8±2.3℃、黑球溫度分別為41.2±4.3℃及34.8±1.9℃、溼度分別為1.5±0.1 kPa及3.0±0.4 kPa、風速分別為1.16±0.4 m/s及0.6±0.2 m/s；而以ISO 7933進行評估，勞工之容許暴露時間分別為316±15分鐘及323±49分鐘。經利用蒙第卡羅模擬及敏感度分析之結果發現，影響鋼鐵廠勞工容許暴露時間之主要環境變項依序為溼度、風速、乾球溫度；而染整廠則為溼度、乾球溫度、風速。經利用前述結果，本研究以最小焓值之工程控制技術可搜尋出容許暴露時間達480分鐘之熱作業環境條件。經運用熱暴露腔驗證之結果發現，鋼鐵廠與染整廠勞工之容許暴露時間，其實驗值與理論推估值之差異均小於10分鐘。綜上所述，本研究所建立之系統分析模式，可合理及有效的選取熱作業場所之改善策略，故對於工業衛生人員控制熱環境危害應有所助益。

The objectives of the present study were to assess the effects of physical environmental factors on workers’ allowable exposure time (AET). The contents of this study include: (1) measuring physiological and environmental variables of workers in thermal environments, and using a physiological-based thermal hazard predicting method (i.e. ISO 7933) to predictive AET; (2) by using appropriate techniques to initiate a control strategy, and using the technique of minimum entropy to obtain an effect control method for thermal environments from energy-saving aspect; (3) by using a thermal exposure chamber to verify the above proposed control strategy and method. One steel casting plant and one dying plant were chosen in this study to conduct environmental monitoring. The result indicates that air temperature was 35.4± 1.4 °C and 33.8± 2.3 °C,globe temperature was 41.2± 4.3 °C and 34.8± 1.9 ℃,humidity was 1.5± 0.1 kPa and 3.0± 0.4 kPa, and air velocity was 1.16± 0.4 m/s and 0.6± 0.2 m/s of steel casting and dying plants, respectivily. Via the use of ISO 7933, the workers’ AET was less than 480 minute. The control strategy and technique in this present study can obtained the environmental combinations that AET reach to 480 minute. AET difference between the theoretical predicted AET and experiment AET in tne thermal exposure chamber were less than 10 minutes. The results obtained from this study will be helpful for industries to resolve thermal hazard problems for workers in thermal environments.

American Conference of Governmental Industrial Hygienists (ACGIH), 1976; “Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1976, ”Cincinnati, OH.
American Conference of Governmental Industrial Hygienists ACGIH, 1990; “Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices for 1990-1991, ”Cincinnati, OH.
American Conference of Governmental Industrial Hygienists ACGIH, 1999; “Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices for 1998-1999, ”Cincinnati, OH.
American Conference of Governmental Industrial Hygienists ACGIH, 2000; “Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices for 1999-2000, ”Cincinnati, OH.
Astrand, P., and Rodhal, K., 1986; “Textbook of Work Physiology–physiological bases of exercise, 3rd Ed., New York, McGraw-Hill: 296-348.
Belding, H. S., and Hatch, T.F., 1955; “Index for Evaluating Heat Stress in Terms of Resulting Physiological Strain, ” Heat Piping Air Cond. 25(6): 129-135.
Beshir, MY., El-Sabagh, AS., and El-Nawawi, MA., 1988; “A Comprehensive Comparison Between WBGT and Botsball, ” Am. Ind. Hyg. Associ. J., 42 (1): 81-87.
Bruce, A. H., and Frederick, S., 1963; “Acclimatization of women during work in hot environments,” Federation Proceedings., 22:810-813.
de Dear, R. J., Leow, K. G., and Ameen, A., 1991; “Thermal comfort in the humid tropics-part I: climate chamber experiments on temperature preferences in Singapore,” ASHRAE Transactions: Symposia., 16-2:874-879.
de Dear, R. J., Leow, K. G., and Ameen, A., 1991; “Thermal comfort in the humid tropics-part II: climate chamber experiments on thermal acceptability in Singapore,” ASHRAE Transactions: Symposia., 16-3:880-886.
Dukes-Dobos, F. N., and Henschel, A., 1980; “Proceeding of a NIOSH Workshop on Recommended Heat Stress Standards, ” U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health (NIOSH), Cincinnati, OH., U.S.A. .
Edwin, L. A., 1983; “Temperature Extremes, ” In Fundamentals of Industrial Hygiene, 3rd (ed), U.S.A., National Safety Council Publishers: 259-265.
Fang, L., Clausen, G., and Fanger, P. O., 1998; “Impact of temperature and humidity on perception of indoor air quality during immediate and longer whole-body exposures,” Indoor Air., 8:276-284.
Givoni, B., and Goldman, R. F., 1973; “Predicting heart rate response to work,environment, and clothing,” Journal of Applied Phydiology., 34 (2): 201-204.
Griefahn, B., 1997; “Acclimation to three different hot climates with equivalent wet bulb globe temperatures,” Ergonomics., 40(2):223-234.
Hawkins, N. C., Jayjock, M. A., Lynch, J. , 1992; “A rationale and framework for establishing the quality of human exposure assessment, ” Am. Ind. Hyg. Assoc. J. 53: 34-41.
Houghten, F. C, and Yaglou, C. P, 1923; “Determing Lines of Equal Comfort, ” ASHVE Trans., 29 (10): 163-176.
International Labor Organization (ILO), 1983; “Encyclopaedia of Occupational Health and Safety, “ 3re Ed, Vol 2, Geneva: 1698-1700.
International Standards Organization (ISO), 1985, Geneva; “ISO 7726: Thermal Environments-Instruments and Methods for Measuring Physical Quantities, ” 2-39.
International Standards Organization (ISO), 1989, Geneva; “ISO 7243: Hot Environment-Estimation of the Heat Stress on Working Man, Based on the WBGT-Index (Wet Bulb Globe Temperature), ” :2-39.
International Standards Organization (ISO), 1989, Geneva; “ISO 7933: Hot Environments-Analytical Determination and Interpretation of Thermal Stress Using Calculation of Required Sweat Rate. Annexes: Computer program Allowing the Calculation of the Required Sweat Rate and of the Allowable Exposure Time in Any Thermal Environment, ”: 1-19.
International Standards Organization (ISO), 1990, Geneva; “ISO 8996: Ergonomics-Determination of Metabolic Heat Production, ”: 1-19.
International Standards Organization (ISO), 1992, Geneva; “ISO 9886: Evaluation of Thermal Strain by Physiological Measurements, ”: 1-13.
International Standards Organization (ISO), 1994, Geneva; “ISO 7730: Moderate Thermal Environments -Determination of the PMV and PPD Indices and Specification of the Conditions for Thermal Comfort. Annexes: Computer Program for Calculating Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD), ”: 1-44.
International Standards Organization (ISO), 1995, Geneva; “ISO 9920: Ergonomics of the Thermal Environment-Estimation of the Thermal Insulation and Evaporative Resistance of a Clothing Ensemble, ”: 1-54.
Jayjock, M. A., 1997; “Uncertainty analysis in the estimation of exposure,” Am. Ind. Hyg. Assoc. J. 58: 380-382.
Keilblock, A. J., and Schutte, P. C., 1988; “Physical Work and Heat Stress, ” In LaDou, J, “Occupational Medicine: Principles and Practical Applications, 2nd Edition, “ Mosby, Chiago, U.S.A. :60-120.
Knochel, J. P., 1974; “Environmental Heat Illness, ” Arch. Intern. Med., 133 (10): 841-864.
Kerslake, D. McK., 1972; “The stress of hot environments “ Cambridge, University Press: 222-254.
Lind, A. R., and Bass, D. E., 1963; “Optimal exposure time for development of acclimatization to heat,” Federation Proceding., 22: 704-708.
Mehnert, P., Malchaire, J., Kampmann, B., Piette, A., Griefahn, B., and Gebhardt, H., 2000; “Prediction of the average skin temperature in warm and hot environments,” 82: 52-60.
Nielsen, B., Hales, J. R. S., Strange, S., Christenden, N. J., Warberg, J., and Saltin, B., 1993; “Human circulatory and thermoregulatory adaptations with heat acclimation and exercise in a hot, dry environment,” Journal of Physiology., 460: 467-485.
Nielsen, B., 1998; “Heat acclimation-mechanisms of adaptation to exercise in the heat,” Int. J. Sports Med. , 19:S154-S156.
Powers, S. K., and Howley, E. T. , 1997; “Exercise physiology, ” the third edition.
Shapiro, Y., Moran, D., Epstein, Y., Stroschein, L., and Pandolf, K. B., 1995; “Validation and adjustment of the mathematical prediction model for human sweat rate responses to outdoor environmental conditions,” Ergonomics., 38 (5): 981-986.
Squire, D. L., 1990; “Heat Illness, ” Pediatric Clinics of North America, 37 (5): 1085-1109.
Stephen, C. S., and Mclellan, T. M., 1998; “Heat acclimation, aerobic fitness, and hydration effects on tolerance during uncompensable heat stress,” Journal of Applied Physiology., 84 (5): 1731-1739.
Takamata, A., Ito, T., Yaegadhi, K., Takamiya, H., Maegawa, Y., Itoh, T., Greenleaf, J. E., and Morimoto, T., 1999; “Effect of an exercise-heat acclimation program on body fluid regulatory responses to dehydration in older men,” American Journal of Physiology., 277 (4 pt 2): R1041-R1050.
World Health Organization (WHO), 1969; “Health Factors Involved in Working under Condition of Heat Stress, ” Technical Report Series No. 412, Geneva: 1-38.
Wyon, D. P., and Sandberg, M., 1996; “Discomfort due to vertical thermal gradients,” Indoor Air., 6:48-54.
Yaglou, C. P., and Minard, D., 1957; “Control of Heat Casualties at Military Training Centres, ” J. Arch. Ind. Health., 16(3):302-320.
Youngren, S. H., Youngren, M. A., Barraj, L., 2001; “Challenges of probabilistic assessment of operator and residential non-dietary exposure,” Ann Occup Hyg 45: s49-s54.
行政院勞委會，1998，台北；“高溫作業勞工作息時間標準”。
葉文裕、林守香、及陳旺儀，1998; “國內勞工熱危害適應評估模式研究”，行政院勞委會勞工安全衛生研究所，IOSH87-H328：17-51。
郭育良等，1998；“職業病概論”。