勞工戶外作業熱危害之研究與建議

Abstract

本研究主要目的為探討戶外熱環境作業對勞工容許熱暴露之影響，以研究如何有效利用規範來將熱危害降低之方法。此研究重點於蒐集戶外熱環境參數資料，例如：乾球溫度、濕球溫度及輻射溫度等變數。研究方法是利用一台高溫環境熱應力監測計，分別在台北、台中及台南三地由九月至十一月，量測上述三個變數進行加權，即可得知室外綜合溫度熱指標(Wet Bulb Globe Temperature，簡稱為WBGT)。戶外工作有許多種，本研究是以割草工作為對象。由美國政府工業衛生師協會(American Conference of Governmental Industrial Hygienists，簡稱為ACGIH)規範可知，割草工作界定為中度工作，在不同的綜合溫度指標下，可以將中度工作的工作時間及休息時間進行不同的分配。但是，濕球溫度和輻射球溫度一般較難以取得，所以再利用酷熱指標(Heat Index)進行熱環境評估，因為酷熱指數是由較容易取得的溫度與相對濕度數值加權而得。以迴歸法進行分析，可得酷熱指標與溫度以及相對濕度之關係。

The purpose of this study is to examin the effect of the outdoor thermal environment on the allowable exposure time of workers. In this study, a suitable specification is chosen and used to evaluate the thermal hazard. Important outdoor thermal environment data, such as Dry Bulb temperature, Wet Bulb temperature and Globe temperature will be collected by an apparatus called a Heat Stress Monitor. The locations and months for measurement were Taipei, Taichung and Tainan from September to November 2010, respectively. From these data, an outdoor Wet Bulb Globe Temperature (WBGT) can be obtained. There are numerous outdoor works. Our subject focuses on workers who use grass trimmers and brush cutters. According to the standard proposed by the American Conference of Governmental Industrial Hygienists (ACGIH), this kind of work is medium duty. However, it is difficult to obtain the data of the wet bulb temperature and globe temperature, Another convenient way to evaluate the thermal environment is to use a Heat Index (HI). The heat index can only be calculated from the temperature and relative humidity through a weighted process. By means of regression analysis the relationship between the heat index, temperature, and relative humidity can then be obtained.