湿热环境重强度劳动时的湿黑球温度界限

WET GLOBE TEMPERATURE LIMIT FOR HEAVY WORK IN HUMID-HOT ENVIRONMENTS

本文依据战士在湿热条件下进行时速6km负重行军时的生理反应,提出适于我军重强度作业使用的湿黑球温度(WGT)的界限值标准.实验在热区野外进行,观察行军过程受试者的肛温、心率、出汗率、皮肤温度等项生理指标以及自觉症状.结果提示:(1)在热环境下重强度劳动者的生理反应与WGT密切相关,p皆小于0.01;(2)WGT能够很好地反映与人体热紧张程度相应的环境热强度;(3)重强度劳动4h的WGT安全上限值为26.5～27.0℃;(4)当WGT为28.2±1.0、29.4±1.0、30.5±0.6℃时,重强度劳动的耐受时间分别为3、2和1h左右.

In a previous study,we found out the safe and tolerable WGT （wet globe temperature） for moderate work in humid hot environments.In this study,we tried to determine the suitable limit for heavy work.The subjects were 60 fit adult males of 20.0±1.0 yrs of age,164.0±4.0cm of height,55.5±4.3kg of weight.In the experiments,the subjects marched at a speed of 6 km·hr-1 with a backpack of about 20kg （33% of body weight） under different WGT conditions ranging from 26.3 to 30.5℃.The physiological parameters including heart rate,sweating rate,rectal temperature,mean body temperature and skin temperature etc were measured.The results showed that the WGT was closely related to physiological parameters of the men working in hot environments.The results further proved that the WGT,measured by TH-A wet globe thermometer,is a desirable heat stress index.The safe limit WGT for men working for 4 hrs is proposed to be 26.5-27.0℃.At WGTs 28.2±1.0,29.4±1.0 and 30.5±0.6℃,the tolerance times for men working in the heat were 3,2 and 1 hrs respectively.