Occupational heat strain in a hot underground metal mine.
OBJECTIVE
In a hot underground metal mine, this study evaluated the relationship between job task, physical body type, work shift, and heat strain.


METHODS
Thirty-one miners were evaluated during 98 shifts while performing deep shaft-sinking tasks. Continuous core body temperature, heart rate, pre- and postshift urine specific gravity (USG), and body mass index were measured.


RESULTS
Cutting and welding tasks were associated with significantly (P < 0.05) increased core body temperature, maximum heart rate, and increased postshift urine specific gravity. Miners in the obese level II and III body mass index categories, as well as those working night shift, had lower core body temperatures (P < 0.05).


CONCLUSIONS
This study confirms that job task, body type, and shift are risk factors for heat strain.
From the Mining Safety and Health Program, Environmental and Occupational Health, Division of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson.
Eric A
EA
Lutz
Rustin J
RJ
Reed
Dylan
D
Turner
Sally R
SR
Littau
D000328:Adult; D015992:Body Mass Index; D001831:Body Temperature; D006339:Heart Rate; D018882:Heat Stress Disorders / Q000209:etiology*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D008906:Mining; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D012307:Risk Factors; D013046:Specific Gravity; D013647:Task Performance and Analysis
D008670:Metals