Citation

Martinson MJ. J. Occup. Accid. 1977; 1(2): 171-193.

Copyright

(Copyright © 1977, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Martinson, M.J., 1977. Heat stress in Witwatersrand gold mines. Journal of Occupational Accidents, 1: 171-193.The Witwatersrand goldfields contain 42 active mines, the deepest of which has reached a depth of 3.6 km below surface. Since the turn of the century, when the maximum working depth was about 1.0 km, an increasing number of mines has experienced hot and humid working conditions due mainly to heat of autocompression being added to air as it flows down intake airways into underground workings and, since early in the century, the widespread use of water for dust suppression. The narrow, inclined tabular reefs containing gold are sandwiched in massive sedimentary quartzites, and ever since the discovery of gold on the Witwatersrand in 1886 mining methods used to extract the auriferous reefs have been based on an abundant supply of migratory Black labour recruited across southern Africa. However strenuous work in oppressive climatic conditions is conducive to high heat stress, and since 1924 heatstroke has been an endemic hazard in some Witwatersrand mines. Although the mortality rate in heatstroke is high the annual deathrate from heatstroke for all Witwatersrand mines has not been more than one or two per cent of the total deathrate for all occupational injuries, but on a few individual mines the deathrate has on occasions been disturbingly high. Other heat disorders -- notably heat exhaustion and prickly heat are undesirable but usually transient, while high heat stress has also been shown to have undesirable effects on accident rates, productivity, absenteeism, and sickness not directly related to heat stress. Strong air circulation and refrigeration are used to control environmental conditions, and Black mineworkers allocated to hot areas are required to undergo rigorous acclimatization before starting work underground.