Chronic obstructive lung disease in gold miners

A survey has been made of 2209 gold miners in the Republic of South Africa. The result showed that there is a significant dose-response relationship between dust inhaled and both chronic bronchitis and airways obstruction. This is found in smokers, ex-smokers and non-smokers. The effect of smoking is more potent than that of dust but there does not appear to be a dose-response relationship in regard to smoking. The effect of smoking differs from the effect of dust in that ex-smokers show less bronchitis and less airways obstruction than smokers, but ex-miners do not show a similar advantage over working miners.