Asthma in goldminers.

OBJECTIVES: To determine whether asthma in goldminers is caused by or contributed to by their working environment. DESIGN: A case-control study in which men with asthma working underground in goldmines were compared with underground goldminers without asthma in relation to their age, duration of exposure to the underground environment, atopy and family history of asthma. SETTING: An in- and outpatient facility providing for the medical needs of approximately 90 000 miners employed on goldmines in the Free State. OUTCOME MEASURES: Occupational history, atopy and family history of asthma were compared in the two groups. The age of onset of asthma and duration of occupational exposure were examined in the men with asthma. RESULTS: The study sample included 78 underground miners with asthma and 46 without asthma. The men in the two groups were of similar age, but those with asthma had worked underground for a longer period than the men without asthma. Twenty of the asthmatic and none of the control group had been exposed to paint and cement in the course of their work. Fifty of the asthmatic and only 3 of the control group were atopic. The mean age of onset of asthma (+/-SD) was 30.6 +/- 10.73 years. Six of the men had developed asthma before starting to work in the mines, and the disease had developed 13.4 +/- 8.22 years after starting to work underground in the remaining 72. CONCLUSION: The late age of onset and the onset after exposure to the underground environment suggest that the disease was work-related.

Silicosis, chronic airflow limitation, and chronic bronchitis in South African gold miners.

In a cross-sectional study of a working population of black South African gold miners, 1,197 men were studied with respiratory and occupational questionnaires, lung function tests, and chest radiographs. The study was designed to examine the effects of silicosis on respiratory symptoms and lung function. A total of 857 men with chronic, simple silicosis and 340 men without silicosis were included in the sample. Other determinants of lung disease including the duration and intensity of underground dust exposure and tobacco smoking were also examined. Three distinct pulmonary disorders could be discerned: silicosis-associated pulmonary dysfunction with dyspnea on effort; chronic airflow limitation, which was related to the duration of underground exposure; and a chronic bronchitic symptom complex, which reflected the intensity of dust exposure in the workplace. Chronic, uncomplicated silicosis was found to be associated with significant loss of lung function, and all of the measured indices, FVC, FEV1, FEV1/FVC%, maximal midexpiratory flow rate (MMEF), and lung diffusion for carbon monoxide measured by the single-breath method (DLCO) were reduced. When comparing men with Category 3/3 nodule profusion with men without silicosis, reductions of FVC of 351 ml, FEV1 of 447 ml, MMEF of 1.04 L/s, and DLCO of 4.7 ml/min/mm Hg (p = 0.0001) were detected after controlling for age, height, the direct effects of the underground environment, and tobacco smoking. Dyspnea on effort was more common in the men with silicosis (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)