Source of Support: None, Conflict of Interest: None
Check
A case control study of deceased quarry workers and controls comparing their age at the time of death was carried out. It showed that the mean age at death was 49.3 ± 12.1 years in quarry workers and 60.0 ± 14.4 years in non-worker controls. In another prospective study, a sample of 314 quarry workers and 40 ex-workers was followed up for a period of 17.4 ± 7.2 months to study their mortality rate. This study demonstrated that there was excess mortality in quarry works (Stanardised Mortality Ratio (SMR) = 1.84, 95% confidence interval 0.79 to 2.90). Mortality was higher in those with opacities suggestive of silicosis in chest skiagrams (age adjusted death rate 66.3 per thousand per year and SMR = 6.95), than in non-silicotics (age adjusted death rate 19.97 per 1000 per year and SMR = 1.63). Workers with pulmonary tuberculosis had significantly higher mortality than other quarry workers. Even in the absence of tuberculosis, mortality was more in silicotics (age adjusted death rate 24.9 per thousand per year, SMR 2.8)