Non-occupational pneumoconiosis at high altitude villages in central Ladakh.

An epidemiological survey was carried out to investigate the occurrence of non-occupational pneumoconiosis in Ladakh, where there are no mines or industries. The clinicoradiological investigations of 449 randomly selected subjects from three villages showed typical cases of pneumoconiosis associated with progressive massive fibrosis and egg shell calcification of hilar glands. The prevalence of pneumoconiosis in these three villages was 2.0%, 20.1% and 45.3% and it corresponded with the severity of dust storms and the use of chimneys in the kitchens. The dust concentrations in the kitchens with no provision for a chimney were very high. The free silica content of the storms was between 60 and 70%. Exposure to free silica from dust storms and soot from domestic fuels are suggested as causes of these cases of pneumoconiosis.