This study was undertaken to investigate cases of respiratory morbidity seen at SNM hospital, Leh, who did not respond to routine treatment and whose radiological picture resembled pneumoconiosis. There are no mines or industries in any part of Ladakh and therefore exposure to dust from these sources is ruled out. Two factors considered responsible for the development of this respiratory morbidity were: (1) Exposure to dust from "dust storms." In spring dust storms occur in most parts of Ladakh. During these storms the affected villages are covered by a thick blanket of fine dust, and inhabitants are exposed to considerable amounts of the dust for several days. The frequency, duration, and severity of these dust storms vary considerably from one village to another. (2) Exposure to soot. The fuels used for heating and cooking consist of wood from a local bush called "malchung" and the dung of yaks, cows, horses, donkeys, and their interbreeds. Due to severe cold, the ventilation in the houses is usually kept at a minimum. The same fireplace is used for cooking and heating purposes. To conserve fuel during non-cooking periods, the wood is not allowed to burn quickly but is kept smouldering to prolong its slow heating effect. The dwellers are thus exposed to high concentrations of soot.Materials and methods Three villages, Saboo (A), Shey (B), and Chushot (C), situated near Leh town, were selected for the study. The characteristics of these villages are as follows: dust storms are rare in village A, moderate in village B, and severe in village C. Chimneys have been used for over 20 years in all houses in village A, for 10-20 years in most houses in village B, and in few houses and only recently in village C.The total populations of villages A, B, and C were 1045, 1136, and 924 respectively. As most of the cases of pneumoconiosis seen in the hospital were older than 50, only those subjects older than 30 were included in this study. Initially, a list of all villagers older than 30 was prepared and from this list 150 subjects from each village were selected for the study. The list showed that in village A and village B there were more women than men, whereas in village C this 825