The correlation of chest radiograph and pulmonary function tests in asbestos miners and millers

An environmental-cum-medical survey was carried out in asbestos mines and milling units at Pullivendalla, Cuddaph (A.P.) India. This was done in two mines and six milling units with 95% of the total work force being surveyed. Out of a total of 633 registered workers, 329 (52%, all males) were employed in mines while 135 (21.4%) workers of whom 114 (84%, all females) were employed in the milling units. All subjects underwent limited medical examination, spirometry and chest radiographs. The levels of asbestos fiber concentration was much below threshold limit value (TLV) in underground mines but several times higher than TLV in milling units. The percentage of workers with abnormal pulmonary function tests (PFT) and chest radiographs increased with duration of exposure in smokers as well as non-smokers. Restrictive pattern of lung functions (159 workers-16.27%) was more common than obstructive (33 workers-5.21%) and combined type (22 workers-3.4%). Similarly, the parenchymal changes (156 workers-24.6%) were more common than pleural (27 workers-4.3%). As most of the males were employed in mines, where the fiber levels were much below TLV, the number of male workers with normal PFT and chest radiographs were ten times (61.3%) more than male workers with both the parameters abnormal (6.3%). As most of the females (114 our of 120--95%) were employed in milling units, where the levels of fibers were several times higher than TLV, the number of females having both the parameters normal 29 (24.1%) or abnormal 35 (29.2%) were similar.