Radiographic survey of perlite workers.

Chest roentgenograms of 240 perlite workers employed for 1 to 23 years in the industry, showed no evidence of pneumoconiosis associated with perlite exposures. One individual, found to have simple pneumoconiosis, and one found to have complicated pneumoconiosis, had formerly been diatomaceous earth workers. Since only 28 of the men had been in the industry over 15 years and only seven for 20 years or more, continued surveillance is essential to make sure that there are no effects with more prolonged exposures. Studies of pulmonary function of the individuals who have had relatively long exposures are needed to supplement radiographic evidence.