Accelerated silicosis in workers exposed to agate dust in Guangzhou, China.

Abstract

An investigation of a small private agate mill was prompted by an agate worker who presented with silicosis in Guangzhou, China, in December 1998. The work processes and records of dust measurements of the mill were examined. The mean total dust concentrations ranged from 3.0 to 9.9 mg/m3; 86-88% of the particles' diameter was smaller than 5.0 microm. Free SiO2 content from agate samples was measured. Occupational history was obtained and X-ray chest and lung function was carried out. Free SiO2 content of the agate was 90.5%. Thirty-two men involved in processing agate stone were examined. The mean ( +/- SD) age was 29.8 ( +/- 4.9) years and the mean (+/- SD) duration of exposure was 3.5 (+/- 1.7) years. Fifteen cases (47%) were diagnosed as accelerated silicosis. Up to September 1999, three had died from respiratory failure and five were in critical condition. Silicosis is an important problem in primitive work environments.