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

Background An investigation of a small private agate mill was prompted by an agate worker who presented with silicosis in Guangzhou, China, in December 1998. Methods 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/m(3); 86-88% of the particles' diameter was smaller than 5.0 mum. Free SiO(2) content from agate samples was measured. Occupational history was obtained and X-ray, chest and lung function was carried out. Results Free SiO(2) 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. Conclusion Silicosis is an important problem in primitive work environments. (C) 2001 Wiley-Liss, Inc.