Risk of silicosis in a Colorado mining community.
Am J Ind Med 1996 Nov; 30(5):529-539
The associations between cumulative dust and silica (14808607) exposures and silicosis were examined in this community based study. One hundred miners and 34 community residents (controls) living in a mining town in Colorado participated in the investigation. Silica exposure data and occupational histories were used to evaluate the silica exposure level of each individual. While none of the controls had an abnormal chest radiograph, 32% of the exposed workers were diagnosed with silicosis, based on the radiographs. Within the exposed group, those with silicosis tended to be older than those without silicosis. The prevalence of silicosis increased with increasing years of exposure. While 15.4% of the miners exposed for less than 20 years developed silicosis, 47.1% of the miners exposed for over 30 years developed the disease. The prevalence of silicosis also increased with increasing exposure level. Workers exposed to dust levels of 0.4mg/m3 or less had a silicosis rate of 10%, while those exposed to dust levels greater than 0.8mg/m3 had a significantly higher silicosis rate of 48.6%. Likewise, increasing dust or silica cumulative exposure resulted in increased incidences of silicosis. Risk assessment based on cumulative silica exposure produced higher rates than that based on cumulative dust exposure. More than 2mg/m3 years of cumulative silica exposure resulted in a silicosis rate of 62.5%. The authors conclude that, although silica exposure levels were below the permissible exposure limits in this occupational situation, silicosis occurred at a high rate among the miners of this community.
NIOSH-Publication; NIOSH-Grant; Humans; Occupational-exposure; Long-term-exposure; Dust-exposure; Silica-dusts; Respiratory-system-disorders; Chest-X-rays; Mine-workers
Medicine National Jewish Hosp/res Ctr 3800 East Colfax Avenue Denver, Colo 80206
American Journal of Industrial Medicine
National Jewish Ctr for Immnlgy/resp Med, Denver, Colorado