Hard-rock mining exposures affect smokers and nonsmokers differently: results of a community prevalence study.
Kreiss-K; Greenberg-LM; Kogut-SJ; Lezotte-DC; Irvin-CG; Cherniack-RM
Am Rev Respir Dis 1989 Jun; 139(6):1487-1493
A community based prevalence study of respiratory function in miners and nonminers was conducted in Leadville, Colorado. Leadville was a single industry, hard rock mining town. The study was begun 5 months into an 18 month layoff, thus allowing the effects of long term cumulative exposures to be studied without confounding the findings with the effects of current exposure. The molybdenum mining industry in this town had surface and underground mines, crushers, a mill and nonindustrial work locations. The average silica (14808607) content in dosimeter samples taken in the crusher area was 19 percent. Personal samples measured between 1977 and 1981 exceeded the current permissible exposure limit for respirable quartz of 100 micrograms/cubic meter in 27 percent of the cases. The subjects, 383 men, were interviewed for respiratory symptoms and occupational history, underwent plethysmographic measurements of lung volume and airflow, and performed a single breath diffusing capacity procedure. The respiratory effects observed these several months after the exposure to dust had stopped suggest that dust induced physiologic changes may be irreversible. Mining exposure affected smokers and nonsmokers differently. Airflow limitation and overdistension were greater in smokers exposed to dust. Lung volumes tended to fall, and the flow rates at the absolute lung volumes were higher in nonsmoking miners. Had measurements been derived from simple spirometry alone, without the added advantage of plethysmography and diffusing capacity, the differential effects of mining exposures in smokers and nonsmokers would not have been elucidated. The only respiratory symptom exacerbated by mining exposures was dyspnea.
NIOSH-Publication; NIOSH-Grant; Pulmonary-system-disorders; Underground-mining; Underground-miners; Dust-inhalation; Dust-exposure; Silica-dusts; Cigarette-smoking; Pulmonary-function-tests
Medicine Natl Jewish Hosp and Res Ctr 3800 E Colfax Ave Denver, Colo 80206
American Review of Respiratory Disease
National Jewish Ctr for Immnlgy/resp Med, Denver, Colorado