|Document ID (ISN)||78517|
|ISSN - Serial title
||1076-2752 - Journal of Occupational and Environmental Medicine
|Convention or series no.
||Graham W.G.B., Vacek P.M., Morgan W.K.C., Muir D.C.F., Sisco-Cheng B.
||Radiographic abnormalities in long-tenure Vermont granite workers and the permissible exposure limit for crystalline silica
||Apr. 2001, Vol.43, No.4, p.412-417. 15 ref.
||To study the prevalence of radiographic abnormalities among retired granite workers, 408 x-ray films were examined. Dust exposures were estimated for workers hired after 1940, when the dust-control standard of 10 million particles per cubic foot (equivalent to 0.1mg/m3) was put in place. Dust levels were gradually reduced from 1940 to 1954, after which average quartz exposures stabilized to average approximately 0.05 to 0.06mg/m3; however, about 10% to 15% of samples after 1954 exceeded 0.1mg/m3. Of the 408 x-ray films, 58 were taken on workers hired before 1940, and 25.9% showed abnormalities. 350 x-ray films were taken on workers hired in 1940 or after, and the prevalence in this group was 5.7%. The radiographic changes in workers hired after 1940 are likely to be due to excessive exposures during the first 15 years of dust control. It is concluded that if the exposure standard of 0.1mg/m3 is rigorously observed in the workplace, radiographic abnormalities caused by quartz dust in long-term workers will be rare.
||threshold limit values; silica; radiological changes; mining industry; respirable dust
||granite; chest radiography; frequency rates; exposure evaluation
||D - Periodical articles
|Country / State or Province||Canada; USA|
||Mines and quarries
|Broad subject area(s)
||Mining and quarrying
Occupational exposure limits