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Work-Related Lung Disease Surveillance System (eWoRLD)

Silicosis: Respirable Quartz Exposures (Archive)

Respirable quartz: Geometric mean exposures and percent exceeding designated occupational exposure limits by MSHA coal mine district and state, MSHA inspector and mine operator samples, 1982-1999
Table showing Respirable quartz:  Geometric mean exposures and percent exceeding designated occupational exposure limits by MSHA coal mine district and state, MSHA inspector and mine operator samples, 1982-1999

- indicates incalcuable field
PEL - permissible exposure limitREL - recommended exposure limitGM - geometric mean

Note:  All geometric means are reported in MRE (Mining Research Establishment) equivalents. For coal mining, the MSHA PEL is [(10 mg/m3 MRE) / (% quartz)] for respirable dust containing greater than 5 percent quartz. The MSHA respirable coal mine quartz exposure data and the NIOSH REL for respirable quartz cannot be compared to each other because they are based on different sampling criteria. See appendices for source description, methods, and agents.

Source:  Mine Safety and Health Administration (MSHA) coal mine inspector and mine operator quartz data.

Reference Number: 2002T03-18

Date Posted: May 2003

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