An evaluation of phase contrast microscopes for asbestos counting.

Details

• Personal Author:
  Busch, Kenneth A. ; Leidel NA
• Description:
  An evaluation was made of five phase contract microscopes for asbestos (1332214) counting, to determine whether there was a possibility of gross differences in asbestos fiber count results when the same filter was counted on different microscopes by the same personnel. Five trained persons counted the fibers on five filter wedges using five microscopes. The samples were collected by drawing air through a membrane filter by means of a battery powered vacuum pump. The filter was charged into a transparent homogeneous plastic mount, and the fibers sized and counted by the microscopes which were modified for use with phase contrast techniques. For each of the five counters the counts obtained using a Nikon microscope were 45 percent higher than those obtained using the particular Leitz, Zeiss, Olympus, or Bausch and Lomb microscopes in this study. The results indicated that film thickness was uniform and that clumping of fibers did not occur. Taking the average of the three counters as 100 percent (as they had statistically homogeneous counts), counter A's average was 16 percent lower and counter E's average was 27 percent higher than this average. Not only did significant differences occur depending on the equipment used, but also with different trained operators.
• Subjects:
  Accidents, Occupational Epidemiology Mortality Occupational Health Occupational Injuries Safety Workplace
• Keywords:
  Air-quality-monitoring Airborne-particles Asbestos-dust Fibrous-dusts Laboratory-equipment Laboratory-workers Mineral-dusts NIOSH-Author Task-performance
• Document Type:
  Text
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DLCD - Division of Laboratories and Criteria Development
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-9
• NIOSHTIC Number:
  nn:00190677
• Citation:
  NIOSH 1974 Mar; :1-9
• CAS Registry Number:
  Asbestos (CAS RN 1332-21-4)
• Federal Fiscal Year:
  1974
• Peer Reviewed:
  False
• Source Full Name:
  Division of Laboratories and Criteria Development, NIOSH, U.S. Department of Health, Education, and Welfare, Cincinnati, Ohio, 9 pages
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a4bab2478939694da2f7e0805050be6d01629dae49f5b4ae104b11bce4058d4cbe1a62b5366a8a35602690b9b0ffa948eca03ecc542c8b706bd3f2a79e703b68
• Download URL:
  https://stacks.cdc.gov/view/cdc/180264/cdc_180264_DS1.pdf
• File Type:
  [PDF - 379.73 KB ]