Analysis of workplace compliance measurements of asbestos by the U.S. Occupational Safety and Health Administration (1984-2011)

Our plain-English summary of Analysis of workplace compliance measurements of asbestos by the U.S. Occupational Safety and Health Administration (1984-2011), by D.M. Cowan, T.J. Cheng, M. Ground, et al (Regulatory Toxicology and Pharmacology, 2015).

The study

• Authors: D.M. Cowan, T.J. Cheng, M. Ground, J. Sahmel, A. Varughese, A.K. Madl
• Journal: Regulatory Toxicology and Pharmacology
• Published: 2015;72(3):615-29
• Type of article: Historical article
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The United States Occupational Safety and Health Administration (OSHA) maintains the Chemical Exposure Health Data (CEHD) and the Integrated Management Information System (IMIS) databases, which contain quantitative and qualitative data resulting from compliance inspections conducted from 1984 to 2011. This analysis aimed to evaluate trends in workplace asbestos concentrations over time and across industries by combining the samples from these two databases. From 1984 to 2011, personal air samples ranged from 0.001 to 175 f/cc. Asbestos compliance sampling data associated with the construction, automotive repair, manufacturing, and chemical/petroleum/rubber industries included measurements in excess of 10 f/cc, and were above the permissible exposure limit from 2001 to 2011. The utility of combining the databases was limited by the completeness and accuracy of the data recorded. In this analysis, 40% of the data overlapped between the two databases. Other limitations included sampling bias associated with compliance sampling and errors occurring from user-entered data. A clear decreasing trend in both airborne fiber concentrations and the numbers of asbestos samples collected parallels historically decreasing trends in the consumption of asbestos, and declining mesothelioma incidence rates. Although air sampling data indicated that airborne fiber exposure potential was high (>10 f/cc for short and long-term samples) in some industries (e.g., construction, manufacturing), airborne concentrations have significantly declined over the past 30 years. Recommendations for improving the existing exposure OSHA databases are provided.

Copyright © 2015. Published by Elsevier Inc.

In plain English

The authors combined two U.S. Occupational Safety and Health Administration (OSHA) inspection databases, CEHD and IMIS, to examine asbestos measurements across industries from 1984 to 2011. The CEHD held 70,901 entries including blanks (55,410 without blanks), and the 29,212 data points matched to IMIS were about 40% of all CEHD entries. Air samples were analyzed by a method (PCM) that cannot identify fiber type. The number of personal air samples fell from 10,779 in the 1980s to 2034 in the 2000s. Personal samples with detectable asbestos ranged from 0.001 to 175 f/cc in 1984–1989 and from 0.003 to 1.1 f/cc in 2010–2011. Levels in 1984–1989 were significantly higher than in later periods. Construction was the most sampled industry. In construction, 1100 of 2218 samples longer than one hour exceeded the limits in force at the time, and PPE use was documented for 125 of those. The authors concluded that concentrations declined over 30 years but that, in some industries, samples exceeded the current limit as late as 2011. They noted that compliance sampling is not random and that PPE information was mostly missing.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Descriptive analysis of OSHA compliance-inspection sampling records, combining the CEHD and IMIS databases to look at trends over time and across industries
• Who was studied: Asbestos air (personal and area) and bulk samples collected by OSHA inspectors at workplaces throughout the U.S., 1984 to 2011. The CEHD held 70,901 samples including blanks, or 55,410 after removing 15,491 blanks. IMIS held 21,676. Combining them gave 29,212 sampling data points, about 40% of the CEHD's samples counted with blanks included.
• Exposure: Airborne asbestos fibers measured by PCM (in f/cc), with fiber type not determined, plus percent asbestos in bulk samples. Industries were grouped by SIC code, and personal air samples by duration (less than 1 h, 1 to 4 h, more than 4 h).
• Main results:
  • The combined data set of 29,212 sampling data points represented approximately 40% of samples from the CEHD database. The arithmetic matches the 70,901 CEHD entries counted with blanks included, not the 55,410 non-blank samples.
  • The number of personal air samples collected declined from 10,779 in the 1980s to 4771 in the 1990s and 2034 in the 2000s.
  • In 1984–1989, personal air samples with detectable asbestos ranged from 0.001 to 175 f/cc.
  • In 2010–2011, personal air samples ranged from 0.003 to 1.1 f/cc.
  • Personal sample concentrations from 1984–1989 were significantly higher (p less than 0.05) than those from the 1990s, the 2000s and 2010–2011.
  • Comparisons between the later periods (for example, 1990s vs. 2000s) were not significantly different.
  • The construction industry as a whole was the most sampled industry (n = 20,248), about 37% of CEHD samples excluding field blanks.
  • Short-term personal concentrations above 10 f/cc, which the article calls the OSHA excursion limit, were found in the construction, manufacturing, and chemical/petroleum industries.
  • In construction, 1100 samples longer than one hour exceeded the contemporaneous PELs from 1984 to 2011. That was 49.6% of all such samples (1100 of 2218).
  • Of those 1100 construction samples over the PEL, 11.4% (125 of 1100) were documented as taken while the worker used PPE. For the other samples, PPE information was not logged.
  • In shipbuilding, detectable personal air samples ranged from 0.01 to 8.99 f/cc in 1984–1989 (n = 25) and from 0.05 to 0.26 f/cc in the 1990s (n = 5). None of the 137 shipbuilding air samples had PPE information.
  • In the automobile industry (sales, service, and repair), 170 of 172 personal air samples in the 1990s were non-detectable. The two detected samples, 0.03 and 0.056 f/cc, were described as well below contemporaneous limits.
• The authors' conclusion: The authors concluded that airborne fiber concentrations and the numbers of samples declined over the past 30 years, in parallel with reduced asbestos consumption. They found that exposure potential was very high (more than 10 f/cc) in some industries such as construction and manufacturing, and that in some industries OSHA samples exceeded the current PEL on occasion as late as 2011. They also called for a more comprehensive combined OSHA database.
• Limitations the authors state:
  • OSHA compliance measurements are not random samples of workplace conditions, which limits how far the results can be generalized.
  • Sampling was often done in response to referrals and complaints, so the data may over-represent high-exposure situations.
  • The data contained errors from user data entry.
  • PCM analysis cannot determine fiber type and can overestimate asbestos-specific exposure.
  • SIC codes describe industries, not actual job type. For example, asbestos abatement at a construction site is classified as construction.
  • Limits of detection were not given for non-detected samples, so reported concentrations represent detected samples only.
  • PPE use was largely unrecorded. Only 15% of construction samples indicated whether PPE was used.
  • Because only about 40% of the CEHD was represented in IMIS, the authors had limited ability to obtain more information on historical exposures.

Topics

Medical terms in this study, explained in our Lexicon: OSHA, Permissible Exposure Limit (PEL), Selection Bias, Mesothelioma, Incidence, Air Sampling.

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