Environmental Asbestos Concentrations In The Unites States

Our plain-English summary of Environmental Asbestos Concentrations In The Unites States, by W.J. Nicholson, A.N. Rohl, I. Weisman, et al (1980).

The study

• Authors: W.J. Nicholson, A.N. Rohl, I. Weisman, I.J. Selikoff
• Published: Biological Effects Of Mineral Fibres (J.C. Wagner, Editor), Lyon: Iarc Scientific Publications, Volume 30, Pp. 823-827 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library, J-M no. 004388. The article is still under copyright, so we describe it here rather than post it.

In plain English

This paper reported air measurements of chrysotile asbestos in the United States and Canada, taken in settings the authors believed were similar to non-work situations in which asbestos disease had been documented. Samples were taken in 10 public schools with damaged asbestos surfacing, in buildings with sprayed asbestos fireproofing in return air plenums, in houses of asbestos mine and mill workers in Copperopolis, California and Baie Verte, Newfoundland, and around the World Trade Center construction site while asbestos fireproofing was sprayed on steelwork. In the schools, concentrations ranged from 9 to 1950 ng/m3 (nanograms per cubic metre), averaging 217 ng/m3. Outside air at three of the schools averaged 14 ng/m3. Near the spraying, some levels were about 100 times those usually measured in outdoor air. Overall, 43 of 89 samples exceeded 50 ng/m3, against three of 209 ambient city air samples. Only 2 of the 89 exceeded 1000 ng/m3. The authors noted that the sampling was designed to capture the more serious cases of contamination. They concluded that the findings should prompt control or remedial action.

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: Environmental air sampling study measuring chrysotile concentrations in several non-occupational settings, compared with ambient city air data
• Who was studied: Air samples, not people. Settings: 10 public schools with damaged asbestos surfaces; buildings with asbestos in return air plenums; 13 samples from houses of asbestos mine and mill employees in Copperopolis, California and Baie Verte, Newfoundland; eight sampling sites around the World Trade Center construction site, New York. Comparison data: 187 quarterly composite samples from 48 US cities and 22 daytime samples from New York City.
• Exposure: Chrysotile asbestos in air from damaged friable asbestos surfacing in schools, sprayed asbestos fireproofing in return air plenums, workers' homes (dusty work clothes, no showers or changing rooms at work), and spraying of asbestos-containing fireproofing on steelwork during construction
• Main results:
  • In the 10 public schools with damaged surfaces, chrysotile concentrations in 4- to 8-hour samples ranged from 9 to 1950 ng/m3, with an average of 217 ng/m3
  • Outside air samples at three of the schools ranged from 3 to 30 ng/m3, with an average of 14 ng/m3
  • At sites within one-half mile of the World Trade Center construction site during spraying of asbestos fireproofing, chrysotile levels in some instances were approximately 100 times the concentrations usually measured in ambient air
  • Samples taken in houses of non-miners in Baie Verte gave concentrations of 32, 45 and 65 ng/m3 (the distribution for the 13 samples from asbestos mine and mill employees' houses is in a table that is unreadable in this text)
  • Across all four settings, 43 of 89 samples exceeded 50 ng/m3. Only three of 209 ambient air samples exceeded this value. Only 2 of the 89 samples exceeded 1000 ng/m3.
  • In the ambient air comparison data from 48 US cities, chrysotile was present in virtually all metropolitan areas
• The authors' conclusion: The authors concluded that the data demonstrate significant environmental contamination by asbestos, that these concentrations appear representative of serious environmental contamination, and that such findings should prompt appropriate control or remedial action
• Limitations the authors state:
  • The schools were selected because of visible damage, so the results cannot be considered typical of all school asbestos surfaces
  • In all settings, sampling was designed to reflect the more serious instances of contamination
  • No air measurements exist from the actual circumstances that led to non-occupational disease. These samples were taken in circumstances believed to be similar.

Topics

Medical terms in this study, explained in our Lexicon: Chrysotile.

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