Biological Effects Of Asbestos

Our plain-English summary of Biological Effects Of Asbestos, by New York Academy Of Sciences (1965).

The study

• Author: New York Academy Of Sciences
• Published: Annals Of The New York Academy Of Sciences 132(1): December 31 (1965)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library, J-M no. 001517. The article is still under copyright, so we describe it here rather than post it.

In plain English

This volume records a 1964 New York Academy of Sciences conference; the supplied text contains only parts of it. The one complete research paper in the text, by Selikoff, Churg and Hammond, studied the 1,522 men in the New York and New Jersey insulation workers' union locals between 1942 and 1962. Of 1,258 men alive in January 1963, 1,117 were examined, with chest X-rays as the main part of the examination. Chrysotile was largely used; some materials had no asbestos, and ship insulation from 1934 also contained amosite. X-ray signs of asbestosis appeared in almost half the men examined. This included 36 of 346 men (10.4 per cent) first exposed less than ten years earlier and 339 of 392 first exposed more than 20 years earlier. Lung cancer was found in 10 men and pleural mesothelioma in one. No lung or pleural cancers were found in examined men first exposed less than 20 years before. The authors concluded that asbestosis and its complications were significant hazards among United States insulation workers. They noted that relying on X-rays alone tends to underestimate asbestosis.

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: Conference proceedings volume (papers and discussions). The only complete research paper in the supplied text is a medical and X-ray examination survey of a union membership group, with review of union work records and death records.
• Who was studied: In the Selikoff, Churg and Hammond paper: 1,522 members of insulation workers' union Local 12 (New York) and Local 32 (New Jersey), members at any time from 1942 to 1962. Of the 1,258 alive on January 1, 1963, 1,117 were examined in 1963 and 1964. The article prints this as 89.9 per cent; 1,117 of 1,258 works out to about 88.8 per cent.
• Exposure: Asbestos insulation work in building construction, shipyards and powerhouses. The authors described the exposure as limited and intermittent, and some materials contained no asbestos. Materials such as magnesia block insulation contained about 15 per cent asbestos. Chrysotile was largely used. Crocidolite was also found, and ship insulation from 1934 also contained significant amounts of amosite.
• Main results:
  • Among all 1,117 men examined, X-ray evidence of pulmonary asbestosis was present in almost half (Table 5 gives 48.5 per cent abnormal).
  • Among men whose exposure began less than ten years before examination, 36 showed any X-ray abnormality. That is 10.4 per cent of the 346 examined men in this group, as Table 5 gives them; the paper's text gives the group as 316 men. The reticular changes were minimal in each case.
  • Among 379 men whose exposure began 10 to 19 years before examination, more than half still had normal X-rays. Of the 167 with an abnormality, only nine had more than minimal asbestosis.
  • Among 392 men examined more than 20 years after first exposure, X-ray evidence of asbestosis was found in 339. In half of these the asbestosis was moderate or extensive.
  • Among men first exposed 20 to 29 years earlier, 56 of 77 had abnormal films. Among those first exposed 40 or more years earlier, only one in 20 showed no abnormality.
  • Among the 392 men with more than 20 years since first exposure, 134 had some degree of shortness of breath, 61 of them with some disability. Among 725 men with less than 20 years since first exposure, only one had significant shortness of breath.
  • Lung tissue was examined from 45 insulation workers, mostly men who had died. All showed typical pulmonary asbestosis: 15 at Grade I, 16 at Grade II and 14 at Grade III.
  • During the examinations, lung cancer was found in 10 men and pleural mesothelioma in one, each confirmed under the microscope. Lung cancer was found in 7 of 984 working members examined (0.7 per cent) and in 4 of 133 retired, ill or withdrawn men examined (three per cent).
  • Among the men examined, no cancers of the lung or pleura were found in those whose work began less than 20 years before examination.
  • The paper's summary stated that among 307 consecutive deaths in this group, lung cancer was at least seven times as common as expected and gastrointestinal cancer three times as common, with 10 cases of mesothelioma of the pleura or peritoneum. The mortality data were to be reported separately.
• The authors' conclusion: The authors concluded that asbestosis and its complications are significant hazards among insulation workers in the United States at that time.
• Limitations the authors state:
  • Asbestosis was judged by X-ray alone, which the authors said tends to underestimate how often it occurs.
  • The lung tissue material was inadequate to evaluate early changes; only one case had less than 15 years from first exposure.
  • The comparison with 11 insulation-factory workers rested on limited data, and conclusions may be unwarranted.
  • Nonunion, some maintenance, sprayed-insulation and other-union insulation workers were not studied.
  • The authors found it difficult to compare their results with earlier surveys of asbestos workers.

Topics

Medical terms in this study, explained in our Lexicon: Insulator, Chest X-Ray, Chrysotile, Amosite, Lung Cancer, Pleural Mesothelioma.

Browse return to medical research.