Permissible Dustiness: Dust Retention of Man

This textbook chapter from Industrial Dust was a review, not an original study, and did not discuss asbestos. The authors reviewed published work on dust retention, lung silica, and suggested 'permissible' dust levels. Using one researcher's replotted data, median nasal filtering efficiency was 27.5 per cent in silicotic men and 46 per cent in normal men. From another researcher's curves, they calculated that an average man breathing twenty times a minute retains 60 per cent of inspired dust. Retention reportedly fell as breathing rate rose to twenty breaths a minute, with no change at higher rates, and increased with particle size. It reviewed suggested limits for quartz, coal, cement, lead, zinc oxide and manganese, including a South African standard of 1 mg per cubic meter. The authors said these figures should not be legal standards but supported using them as guides for designing dust-control equipment. They noted limits: free-silica content can vary with particle size, so two dusts' silicosis-producing capacities cannot be compared on bulk silica content alone; sudden heavy 'dust floods'; and less fit workers leaving dusty jobs.

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.

From J-M's medical library

This copy comes from the Johns-Manville medical library. It was among the papers J-M kept in its medical library without an index entry.

We publish pages from a book for research and commentary: it shows what the medical literature in a leading asbestos company's own library said on the subject, and when. Our summary above is our own reading of it. The copyright stays with the publisher.