Two 1968 Letters Between J. A. Riddle and P. W. McDaniel on Mesothelioma, Crocidolite, Chrysotile and the 5 MPPCF Dust Limit (1968)

Two internal Union Carbide letters. On January 11, 1968, J. A. Riddle at King City sent Paul McDaniel a San Francisco Chronicle article on mesothelioma and asbestos and asked whether 5 MMPCF was still adequate and whether there was comparative toxicology on asbestos types. On January 19, 1968, McDaniel replied that the crocidolite-mesothelioma link seemed strongly established, the chrysotile link was unclear, and dust in company chrysotile operations should be controlled as far below 5 MPPCF as reasonably possible.

What the document holds

• Page 1: Letter from Paul W. McDaniel (Medical) to John A. Riddle, January 19, 1968, replying on mesothelioma, crocidolite and chrysotile, and the 5 MPPCF limit (A11918)
• Page 2: Letter from J. A. Riddle to Paul W. McDaniel, January 11, 1968, enclosing a San Francisco Chronicle article on mesothelioma and asbestos and asking about the 5 MMPCF limit (A11917)

People and organizations

From Paul W. McDaniel (Industrial Hygiene Engineer); J. A. Riddle (Chemicals and Plastics, King City, California) to Mr. John A. Riddle (Chemicals & Plastics, P. O. Box K, King City, California); Paul W. McDaniel (4th Floor, NYC).

• Paul W. McDaniel (author, recipient)
• John A. Riddle (author, recipient)
• Medical Department (its organization)
• Union Carbide Corporation (its organization)
• San Francisco Chronicle (named)

Related pages

Pages on our site about what this document covers: California Asbestos Exposure Sites: Worksites, Industries, and Trust Coverage · Chrysotile: White Asbestos, the Most Common Type · Crocidolite: Blue Asbestos, the Deadliest Type · Mesothelioma: What It Is, How It's Diagnosed, and How It's Treated.

About this copy

This is document UC-132 of the Union Carbide documents, documents produced and used as evidence in asbestos lawsuits against Union Carbide, 2 pages. Production numbers A11918 to A11917.