Dr. William E. Smith of Fairleigh Dickinson University to Fred L. Pundsack on Chrysotile and Benzo(a)pyrene (1973)

A one-page letter of April 17, 1973, from Dr. William E. Smith, director of the Health Research Institute at Fairleigh Dickinson University in New Jersey, to Dr. F. L. Pundsack of Johns-Manville, sending the abstract of a paper for the American Industrial Hygiene Association meeting in Boston on May 23. The paper offered data showing "that chrysotile delays clearance of benzo(a)pyrene from hamster lungs"; benzo(a)pyrene is a carcinogen in cigarette smoke. With other work, Smith wrote, it suggested "that non-specific irritation of lungs may allow carcinogens to reside longer and hence enhance tumorigenesis."

What it shows

The research was carried out with support from the Johns-Manville Fund and the Rippel Foundation, and Smith promised to offer his manuscript to J-M "for your comment before submitting it to a journal." It gave J-M, the sponsor, an early look at animal evidence that chrysotile might help cigarette carcinogens cause cancer.

In Johns-Manville's chronology

Johns-Manville's own chronology of what the company knew describes this document as follows:

Benzo(a)pyrene is a carcinogen known to be present in cigarette smoke. Dr. William E. Smith (Director, Health Research Institute, Fairleigh Dickinson University, New Jersey) found that chrysotile delays clearance of benzo(a)pyrene from hamster lungs. The J-M Fund and Rippel Foundation supported Dr. Smith's research. This research along with other research "suggest that non-specific irritation of lungs may allow carcinogens to reside longer and hence enhance tumorgenesis." Dr. Smith is preparing a manuscript of his research and will offer it to J-M for comment before submitting it to a journal.