Spectrum of Asbestos-RELATED Disease

Adequate knowledge concerning the full dimensions of human disease associated with asbestos exposure has been hampered by a number of epidemiological constraints. The first is the size of populations studied.

Since we generally compare what is seen among exposed groups with the same findings in unexposed groups (expected rates), we need to have available sufficient experiences to be able to judge whether or not there is an increase in incidence and whether that increase can be reliably said to be present, from a statistical point of view. This would, of course, be particularly true for diseases of lesser frequency.

This constraint was very much in evidence in Richard Doll's classic report in 1955 of lung cancer among workers in the asbestos textile factory in which Cooke's case was employed; there were only 39 deaths among the 113 individuals being followed (40). While this was enough to identify a significant increase in lung cancer (11 cases versus fewer than 1 expected), there were simply not enough data to permit analysis of the incidence of other asbestos-associated diseases, including neoplasms of other sites.

This difficulty exists in both clinical and mortality studies, and is even more obvious in the mortality studies because collection of series of deaths add the constraint of adequate time of observation during which deaths might occur.

To review the references in Dr. Selikoff’s article see Pages 275-276 of his report.