- Relied on epidemiologic studies of workers in large industries or broad categories of employment.
- Did not consider exposures in smaller work places or from indirect contact with carcinogens, such as asbestos in maintenance operations.
Excluded deaths of people 65 and over.
They maintained that this data was unreliable.
They missed effects seen in older people whose cancers may have been caused exposures while working.

- 1950’s and ’60’s, Doll was outspoken about the dangers of occupational carcinogens.
- Later, Doll seemed to succumb to the interests of industry. He increasingly found himself on the payroll of industry.

Source on above two points: Epstein SS, Ashford NA, Blackwelder B, et al., The crisis in U.S. and international cancer policy. International Journal of Health Services, Vol. 32, Nu. 4, pp 660-707, 2002.