Two major US reports published shortly before the 1981 Doll/Peto report – one from US government organisations  and another backed by employers’ organisations – put the occupational cancer contribution at least 20 per cent of all cancers, with the industry-backed report conceding occupational cancer constituted “a public health catastrophe”.

Bridbord K and others. Estimates of the fraction of cancer in the United States related to occupational factors. Bethesda, MD: National Cancer Institute, National Institute of Environmental Health Sciences, and National Institute for Occupational Safety and Health, 1978.

Proctor R. Cancer Wars. New York: Basic Books, 1995 (includes reference to the early industry-backed estimate).

The study uncovered high rates of leukaemias in a population exposed only to the solvent benzene and where benzene levels were generally below recommended limits. The authors acknowledge that the figures underestimate the scale of the problem. It was  the first cohort study of workers linking benzene exposure directly to leukaemia. Under-reporting remains a problem to the present. The industry was criticised in 2014 after it was revealed it has operated a long-term project to suppress or rebut evidence of this cancer link (see CPI, 2014). A 2004 study confirmed health risks at low level exposure to benzene. Concerns were raised in 2014 about harmful benzene exposure levels in the vicinity of fracking operations (see Macey and others, 2014).

Peter Infante, Robert Rinsky, Joseph Wagoner, and Ronald Young. Leukaemia in benzene workers, Lancet, volume 2(8028), pages 76-78, 9 July 1977.