“…For this purpose, we estimated the CNS cancer potency of acrylonitrile in rats on the basis of an inhalation bioassay (Quast J, Schuetz D, Balmer M, Gushow T, Park C, McKenna M. A two-year toxicity and oncogenicity study with acrylonitrile following inhalation exposure in rats. Prepared by the Toxicology Research Laboratory, Health and Environmental Sciences, Dow Chemical, Midland, Michigan, United States, for the Chemical Manufacturing Association in 1980, unpublished observations) and, unlike Ward & Starr (9) or Collins & Strother (10), applied the potency to the actual observed follow-up time in the epidemiologic studies. By calculating the number of deaths predicted for the actual follow-up time of the workers and comparing them with the observed number of deaths and their confidence intervals, we explored the role of dose and follow-up time in explaining the apparently contradictory results for CNS cancer and exposure to acrylonitrile.…”