Reconciling animal and human data in a cancer risk assessment of acrylonitrile
- UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
- Mark R. Schulz, Assistant Professor (Creator)
- Institution
- The University of North Carolina at Greensboro (UNCG )
- Web Site: http://library.uncg.edu/
Abstract: Objectives Bioassays of rats exposed to acrylonitrile have consistently detected an elevated incidence of central
nervous system (CNS) cancer. In contrast, epidemiologic studies have not found a statistically stable increase in
CNS cancer mortality. The purpose of this paper is to examine whether or not CNS cancers predicted from the
most appropriate inhalation bioassay in rats are consistent with CNS cancers observed in 3 recent, large
epidemiologic studies.
Methods A linearized multistage model was fit to dose-response data from a rat inhalation bioassay to estimate
carcinogenic potency. This potency was applied to epidemiologic studies of acrylonitrile-exposed workers. After
adjustment for less than complete lifetime follow-up in the epidemiologic studies, consistency was examined
between CNS cancers predicted by the model fit to the animal data for the exposure levels and sample sizes of the
epidemiologicy studies and the CNS cancers observed in the epidemiologic studies.
Results The model predicted totals of 17.7, 3.6, and 7.6 CNS cancer deaths for the studies. These predictions
were not far from the observed CNS cancer deaths (12, 6, and 6) and were well within their 95% confidence
intervals of 6.9—22.3, 2.2—13.1, and 2.2—13.1, respectively.
Conclusions The CNS cancer potency estimated from the best available inhalation bioassay was consistent
with the observed deaths in the epidemiologic studies as long as continuous lifetime exposure was chosen as the
exposure metric. The lack of observed excess in CNS cancer among the studied workers may have been due to
low exposures, insufficient follow-up times, or both.
Reconciling animal and human data in a cancer risk assessment of acrylonitrile
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Additional Information
- Publication
- Scand J Work Environ Health 2001;27(1):14—20
- Language: English
- Date: 2001
- Keywords
- bioassays, carcinogenic potency, central nervous system cancer, epidemiologic studies, follow-up
time, interspecies comparison