home edit2 whole TSD November 2002 PDF format - OEHHA

Table 2 (continued).
Cupferron-induced hemangiosarcoma incidence in male and female F344 rats
and B6C3F 1 mice (NCI, 1978)
1. Doses as reported by Gold et al. (1984).
2. Tumor incidences as reported by Gold et al. (1984)
IV.
DERIVATION OF CANCER POTENCY
Basis for Cancer Potency
Results of the NCI (1978) feeding study in male and female B6C3F 1 mice and Fischer 344 rats are
listed in Gold et al. (1984). Benign and malignant vascular tumors as well as tumors at other sites were
observed in mice and rats of both sexes treated with cupferron. Cancer potency is based on the data
for vascular tumors in the male rat (see Table 2) because the rat is the more sensitive of the species
tested, and the male appears to be slightly more sensitive than the female (Cal/EPA, 1992).
Methodology
Expedited Proposition 65 methodology (with cross-route extrapolation) was used to derive a cancer
potency factor. Analysis of the data set using the computer program TOX_RISK (Crump et al., 1991)
indicated that inclusion of the high dose group resulted in a p-value of = 0.05 based on the chi-square
goodness-of-fit test, indicating non-linearity. Following procedures described by US EPA (Anderson
et al., 1983), the high dose group was excluded from the analysis to correct for the poor fit (Cal/EPA,
1992). A unit risk factor was then calculated by OEHHA/ATES from the cancer potency factor using a
reference human body weight of 70 kg and an inspiration rate of 20 m 3 /day.
V. REFERENCES
Anderson, EL and the Carcinogen Assessment Group of the U.S. Environmental Protection Agency
1983. Quantitative approaches in use to assess cancer risk. Risk Anal 3:277-295.
California Environmental Protection Agency (Cal/EPA) 1992. Expedited Cancer Potency Values and
Proposed Regulatory Levels for Certain Proposition 65 Carcinogens. Office of Environmental Health
Hazard Assessment, Reproductive and Cancer Hazard Assessment Section, Berkeley, CA.
Crump KS, Howe RB, Van Landingham C and Fuller WG. 1991. TOXRISK Version 3. TOXicology
RISK Assessment Program. KS Crump Division, Clement International Division, 1201 Gaines Street,
Ruston LA 71270.
Gold L, Sawyer C, Magaw R, Backman G, de Veciana M, Levinson R, Hooper N, Havender W,
Bernstein L, Peto R, Pike M and Ames B. 1984. A Carcinogenic Potency Database of the
standardized results of animal bioassays. Environ Health Perspect 58:9-319.
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