Tumors, carcinogen risk assessment

Carmichael, N.G., H. Enzmann, I. Pate, and F. Waechter, 1997. The significance of mouse hver tumor formation for carcinogenic risk assessment results and conclusions from a survey of ten years of testing by the agrochemical industry. Environ. Health Perspect. 105 1196-1203. 

The US-EPA has in its 1996 Proposed Guidelines for Carcinogen Risk Assessment (US-EPA 1996) adopted the dose descriptor LEDio (the 95% lower confidence limit on a dose associated with a 10% extra tumor risk) whereas in its 2005 Guidelines for Carcinogen Risk Assessment (US-EPA 2005), no defined incidence has been recommended (see Section 6.3.2). Within the EU chemical s regulation, the dose descriptor T25 has been proposed (see Section 6.3.3). In the newly proposed MOE approach, the JECFA and the EFSA have recommended the dose descriptor BMDLio (see Section 6.4). 

DAVIES T s and monro a (1994) The rodent carcinogenicity bioassay produces a similar frequency of tumor increases and decreases implications for risk assessment . Regulatory Toxicol Pharmacol. 20 281-301. 

R40 (Care. Cat. 3) was proposed. The tumors occurred in mice exposed to bifenthrin on multiple sites (urinary bladder, leukemia), and therefore without robust mechanistic data the carcinogenic potential of bifenthrin could not be excluded. It was noted the tumors did not impact on the risk assessment [65],... 

A chemical may constitute a number of hazards of different severity. However, the primary hazard (or critical effect) will be the one used for the subsequent stages of the risk assessment process. For example, a chemical may cause reversible liver toxicity at high doses but cause tumors in the skin at lower doses. The carcinogenicity is clearly the hazard of concern. 

Benigni, R. and Giuliani, A., Tumor profiles and carcinogenic potency in rodents and humans value for cancer risk assessment, Environ. Carcinogenesis Ecotoxicology Rev., C17, 45-67, 1999. 

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