International Agency for Research on Cancer (IARC) - Summaries & Evaluations

(Group 2B)

For definition of Groups, see Preamble Evaluation.

VOL.: 46 (1989) (p. 321)

CAS No.: 5522-43-0
Chem. Abstr. Name: Pyrene, 1-nitro-

5. Summary of Data Reported and Evaluation

5.1 Exposure data

1-Nitropyrene has been detected in some carbon blacks, in stack gases from coal-fired power plants and aluminium smelters and in particulate emissions from other stationary sources and from diesel and gasoline engines. 1-Nitropyrene also occurs at low concentrations in ambient air.

5.2 Experimental data

1-Nitropyrene was tested for carcinogenicity by oral administration in rats, by skin application in mice, by intratracheal instillation in hamsters, by intrapulmonary administration in rats, by subcutaneous injection in mice and in newborn and young rats and by intraperitoneal injection in newborn and young mice and in rats. Two experiments by oral administration to rats were considered to be inadequate for evaluation. One experiment on mouse skin gave negative results; the other was considered to be inadequate. Following either intratracheal instillation in hamsters or intrapulmonary administration in rats, negative results were obtained.

One study by subcutaneous injection in young mice gave negative results, however the group was quite small. In one study in newborn rats, 1-nitropyrene produced sarcomas at the site of injection and an increased incidence of mammary tumours, including adenocarcinomas. In two other studies using newborn rats (including one using two different strains), no tumour was observed at the site of injection and there was no increase in the total number of mammary tumours. Two studies with young rats given subcutaneous injections of 1-nitropyrene yielded negative results, but the groups were small and the observation periods relatively short.

In a screening test by intraperitoneal injection using strain A mice, lung tumour incidence and the number of adenomas per mouse were significantly increased. One study using intraperitoneal injection in newborn mice showed an increase in the incidence of liver-cell tumours in males. One study on weanling rats showed an increased incidence of mammary tumours; a second study from the same laboratory showed a nonsignificant increase in the incidence of mammary tumours.

N.-B. - Subsequent to the meeting, the Secretariat became aware of a newly published study (El-Bayoumy et al., 1988) describing the induction of mammary adenocarcinomas in female Sprague-Dawley rats given 1-nitropyrene (purity, > 99.9%) by gavage from birth to 16 weeks of age.

5.3 Human data

No data were available to the Working Group.

5.4 Other relevant data

The association of 1-nitropyrene with diesel particles led to a substantial reduction in clearance of the compound from the lungs of rats.

Metabolism of 1-nitropyrene led to DNA adduct formation in cultured human and mammalian cells and in animals. 1-Nitropyrene induced DNA damage and sister chromatid exchange in rodents; DNA damage, mutations and transformation in cultured human cells; and DNA damage, sister chromatid exchange, chromosomal aberrations, mutation and transformation in cultured animal cells. It was not recombinogenic to yeast but induced DNA damage and mutation in bacteria.

5.5 Evaluation

There is sufficient evidence for the carcinogenicity in experimental animals of 1-nitropyrene.

No data were available from studies in humans on the carcinogenicity of 1-nitropyrene.

Overall evaluation

1-Nitropyrene is possibly carcinogenic to humans (Group 2B).

For definition of the italicized terms, see Preamble Evaluation.

Previous evaluations: Vol. 33 (1984) (p. 209); Suppl. 7 (1987) (p. 67)

Last updated 01/21/98

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