INT- IARC - A review of human carcinogens 08.12.2009
INT- IARC finds sufficient evidence for hematopoietic carcinogenicy of formaldehyde, carcinogenicity of additional polychlorinated bipphenyls and occupational exposure as a painter, with limited evidence of effects on offspring.
Just published: A review of human carcinogens - Part F: Chemical agents and related occupations - Highlights and Summary of evaluations now available in PDF.
In October 2009, 23 scientists from 6 countries met at the International Agency for Research on Cancer (IARC) to re-assess the carcinogenicity of a number of chemical compounds, complex mixtures and occupational exposures previously classified as carcinogenic to humans (Group 1) and to identify additional tumour sites and mechanisms of carcinogenesis. These assessments will be published as the sixth and last part of Volume 100 of the IARC Monographs.
Dioxin (2,3,7,8-TCDD), now has sufficient evidence in humans. The Working Group extended the Group-1 classification to 2,3,4,7,8-pentachlorodibenzofuran and 3,4,5,3',4'pentachlorobiphenyl, which are indicator chemicals for a larger class of dioxin-like chlorinated dibenzofurans and dioxin-like polychlorinated biphenyls (PCBs).
Formaldehyde was confirmed as carcinogenic to humans. There is sufficient evidence in humans of an increased incidence of nasopharyngeal
Carcinomas. In addition, the epidemiological evidence on leukemia has become stronger, and new mechanistic studies support a conclusion of sufficient evidence in humans. This highlights the value of mechanistic studies, which in only 5 years have replaced previous assertions of biological implausibility with new evidence that formaldehyde can cause blood-cell abnormalities that are characteristic of leukemia development.
Occupational exposure as a painter causes cancers of the lung, urinary bladder and pleural mesothelioma in humans. Due to the diversity and complexity of the exposures, it is difficult to identify causal agents or a causal mechanism, although there is strong evidence that the exposures are genotoxic. The Working Group found limited evidence of an association between maternal exposure to painting before and during pregnancy and an increased risk of
childhood leukemia in the offspring. These findings confirm those of a previous Working Group (2007).
Overview of the evaluations (summaries available at http://monographs.iarc.fr/ENG/Meetings/vol100F-evaluations.pdf):
Aflatoxins, 4-Aminobiphenyl, Benzene, Benzidine, Dyes metabolized to benzidine, Bis(chloromethyl)ether and chloromethyl methyl ether (technical grade), 1,3-Butadiene, Ethylene oxide, Formaldehyde, 4,4′-methylenebis(2-chloroaniline), Mustard gas, 2-Naphthylamine, 2,3,7,8-TCDD, 2,3,4,7,8-PeCDF, PCB 126, o-Toluidine, Vinyl chloride, Benzo[a]pyrene, Soot, as found in occupational exposure of chimney-sweeps, Coal gasification, Occupational exposures during coal-tar distillation, Coke production, Coal-tar pitch, Untreated or mildly treated mineral oils, Shale oils Occupational exposures during aluminum production, Auramine production, Occupational exposures during iron and steel founding, Isopropyl alcohol manufacture by the strong-acid process, Magenta production, Occupational exposure as a painter, Occupational exposures in the rubber manufacturing industry, Mists from strong inorganic acids were found to be carcinogenic to humans (group1). Auramin and magenta were found to be possibly carcinogenic to humans (Group 2B).
