A Lancet Oncology report summarises the conclusions from IARC’s June 2012 meeting on diesel and gasoline engine exhausts and some nitroarenes. The full meeting report will ultimately be issued as volume 105 of IARC’s prestigious series of Monographs on the Evaluation of Carcinogenic Risks to Humans.

Epidemiological studies linking exposure to lung, and possibly bladder, cancer provided “sufficient” evidence for the carcinogenicity of diesel engine exhaust in humans. Animal evidence associating lung cancer with exposure was also judged to be “sufficient”, and “strong evidence” was seen for a genotoxic mode of action. As a result, diesel engine exhaust was classified as “carcinogenic to humans” (Group 1).

Human data on the carcinogenicity of gasoline engine exhaust were “inadequate”, but animal studies provided “sufficient evidence” for the carcinogenicity of its condensates (increased lung and skin tumours were observed). “Strong evidence” was seen for a genotoxic mode of action. Overall, gasoline engine exhaust was considered to be “possibly carcinogenic to humans” (Group 2B).

Ten nitroarenes found in diesel engine exhaust were also evaluated, with conclusions based on laboratory animal and mechanistic evidence. All were seen to be genotoxic to various extents in different assays, and the following were classified as “probably carcinogenic to humans” (Group 2A):

  • 6-nitrochrysene
  • 1-nitropyrene

Those below were considered to be “possibly carcinogenic to humans” (Group 2B):

  • 3,7-dinitrofluoranthene
  • 3,9-dinitrofluoranthene
  • 1,3-dinitropyrene
  • 1,6-dinitropyrene
  • 1,8-dinitropyrene
  • 3-nitrobenzanthrone
  • 2-nitrofluorene
  • 4-nitropyrene

Benbrahim-Tallaa L et al. (2012). Carcinogenicity of diesel-engine and gasoline-engine exhausts and some nitroarenes. Lancet Oncology 13, 663-4.

The above item was taken from the August 2012 issue of Toxicology and Regulatory News which is sent automatically to members of bibra (click here for more details).

News Home Guest Write For Us? Contact Us