A report from the International Agency for Research on Cancer (part of the World Health Organisation) has said there is strong evidence that diesel fumes cause cancer.
The working group chairman, Christopher Portier, said: "The scientific evidence was compelling and the working group's conclusion was unanimous: diesel engine exhaust causes lung cancer in humans." However, the car industry's attitude to the study is that the participants seem to have been living in a cave for the last ten years.
The basis of the environmental argument is that soot particles from diesel are carcinogenic – very few scientists doubt that. However any diesel car sold in Europe since 2010 barely emits soot. All diesel cars meeting the current Euro V regulations have particulate traps to catch the soot in the exhaust system, with the result that a new car today emits 1/5th as much soot as a car of 2008 and 1/10th as much as a car of the late 1990s.
The European automotive component suppliers association said it was "concerned about the misleading conclusions of the International Agency for Research on Cancer in their review of the health hazard classifications of gasoline and diesel exhausts." Car companies are certainly annoyed: they (and therefore their customers) have spent hundreds of pounds per car on eliminating something only to be told that it used to be a problem.