Thursday 14 June 2012

Group One Carcinogens!

I love how newspapers always catch the really scary carcinogens in the Group 1 list for comparison purposes. Turns out diesel exhaust is a Group 1 carcinogen.

Here's the Toronto Star:
The decision is a result of a week-long meeting of independent experts who assessed the latest scientific evidence on the cancer-causing potential of diesel and gasoline exhausts.
It puts diesel fumes in the same risk category as noxious substances such as asbestos, arsenic, mustard gas, alcohol and tobacco.
Otago Daily Times:
The decision puts diesel fumes in the same risk category as a number of other noxious substances including asbestos, arsenic, mustard gas, alcohol and tobacco.
Our public broadcaster, OneNews:
Diesel engine exhaust fumes cause cancer in humans and belong in the same potentially deadly category as asbestos, arsenic and mustard gas, World Health Organisation (WHO) experts say.
...The decision puts diesel fumes in the same risk category as a number of other noxious substances including asbestos, arsenic, mustard gas, alcohol and tobacco.
Reclassifying diesel exhaust as carcinogenic puts it into the same category as other known hazards such as asbestos, alcohol and ultraviolet radiation.
But, 3News also helps put things in perspective:
"It's on the same order of magnitude as passive smoking," said Kurt Straif, director of the IARC department that evaluates cancer risks.
The Christchurch Press and NZ Herald give the same summary as 3News. But the Herald gave a scarier assessment in a second article:
The exhaust from diesel was added to the World Health Organisation's list of most carcinogenic substances yesterday. It ranks alongside arsenic, asbestos, formaldehyde, mustard gas and plutonium as a major health hazard.
Plutonium! That's really scary! Way scarier than passive smoking!

So, what else is in Group One? Here's the Cancer Society. Lots of scary stuff like plutonium. But also a few other things that are a bit less worrying. As I wrote back in 2009 when Doug Sellman was putting alcohol up against plutonium and Gamma Radiation and Mustard Gas:
But here are some other known carcinogens that could have been listed alongside alcohol instead and would have been perhaps a bit less scary: ciclosporin (used to prevent organ rejection after transplant), estrogen-based oral contraceptives and menopausal therapy, risky sex (Hepatitis B & C, HPV, HIV), the sun, mineral oils, salted fish, wood dust, painting, boot and shoe manufacture and repair.
I call a win for the news outlets that quoted the IARC specialist that diesel exhaust is about as bad as second hand smoke. It's a heck of a better way of putting risks in perspective than pointing to freaking plutonium. I call place for those that gave a range of risks that included UV radiation - people have a handle on the riskiness of the sun. And a great big loss to anybody reckoning plutonium comparisons helped enlighten their readers. It would have been helpful if the Science Media Centre had put up the quote from Straif that helps readers contextualize things.

I still don't get how import restrictions on older vehicles, including both petrol and diesel, make more sense than better smog checks on older cars. I sit behind an awful lot of very horrible smelly mid 90s Toyota LandCruisers in Christchurch. Old vans are terrible too. Banning the import of 2004 models seems a pretty roundabout way of getting those stinkers off the roads.


  1. you shift over to Fendalton road Eric, and you can drive behind a 2012 Toyota cruiser, not nearly so smelly, carcinogen free wheel driving

  2. I believe that the Cat A grouping is more about the certainty of the evidence that it carcinagenic, rather than its actual riskiness.

    1. It is! That's why it's nuts that people keep referring to "in the same category". It's a category of things that we know can cause cancer.

      You might as well say that water is in the same category as strychnine because both can poison you. It's just that the LD50 of the one's a bit different than the other.