....according the the World Health Organization. I know this has been mentioned in other threads, but I think a thread dedicated to this is a good idea.
World News: Diesel exhaust as cancerous as asbestos, says WHO - thestar.com
Other articles I have found mention that 07+ engines with DPFs only slightly reduce the effects.
It kind of scares me because I work in the shop at a heavy duty truck dealership. We do have exhaust fans that slip over the exhaust stacks, but they are not 100% effective at removing all the exhaust from the building. Plus, there is a mentality that anything with a DPF is harmless, so the exhaust fans sometimes do not get used at all.