So explain this then in ways that make you and your industry look good
http://www.bbc.co.uk/news/health-18415532
Good one! Have you actually read the article you linked? It was written in 2012 and considers particulates and low sulfur fuels (which came in nearly 20-years ago).
Among other things it says Diesel emissions cause less cancer than smoking and is now grouped with other commonly known carcinogens such as wood dust. Not news to the industry (not 'my' industry by the way). Diesel particulates are harmful not because of their chemistry, but because they are very small. Direct Injection Gasoline engines make very small particulates too, these are also harmful to health. The number of particles emitted is now regulated for both diesel and gasoline cars and not a minute too soon. Particulate traps in the exhaust have massively reduced tailpipe diesel particulate emissions. I think they should also be fitted to gasoline cars and think they will be in future.
Tyres, as they wear down release particulates into the atmosphere too, even on electric vehicles. Guess what, they are harmful too and are not currently regulated at all. Don't often even see a discussion about this.
Airborne particulate matter is harmful to health. Where this is from road transport, reducing the number of vehicles is the most effective way of reducing these missions. Congestion charges and making city centres vehicle free zones is the best strategy for improving local air quality in cities. Not popular though. Getting the old gross emitting vehicles off the road should be a priority, though again it's not a popular policy as it penalises those that can least afford to buy a car with newer technology.
The current focus is on NOx emissions from diesel. This has been a thorny issue for years and in my opinion de-NOx technology such as AddBlue SCR, should have been mandated 10-years ago when particulate filters came in. As it is, only Euro 6 diesel cars have this technology and even then I don't think it's mandated, only that it's very difficult to meet the emissions limits for NOx without it. Euro 5 Diesel engines typically have EGR, which is one tool for reducing NOx made during combustion, but this only goes so far before particulate emissions increase substantially. This puts a lot of pressure on the durability of the DPF, so care is needed when going this route.
Other issues revolve around the relevance and evolution of laboratory emissions measurements versus so-called real-world emissions measurements. This is a very complex area with a number of competing interests. The principle sticking point in my opinion is that in the event laboratory testing was conducted under more realistic conditions, the emissions would be higher than the limits right across the board. The government's air quality models will all need to be re-built, their assumptions on air quality will all be wrong (are wrong), new vehicle models won't look as environmentally friendly as the previous model, all of the emissions testing methodologies and regulations will all have to be re-written and ratified. Overall it's a mess and has been for years.
FWIW I neither worked for a vehicle OEM or the government, so from a testing viewpoint was a neutral. We just wanted to understand the methods and be able conduct test measurements in accordance with the regulations (when appropriate for our programs of work).
