World Health Organization - diesel causes cancer

We have had this news before, to most of us it was not news that diesel exhaust was not healthy, there are strong indications that gasoline exhaust is unhealthy too.

One key here from the article.

US regulators knew about the problem and acted before the WHO report. The diesels talked about are not the new SCR diesel cars with DPF. These are much cleaner than the old diesels studies, but hybrid cars are even less unhealthy.

The big takeaway from this report for US policy makers is certain jobs have an environmental risk from diesel pollution. Toll collectors and miners were spelled out in the article.

 

Precisely the point: modern diesels with working DPFs are not a problem. This study is based on the most extreme case of unfiltered diesel engines in enclosed environments.

However, it's clear that people who remove their DPFs are selfish, um, people who shouldn't be driving. Grumpy's mentioned that cab drivers will remove their DPFs between inspections.

 

no, they talk about diesel fumes, period. Cars with DPF are still diesels and while they emit less of these so called ultra-fine particles, they still do emit them.

In Europe, it was found out that VW and BMW turbo petrols emit a lot of particulates, but I am not sure if these are the same type that causes cancer. Other turbos emit much less and non turbos not much at all.

 

I think that particles emission are with correlation to direct injection (diesel or petrol) not turbos. The article doesn't say how much cleaner a gasoline exhaust is.

 

I said SCR (selective catalytic reduction) and DPF, and referred to the US. SO2 and NOx have been dropped to 5% of their previous levels. I also did not say that we know of safe levels. Exhaust from both diesel and gasoline engines are probably still carcinogenic with high exposures.

You have different standards over there. I do not know the levels being produced by the european fleet. Sulfur dioxide is determined by the fuel used. NOx and particulates are determined by the heat and compression, these will be higher in higher compression cars regardless of diesel or petrol, but mitigated by exhaust after treatment. Diesel cars emit more from the engine but often less at the tailpipe in the US cars because of more aggressive pollution control. US standards are tougher than european standards when it comes to diesel pollution. The other pollutant NMOG is likely also carcinogenic, but I have no idea whether newer pollution regimens have significantly reduced it, but this was a main target in the early days of the catylitic converter.

The biggest problem in the US appears to be diesels used in mining and older diesel trucks, and this may most benefit from removing grandfathering of old equipment.

 

I am no huge fan of diesel cars, but how does the experience of miners being pummeled with diesel exhaust equate to a person behind a car with diesel exhaust? By the time the diesel exhaust gets into the cabin of a car behind it it's been diluted dozens if not hundreds or thousands of times (depending on distance, wind, etc.) by the ambient air.

 

The TDI clean diesel exhaust system and how it works.
VW Audi DPF filter regeneration with DPF problems like clogging and why you can't do a DPF bypass or DPF delete with a kit

 

Thanks for the information, I learned something. I did not realize that the DPF was why biodiesel can not be run in these new engines.

 

Keep in mind over the last 10-years EPA has forced the oil industry to remove virtually all (99.9+% removal) of sulfur from gasoline and diesel. How do you get 99.9% sulfur removal, from a chemists persepctive? You need humongous and costly hydrogenation reactors, at the expense of hundreds of $billions in USA alone. Happily these long term construction projects are mostly completed, and we now live in a new ultra-low-sulfur fuels world. The reason for removing sulfur was to not to reduce sulfur emissions, but to allow the fuels to burn cleaner (less particulates etc). But primarily to allow the post-treat-catalysts in the vehicles to work at top efficiency (since sulfur is catalyst poison). I still would not breath the exhaust directly, but we're talking the problem has not been ignored.

 

...point of confusion for me, EU does use biodiesel to the tune of 5%. Does that mean EU diesel cars are different or can the DPF handle 5% bioD?

 

That blurb said B5 was safe if oil was changed with less than 10,000 miles, on vw cars. B10 seemed like it might be safe too, but might compromise the oil much quicker. It was only about vw cars, and its routines to do post combustion injection of fuel to clean the DPF, but other manufacturers have similar routines.

 

VW's official limit is 5% biodiesel.

 

The study is based on the exposure of miners to diesel fumes from industrial engines without particulate filter.

Yes indeed, that's the thing. The smaller particulates are believed to major carcinogens. Truly, all cars should have particulate filters but that would be politically difficult.

 

Many European cars can run on a small percentage of bio diesel without any warranty issue. I think all our diesel now has at least 5% bio diesel by legislation, though I believe they want to increase this in time.

I'm not sure about VW/Audi but I know the French diesels such as Peugeot will allow a mix upto 30% and continue to be warrantied and causing no issues with the emissions system. Just had a quick look on their website and apparantly every Peugeot since 1998 can run on this mix (though particle filters only came out in 2000).

 

OK thanks GC yes I know EU wants to increase biodiesel content but I believe the logic of 5% bio is that's a practical level where the standard diesel quality specs are maintained re: stability etc. once you go over 5% you are getting into somewhat of a new biofuel quality regime. I hate to ask but I wonder why USA does not put 5% bio in diesel like EU? I am not a big fan of bio I think it is mainly an opportunity to give the ag business share of the energy market, but wonder how US escaped mandated 5% bio in all diesel.

 

OK thanks GC yes I know EU wants to increase biodiesel content but I think the logic of 5% is that's a comfortable level re: fuel quality equivalence and universal good performance compared to conventional diesel. Wonder how we escaped 5% mandated bio in US diesel, not that I agree with adding bio.

 

From el dobro's link on vw those systems would not be happy with higher percentages of biodiesel. It has to do with the post combustion injection used to burn off the particulates.
VW Audi DPF filter FAQ with DPF problems like clogging and why you can't do a DPF bypass or DPF delete with a kit

 

The Feds and biodiesel.
Alternative Fuels Data Center

 

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As mentioned, it is the regeneration method used. The post combustion cylinder injection of fuel for burning off the soot in the DPF is a common method because it is cheap. Biodiesel's physical properties can lead to problems with this method. Exhaust injection would avoid those problems, but requires more parts which increases cost.

Saw a new F250/350 diesel on the road and its emblems declared it B20 capable. Earlier models only recommended 5% at most. The DPF was a major reason for this, but it also because of the ease of homebrewing biodiesel. Engine manufacturers just didn't have control over the quality of the biodiesel going into the tank. Even commercial manufacturers had quality issues.

Montana(iirc) once had a B5 requirement. A major supplier for the biodiesel didn't remove all the gycerol, and it led to gunked up fuel filters. Biodiesel cleans out the fuel tank, and the freed up dirt will also clog the filter, but this went beyond that. So the state backed off on the requirement.