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Masaru Sagai: 'Clean' diesel cars may worsen air pollution
http://www.asahi.com/english/Herald-asahi/TKY200812020050.html

...incomplete combustion is unavoidable with diesel engines, and could be a fatal defect. The high-pressurized fuel injection systems improved combustion efficiency of diesel engines. As a result, PMs (particulate matter) are released in the form of a fine mist and black fumes have seemingly disappeared. In exchange, however, the level of invisible ultra-fine nano-particles of less than 0.1 micrometer in diameter rose more than several tens of thousands of times. A micrometer is one-millionth of a meter. In short, the particles only became finer and invisible to the naked eye.

It is known that PMs measuring several micrometers can enter the respiratory system and trigger illnesses such as asthma. But nano-particles pass through the respiratory system and enter blood vessels. Furthermore, recent animal tests have proved that they even reach circulatory organs including the heart, as well as the brain, nerve and reproductive systems.
...
Since last year, the Environment Ministry has been studying to establish new environmental standards for PM2.5. But the work is making slow progress and the spread of clean diesel cars will not encourage the government to introduce new regulations.

Since I have asthma, this really concerns me. Does anybody have further information or opinions on this?

We need to start looking at the emissions of smaller particulates than PM10. PM2.5 and PM0.1 are both probably worth looking at, and until that happens, DPF's are just trading the emissions of a regulated particulate size for emissions of an unregulated particulate size. Gasoline engines don't make much around 10 micrometers, but can be as bad as diesels in the PM2.5 and PM0.1 range.

If true, this is bad news!

Dan's son in Houston has been treated for asthma. Turns out Houston is the asthma capital of the US. :( This may be an extra reason to resent diesel-clanging doolies with cowboys that are all hat - no cattle....plenty of them in Houston and D/FW.

A whole lotta diesels around here too. About 50% of them don't even have hitch recievers. 75% of the ones that do have obviously never been used.

If true, this is bad news!

Dan's son in Houston has been treated for asthma. Turns out Houston is the asthma capital of the US. :( This may be an extra reason to resent diesel-clanging doolies with cowboys that are all hat - no cattle....plenty of them in Houston and D/FW.

That and all the Houston-area refineries needed to support the guzzlers, both here and across the country. Houston-refined fuel goes a lot of places...

We need to start looking at the emissions of smaller particulates than PM10. PM2.5 and PM0.1 are both probably worth looking at, and until that happens, DPF's are just trading the emissions of a regulated particulate size for emissions of an unregulated particulate size. Gasoline engines don't make much around 10 micrometers, but can be as bad as diesels in the PM2.5 and PM0.1 range.

Well that sucks!
I did a quick google and PM0.1 and smaller are referred to as "ultrafine" particles and the smallest of them are called "nanoparticles". It seems that effects of these smaller particle sizes hasn't been researched as much so naturally regulation will lag behind...

Not sure what country the author of the linked article is from (Japan?), but it doesn't appear it's applicable to the U.S./Canada, at least not the latest clean diesel versions.

All diesel vehicles (cars, HD trucks, SUVs, pickups) manufactured since January 2007 have come OEM-equipped with diesel particulate filters (DPF). DPF has been shown to be extremely effective across the entire particle size distribution.

Several studies have actually shown that DPF reduces particle numbers below ambient (e.g., Färnlund et al., "Emissions of Ultrafine Particles from Different Types of Light Duty Vehicles." Swedish National Road Administration; Environmental and Health Impact From Modern Cars, Ecotraffic (Sweden); John Storey et al., ORNL, "Comparison of Direct Exposure of Human Lung Cells to Modern Engine Exhaust Particles." Proceedings of the 9th Annual DEER Conference). One even shows PM number emissions below that of filtered dilution air (http://www.dieselnet.com/papers/0209czerwinski/).

Even CARB has acknowledge that cars equipped with DPF have lower PM emissions than typical modern gasoline cars (http://findarticles.com/p/articles/mi_m0CYH/is_5_7/ai_99232199).

I would also take issue with the assumption that gas vehicles don't produce much ultrafine PM. At least one study shows gas vehicles under some common driving conditions (high speed/load, cold ambient temperatures) produce utrafine PM that can approach or even exceed uncontrolled diesel engines (http://www.osti.gov/bridge/servlets/purl/829821-SQYKH6/native/829821.pdf).

wxman, I'm very happy to hear all of this. Subaru may be releasing a diesel, so if they do I won't feel bad about driving it.

I think 10 microns or less is the size of particle that can make it down the smallest airways all the way to the alveoli. This is roughly the size of a red cell.

I had no idea that we-in the USA- don't filter out these small particles. If we do- how do we do it? I mechanical filter that fine would have to add a lot of back pressure wouldn't it? Maybe the filters charge theses particles and pull them via the charge to a charged plate.I think industrial stack scrubbers work like this.
Charlie

Not sure what country the author of the linked article is from (Japan?), but it doesn't appear it's applicable to the U.S./Canada, at least not the latest clean diesel versions.

All diesel vehicles (cars, HD trucks, SUVs, pickups) manufactured since January 2007 have come OEM-equipped with diesel particulate filters (DPF). DPF has been shown to be extremely effective across the entire particle size distribution.

...

I would also take issue with the assumption that gas vehicles don't produce much ultrafine PM.
...
(http://www.osti.gov/bridge/servlets/purl/829821-SQYKH6/native/829821.pdf).

Yes, the author is from Japan.
Thanks for the interesting links; I'll read them after Xmas.

Welcome to cleanmpg, wxman!!!
--Walter

Walter - thank you for the welcome.

I neglected to mention in my initial post that EPA recently acknowledged that they have been underestimating PM mass emissions from gasoline vehicles by about 60% (“Analysis of Particulate Matter Emissions from Light-Duty Gasoline Vehicles in Kansas City.” April 2008). This is primarily PM2.5, but since the normal size distribution of gasoline vehicle PM is typically skewed to the left (i.e., smaller) than the typical normal size distribution of diesel PM, it is likely that ultrafine PM from gasoline vehicles also has been/is being underestimated.

Hi All,

Have you all seen the Nova episode on Global Diming? It seems PM can prevent rainfall.

Does it seem currious that the rise of deisels in Europe coincides with the Ethiopian drought? I think there is a connection there. And now as Europe is mandating DPF's, even on existing existing Diesel cars, the Ethiopian drought has diminished.

The transcontinental climate impacts due to Diesel PM appear to be quick acting and severe.

Walter - thank you for the welcome.

I neglected to mention in my initial post that EPA recently acknowledged that they have been underestimating PM mass emissions from gasoline vehicles by about 60% (“Analysis of Particulate Matter Emissions from Light-Duty Gasoline Vehicles in Kansas City.” April 2008). This is primarily PM2.5, but since the normal size distribution of gasoline vehicle PM is typically skewed to the left (i.e., smaller) than the typical normal size distribution of diesel PM, it is likely that ultrafine PM from gasoline vehicles also has been/is being underestimated.

Which is why we should all strive to use as little carbon in our fuels, and little fuel as possible.

Diesel exhaust is a significant source of fine particle pollution, as well as a combination of more than 40 substances that are listed as hazardous pollutants. Because of their microscopic size, these fine particles can become trapped in the small airways of the lungs when they are inhaled.

Sources of diesel emissions include diesel-powered trucks, buses and cars (on-road sources); diesel-powered marine vessels, construction equipment, trains and aircraft support equipment (non-road sources).

Particulate matter from diesel exhaust overwhelmingly presents the highest health risk in the Puget Sound area, making up an estimated 78 percent of the potential cancer risk from exposure to outdoor air toxics.1 Diesel particulate matter is also linked with health effects including heart problems, aggravated asthma, chronic bronchitis and premature death.

Diesel exhaust is a significant source of fine particle pollution, as well as a combination of more than 40 substances that are listed as hazardous pollutants. Because of their microscopic size, these fine particles can become trapped in the small airways of the lungs when they are inhaled....

Again, DPF virtually eliminates PM from diesel engines. Even then, DPM represents only one of a myriad of sources of ambient PM2.5.

Gasoline exhaust contains those hazardous components too, only generally in greater amounts per unit volume of fuel burned.

...Particulate matter from diesel exhaust overwhelmingly presents the highest health risk in the Puget Sound area, making up an estimated 78 percent of the potential cancer risk from exposure to outdoor air toxics.1 Diesel particulate matter is also linked with health effects including heart problems, aggravated asthma, chronic bronchitis and premature death.

Are you aware of any study that exonerates PM2.5 from gasoline exhaust, or any other source for that matter? Public health agencies have decided to arbitrarily assign all cancer risks to DPM and none to other ambient PM, thus the apparent "overwhelming" cancer rsik from DPM. There are no reasons to believe other PM2.5 isn't just as harmful as DPM, especially from combustion sources.

Two newbies in battle, with one advertising wood pellets, there must be at least one agenda here. :eyebrow:

I'm skeptical that we know with any accuracy that 78% of Puget sounds outdoor air cancer risk is because of diesel.

Ill take another step... we utilize hydrodesulfurization as a means of producing the 15ppm fuel necessary to allow pollution controls to operate and live. Guess where that hydrogen comes from??? Some from catalytic cracking of fuel, the rest of the make-up (which can be a lot depending upon how nasty the crude is) is made by steam reformation of methane... trading methane, which could be used to heat our homes, showers, and produce fertilizer, to non-selectively crack fuel.

Most of it is wasted opening aromatic rings and double/triple bonds, not removing sulfur.

So were doing double waste duty...

Then we enable diesels with pollution controls, which not only sap power and fuel economy, but make diesels more expensive to produce, operate and maintain.

In the long run, considering the environmental effects of producing, recycling and reclaiming metals for batteries (especially since much of this is done in China where there are limited pollution controls), a "dirty diesel" getting 60 MPG could be cleaner than a hybrid, full circle. hydrogen could be used for superior causes, or even for a hydrogen infrastructure to help rovide cleaner air in cities and congested areas.

Instead we get this supposedly beneficial technology, which just costs more and is likely to cause consumers to swap cars more often (lets face it, most wont want to have to deal with a $3000 emissions system or a $3000 hybrid battery), driving manufacturing-based pollution up further and introducing more issues...

We have potentially as much of this matter coming from ga$$ers, and we take away the benefits of diesels to some extent - longevity and operational economy. Some of the longevity is due to stouter designs which raise the cost - but then we raise the cost more with expensive pollution controls.

With mandatory inspections and proper tuning, plain old diesels can run awfully clean... and higher fuel economy means lower overall tonnage, which is a win for all involved.

Instead we get this supposedly beneficial technology, which just costs more and is likely to cause consumers to swap cars more often (lets face it, most wont want to have to deal with a $3000 emissions system or a $3000 hybrid battery), driving manufacturing-based pollution up further and introducing more issues...

With mandatory inspections and proper tuning, plain old diesels can run awfully clean... and higher fuel economy means lower overall tonnage, which is a win for all involved.
The diesel upgrade for a VW is about $2200 and $1000 for a Mercedes. That includes the more expensive diesel engine, turbocharger, 20000+ PSI piezo fuel injectors, plus all emissions controls. So unless Mercedes and VW are underpricing the diesel package for some reason, there is no way the emissions system alone is $3000.

Well tuned diesels may not emit visible smoke, but their emissions from are still nowhere near as clean as what comes out of the new clean diesels. My 2001 was allowed to emit 18x as much NOx and 10x as much PM as a 2009 TDI. If somebody told me I could meet 2009 emissions standards but it meant giving up 10% of power and 3mpg, I would gladly do it.

I just purchased an 2009 VW Sportswagan TDI. My first tank-full I pushed the car to see what it could do(36.8mpg). I'll take that, with the new car average at around 24.5mpg. One thing, the car makes a diesal sound only when it starts after about 4 minutes in the cold it sounds like a gas car. I love it.
Joe the new guy

Congrats on the purchase, Joe! The SportWagon is a very nice car and with the TDI, nothing that size can match its fuel economy. I know it can do a lot better than 36.8mpg though. I've seen some reports on TDIclub of people with 50+ mpg tanks and you can beat that easily by applying and understanding the techniques described in Beating the EPA - The Why’s and How to Hypermile (http://www.cleanmpg.com/forums/showthread.php?t=1510). Take a read through it, don't be afraid to ask questions if something doesn't make sense, and enjoy your new car!

Masaru Sagai: 'Clean' diesel cars may worsen air pollution
http://www.asahi.com/english/Herald-asahi/TKY200812020050.html

Some diesel are cleaner than others. No diesel is clean.

Since I have asthma, this really concerns me. Does anybody have further information or opinions on this?

The London congestion charge has proven efficiency in health. iirc (I can't find an article about that by a quick search) asthma has diminished by several tens percent in the first 6 months. Now as all particles has diminished it's difficult to say which permitted such a result.

Now from latest French studies [1], while 50% of cars are diesel, only 9 to 16% of PM are from road usage :

9% for all particles in suspension
11% for PM10
12% for PM2.5
16% for PM1.0

While agriculture is the 1st culprit for bigger particles (47%), residential (burning of wood, coal and fuel) is the one for the smallest one (66%). For medium particles, industries, residential and agriculture share the responsibilities (respectively 26, 41 & 17% for PM2.5 and 28, 27 & 30% for PM10).

1) Sorry, French only...
http://www.citepa.org/emissions/nationale/Poussieres/Emissions_FRmt_PM.pdf

Denis.