dagblog - Comments for "Diesels: So Bad?"

W.H.O. Declares Diesel Fumes

artappraiser — Wed, 13 Jun 2012 18:04:40 +0000

W.H.O. Declares Diesel Fumes Cause Lung Cancer
By DONALD G. McNEIL Jr., New York Times, June 12, 2012

Diesel fumes cause lung cancer, the World Health Organization declared Tuesday, and experts said they were more carcinogenic than secondhand cigarette smoke.

The W.H.O. decision, the first to elevate diesel to the “known carcinogen” level, may eventually affect some American workers who are heavily exposed to exhaust. It is particularly relevant to poor countries, where trucks, generators, and farm and factory machinery routinely belch clouds of sooty smoke and fill the air with sulfurous particulates.

The United States and other wealthy nations have less of a problem because they require modern diesel engines to burn much cleaner than they did even a decade ago. Most industries, like mining, already have limits on the amount of diesel fumes to which workers may be exposed.

The medical director of the American Cancer Society praised the ruling by the W.H.O.’s International Agency for Research on Cancer, saying his group “has for a long time had concerns about diesel.”

The cancer society is likely to come to the same conclusion the next time its scientific committee meets, said the director, Dr. Otis W. Brawley.

“I don’t think it’s bad to have a diesel car,” Dr. Brawley added. “I don’t think it’s good to breathe its exhaust. I’m not concerned about people who walk past a diesel vehicle, I’m a little concerned about people like toll collectors, and I’m very concerned about people like miners, who work where exhaust is concentrated.” [....]

My anecdotal is that the slow

artappraiser — Thu, 24 May 2012 03:15:44 +0000

In reply to Good points. I walked past an

My anecdotal is that the slow transition (still not complete) of the NYC bus fleet from conventional diesel to diesel with more filters or natural gas or diesel/electric hybrids has made an incredible difference in the foul air stench of Manhattan (now you can actually smell the urine and rotting garbage in the summertime, before you couldn't because you were busy choking on the all the idling bus fumes! )

But you don't have to believe just my anecdotal, see here:

The study found that conventional diesel buses are comparatively fuel efficient, but produce nitrogen oxide pollutants that can contribute to photochemical smog as well as large amounts of fine soot and sulfate particles, which are suspected to contribute to heart disease and lung cancer

Yeah, we're talking good ole time plain vanilla air pollution here, smog and soot, the stuff that makes you choke and your eyes smart, not any of that fancy greenhouse gas stuff. When the diesel is idling in traffic, and then when it accelerates up again, it's pretty damn noxious stuff. I believe you can also see this discussed on websites about why urban kids have so much asthma, though there's no definitive answer on that question.

Good points. I walked past an

Donal — Thu, 24 May 2012 00:04:44 +0000

In reply to Have not kept up with diesel

Good points. I walked past an old Benz 300D after swimming. The back half was filthy with exhaust and fume deposits.

Have not kept up with diesel

chucktrotter — Wed, 23 May 2012 23:41:53 +0000

In reply to Diesels: So Bad?

Have not kept up with diesel technology, but will agree with your positive assertions relative to the subject. I have considered diesel relative to choosing my future automobile purchases. There are some negatives that should influence your decision to go to diesel propulsion: Few auto mechanics are diesel qualified. As stated the two systems are unique when it comes to ignition. As diesel components are a rarity inside the States, expect long waits for replacement parts. In areas of extremely cold temperatures, diesels can be very hard to start. (I'm not certain now, but in the old days, diesel locomotives sat idling for days rather than being shut-down because of fear of inability to restart them.) Once again, over time, these weaknesses may have been corrected, but in my experience. diesels had such wide tolerances, you could have thrown a cat between the piston rings and the cylinder walls.

This Dagblog needs more manly

The Decider — Tue, 22 May 2012 16:41:16 +0000

In reply to Diesels: So Bad?

This Dagblog needs more manly articles like this. The diesel engine is so dam much more efficient than a gasoline engine. It operates at a very high compression rate. In fact, the fuel/air mixture is ignited by compression rather than by a spark (plug) as in a standard gas engine. They are often designed to maximize power, but when designed to maximize burning efficiency, can be the cleanest engines in the world.

According to hyperphysics: "In the diesel engine, air is compressed adiabatically with a compression ratio typically between 15 and 20. This compression raises the temperature to the ignition temperature of the fuel mixture which is formed by injecting fuel once the air is compressed.

The ideal air-standard cycle is modeled as a reversible adiabatic compression followed by a constant pressure combustion process, then an adiabatic expansion as a power stroke and an isovolumetric exhaust. A new air charge is taken in at the end of the exhaust..."

In Europe where fuel costs are much higher, about 50% of the cars run on diesel. They are about 1/3 more efficient than gasoline engines in converting fuel (explosive charge) energy into mechanical energy. Maybe even more important, refining diesel from petroleum occurs directly. The process of squeezing gasoline out of diesel through catalytic reforming adds steps and costs. The fact that diesel costs more than gas at the pump DOES NOT reflect the cost and environmental advantages of producing diesel, which are decidedly superior to gasoline. And I am the Decider.