Diesel exhaust a danger after 2 hours

Status
Not open for further replies.
Joined
Dec 19, 2004
Messages
7,428
Location
beaver land EH?
https://ca.news.yahoo.com/diesel-exhaust-danger-2-hours-160631776.html

Just two hours of exposure to diesel exhaust is enough to cause significant damage to the human body, a new UBC study concludes.
The study, led by Dr. Chris Carlsten, looked at how pollution particles affect the way genes are expressed in the body.
Adults volunteers were put in an enclosed booth about the size of a standard bathroom, and made to breath diluted and aged exhaust fumes equal to the air quality along a Beijing highway, or a busy port in British Columbia.
Carlsten says the impact of the pollution "exceeded our expectations."
"Quite rapidly, it turns out, we're showing in hours, you observe changes in the blood that may have long-term implications," said Carlsten.
It's believed exposure to the particles affects the chemical "coating" that can attach to parts of a person's DNA.
"That carbon-hydrogen coating, called methylation, can silence or dampen a gene, preventing it from producing a protein – sometimes to a person’s benefit, sometimes not. Methylation is one of several mechanisms for controlling gene expression, which is the focus of a rapidly growing field of study called epigenetics," said a statement issued by UBC.
"The study, published this month in Particle and Fibre Toxicology, found that diesel exhaust caused changes in methylation at about 2,800 different points on DNA, affecting about 400 genes.
"In some places, it led to more methylation; in more cases, it decreased methylation."
Carlsten says the next step is to figure out how to reverse the damage.
"Any time you can show something happens that quickly, it means you can probably reverse it – either through a therapy, a change in environment or even diet."
 
I sure am glad I limit my time of sitting infront of the exhaust of my car to 1 1/2 hours.
 
"...Meanwhile, in the other booth where they were studying the effects of gasoline combustion exhaust on the human body, the subjects all keeled over dead after approximately 15 minutes' exposure..."
 
Originally Posted By: OneEyeJack
Sounds like a good business model. Cause a problem and then show up with the cure or solution.


Isn't that pretty much how most of this "green" stuff gets started?

Like the guy who invented the internet creating carbon trading to become even more rich ...
 
Did any of you even read the article? Look at this quote:
Quote:
Adults volunteers were put in an enclosed booth about the size of a standard bathroom, and made to breath diluted and aged exhaust fumes equal to the air quality along a Beijing highway, or a busy port in British Columbia.

These are real world conditions that people encounter every day. They didn't just stick an exhaust pipe in someone's face for two hours.


You guys make it seem like the experiment went like this:
 
My cousin told me a regular diet containing delta smelt from the Sacramento delta will counteract any effects from diesel exhaust. Go, go, go!
 
The volunteers all did have asthma, & I wonder how much exhaust aftertreatment was on the test engine (DPF, SCR, EGR?)? I wonder how much exposure to coal-fired power plants, & poor running coal-rolling CSX diesel locomotives in my neighborhood would cause the same problems?
 
Ah, good old Yahoo News. "Just two hours of exposure to diesel exhaust is enough to cause significant damage to the human body, a new UBC study concludes. " Yep, that will get a readers attention no matter that the paper didn't actually claim that. Got to get those web hits somehow.

Further down in the Yahoo article... "Quite rapidly, it turns out, we're showing in hours, you observe changes in the blood that MAY have long-term implications," said Carlsten. Guess Yahoo News must have missed the MAY part.

It was a proof of concept paper showing how changes in DNA methylation caused by particulate matter, from diesel exhaust, can be quantified. Yes most genes that were methylated were involved in inflammatory pathways. However, no damage to the human body was shown, recorded or attempted to be even quantified in the first place so I'm not sure what Yahoo News was even reading.

The diesel exhaust concentration was measured as micrograms per meter cubed at a PM of 2.5. Essentially, the subjects were exposed to air that contained 300 micrograms, of 2.5 micron sized particles, per meter cubed. Looking at airnow.gov's PM2.5 webpage some cities are not to far off from that number on certain days.

I think the "aging" bit has something to do with allowing the larger particulate (I assume stuff greater than 10 micron) to settle out.

Looking at their methods they used a diesel generator, not a vehicle, to collect the exhaust. The generator is stated to be EPA Tier-3 compliant running ULSD. I'm not familiar with how this compares to on-road vehicles.
 
Originally Posted By: gomes512


Looking at their methods they used a diesel generator, not a vehicle, to collect the exhaust. The generator is stated to be EPA Tier-3 compliant running ULSD. I'm not familiar with how this compares to on-road vehicles.

I'm pretty sure my 2011 tractor is has a tier 3 engine, with no emissions system on the exhaust. It runs quite clean with no visible smoke at all until it goes WO and the rpms start to drop(basically overloading it). You can still smell it quite clearly though if the wind blows the wrong way and I try to avoid inhaling the exhaust anyways.
Here's the technical specs on what's allowed for offroad diesel emissions.
https://www.dieselnet.com/standards/us/nonroad.php
 
I should be dead then. All those years of running the back up diesel on Submarines for hours and hours at a time with diesel fumes all over the boat. Oh well, we don't get out this world alive anyway.
 
Originally Posted By: bullwinkle
The volunteers all did have asthma, & I wonder how much exhaust aftertreatment was on the test engine (DPF, SCR, EGR?)? I wonder how much exposure to coal-fired power plants, & poor running coal-rolling CSX diesel locomotives in my neighborhood would cause the same problems?
I lived near a terminallong ago where the (Massachusetts Bay) TA left their self propelled cars running all night in winter, "saving fuel" by turning off all but one ot two cylinders. The smoke, AND the noise were annoying.
 
Originally Posted By: gomes512
Ah, good old Yahoo News. "Just two hours of exposure to diesel exhaust is enough to cause significant damage to the human body, a new UBC study concludes. " Yep, that will get a readers attention no matter that the paper didn't actually claim that. Got to get those web hits somehow.

Further down in the Yahoo article... "Quite rapidly, it turns out, we're showing in hours, you observe changes in the blood that MAY have long-term implications," said Carlsten. Guess Yahoo News must have missed the MAY part.

It was a proof of concept paper showing how changes in DNA methylation caused by particulate matter, from diesel exhaust, can be quantified. Yes most genes that were methylated were involved in inflammatory pathways. However, no damage to the human body was shown, recorded or attempted to be even quantified in the first place so I'm not sure what Yahoo News was even reading.

The diesel exhaust concentration was measured as micrograms per meter cubed at a PM of 2.5. Essentially, the subjects were exposed to air that contained 300 micrograms, of 2.5 micron sized particles, per meter cubed. Looking at airnow.gov's PM2.5 webpage some cities are not to far off from that number on certain days.

I think the "aging" bit has something to do with allowing the larger particulate (I assume stuff greater than 10 micron) to settle out.

Looking at their methods they used a diesel generator, not a vehicle, to collect the exhaust. The generator is stated to be EPA Tier-3 compliant running ULSD. I'm not familiar with how this compares to on-road vehicles.
"There are lies, D** lies, and statistics"....Mark Twain.
 
I should be dead also! After growing up on the farm in 60's and breathing all that exhaust from ag equipment, and from operating cat dozers, case backhoes, speicher trenchers, etc for the family other business since I was put on a tractor at 7 years old. Then all those deuce and a half trucks in the Army and the armored personnel carriers. Then 32 years in trucking. If all that diesel smoke was such a negative, I should be living on oxygen tanks, in a wheel chair, and on Social Security disability and Medicare. As it is, my blood pressure is quite normal, no medical problems of any kind, still putting in up to 70 hrs a week at work (owning a business is different than being an employee). Even my 2013 semi has a pre-emission, made in 2000, engine in it. I have never owned a diesel in my life with emissions controls on it. And I have lost track of the number of diesels I have owned over the years.

But George Carlin showed how paranoid many folks are over their environment when he gave one of his famous comedic news casts..... "Scientists have shown that saliva causes stomach cancer. However, only when swallowed in small amounts over a long period of time."
 
Status
Not open for further replies.
Back
Top