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UC Irvine study finds organic constituents of UFP play important role in heart disease; suggestions for more effective emission control

Particle scale. Inset: 4 polydisperse modes of traffic-related ambient particulate matter span approximately 4 orders of magnitude from below 1 nm to above 10 μm. Source: Kleinman presentation. Click to enlarge.

Results of a study funded and released by the California Air Resources Board (ARB) suggest that the organic constituents of ultrafine PM (UFP, particles ≤ 0.18 μm aerodynamic diameter) resulting from internal-combustion engine exhaust and from chemical reactions in the air play an important role in the progression of heart disease, the leading cause of death in the US. The findings thus suggest a direction for mor effective emission control measures—i.e., technology for the removal of the organic constituents as well as the reduction of the number of particles.

Led by Dr. Michael T. Kleinman of the University of California Irvine, the new study used a novel approach to determine whether or not the toxicity of UFP particles depends on the concentration and composition of semi-volatile and non-volatile fractions of the PM.

PM comprises solid, liquid, and semi-volatile organic components. Traffic-related particulate matter spans approximately 4 orders of magnitude from below 1 nm to above 10 μm and is formed by a number of different mechanisms.

Numerous studies have found that exposure to PM air pollution may contribute to both disease and death. Other work at UC Irvine has shown that Ultrafine PM is more effective than Fine PM in promoting atherosclerosis, and that the large surface area of UFP may act as a “carrier” that brings chemicals into areas that they couldn’t ordinarily reach.

The observed associations between PM exposure and human heart disease and death may be related to PM-induced oxidative stress and/or inflammation in the body; however, the specific mechanisms by which PM exposure worsens heart function and cardiovascular disease are not well understood.

Preliminary studies have shown that if most of the organic components were removed from the particles, the particles would become much less chemically reactive. This new study thus tested the hypothesis that adverse effects of exposure to UFP, which are highly enriched in semi-volatile components, would be significantly attenuated by removal of those semi-volatile components from the aerosol. Dr. Kleinman used a novel mobile in vivo rodent exposure system in combination with a particle concentrator and thermal denuder—a heating method to remove organic compounds from the particles—to study the cardiopulmonary effects of UFP, before and after the removal of the semi-volatile components.

The thermal denuder removed more than 60% of the particle-associated organic compounds (OC) but did not remove the non-volatile components such as elemental carbon (EC) or trace metals.

Genetically modified mice with impaired lipid metabolism and predisposed to the development of atherosclerotic-like plaques were exposed to UFP 6 hr/day, 4 days per week for 8 weeks; the experiments were conducted near the University of Southern California campus in central Los Angeles.

The study found that mice exposed to either fully intact particles or just the organic components of the particles had more rapid development of atherosclerotic plaques, compared to mice exposed to particles without the organics. The intact particles also had other negative effects on heart health. Atherosclerosis is hardening of the arteries, a factor contributing to heart attacks.

We therefore conclude that the organic constituents of UFP contribute to the accelerated development of atherosclerotic plaque in arteries, lipid oxidation is an important mechanism of action in PM-induced coronary artery disease, and that removal of the organic compounds from PM greatly ameliorates plaque development associated with air pollutant exposure.

These findings suggest that emission control measures that remove and sequester or destroy organic constituents of combustion generated aerosols could benefit public health because coronary artery disease is a leading contributor to heart-related deaths, which represents about 50% of deaths, annually, in California and other states as well.

—Dr. Kleinman

Such emission control measures might include thermal denuding technology such as afterburner emission controls not only to reduce pollution but also to reduce the toxicity of the residual particles, Dr. Kleinman suggested.

Dr. Kleinman presented his findings at a seminar on 9 October at the Cal/EPA Headquarters Building in Sacramento.



Kit P

“The observed associations between PM exposure and human heart disease and death may be …”

Either it is or it is not. What we know is that smoking, a high fat diet, lack of exercise, and genetics are important factors in heart disease.

Therefore, the levels of air pollution California is not important.

Nick Lyons

Therefore, the levels of air pollution California is not important.

Say what??? Care to make a more rational argument?


Kat does rationalising, not rational.
Non sequiturs are a speciality of the house.


Nick, from a guy who says "There is no evidence of AGW, it is just a theory about the future." this should not surprized you. Denial is his thing.


If obesity is proven to be related to hearth disease and death and everybody knows this, why are people in California so big? The same could be said about smoking, sedentary lifestyle and any other risk factor related to the American way of life.


I am not persuaded the mice based research is valid, for all the obvious reasons. They were immersed in a horrid environment and they got the expected results. Next, we can try swimming in gasoline...

Heart disease has been with humans for all of recorded history. Careful study of well preserved ancient bodies clearly show heart disease to have been common. Early death due to atherosclerosis has a large genetic component.

I wonder if ancient man died early due to sitting around the campfire? Or if the type of wood used in said campfire affected lifespan?


Hi Kit:
Trying a new nom de plume?
There can't be two people as dim as you and cujet.

I know the credibility of the KitP thing is finished, but one absurd comment on the same lines from 'cujet' puts your new face on the same level.


I think UCI is right on target!

In regards to the quote below, our forefathers not only used campfires, they had smokey sweat lodges (USA natives), they built fires inside cabins and sometimes slept over the spent fires (Scandinavia), protected form excessive heat by rocks or brick, they used whale oil lamps (most of Europe) The middle east used other forms of smokey oil lamps. Others have used coal, or cow patties, or anything that combusted and produced heat and light was a fuel. It is not surprising that many of these people died of heart diseases, as they got a large amount of particulate. It is naive to believe prior generations had clean energy in their environment, as this writer seemed to believe: "Heart disease has been with humans for all of recorded history. Careful study of well preserved ancient bodies clearly show heart disease to have been common. Early death due to atherosclerosis has a large genetic component."


Ummm, Davemart, It was a bit "tongue in cheek". But I guess you are to "dim" to get it.

Kit P

“Say what???”

Nick stop being such a clueless valley girl and tell me what the air quality is where you. Please no junk science links al la ai vin but real time data.

Or you could follow davemart and provide a link to a 13 year old study.

Two important concept the fear mongers do not get. First we have solve the problem in North America. Second when a lame theory cannot be validated after considerable research, the theory is not valid.


I am famous for my beauty, not my brains!

It is a bit difficult to spot irony on the net, as morons come out with this stuff in all seriousness......

Kit P

I suspect davemart is the Brit equivalent of a California personal injury trial attorney. Evidence and solving problems based on the root cause is not important. Those who think so are morons.


Posters who still claim that smoking have/had no effect on lungs health will no doubt maintain the same argument about other/all sources of air pollution.

The only exception may be those dying with deadly lung cancer?

Kit P

“Posters who still claim that smoking have/had no effect on lungs health…”

My claim is that smoking does have a significant effect health and current level of air pollution in North America has an insignificant effect.

Clearly many posters at GCC do not have the ability to understand small numbers (significant risk) from very, very small numbers (insignificant risk). There are some who spend a large part of their waking day with a cigarette in one hand and a beer in the other putting one or the other down to stuff potato chips into their mouth.

My wife and I are driving back from visiting friends and family in California and Loss Vegas. There is a large risk when driving in rural areas from fatigue and deer. In congested area where there used to be poor air quality the risk is from aggressive divers.

I do not have a problem with studying risk but when the results show the risk is insignificant just say so. I am not sure how many show up in emergency rooms from a heart attack resulting in a two pack a day habit but there sure was a bunch in the news in critical condition because some drunk driver could not stay on the right side of the road.


Kit P...yes we have developed many risky habits, often with the help of our so called clean industries?

Car Ads continuously do their best to convince our young drivers to drive faster and faster and take more and more risks resulting into more accidents and casualties.

Air pollution in USA and Canada has reached a temporary plateau because we have shifted industrial production to Asia and other places. However, the total worldwide effect on GHG and climate changes is as bad and even worst.

Many brain, heart, liver, lungs (etc) malfunctions and many cancers are related to our damaged environment, specially what we touch, eat, drink and breathe. Repairs make the drug and health industries very rich and happy.

Fixing those problems at the sources would make good common sense but all the people and industries currently benefiting would object very loudly?

Kit P

Harvey makes wild leaps of logic while ignoring the facts. Air pollution from automobiles and trucks is down because of pollution controls. It has nothing to do with China. Death from traffic accidents is also way down because of air bags and seat belts.

As far as young people are concerned, it is the adults in the community that have the responsibility to teach risk reduction skills. If you see a hot new mustang in a high school parking lot, I can guarantee you that I did not buy such a car for a young driver.

My point here is that risk can be greatly reduced by personal responsibility rather than playing the blame game.

“Fixing those problems at the sources would make good common sense but all the people and industries currently benefiting would object very loudly? ”

Which problems are not fixed?

“rich and happy ”

I am rich and happy and have worked in industry for 40 years. I am also sure that I have protected the environment to that no one would be hurt.

Maybe would like to explain how he has made the world a better place since he is so eager to blame the people that supply what he needs and wants.


Air pollution a leading cause of cancer

Kit P

“Air pollution a leading cause of cancer ”

Really? Headlines are written to attract the readers attention by folds that are as ignorant of science as SJC. Furthermore the article linked was written by a journalist who rivals SJC in ignorance of science.

Now for the science as presented in my environmental engineering text books. You can kill someone with a poison. Fatal dose levels of a toxic substance are are well know. However, you can not cause some to get cancer. Risk for getting cancer is different from killing someone. We know the risk for lots of things. For example, from SJC link:

“Depending on the level of exposure in different parts of the world, the risk was found to be similar to that of breathing in second-hand tobacco smoke, Kurt Straif, head of the agency's section that ranks carcinogens, told reporters in Geneva.”

So what is the only significant risk factor for 'the risk of developing lung cancer ' is smoking and getting old. Another significant risk factor for cancer is drinking ethanol.

Smoking and drinking alcohol are voluntary activities.

The reason engineers like me study lots of science is so we can design systems for industry to prevent exposure which would cause involuntary risk. Regulation for the US power industry require that the risk be reduced to an insignificant level for both workers and people living near power plants.

So while I am crucial of a UC Irvine medical doctor's understanding of toxic pollutant, SJC says what about the insignificant risk of cancer in China. This is the problem with an inadequate science education in the California nanny state.

Again SJC, what problem do you want me to solve in California? Please do not tell me it is air pollution, The good doctor at UC Irvine is investigating a very small problem if one exists at all. It is a logical conclusion that the rest of the world that has air pollution problems can solve the problems using similar science and technologies.


Kit P's eyes and ears are still wide shut. An extended stay in a few highly polluted large manufacturing Chinese cities could open a pathway to his brain and may be not.

Kit P

"Chinese cities"

In California?


KitP...those Chinese cities are not in California but that's where most of the Cell phones, laptops, tablets, TVs, batteries and 1001 others things you (and we) use are made.

Yesterday, we ate our first made in China frozen pizza. It was excellent. Chinese Burgers may be next?


KitP...air pollution is a worldwide problem. You have to look way over USA's borders to see that total air pollution is still going up month after month.

More and more people in USA/Canada are getting sick. Corrective care is very costly (up to 18% of GNP in USA and rising). Average life expectancy has effectively gone down in USA in the last 10-20 years. USA's children and new born are more deformed and sick year after year.

Kit P

No one where I live are getting sick from pollution in China.

Harvey if you want to solve a problem you address the root cause not rant about stuff you make up.

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