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January 17th, 2008:

Ultrafine Particles In Air Pollution May Cause Heart Disease

Study shows how ultrafine particles in air pollution may cause heart disease

By Rachel Champeau | 1/17/2008 1:00:00 PM UCLA News

Patients prone to heart disease may one day be told by physicians to avoid not only fatty foods and smoking but air pollution too.

A new academic study led by UCLA researchers has revealed that the smallest particles from vehicle emissions may be the most damaging components of air pollution in triggering plaque buildup in the arteries, which can lead to heart attack and stroke. The findings appear in the Jan. 17 online edition of the journal Circulation Research.

The scientists identified a way in which pollutant particles may promote hardening of the arteries — by inactivating the protective qualities of high density lipoprotein (HDL) cholesterol, known as “good” cholesterol.

A multicampus team from UCLA, the University of Southern California, the University of California, Irvine, and Michigan State University contributed to the research, which was led by Dr. Andre Nel, UCLA’s chief of nanomedicine. The study was primarily funded by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency (EPA).

“It appears that the smallest air pollutant particles, which are the most abundant in an urban environment, are the most toxic,” said first author Dr. Jesus Araujo, assistant professor of medicine and director of environmental cardiology at the David Geffen School of Medicine at UCLA. “This is the first study that demonstrates the ability of nano-sized air pollutants to promote atherosclerosis in an animal model.”

Nanoparticles are the size of a virus or molecule — less than 0.18 micrometers, or about one-thousandth the size of a human hair. The EPA currently regulates fine particles, which are the next size up, at 2.5 micrometers, but doesn’t monitor particles in the nano or ultrafine range. These particles are too small to capture in a filter, so new technology must be developed to track their contribution to adverse health effects.

“We hope our findings offer insight into the impact of nano-sized air pollutant particles and help explore ways for stricter air quality regulatory guidelines,” said Nel, principal investigator and a researcher at UCLA’s California NanoSystems Institute.

Nel added that the consequences of air pollution on cardiovascular health may be similar to the hazards of secondhand smoke.

Pollution particles emitted by vehicles and other combustion sources contain a high concentration of organic chemicals that could be released deep into the lungs or even spill over into the systemic circulation.

The UCLA research team previously reported that diesel exhaust particles interact with artery-clogging fats in low-density lipoprotein (LDL) cholesterol to activate genes that cause the blood-vessel inflammation that can lead to heart disease.

In the current study, researchers exposed mice with high cholesterol to one of two sizes of air pollutant particles from downtown Los Angeles freeway emissions and compared them with mice that received filtered air that contained very few particles.

The study, conducted over a five-week period, required a complex exposure design that was developed by teams led by Dr. Michael Kleinman, professor of community and environmental medicine at UC Irvine, and Dr. Constantinos Sioutas, professor of civil and environmental engineering at USC.

Researchers found that mice exposed to ultrafine particles exhibited 55 percent greater atherosclerotic-plaque development than animals breathing filtered air and 25 percent greater plaque development than mice exposed to fine-sized particles.

“This suggests that ultrafine particles are the more toxic air pollutants in promoting events leading to cardiovascular disease,” Araujo said.

Pollutant particles are coated in chemicals sensitive to free radicals, which cause the cell and tissue damage known as oxidation. Oxidation leads to the inflammation that causes clogged arteries. Samples from polluted air revealed that ultrafine particles have a larger concentration of these chemicals and a larger surface area where these chemicals thrive, compared with larger particles, Sioutas noted.

“Ultrafine particles may deliver a much higher effective dose of injurious components, compared with larger pollutant particles,” Nel said.

Scientists also identified a key mechanism behind how these air pollutants are able to affect the atherosclerotic process. Using a test developed by Dr. Mohamad Navab, study co-author and a UCLA professor of medicine, researchers found that exposure to air pollutant particles reduced the anti-inflammatory protective properties of HDL cholesterol.

“HDL normally helps reduce the vascular inflammation that is part of the atherosclerotic process,” said Dr. Jake Lusis, study co-author and a UCLA professor of cardiology, human genetics and microbiology, immunology and molecular genetics. “Surprisingly, we found that exposure to air pollutant particles, and especially the ultrafine size, significantly decreased the positive effects of HDL.”

To explore if air particle exposure caused oxidative stress throughout the body — which is an early process triggering the inflammation that causes clogged arteries — researchers checked for an increase in genes that would have been activated to combat this inflammatory progression.

“We found greater levels of gene activation in mice exposed to ultrafine particles, compared to the other groups,” Lusis said. “Our next step will be to develop a biomarker that could enable physicians to assess the degree of cardiovascular damage caused by air pollutants or measure the level of risk encountered by an exposed person.”

Researchers added that previous studies assessing the cardiovascular impact of air pollution have taken place over longer periods of exposure time, such as five to six months. The current study demonstrated that ill effects can occur more quickly, in just five weeks.

“Further study will pinpoint critical chemical and toxic properties of ultrafine particles that may affect humans,” Nel said.

The research team included investigators from the fields of nanomedicine, cardiology and genetics. Additional co-authors included Berenice Barajas, Xuping Wang, Brian J. Bennett and Ke Wei Gong of the David Geffen School of Medicine at UCLA, and Jack Harkema from the department of pathobiology and diagnostic investigation at Michigan State University.

Additional grant support was provided by the National Institute of Allergy and Infectious Diseases; the National Heart, Lung and Blood Institute; and the Robert Wood Johnson Foundation.

Rachel Champeau,

Hong Kong Smog Third Worst Since 1968

Cheung Chi-fai – SCMP – Jan 17, 2008

Guangdong was plagued last year by the worst smog in 59 years, with 27 major cities and counties reporting record numbers of smoggy days, according to the province’s meteorological bureau.

A bureau report reviewing the atmospheric state of Guangdong last year said the average number of smoggy days reported was 75.5, the highest since 1949 when the People’s Republic of China was founded.

It also revealed that some inland cities which had been relatively free of smog had started to report an increasing number of smoggy days.

In Hong Kong, smog last year was the third-worst since 1968, with the number of hours with reduced visibility reaching 1,298. December was also the worst recorded month of reduced visibility – 305 hours.

Xinhua reported that the Guangdong Meteorological Bureau said the number of smoggy days in 27 cities and counties in the province had broken previous records. The western Guangdong county of Enping suffered from the worst smog – with 240 smoggy days recorded last year. Dongguan city , where many Hong Kong factories are based, recorded 213 smoggy days.

In the northeastern city of Heyuan , once a pristine rural area and site of the province’s biggest water reserve, the number of smoggy days increased dramatically – from three days in 2005 to 182 last year.

The deterioration was believed to be a direct result of relocation of industries further inland.
The report, which reviewed the development of air pollution in the province, also found that the worst season for smog was winter rather than summer.

The worst month was December, when areas throughout the province recorded an average 11.4 days of smog. Provincial capital Guangzhou reported 22 smoggy days during that month, the highest since 2000.

Bureau atmospheric scientist Wu Dui said while use of aerosols in the Pearl River Delta had shown signs of declining in recent years, the proportion of fine particles which caused haze, low visibility and smog had increased.

Green Power chief executive Man Chi-sum said the worsening haze rang alarm bells over whether Guangdong could meet 2010 emissions reduction targets agreed with Hong Kong.

“It is a worrying trend,” he said, citing an earlier report reviewing the progress of emissions curbs which said the region’s emissions had increased, not decreased, since 2002.

HSBC Fund Seeks Firms Tackling Climate Change

Thu Jan 17, 2008 12:29pm GMT – Reuters

By Tom Miles

HONG KONG (Reuters) – HSBC Holdings launched a climate change fund on Thursday to give investors a chance to turn a threat into an opportunity by buying into the increasing number of firms trying to tackle global warming.

“As recently as five years ago, who talked about climate change? Very few people. It was fashionable to be sceptical… It seems the tide has turned quite significantly,” said Patrice Conxicoeur, chief executive of SINOPIA, the quantitative investment arm of the global bank, which will manage the fund.

“The market has taken notice,” he told a news conference to launch the fund.

The fund, “HSBC Global Investment Funds – Climate Change” will aim to outperform HSBC’s own climate change benchmark index by 3 percent per year, which the bank said had shown a 164 percent return since January 1, 2004.

“In terms of return profile, I think this should generate for our investors returns which are commensurate with the type of returns they would expect from investing in emerging companies,” said Conxicoeur.

“Clearly it’s an emerging industry and an emerging theme… It’s not going away. Even if all those companies come up with very nice solutions overnight – which is not going to happen, it’s going to be a long slog.”

The fund, which opened to Hong Kong retail investors on Thursday and is expected to be available globally, will target 50-70 of the 300 companies in the benchmark index.

It will invest in three areas: producers of low carbon energy including renewables, gas and nuclear; firms with energy-efficient products such as fuel cells and insulation; and companies dealing with water, waste and pollution control.

Potential investments might be firms such as environmentally friendly battery maker BYD Co Ltd, solar cell manufacturer Q-Cells AG and water firm Veolia Environnement SA, Conxicoeur said.

The make-up of the index, and therefore the fund’s portfolio, would change over time to reflect development of the sector, potentially adding stocks such as companies building flood defenses and specialized financial firms, he said.