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May 14th, 2008:

Pollution A Risk Factor In Blood Clots, Study Finds

Loretta Fong, Bloomberg and Reuters – Updated on May 14, 2008

Hongkongers were warned yesterday to be alert to the risk of developing blood clots in their legs after research showed that air pollution could be a factor in the potentially fatal condition.

A Hong Kong University blood expert said that while the findings were not conclusive, they could be an indicator that the city should take notice of.

A Harvard University study, published in the Archives of Internal Medicine on Monday, is the first research into air pollution’s effects on clotting in the veins.

It suggested that long-term exposure to air pollution heavy in small particles might cause blood clots in the legs, similar to the condition known as deep vein thrombosis that affects air travellers.

Researchers examined 870 patients in Italy who had been diagnosed with deep vein thrombosis (DVT) in their legs from September 1995 to 2005, and compared their risk to another 1,210 people in a control group, who did not have DVT. The findings showed that for every increase in particulate matter of 10 micrograms per square metre in the previous year, the risk of deep vein thrombosis also went up 70 per cent.

Deep vein thrombosis forms in the vessels that carry blood back to the heart. Clots can break off and travel to the lungs, blocking blood flow there, possibly leading to lung damage or death.

Andrea Baccarelli, the study’s lead author and associate professor of environmental health at Harvard’s school of public health in Boston, said that doctors might wish to consider pollution as a new risk factor for clots.

James Chim Chor-sang, an associate professor in the department of medicine (haematology) at Hong Kong University, said the finding could be an indicator.

“Air pollution is a worldwide problem, as well as here in Hong Kong, so people should take notice of it,” he said.

But he added that it was too early to tell whether long-term exposure to particulate air pollution meant a higher risk of DVT.

“I believe another study should be done to confirm the association between the two,” he said.

“In the case of Hong Kong, it is also hard to say now as we are short of data on the number of people with DVT.”

He also noted that the incidence of DVT among Asians was 40 to 50 per cent less than people in western countries.

The green group Friends of the Earth said air pollution was already known as a risk factor in other conditions such as heart disease and lung ailments, and the government should work harder to control vehicle emissions.

Director Edwin Lau Che-feng said the most threatening particulate matter was roadside pollutants caused by heavy diesel vehicles, buses, container trucks and trucks.

“When you walk in the street, you can see black smoke coming out from the car pipes,” he said. “And since the streets in Hong Kong are packed, people such as street hawkers suffer a lot.”

The Government Says Beijing’s Air Is Better

Hazy on the detail

The government says Beijing’s air is better, but experts doubt its claims – and its commitment to cleaner air after the Games

Shi Jiangtao – Updated on May 14, 2008 – SCMP

Beijing was counting its blessings when it rained on the morning of a marathon trial late last month, just in time to disperse thick smog that had blanketed the Olympics host city for the previous five days.

The shroud of smog had prompted fresh fears that the capital’s choking air pollution, despite the government’s repeated pledges, is still threatening to spoil the country’s coming-out party. Although the chilly spring rain, the most in five years, couldn’t have been more timely, washing away some of the dust, it will take much more to restore public faith in Beijing’s ability to tackle pollution and deliver a “green” Olympics.

Beijing seems to have basked in the success of its frequently ruthless efforts to remake itself in the past decade. Underground lines and roads have been expanded, new venues and high-rise buildings built and the city’s historic quarters demolished.

But the environmental impact of the construction boom and the headlong rush to urbanisation has created environmental problems the city authorities have been unable to solve.

Beijing has taken many measures to combat deteriorating air quality. There have been efforts to reduce coal consumption by converting coal-fired boilers to clean energy sources, expanding the use of natural gas, shutting and relocating polluting industries, planting millions of trees every year and imposing stricter emissions standards for new cars.

Boosting environmental investment is another key move to allay fears that the Olympics will be blighted by smog. Yet many Beijingers are sceptical about the official claim that air quality is improving.

Beijing has spent more than 120 billion yuan (HK$134 billion) on pollution control since 1998, with investment in environmental measures topping 25 billion yuan in 2006. Officials say the amount spent last year was similar to the 2006 figure. The capital has also pinned its hopes on banning private cars in certain areas and halting industrial production and earthworks at construction sites during the three weeks of the Games.

City authorities have also applied tougher vehicle emission and fuel quality standards, and in March they banned the sale of new petrol-fuelled light vehicles that fail to meet the Euro IV standard. But the move was described by mainland experts as a largely symbolic step ahead of the Olympics as it failed to deal with the more than 3 million cars already on the road in Beijing, which are the main cause of the city’s smog.

The restrictions would not make much difference to the capital’s air quality in the short term, they said.

Wang Canfa , an environmental expert at the China University of Political Science and Law, said the new policy failed to impress many due to widespread doubts over the accuracy of pollution statistics.

The capital began implementing the Euro I standard in 1999 and Euro II in 2002. The standard was raised to Euro III in 2005, when European countries implemented Euro IV. Although the city has done relatively well in controlling the two main air pollutants – sulfur dioxide and nitrogen dioxide – it lags far behind in tackling fine particulate matter and ground-level ozone, the two biggest health hazards.

Beijing’s average ambient concentration of particulate matter with a median diameter of less than 10 micrometres – the predominant pollutant in most mainland cities – jumped by 13.4 per cent, to 161 micrograms per cubic metre, in 2006, well above the 100-microgram national standard recommended for residential areas and more than double the World Health Organisation’s 70 microgram guideline for developing countries.

But most industrial countries and the WHO believe much smaller particulate matter – particles of 2.5 micrometres or less in diameter – represent a more accurate standard for evaluating airborne pollution. Fine particulate matter from the burning of fossil and other types of fuels, industrial emissions and dust pollution from construction sites is believed to be linked to cancer, respiratory disease and other fatal illnesses.

Mortality rates among the mainland’s urban population have soared in recent years due to widespread air pollution. About 358,000 people in 600 mainland cities died from pollution-related illnesses in 2004 and health costs from premature deaths and serious illness associated with air pollution were estimated at 152.7 billion yuan, according to a government report.

Abnormal ground-level concentrations of ozone – a gas produced by mixed emissions from industry, vehicle exhausts and fuel vapours in sunlight – can cause long-term damage to health, according to WHO studies.

Beijing’s Environmental Protection Bureau recorded 55 days in 2006 when ozone concentrations exceeded the national standard, which is far higher than international safety standards.

The most prominent drop-out from the Olympics so far is Ethiopian distance great Haile Gebrselassie, who announced earlier this year that he would not run in the Olympic marathon because of concerns over Beijing’s air quality.

The Games were further diminished by warnings from various sports experts and professionals that pollution and the constant threat of smog posed serious health risks to all athletes competing this summer.

But the authorities have rejected such criticism, insisting that the key air pollution indices such as dust particles, carbon dioxide and sulfur dioxide had shown marked improvement over the years.

Yu Xiaoxuan , director of the environmental activities department at the Beijing Organising Committee for the Olympic Games (Bocog), said assumptions should not be made based on feelings.

Jin Ruilin , an environmental expert at Peking University, said the city authorities had made huge efforts to cut pollution and green the city ahead of the Games. “The air quality is getting better in the past two years thanks to the support of the central government and the involvement of neighbouring provinces.”

But he and other experts expressed concerns over the authorities’ lack of motivation to tackle the root causes of pollution rather than providing a temporary fix for the Games.

“Temporary measures, such as traffic bans, may be effective to clear up the sky for the Olympics, but what about the real problems,” asked Professor Jin, who predicted Beijing’s pollution problems would return immediately following the event.

Although experts are divided over whether the government should restrict increasing private car ownership, they agree that authorities have done little to improve traffic flows, which continue to worsen as more people take to the roads, and which have exacerbated the city’s pollution.

“It is a shame that the authorities only care about the air quality during the Games and everything they’re doing at the moment seems to be for the Olympics only,” said Beijing-based political analyst Liu Junning .

Li Dun , with the Research Centre on Contemporary China at Tsinghua University, criticised the government’s lack of transparency in pollution-related information.

Although government officials have been keen to deny accusations they have falsified pollution statistics to mask the capital’s air quality problems,

Professor Li said authorities had done a poor job in responding to public queries, such as the collection of pollution-monitoring data, and failed to shed more light on their policy of selective dissemination of information.

Like many experts who have cast doubt over the city’s claims of victory in improving air quality, Gilbert Van Kerckhove, a consultant to Bocog, said pollution was worse than the official figures indicated.

Despite Beijing’s efforts to improve public transport, and the fact that official statistics claim a substantial increase in blue-sky days, pollution levels remain high – too high for endurance sports and for people with any respiratory weakness, he said. “I hoped Beijing could prove to the world that it is indeed making a tremendous progress,” he said.

Professor Wang said the central and municipal governments should think about relocating their offices from the heart of the city to suburban areas.

“It will take tremendous courage for the government to heed the suggestion, which involves the interests of hundreds of thousands of officials,” he said. “But without a dramatic change in urban planning, a real solution to the city’s pollution and traffic woes seems unlikely.”