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July 15th, 2009:

Roadside air pollution up sixfold in 4 years – HK traffic not Guangdong factories to blame: scientists

Cheung Chi-fai – SCMP


Air pollution at street level has soared in the past four years while improving at the city’s rooftops, calling into question assertions that Hong Kong’s chronic air-quality problems have a regional more than local source.

Roadside monitoring stations recorded more than six times as many periods of health-threatening pollution levels in the first half of this year than in the same period in 2005.

The stations, in Central, Causeway Bay and Mong Kok, registered 1,066 hours – the equivalent of more than 44 days – during which the air pollution index rose above the “very high” 100 level. (A 100 level prompts a health warning to those with heart and respiratory conditions.)

But above street level, the number of such hours recorded by general monitoring stations – which track sulphur dioxide, nitrogen dioxide, ozone and respirable suspended particles – fell by more than half, to 56, according to an analysis of Environmental Protection Department data by the South China Morning Post (SEHK: 0583, announcements, news) .

There are 13 general monitoring stations across the city, located on building rooftops 11 to 25 metres above ground.

Scientists consulted by the Post say the improvement in air quality high above ground is due largely to Guangdong’s efforts to install sulphur scrubbers in power plants and the closure of many factories because of the recession.

The worsening street-level air is likely the product of cars and trucks on the city’s congested streets, the experts say.

“It is undeniably a local pollution problem at street level. All we need is a lot more and urgent measures to address vehicular pollution to protect public health,” said Alexis Lau Kai-hon, an atmospheric scientist from the University of Science and Technology.

But the Environmental Protection Department blamed regional air pollution for deteriorating street-level air quality. It said three key pollutants emitted by motor vehicles had in fact fallen, while regionally generated ozone was combining with other pollutants to form nitrogen dioxide by the road, pushing up the figures.

The department said changes in pollutant concentration readings were more reliable than the index in reflecting air quality trends.

It credited emission-control measures introduced in the past decade for bringing down levels of sulphur dioxide, suspended particles and nitrogen oxides by about 20 per cent between 1999 and last year.

But another roadside pollutant, nitrogen dioxide, rose 9 per cent in the first six months of this year and has remained at 1999 levels.

“The increase is mainly due to the rise in ambient background ozone concentration, which has aggravated the conversion of nitrogen oxides from motor vehicles to nitrogen dioxide,” a spokesman said.

Levels of ozone – the major component of smog – have risen 18 per cent in the first six months of the year and in recent years have been at higher levels than in 1999. Ozone can react with nitrogen oxides to form nitrogen dioxide.

But the government’s explanation was not accepted unquestionably by scientists.

“Without a high level of roadside nitrogen oxides from vehicles, the ozone would not have caused more serious secondary pollution of nitrogen dioxide,” Professor Lau said.

Chan Chak-keung, a professor in chemical and biomolecular engineering at HKUST, said controlling ozone-inducing volatile organic compounds coming from a wide spectrum of sources such as vehicles, factories and products like paints was never an easy task. There are nearly 636,000 cars, buses and trucks on the road in Hong Kong, up 5.7 per cent from the end of 2005.

Roadside pollution is also linked to poor dispersion of pollutants, caused by an urban design that favours high-rise towers even in congested streets.

Clean-air ideas abound but hard choices rare, green groups charge

Joyce Ng – SCMP

Green groups blame the city’s high roadside air pollution on the inadequacy of steps to curb bus and truck emissions and the failure to implement other long-discussed ideas.

Despite a series of attempts to tackle the problem over the past decade, high pollution levels have persisted.

The groups also pointed to reluctance among operators to join a voluntary subsidy scheme to get rid of old, polluting trucks and buses, and say it should be made compulsory.

Friends of the Earth environmental affairs manager Hahn Chu Hon-keung said: “The government is never short of proposals to improve air quality; lots of ideas have been thrown at it in the past decade. It’s just a question of determination.”

Efforts to tackle traffic pollution include the 2000 introduction of taxis burning liquefied petroleum gas instead of dirtier diesel.

More recent measures include tax concessions for those buying environment-friendly petrol cars in 2007, and the introduction of electric cars this year. By May, about 7,500 tax-reduction applications had been approved, about 11 per cent of all newly registered motor vehicles.

But Green Power chief executive Man Chi-sum said old diesel trucks, buses and minibuses were the types of vehicle that contributed most to dirty roadside air, and the most urgent task was to deal with them.

About a third of the franchised bus fleet on Hong Kong’s roads still does not meet Euro IV emission standards, the second-highest of five sets of standards that have been introduced progressively in Europe since 1992 and adopted internationally.

The last of the 1,800 pre-Euro and Euro I buses – which are more than twice as polluting as the newer models – will only be taken off the roads in 2015. Bus companies have said that replacing them immediately would be costly and require a fare rise.

“Whenever these buses start their engines, black smoke pours out,” Dr Man said. “It is time the government took bold action [such as] setting up a fund to subsidise bus companies in speeding up the process.”

A HK$3.2 billion subsidy scheme introduced in 2007 to replace the pre-Euro and Euro I diesel vehicles is regarded as a failure, with owners of fewer than a quarter of them applying for the subsidy by the end of last year. Dr Man and Greenpeace campaign officer Prentice Koo Wai-muk said the government should increase grants, make the scheme mandatory and set a deadline for replacement.

In November, the government proposed raising licence fees for more than 30,000 older commercial vehicles, but nothing further was done after truck drivers’ groups expressed opposition.

New measures such as electronic road pricing, further bus-route rationalisation and pilot low-emission zones have been proposed by concern groups for many years. They are now included in a consultation paper on the air-quality-objective review to be released this summer. But no timetable has been laid out for their introduction.


Tough action needed now on air pollution

Jul 15, 2009

The government has long blamed high pollution levels in Hong Kong largely on emissions from factories and power plants in Guangdong province. Clear skies of late have been put down to effective policies on both sides of the border. This newspaper’s study of data from the Environmental Protection Department’s monitoring stations certainly shows an improvement in air quality at the rooftop level over the past four years. Alarmingly, though, what we breathe on our streets has become dangerously unhealthy.

We found that during the first half of this year, the air pollution level at roadside stations in Central, Causeway Bay and Mong Kok was above the “very high” 100 mark for 1,066 hours, or the equivalent of more than 44 days. The figure was more than six times worse than in 2005. Predictably, authorities have responded by pointing to Guangdong. They say regionally produced ozone is mixing with pollutants which descend to street level, causing the high readings.

The explanation is at odds with what scientists we have spoken to contend. They say that purely and simply, the problem is homegrown. Vehicle exhaust fumes are mostly at fault.

Scientific study of pollution is not exact. A multitude of often complex factors can cause poor air quality. Findings are open to interpretation. But there can be no quibbling with the data; in this case, it shows that we are increasingly exposed to unhealthy air when we take to our busiest streets.

It is wrong for officials to shrug their shoulders and say there is little they can do because the source of the problem is out of their reach. Their lack of urgency in tackling pollution from vehicles reveals an ignorance of data that their own environmental department has collected. Policies have been implemented, but they are clearly not sufficient. Options long available to the government, ranging from action on idling vehicle engines to electronic road pricing remain untried. The approach belies the seriousness of the problem.

The government is not ignoring the problem. Taxis and many buses now run on clean fuel. Tax breaks are on offer for buyers of environmentally friendly cars. Nonetheless, the poor air quality readings show that a tougher stand is necessary.

A sound start would be to adopt higher World Health Organisation standards than those proposed by a review of our air quality objectives, and to put in place a timetable for their implementation. The government has suggested that the least-stringent control level be adopted for the key pollutants sulphur dioxide, ozone and fine air particles. Legislation banning idling vehicles with running engines has to be promptly put before lawmakers. Next, concerted effort must be made to rid our roads of the tens of thousands of old buses and trucks with polluting diesel engines. Road pricing and pedestrian streets must be among measures given serious consideration.

The health risks of high pollution levels are well proven. Hong Kong cannot afford to take the least intrusive steps. The problem is a collective one, but the government has to take the lead. Tough action is needed and it has to be taken quickly.