Author: John Lee, Antonio Da Roza

Originally: Christine Loh, James Paterson (published by CLSA, Civic Exchange)Civic Exchange logo

Date: 8/8/10

Originally: September 2006


Clean air is vital to human health and wellbeing, yet the air we breathe is increasingly polluted. The Earth now supports 6.5 billion people, half living in East and South Asia – so it is unsurprising the problem is particularly acute in Hong Kong. Part of the problem has been the rapid population and economic growth taking the atmosphere for granted.

Despite its geographical coverage, the atmosphere is 1,000 times less dense than water, and so in terms of mass is actually 500 times smaller than the world’s oceans. This is why although a great deal of pollution has been dumped in the oceans, a global oceanic pollution crisis has not yet been triggered.

By contrast, acid rain represented the first real crisis for the atmosphere, and no sooner had it been addressed than a second crisis emerged – the hole in the ozone layer, which was eventually addressed by the Montreal Protocol banning CFCs and HFCs that were depleting the ozone.

Now we face a third, and more dire pollution crisis: the build up of greenhouse gases in the atmosphere, leading to global warming and climate change.

Hong Kong should focus on CO2 emissions from buildings and not just vehicles and power plants. In 2004, CO2 accounted for more than 99% of greenhouse gas emissions by weight, and in excess of 85% of global-warming potential in Hong Kong. Methane (CH4) came second and accounted for more than 11% of the warming potential. Other greenhouse gases commonly found in Hong Kong are nitrous oxides (NOx), hydrofluorocarbons, perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). Methane is 60 times more potent at capturing heat energy than CO2, but lasts fewer years in the atmosphere; nitrous oxide is 270 times more efficient at trapping heat than CO2, it is far rarer than methane but it lasts 150 years in the atmosphere. The principal sources of greenhouse gas pollution are electricity generation and transport.

Electricity generation – as China struggles to meet demand for electricity, it will inevitably burn more coal. If it concentrates too heavily on this form of power generation, it could well destabilise the Earth’s climate. Increasing efficiency of electricity generation, transmission and use will all become vital tools in the battle to combat climate change.

Transport – by the development of hybrid technologies, great efficiency gains can be made in the road-transport sector. Shipping and air travel, however, represent more serious problems.

Shipping – one of the foulest pollutants on Earth is the fuel oil that powers shipping. Yet using modern wind and solar technologies and energy-efficient engines, sea cargoes may once again be traveling carbon-free.

Air travel – air travel requires large amounts of high-density fuel of a type that at present only fossil fuels can provide. Recently, the European Union introduced a carbon tax on all flights originating from and arriving in member states, hoping to encourage video-conferencing in place of business travel, as well as some switching to rail and other ground transportation, which is less polluting.


A recent poll by the American Chamber of Commerce suggests Hong Kong’s worsening air quality is deterring foreign investment and the inflow of overseas talent.

The Government blames cross-border pollution for many of the city’s problems. While it is difficult for the Government of the HKSAR to influence the geographical origin of pollution from mainland China (the Pearl River Delta Regional Air Quality Plan is a useful first step), given that an estimated 90,000 factories over the border are owned by Hong Kong interests, the government and the business community can clearly instigate significant change from within Hong Kong itself.

The Government refuses to publish accurate data, which keeps the community in the dark about the depth of the problem. Also, Hong Kong’s outdated Air Quality Objectives understate the seriousness of its air pollution. Two key inputs from the Government would help: updated and legislated targets for air standards in Hong Kong; and full transparency on the extent of the problem.

The air that we breathe

The truth behind the level of pollution in Hong Kong is obscured by lax standards and averaging. For example, despite the “average” PM10 levels remaining close to Hong Kong’s stated Air Quality Objectives, they are 200% higher than the latest WHO guidelines. Hong Kong does not have statutorily-backed air quality standards. What it has is a set of air quality objectives that the Government aims to meet on a best-efforts basis. The Government set the Air Quality Objectives in 1987, and while many cities around the world have tightened their air quality standards over the years, Hong Kong has not.

Vehicular pollution is exacerbated by the “street canyon” effect. Street-level pollution is a major air quality problem. Roadside NO2 and PM10 concentrations remain high and harmful to human health, and SO2 concentrations are edging up again.

Yuen Long and Tung Chung recorded some of the highest hourly and daily readings for pollutant concentrations in recent years. These locations serve as the first screening stations for regional pollutants coming from the mainland.

The highest growth rates of SO2 emissions are concentrated in areas close to marine activity and the container terminals in Kwai Chung, Tsuen Wan and Sham Shui Po.

The power-generation sector’s contribution to pollution has been rising again over the past four to five years. It is possible that growing electricity demand from different sectors is outweighing emission-reduction benefits gained via various pollution control measures and the commissioning of gas-fired plants.

An Air Pollution Index value higher than 100 may have immediate negative health effects on people with existing heart or respiratory illnesses. If a person is persistently exposed to air pollution that gives an API of 51-100, he may not suffer immediate health effects but chronic health problems may develop in the long term. An API of 50 corresponds to 55µg/m3 in Hong Kong. However, the same concentration translates to an API of 100 in the EU and California. Similarly, moderate or high API readings for Hong Kong would become very high and severe API readings if the indices were calculated based on tighter air quality standards used elsewhere.

Hong Kong’s Air Quality Objectives, set in 1987, were based on limited knowledge about the impact of air pollution on human health, and it is the Government’s responsibility to keep updating its standards for the wellbeing of its citizens.

The World Health Organisation considers it necessary to tighten air quality standards as its previous guidelines, revised in 2000, were found to still be insufficient to protect the health of the general public and that more stringent guidelines are needed. The WHO is also of the view that cities and countries must take action to improve their air quality to protect the health of their people.

Recent health studies have been unable to find a threshold below which particulate matter has no effect on health – there is no safe level of PM. Finer particles (PM2.5 or less) are more hazardous than larger ones (PM10) in terms of mortality and cardiovascular and respiratory illness. Long term exposure to PM is associated with reduced survival, prevalence of bronchitis symptoms in children, and reduced lung function in children and adults. These effects have been observed at annual average concentration levels below 20ug/m3 (as PM2.5) or 30ug/ m3 (as PM10). Note that WHO 2006 guidelines for PM10 is 25ug/m3 and HK’s PM10 annual standard for is 55ug/m3. Currently HK has no standard for PM2.5.

The Environmental Protection Department’s rationale for not tightening the Air Quality Objectives in Hong Kong is that to adopt too stringent a standard would be pointless as nobody is able to comply. In other words, the Hong Kong Government was unwilling to use the most potent tool it has to drive down air pollution.

The cost of air pollution

Since 2003, the number of hazy days (visibility less than 8km) has doubled. A recent public health report has estimated that Hong Kong could avoid 1,600 deaths and some 64,000 hospital bed days each year if it could upgrade its average pollution days (using 2004 as the benchmark) to good levels. This would result in annual dollar savings of HK$1-1.5 billion in avoided healthcare costs; HK$0.3-0.5 billion in lack of lost productivity; and up to HK$19 billion in intangible costs (including value of lives lost and willingness to pay to avoid illness).

Tourism will suffer as people can be put off visiting on public health grounds. Business will be lost as firms choose to relocate their hubs and headquarters to say Singapore, which is capitalizing on its green image.

On more than 75% of days in a year, people in HK are exposed to PM10 and O3 concentrations that fall within poor and average levels. In a survey published in 2003, 30% of elderly citizens over the age of 70 complained about respiratory problems because of bad air, compared with 4.9% in 1991. Electricity generation is the biggest source of air pollution in HK (92% of SO2, 50% of NOx, and 50% of PM10).

Near-term priorities

- Release full real-time regional air pollution data via the regional monitoring system between Hong Kong and Guangdong instead of an aggregate regional API.

- Focus on the total true cost of not acting quickly rather than just on the economic costs of introducing tougher controls.

- Develop a comprehensive Hong Kong energy policy that sets clear goals on the optimal fuel mix for its electricity generators.

- Create a solid regional air management structure that sets China’s national pace to improve air quality management.

- Explore short-term wins by using cleaner fuels in manufacturing across the border, particularly with Shenzhen and Dongguan.

- Clean up shipping, port and logistics operations in Hong Kong and Shenzhen as these witness greater port export related activity than elsewhere in the world.

- Expand rail/subway networks ahead of investments in more roads.

What systems do we have in place to control air pollution in Hong Kong?

Coal, LNG and emissions trading – 46% of Hong Kong’s primary energy need comes from coal. Coal makes up 39% of CLP’s fuel consumption and 100% of Hongkong Electric’s. Both power companies have phased retrofit plans (flue gas desulphurisation and catalytic reduction) to lower emissions further between now and 2010 although the government states these measures will not be enough for Hong Kong to meet its emissions targets. However, the Hong Kong Government has not expressed its own view about the extent to which the utilities should transit out of coal in the longer term.

Since 1999, the government’s efforts include

- Controlling vehicular emissions and fuels, and reducing VOCs.

- Subsidizing owners to replace diesel taxis with LPG taxis. Programme was completed in 2003.

- Subsidizing mini bus owners to replace diesel light buses with LPG or electric buses. Since 2002, more than 75% of vehicles have switched to using LPG.

- Introducing the ultra low sulphur diesel to HK and keeping the duty down to ensure widespread usage, as well as tightening petrol standards with effect from 2005.

- Requiring pre-Euro diesel vehicles (eg. commercial trucks and buses) to install catalytic converters and particulate traps since 2003.

- Requiring new vehicles to meet Euro III emissions standards from 2001 and from 2006 new vehicles have to meet Euro IV emissions standards. - Improving vehicle testing and increasing the penalty for smoky vehicles from HK$450 to HK$1,000.

- Requiring installation of vapour-recovery systems for vehicle refueling at petrol stations from March 2005.

- Reducing VOC emissions from printing, paints and consumer products with effect from 2007.

Other measures still needed

- Turning Hong Kong’s Air Quality Objectives into air quality standards with statutory backing so that the standards must be met over a stated period of time, including having a standard for PM2.5 and not just PM10.

- Forming a clear and comprehensive energy policy so that HK can better promote energy efficiency, energy conservation, cleaner energy usage, environmental protection and public health, as well as reduce the climatic impact.

- Subsidizing the 40,000 pre-Euro diesel vehicles to be replaced with new ones since the maximum emissions benefit can best be reaped by combining cleaner engines with cleaner ultra low sulphur diesel.

- Using urban planning and design regulation to reduce the prevalent “street canyon” effect, particularly in new development areas (such as Tamar-Central, West Kowloon, South East Kowloon, etc.)

- Implementing the existing rail-led transport policy by giving priority to expanding the rail/underground systems rather than continuing to give priority to building roads.

- Ensuring marine emissions and port and logistics operations at Kwai Chung are properly controlled to reduced air pollution.


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