Trying to understand air pollution can be like chasing the wind. Just as you begin to grasp the problem, it changes direction, picks up speed or races far ahead. To the casual observer of Hong Kong's skies, these shifts and movements have often made it difficult to appreciate improvements in air quality. As one problem begins to get solved, another emerges that diverts our attention. And each new problem seems to be bigger than the last.

Measures to reduce motor vehicle emissions have resulted in marked improvement in street level air quality.

Over the past 15 years or so, concerns about air pollution have shifted from the localised problem of chimneys and other stationary sources, to the Hong Kong-wide problem of motor vehicles, then to the cross-boundary problem of smog. The visual impact of smog in particular has tended to overshadow improvements in other areas, but there have been significant achievements in reducing sulphur content in industrial fuel, controlling emissions from motor vehicles and cutting back pollution from power plants. Nonetheless, an overall improvement in our air quality - and reduction in smog - will not be possible without improvements to regional air quality. Hong Kong and Guangdong are committed to reducing that problem by 2010.

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Regional air pollution developed throughout the 1990s, as a result of the rapid development and growing wealth of Guangdong and Hong Kong. Electricity demand, motor vehicle use and industrial activity all increased by leaps and bounds. The emissions from these sources combined into smog, which began to appear more frequently in the late 1990s, fuelling public pressure for a solution to be found. In 1999, the Hong Kong SAR Government and the Guangdong Provincial Government agreed to try to address the problem together. A joint study was launched which resulted, in 2002, in targets being set and recommendations being made on the way forward.

The two governments have agreed on ambitious reductions in smog-related air pollution by 2010, taking 1997 as the base year. Respirable suspended particulates and volatile organic compounds (VOCs) will each be cut by 55 per cent, sulphur dioxide by 40 per cent and nitrogen oxides (NOx) by 20 per cent. In order to do this in a co-ordinated manner, a special panel was set up to, among other things, prepare an air quality management plan for the whole Pearl River Delta region. This was completed and endorsed in 2003 by the Joint Working Group on Sustainable Development and Environmental Protection, which has representatives from both administrations.

		The Hong Kong and Guangdong administrations are committed to improving cross-boundary air pollution. In 2003 they made progress on several fronts: An air quality management plan for the Pearl River Delta region was prepared and endorsed (see main text for details). A joint handbook was being drafted defining how air pollution would be calculated - a tool which will be critical in determining if improvements are being made. Preparations were made to set up 16 air quality monitoring stations around the region, which will start operating in 2004. A draft joint inventory of emissions was completed. Technical exchanges and workshops were carried out on such topics as air quality monitoring and pollution control.

The plan identifies the need for Guangdong to reduce emissions across the board, from power plants, industry and motor vehicles. Hong Kong has less of a problem with industry, but needs to continue to reduce emissions from motor vehicles and power plants. It also needs to tackle VOCs, which come from a variety of sources such as solvent-borne paints, printing ink, building and furnishing materials, some consumer products such as cleaners, and pesticides (see box on Volatile Organic Compounds for details).

		(left) A labelling scheme is being proposed to require various consumer products to list their VOC content. (Right) Petrol filling stations are required to be equipped with a vapour recovery system for unloading petrol to petrol storage tank.   Volatile organic compounds (VOCs) contribute to smog and, in very large quantities, can be harmful to health. Controlling them is complicated by the fact that there are thousands of compounds and they are emitted by a wide range of everyday materials. Paints, printing ink, building materials and furnishing products, and some consumer products such as cleaners, pesticides and hair spray are just some of the sources involved. The EPD therefore is proposing a labelling scheme requiring manufacturers and importers to inform consumers about VOC content in consumer products. The labelling scheme will be proposed for public consultation in 2004. If the scheme is approved, the next stage would be to examine whether further controls are needed to restrict the VOC content in individual products. (Top and Left) Vapour recovery control for refueling will be introduced in 2005. (Bottom) A petrol dispensing nozzle with vapour inlet holes and a vapour line for vapour recovery during refueling.   One source of VOC emissions is already being controlled - petrol filling stations. Vapours containing VOCs are emitted when tanks are being filled. A regulation was put in place in 1999 to recover the vapours when petrol is unloaded from tankers into storage tanks. In 2004, the EPD will propose to amend the regulation to extend this control to the re-fuelling of vehicles at petrol filling stations. The oil industry and the Legislative Council have been consulted.

(Top) 80 per cent of newly-registered public light buses had chosen LPG by the end of 2003. (Bottom) Nearly all taxis had switched to LPG by the end of 2003.

One of the most significant environmental improvements in Hong Kong in recent years has in fact been with motor vehicle emissions. Street-level pollution has improved markedly as a result of efforts supported by all sectors of the community and financed by a $1.4 billion package of measures announced by the Chief Executive, Mr Tung Chee-hwa, in his 1999 policy address.

The package aims to reduce respirable suspended particulate emissions from vehicles by 80 per cent by 2005, and NOx by 30 per cent. Both of these pollutants have harmful effects on health, and both are linked to Hong Kong's heavy reliance on diesel vehicles. Prior to 2000, one-quarter of all vehicles used diesel, as compared with 17 per cent in Singapore and four per cent in the United States. The first priority therefore has been to reduce reliance on diesels.

Taxis have been offered subsidies to switch from diesel to cleaner liquefied petroleum gas (LPG). By the end of 2003, nearly all taxis had made the switch to LPG, which is now compulsory for all new taxis. Public light buses are also switching to LPG in a voluntary programme. 80 per cent of newly-registered public light buses had chosen LPG by the end of 2003.

The remaining diesel vehicles on the road - mainly vans and trucks - have been subject to tighter controls. All new diesel vehicles are required to meet the latest stringent European emission standards. Vehicles imported before the standards started being tightened in 1995 are being fitted with devices to remove particulates. 80 per cent of older light diesels (not more than four tonnes) are now fitted with the device and the rest were required to do so in order to renew their vehicle license, as of December 2003. About half of the heavy diesels (over four tonnes) have been fitted out and they will face the same license renewal condition in future. Apart from these requirements, petrol filling stations carry only ultra-low sulphur diesel, tests for smoky vehicles have become stricter and the fixed penalty for smoky vehicles has been increased to $1,000.

These measures have resulted in considerable improvements in street-level air quality. By the end of 2003, vehicles were emitting about 60 per cent fewer particulates and 27 per cent fewer NOx, well on the way to meeting the 2005 targets laid down by Mr Tung. At the roadsides, that translated into 13 per cent fewer particulates, 23 per cent less NOx, and 74 per cent fewer smoky vehicles being spotted, as compared with 1999. The number of hours during which the Air Pollution Index at roadsides exceeded the 100 mark, indicating air pollution was very high, has also dropped by 35 per cent since 1999. There are obviously still improvements to be made, but we are progressing well in reducing both street-level pollution and contributions from motor vehicles to regional air pollution.

Power plants are required to implement effective air pollution control measures to reduce the impact on regional air quality.

Pollution from industry and other stationary sources may seem a thing of the past, in comparison to motor vehicle and regional air pollution. Concern about this problem peaked in the 1980s, when many small factories were located close to residential areas. One of Hong Kong's first environmental successes was the banning of high-sulphur fuel by industry in 1990, which resulted in an overnight improvement in air quality. Other controls were also introduced which have successfully contained industrial pollution. But pollution from another stationary source - power plants - is more problematic, especially on a regional scale.

Hong Kong's two power companies, CLP Power Hong Kong Ltd. and The Hongkong Electric Co. Ltd., have implemented many significant improvements over the past 15 years, but the sheer volume of their output means they continue to have a major impact on regional air quality. Since 1990, they have introduced clean gas fuel, de-sulphurisation and low NOx burners, resulting in major reductions in air pollution even while consumption rose. Between 1990 and 2002, emissions dropped by more than 45 per cent, even though consumption rose by 60 per cent. The EPD has strongly encouraged the power plants in their efforts to reduce their emissions. But as the focus has turned to cross-boundary air quality, they face pressure to do even more. Power plant emissions comprise the largest share of Hong Kong's contribution to regional air pollution. Any further reduction by the power stations is likely to be very costly. An emissions trading scheme therefore is being explored with the aim of reducing the cost implications to the community.

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| Click to Enlarge | See Data |

There is strong determination by both Hong Kong and Guangdong to tackle regional air pollution, but it will not be cheap or simple. The EPD has had successes in reducing some sources of air pollution, such as high-sulphur fuel and motor vehicle emissions, but only after overcoming initial resistance and objections. A dialogue with the affected parties, plus commitment by government and an agreement all around that local air quality was deteriorating to unacceptable levels, smoothed the way for the introduction of anti-pollution measures. With regional air pollution, a similar approach of determination and dialogue will be needed. There will be costs, but if the community's aspirations for cleaner air can be turned into firm actions to reduce regional air pollution, the air over Victoria Harbour could one day be clear and clean again.

		The EPD Indoor Air Quality Information Centre is the first to be awarded an Excellent Class Certificate. The EPD introduced a voluntary certification scheme for indoor air quality in Hong Kong in September 2003, one of the few places in the world to do so. Standards have been set for good indoor air quality in offices and public places and building owners can hire private consultants to assess the air quality in their premises. If they meet the standards, they are issued with a certificate. The EPD's Indoor Air Quality Information Centre at the Hong Kong Productivity Council was the first to be awarded with an Excellent Class Certificate. Air quality on buses and trains was also addressed. The EPD issued guidelines and set benchmarks for the air quality in air-conditioned bus and train compartments and stations in 2003.       (Left) Publications and pamphlets on indoor air quality. (Right) A sample of the Indoor Air Quality Excellent Class Certificate.

		The EPD continued its efforts to protect the ozone layer by phasing out and licensing the import and export of ozone-depleting substances, in accordance with the Montreal Protocol. The consumption of these substances was reduced to 145 tonnes in 2003, about 2.6 per cent of the baseline level. From January 2004 onwards, the import quota of HCFCs will be further reduced by 35 per cent, in line with the phasing-out schedule established under the Protocol. Click to Enlarge The EPD has also made extra efforts to reduce the release of methyl bromide by local fumigators during preshipment fumigation. Methyl bromide is a chemical with strong ozone depleting potential, but its use in preshipment fumigation is not yet regulated under the Montreal Protocol. In a fumigation operation for imported woodlogs for re-export in mid-2003, the fumigator was required to install an activated carbon system to recover most of the spent methyl bromide that would otherwise be emitted after fumigation.