Air quality visibly diminished on several occasions in 2004, pushing the issue high up on the public agenda. At times, the air was so thick with smog that it was impossible to see buildings just a few hundred metres away. The readings were duly recorded in the Air Pollution Index. Despite many positive achievements in recent years, particularly in motor vehicle emissions, it is clear more must be done to improve air quality.

The appearance of more and thicker smog was the result of a build-up of pollutants that exceeded the cleansing capabilities of the atmosphere, particularly when the weather was calm. The pollution sources are spread out across the Pearl River Delta region, making control complicated, but both the Hong Kong and Guangdong administrations have stated their commitment to improve air quality and reduce pollution. As they continue to lay the groundwork for achieving cleaner skies, patience will be needed to await the results.

Hong Kong and Guangdong authorities are working together to improve the air quality in the Pearl River Delta region.

The reasons for declining air quality are largely economic. The Pearl River Delta region is one of the fastest growing economies in the world, and energy demand is growing with it. It has been estimated that between 1997 and 2010, the economy will have grown by 150 per cent, the population by 20 per cent, electricity demand by 130 per cent and vehicle mileage by 180 per cent. Coupled with Hong Kong's economic recovery in 2004, the quantity of air pollutants emitted to fuel that growth has been clouding our skies.

Hong Kong's air quality is under pressure from rapid urban development in the Pearl River Delta region.

The worsening regional air quality was reflected in the ambient levels of pollutants measured at our general air monitoring stations. In 2004, the ambient levels of respirable suspended particulates (RSPs) and ozone, which are major constituents of smog, rose 11 per cent and eight per cent respectively as compared with 2003. The Air Pollution Index reached "very high" on a record 87 days in the year, up from 53 days in 2003.

A roadside air quality monitoring station in Central.

While the poorer ambient air quality increased the background air pollution, there were still improvements in roadside air quality, thanks to a programme to reduce emissions from motor vehicles implemented in recent years. Since 1999 roadside RSPs have dropped nine per cent and nitrogen oxides (NOx) 24 per cent.

The Hong Kong SAR Government and the Guangdong Provincial Government both recognise their contributions and responsibilities to improve air quality. In 2002 they agreed to an ambitious plan to make the air cleaner. Taking 1997 as the base year, they want to reduce RSPs and volatile organic compounds (VOCs) by 55 per cent each (VOCs also contribute to smog), sulphur dioxide (SO2) by 40 per cent and NOx by 20 per cent - all by 2010. Both sides would aim to cut emissions from industry, motor vehicles and power plants. Although rapid economic growth in the past couple of years has put greater pressure on air quality, these targets can still be achieved if the plan is carried out in its entirety.

This bus complies with the Euro III emission standards. Newly registered trucks and other vehicles require to comply with Euro III emission standards.

Hong Kong is already well within reach of achieving several of its targets. Industrial emissions are not a major problem here because many Hong Kong-owned factories have moved to Guangdong. And, as mentioned above, our programme to reduce vehicle emissions has achieved much success. Virtually all taxis are now fuelled by liquefied petroleum gas, which is cleaner than diesel. Public light buses are also being encouraged to switch, with nearly 80 per cent of all new public light buses in 2004 operating on LPG. Euro III emission standards are required for all new vehicles and we will upgrade to Euro IV, the tightest standards available, by 2006. Diesel trucks and vans that have been in operation since before the introduction of Euro standards in 1995 have mostly been retrofitted with particulate reduction devices. By the end of 2004, more than 32 000 heavy diesel vehicles had been retrofitted, while 3 500 long idling heavy diesel vehicles will be invited for retrofitting in 2005. In addition, ultra-low sulphur diesel has been the statutory standard for motor diesel in Hong Kong since April 2002, on a par with Euro IV fuel standards (petrol will meet these standards early in 2005). As a result of these measures, sightings of smoky vehicles have dropped by 77 per cent since 1999.

		Mr Roy Tang, Deputy Secretary for the Environment, Transport and Works (Environment), addresses the Motor Vehicle Emissions Control Workshop 2004 held in Hong Kong in December. The Motor Vehicle Emissions Control Workshop 2004 was organised by the EPD in December to promote exchanges of technology and experiences. A substantial delegation attended from the Pearl River Delta region and other Mainland cities. The EPD used the opportunity to explain our control measures to them, with the hope of encouraging early introduction of tighter emission controls. Experts from the United States and elsewhere in Asia were also in attendance.

Other emission sources are in the process of being addressed. A mandatory registration and labelling system for VOCs, which are found in such consumer products as hair spray, insecticides and paints, went out for public consultation in 2004. The goal is to have the scheme in place by the end of 2005. In addition, subject to Legislative Council approval, petrol filling stations will be required from March 2005 to recover VOCs emitted during re-fuelling by installing vapour recovery systems. These stations have already installed controls on VOC emissions from the re-filling of storage tanks.

The cleaner-burning natural gas plant of the CLP Power Hong Kong Ltd. at Black Point.

Hong Kong still faces a real challenge, however, in the form of power plant emissions. The two local power suppliers account for 89 per cent of our SO2 emissions and 45 per cent of NOx. Some power generation units are installed with flue gas desulphurisation, which can reduce SO2 by 90 per cent, and low NOx burners, and CLP Power Hong Kong Ltd. also has a cleaner-burning natural gas plant at Black Point. However, recent instability in gas supplies has meant the company has to increase the use of coal. As a result, emissions from power plants are soaring. Negotiations between the government and the power companies are underway on reducing emissions.

		A labelling scheme for products containing VOCs is planned to be implemented by the end of 2005. The public was consulted on a proposed scheme to require mandatory registration and labelling of products containing VOCs in 2004. VOCs are a major contributor to photochemical smog. The intention is that market forces could be used to control VOCs because buyers would opt for more environmentally friendly products. The proposal received general support and most suppliers of major sources of VOCs, such as paints, printing ink and building materials, did not consider labelling to be a problem. However, concerns were expressed on such issues as product laboratory testing requirements, pre-approval procedures, and inclusion of certain products in the proposed scheme. Makers of consumer products also complained they would have to reveal trade secrets. Their concerns are being taken into account and it is hoped to have a system in place by the end of 2005. In a related development, a regulation to require the installation of vapour recovery systems for vehicle re-fuelling has been introduced to the Legislative Council. Subject to approval, the regulation will take effect from March 2005. Vapour recovery systems for vehicle re-fuelling are another measure for controlling VOC emissions to the atmosphere.

Hong Kong's efforts can reduce our emissions, but they will not improve overall air quality without a regional effort. For its part, Guangdong has been pressing ahead to control air pollution within its borders. Euro II emissions were adopted for new vehicles manufactured from 2004. The sulphur content of motor diesel has been reduced from 0.5 per cent to 0.2 per cent, and even as low as 0.05 per cent in some areas. Subways are under construction, along with four liquefied natural gas power plants. And flue gas desulphurisation systems are being installed in all power generation units of a capacity above 125 megawatts, a programme that will take until 2007 to complete. Guangdong is also committed to phasing out inefficient coal-fired boilers, industrial boilers and other equipment that emit high levels of pollution.

Together, Hong Kong and Guangdong are also co-operating on a joint programme to monitor air quality and share technical expertise. A monitoring network is almost ready to start operating. Sixteen stations are being set up - three run by the EPD, three by the Guangdong Environmental Protection Bureau and 10 by individual cities. The EPD provided technical assistance and training, drawing on its long experience in air quality monitoring. The data collected by the network will not only measure air quality, but also indicate if air pollution control measures are achieving results. Apart from the network, a manual to standardise the way emissions are estimated was completed in 2004, thus ensuring consistency across the region.

A satellite image shows the spatial distribution of particulates over the Pearl River Delta region on 7th December 2004. Red and yellow areas indicate relatively higher levels of particulates.

The air quality may appear to be bleak, but Hong Kong and Guangdong are both working hard to reduce pollution. The effects of many of the initiatives described above will not be felt for several years. Of course, more can always be done. Hong Kong needs to consider the affordability of cleaner fuels for its power generation and learn to save energy (for its part, the government has set the air-conditioning temperature in all of its offices at 25.5 degrees Celsius). The government also is seeking to build up partnerships with Hong Kong companies operating in the Pearl River Delta region, to encourage them to control their pollution.

Additionally, the two administrations are seeking to deepen their working relationship in everything from motor vehicle emissions to environmental monitoring. Hong Kong has a great deal of expertise that it can share, although doing so will require resources. In fact, all areas of air pollution control require investment of some sort, from funding the switch of vehicles to cleaner fuels to using less-polluting fuel in our power plants. The air may be free, but clean air is not. Hong Kong and Guangdong can achieve better air quality by implementing all of the initiatives they have agreed to, but this will require the community to decide how much it is willing to invest to achieve cleaner air and blue skies.

		Hong Kong has adopted air quality objectives (AQOs) for seven major air pollutants, with reference to research in the United States and the local situation. Recently, concerns have been raised about whether we should introduce a new standard for the pollutant PM 2.5 (particulate matter smaller than or equal to 2.5 microns). The US and the European Union are reviewing PM 2.5 standards and are expected to complete the reviews in one or two years. The government is keeping abreast of the latest scientific research on PM 2.5 and will make reference to the results of the US and European reviews, and our own local studies, in considering whether there is a need to revise Hong Kong's AQOs. Calibration work is carried out with the NIST ozone calibrator. An EPD staff member carries out certification of the gas working standard as part of quality assurance procedures. The EPD is keen to share its air quality measurement experience and skills with others. In 2004, we introduced a sophisticated standard reference photometer (SRP) for use as a regional calibration standard for ozone measurement. The SRP was designed and produced by the National Institute of Standards and Technology (NIST) in the United States. Other monitoring authorities in the region, such as Macau, Beijing and Guangdong, have checked their ozone calibrators against the SRP in our laboratory. The department has also been closely involved in the setting up of the Quality Assurance Laboratory in the Mainland to support the regional air quality monitoring network.

		To reduce the emission of ozone depleting substances, a voluntary programme has been launched to promote the transition to CFC-free treatment inhalers for asthma and chronic obstructive pulmonary disease. The programme has received widespread support from stakeholders. The public health care sector, which accounts for 90 per cent of usage of the inhalers, is working progressively to adopt non-CFC replacements, which will help reduce the use of CFC-metered dose inhalers, particularly CFCsalbutamol inhalers. The Hong Kong Private Hospital Association also supports the move. The transition will be monitored and any new protocol control measures that advance the goals of the Montreal Protocol will be pursued. Separately, a reduced quota for local consumption of HCFCs was successfully launched in 2004, following a publicity programme to encourage the use of ozone-friendly alternatives. The IAQ Information Centre at the Hong Kong Productivity Council is one of six buildings/ premises that have been certified with the "Excellent Class" IAQ Certificate. The voluntary Indoor Air Quality (IAQ) Certification Scheme for Offices and Public Places was introduced in September 2003 to recognise good IAQ management practices and provide incentives for owners of premises and buildings and property management companies to pursue the best level of IAQ. The scheme offers two grades of certificates, Excellent Class and Good Class. Participants must arrange for assessment by competent examiners and take remedial actions to gain certification. Many public seminars and roadshows have been organised to promote the scheme. By the end of 2004, six sites had achieved "Excellent Class" and 44 sites "Good Class". The "Excellent Class" sites were the Shui On Centre, the Bank of China Tower, Hysan Development Co. Ltd.'s head office, ISS Hong Kong Services Ltd. offices, Lawn Environmental Protection Ltd. offices and the Indoor Air Quality Information Centre at the Hong Kong Productivity Council. The certificates are renewed annually, based on measurements of carbon dioxide and respirable suspended particulates, and every five years measurements are taken for a full range of 12 parameters.

Start operation of the regional air quality monitoring network. Introduce a labelling scheme for products containing volatile organic compounds. Implement a regulation requiring petrol vapour to be recovered during vehicle re-fuelling at petrol filling stations. Start retrofitting pre-1995 diesel vehicles that require prolonged idling during operation, with emission reduction devices.