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LCQ5: Improvement to air quality

     Following is a question by the Hon Dennis Kwok and a reply by the Secretary for the Environment, Mr Wong Kam-sing, in the Legislative Council today (November 26):


     In February this year, the Subcommittee on Issues Relating to Air, Noise and Light Pollution under the Panel on Environmental Affairs of this Council submitted its report to the Panel, putting forth a number of suggestions on issues relating to the improvement to air quality to be made by the Government, etc.  Regarding the progress of the follow-up actions on these measures which the Government has pledged to take, will the Government inform this Council:

(1) given that the Air Quality Objectives must be reviewed at least once every five years as required by the law and the authorities have undertaken to report to the Panel on Environmental Affairs of this Council before the end of next year on the progress of formulating the approach and methodology for conducting the review, of the progress of such task, including whether the authorities will submit regular progress reports before reporting such progress to the Panel so that the first review can be rolled out in 2019; what criteria the authorities plan to adopt for assessing the health hazards caused by air pollution;

(2) as the authorities have indicated that the Environmental Protection Department is launching the strengthened emission control on petrol and liquefied petroleum gas vehicles by using roadside remote sensing equipment and dynamometer for emission testing while the Transport Department is planning to adopt dynamometer-based emission testing in its vehicle roadworthiness examination, of the progress and effectiveness of the two tasks; whether the two departments have worked together to enhance the effectiveness of the tests; if they have, of the details; if not, the reasons for that; and

(3) since it was as early as the middle of last year when the authorities stated that it was upgrading an air quality modelling system known as "Pollutants in the Atmosphere and their Transport over Hong Kong" (i.e. "PATH"), of the reasons why the new system will not be launched until January next year, and the present progress of such task; what measures the authorities will take to help research institutions such as universities and green groups, etc. learn about the new system?



     At the meeting of the Panel on Environmental Affairs of the Legislative Council held on July 17 this year, the Environment Bureau provided response to suggestions raised in the report issued by the Subcommittee on Issues Relating to Air, Noise and Light Pollution and briefed Government¡¦s latest progress of follow-up actions. As for the question raised by Hon Dennis Kwok, our reply is as follows:

(1) The World Health Organization (WHO) recommends that different regions when formulating their air quality standards, should consider carefully their own circumstances and take into account health risks associated with air quality, practical technologies, as well as economic, political and social factors. The WHO also recommends interim targets to reduce air pollution in a progressive manner.

     When formulating the new Air Quality Objectives (AQOs) implemented in 2014, we made reference to the interim and ultimate targets recommended by the WHO and air quality standards of other advanced countries.  The new AQOs are broadly comparable to those adopted by advanced countries such as the United States and the European Union. In order to protect public health and keep improving the air quality, the Air Pollution Control (Amendment) Ordinance also stipulates that the AQOs will be reviewed at least once every five years so as to achieve the long term goal of meeting the ultimate targets under the WHO's Air Quality Guidelines.

     In the coming review of the AQOs, we will take full account of the above considerations.  Specifically, we will assess the effectiveness of the air quality improvement measures, the emission trend in the Pearl River Delta region, the development of emission reduction technologies and the risk of air pollution to human health.

(2) Poorly maintained petrol and liquefied petroleum gas (LPG) vehicles emit excessive nitrogen oxides and hydrocarbons, causing high concentrations of nitrogen dioxide (NO2) at roadside. As commercial vehicles have much higher mileage than private cars, our previous surveys indicated that some 80 per cent and 45 per cent of LPG taxis and light buses respectively had excessive emission problems, which were much higher than that of private cars at 7 per cent.

     One of the major reasons that causes excessive emissions from taxis and light buses is the failure of their catalytic converters and oxygen sensors.  Between October 2013 and April 2014, the Government launched a one-off subsidy scheme to replace catalytic converters and oxygen sensors. 13 942 taxis and 2 881 light buses participated in the scheme, accounting for some 80 per cent of eligible vehicles. In the first half of this year, the meteorological factor caused a 6 per cent increase in the average concentration of ozone recorded in Tap Mun Air Quality Monitoring Station over the same period last year, accelerating the conversion of nitrogen oxides emitted by vehicles to NO2.  During the same period, however, instead of an increase, the average concentration of NO2 recorded at roadside air monitoring stations decreased by 6 per cent when compared with that of last year. It indicates that the emission reduction measures we put in place are taking positive effect.

     Furthermore, starting from September 1 this year, the Environmental Protection Department (EPD) has deployed roadside remote sensing equipment to detect emissions from petrol and LPG vehicles. Owners of vehicles with excessive emissions are required to repair their vehicles within a specified period of time and pass the specified emission test. Failure in the specified test will lead to cancellation of the vehicle licence. The strengthened emission control can help owners develop the habit of proper vehicle maintenance and repair.  

     September and October this year, the roadside remote sensing equipment detected the emissions of about 59 000 vehicles, which accounted for about one-tenth of the petrol and LPG vehicles in Hong Kong.  Taxis, light buses and private vehicles found with excessive emissions accounted for 3.3 per cent, 4.8 per cent and 0.5 per cent respectively of the detected vehicles.  This shows that taxis and light buses with excessive emissions have reduced significantly.

      Transport Department (TD) and EPD are studying jointly the feasibility of including the dynamometer-based test in the annual examination for licence renewal of taxis and light buses. Vehicle found with excessive emissions and failed to pass the emission test within the time specified by EPD will have its licence cancelled by the TD.  

(3) "Pollutants in the Atmosphere and their Transport over Hong Kong" (PATH) is a modelling system to assess the impact of air quality caused by air pollutant emissions at a certain location.  The PATH is extensively used in environmental impact assessment (EIA) studies.  The PATH system comprises meteorological, chemical and transport modules, and each module involves sophisticated scientific theories and calculation.  Assessment on the impact of air quality has to take into account the characteristics of air pollutant emissions, meteorological information, chemical reactions, topography and the background air quality.  

     In order to complete the updating process more efficiently, EPD invited in August 2013 academics in the modelling field to form an ad hoc working group to study in-depth the various modules; to validate the system;  to enhance its performance as well as to verify the results. In updating the PATH system, the verification and enhancement work requires a lot of time and care must be taken to ensure data accuracy. We expect that the updating of the system will be completed by mid-2015. We, together with the ad hoc working group, will brief the relevant users about the operation and application of the new modelling system before it is launched.

Ends/Wednesday, November 26, 2014
Issued at HKT 16:21


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