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LCQ7: Air quality standards in Hong Kong and WHO
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    Following is a question by the Hon James Tien and a written reply by the Secretary for the Environment, Transport and Works, Dr Sarah Liao, at the Legislative Council meeting today (December 20) :


Question:

     Some community organisations and environmental scholars have recently pointed out that Hong Kong's Air Quality Objectives (AQOs) are seriously outdated and set at levels far below the standards prescribed in the new Air Quality Guidelines (AQGs) announced by the World Health Organization (WHO) in October this year, thereby exposing the public to health hazards.  In this connection, will the Government inform this Council:

(a)  as the current AQOs of Hong Kong were established in 1987 and have not been updated for almost 20 years since then, whether the authorities know the number of times that WHO, the United States of America, the European Union, Norway, Japan and New Zealand have amended their respective guidelines/standards on air quality during this period, and why Hong Kong has all along not amended its AQOs accordingly;

(b)  of the findings of the analyses of air pollution in Hong Kong in the past three years based on Hong Kong's AQOs and WHO's new AQGs respectively; and

(c)  whether it has assessed the respective impact on Hong Kong if its AQOs have not been immediately amended to comply with the standards prescribed in WHO's new AQGs and if the AQOs have been so amended; if it has, of the assessment results?

Reply:

Madam President,

(a)  The Air Quality Guidelines (AQGs) promulgated by the World Health Organization (WHO) in October 2006 is the first global guidelines issued by WHO.  In 1987, the WHO published its "Air Quality Guidelines for Europe".  These AQGs were reviewed with the pollutant limit values amended in 2000.

    In 1997, in the course of revising the air quality standards that had been in force since the mid-1980s, the United States Environmental Protection Agency (USEPA) established the 8-hour average ozone limit values and the standards for particulates of 2.5 microns or less (PM2.5).  Due to legal disputes, the new limits and standards were only formally enforced in 2001 and 2005 respectively after resolution of disputes.  USEPA decided to abolish the annual average PM10 limit values and revise the PM2.5 standards in 2006.  The new standards were formally introduced in September 2006.

    The European Union (EU) did not set air quality standards for Member States until 1999 when it standardised the air quality standards for sulphur dioxide, nitrogen dioxide, respirable suspended particulates and lead.  These standards have not been amended so far.  Japan has not revised its air quality objectives (AQOs) since 1978, while New Zealand did not establish its own AQOs until 2004 and no amendment has been made so far.  As for Norway, we do not have any information on its amendment to AQOs.

    We have been closely monitoring the international developments on reviews of air quality standards and AQOs.  Recent scientific research findings suggest that particulate matters smaller than 2.5 microns have more direct health impacts than those of larger sizes.  Moreover, the concentration levels of air pollutants that can affect human health may be lower than those indicated in previous studies.  In view of such findings, in recent years, a number of countries including the US, the Member States of the EU and WHO have been examining the need for introducing a new set of air quality standards for particulate matters smaller than 2.5 microns (i.e. PM2.5) and revising the current air quality guidelines and standards.  As for Hong Kong, we have to find out the justifications in the international community for reviewing and revising the AQOs before considering how to revise ours.  Upon learning that the reviews of air quality standards conducted by the US and the WHO were nearing completion in July 2006, the Environmental Protection Department (EPD) took the initiative to announce its plan to launch a detailed study, which includes the following:

(i)  review and characterise the current state of air quality in Hong Kong, including the prevailing exposure levels, developing trend, major pollution sources and origins, the impacts of external and non-anthropogenic sources on Hong Kong's air quality, as well as policies, programmes and legislation in place for controlling air pollution;

(ii)  examine and make reference to the different rationale of the WHO and the USEPA in devising their respective air quality guidelines or standards, including concrete research results on long-term and short-term health impacts;

(iii)  use methods including air modelling to assess air quality under different scenarios and with mitigation measures adopted; to recommend specific measures required and options available to achieve interim targets and the specified standards if the new WHO AQGs are to be adopted; to examine in depth the need for co-operation with neighbouring cities and provinces;

(iv)  assess the implications of implementing the measures identified under different options, including economic costs, the time required for introducing the measures, the need to work with the Mainland as well as impacts on other policy areas such as energy, transportation, industrial development, urban planning and conservation;

(v)  taking into account (iii) and (iv), devise practicable options to revise Hong Kong's AQOs, including whether it is necessary to have different targets for roadside air quality, and to identify strategies and measures required in the form of action plan to achieve the revised AQOs, with implications identified for each option, so as to facilitate public participation and comments; and

(vi)  review the need and means to align the release of air quality monitoring data with international practice to facilitate fair comparison with other economically advanced cities.

(b)  There are currently 14 monitoring stations in Hong Kong for ongoing measurement of five key air pollutants, with the highest relative reading published as the daily air pollution index.  Hong Kong's AQOs and WHO's AQGs as well as the AQOs of other advanced countries are at Annex A.  The compliance status in respect of various air pollutants in Hong Kong in the past three years based on Hong Kong's current AQOs and the new WHO AQGs respectively is at Annex B.

(c) In the past, no economically developed countries, including the US, the EU, Canada, Australia and Japan, have fully adopted the old WHO AQGs as their local AQOs.  So far, we have not heard of any countries announcing plans to fully adopt the new WHO AQGs.  In fact, the UK government considers it impracticable to fully achieve the air quality standards recommended by WHO across the UK by 2020.  The UK estimates that it can only meet the standards for some air pollutants by 2050.  The standards currently adopted in Hong Kong are based on studies mainly conducted in the US and the local situation of Hong Kong.  Generally speaking, although Hong Kong's air quality standards were formulated as early as 1987, they are fairly close to the levels of standards currently adopted in the US, except that there is not yet any objective for PM2.5.  It was not until late September this year that the US announced the new air quality standards for particulate matters.  These new standards are far less stringent than those in the new AQGs recommended by the WHO and the dates for meeting the targets are as late as 2015 or 2020.

    The WHO points out that the air quality standards set by different countries would vary.  A balance has to be struck among factors such as health risks posed by air quality to the local population, technological feasibility, economic considerations and other political and social factors, etc.  The WHO clearly advises the administrations of various places to consider their own local circumstances carefully before adopting the WHO guidelines as statutory standards.

    When launching the detailed study in early 2007, the Government will make careful reference to the new WHO AQGs and the latest research findings of the EU and the US, in order to draw up different options and analyse their cost effectiveness, social impact, the required technical know-how, the time required for introducing the measures, the need to co-operate with the Mainland and co-ordination with other policy areas such as energy, transportation, industrial development, urban planning and conservation.  We will also conduct public consultation with a view to formulating a comprehensive, proactive and feasible air quality management strategy with interim and long-term targets.

Ends/Wednesday, December 20, 2006
Issued at HKT 16:31

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