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LCQ16: New Air Quality Objectives

Hong Kong (HKSAR) – Following is a question by the Hon Abraham Shek Lai-him and a written reply by the Secretary for the Environment, Mr Edward Yau, in the Legislative Council meeting today (June 6):

The Government proposed in January 2012 a set of new Air Quality Objectives (AQOs) which lays down the atmospheric concentration limits for seven pollutants together with a host of air quality improvement measures to help Hong Kong achieve the AQOs. However, in the new AQOs, the concentration limits of four pollutants (i.e. sulphur dioxide (SO2) (24-hour mean), ozone, respirable suspended particulates and fine suspended particulates (PM2.5) (annual-mean and 24-hour mean)) fail to match the highest levels prescribed in the World Health Organization (WHO)’s Air Quality Guidelines published in 2006, and the green groups have criticized the Government for taking a “half-hearted” approach to implement the air quality improvement measures. In addition, it has been reported that according to the China Statistical Yearbook 2011, Hong Kong’s nitrogen dioxide level ranks 31st out of 32 major cities in China. In this connection, will the Government inform this Council:

(a) whether the Government has considered the public health impact with limits of SO2 (24-hour mean) and PM2.5 benchmarked against WHO’s Interim Targets and Air Quality Guidelines; if it has, of the details; if not, the reasons for that; whether it knows any details of affirmative overseas examples in which limits comparable to those in the new AQOs are adopted; of the principles considered and views from the public consultation in 2009 which affirm the proposed limits;

(b) given that it has been reported that the Ministry of Environmental Protection on the Mainland has proposed a tougher limit for nitrogen dioxide than that of Hong Kong, whether it will consider imposing a standard at least on par with that proposed by the Ministry; if it will, of the details; if not, the reasons for that;

(c) whether it has considered the difficulties construction projects will encounter and additional compliance cost they will incur in securing approval against the new AQOs under the Environmental Impact Assessment Ordinance (Cap. 499), including but not limited to, as reported, the proposed construction of the third runway at Hong Kong International Airport the emission level of nitrogen dioxide of which may exceed the proposed limit; if it has, of the details with any follow-up mitigation measures taken in alleviating the situation; and

(d) given the absence of any government figures in evaluating the public health impact of air pollution, whether the Government has considered establishing a mechanism similar to the Hedley Environmental Index in assessing the public health impact of air pollution and publicizing the real-time information on the impact; if it has, of the details with the expected cost and manpower resources involved; if not, whether it has considered any ways besides the established measures in enhancing public awareness of the health impact of air pollution?



(a) In setting our new Air Quality Objectives (AQOs), we have made reference to the recommendations of the World Health Organisation (WHO) as well as the standards of other advanced places. When the WHO published its new Air Quality Guidelines (AQGs), it also reminded governments that they should consider their own local circumstances carefully before using the guidelines directly as legal standards. It also pointed out that the standards set in each country will vary according to specific approaches to balancing risks to health, technological feasibility, economic considerations and other political and social factors. In fact, WHO also recommends interim targets as incremental steps in a progressive reduction of air pollution in more polluted areas and to promote a shift from concentrations with acute, serious health consequences to concentrations that if achieved, would result in significant reductions in risks to health. Such progress towards the guideline values should be the objective of air quality management and health risk reduction in all areas.

The AQOs we are proposing have been drawn up in accordance with the above WHO guidelines .As far as we know, no country has fully adopted the WHO’s ultimate guidelines values as their statutory air quality standards. Apart from suspended particulates which are under strong regional influence, our new AQOs are on par with those of other advanced countries, such as the European Union (EU) and the United States (USA).We have adopted the WHO’s ultimate AQGs in their entirety for three of the seven major pollutants (i.e. nitrogen dioxide, carbon monoxide and lead) and in part for another pollutant (i.e. sulphur dioxide).

In addition, we will review every five years the feasibility of tightening the AQOs and formulate corresponding air quality improvement plans.

As for sulphur dioxide (SO2), the 10-minute limit in the proposed AQOs has already benchmarked against the AQG of WHO and the 24 hour-limit is same as that of EU (i.e. IT-1 of WHO), which is on a par with the standard currently adopted by advanced countries/economies. This has been reduced by more than 60 per cent comparing to the existing AQO value.

We note that our PM2.5 level has been under strong regional influence. The particulate matter emissions of Hong Kong and the Pearl River Delta region are in the proportion of 1:99.The particulate concentrations of Hong Kong are, therefore, under strong regional influence. While we and the Guangdong Provincial Government have already endeavoured to implement a number of measures to improve regional air quality, taking into account the regional influence, we would not able to update the air quality objectives for suspended particulates with just one go, but have to take a more practical approach. We propose the WHO IT-2 for respirable suspended particulates (PM10) be adopted. With fine suspended particulates (PM2.5) accounts for about 70 per cent of PM10 found in Hong Kong, we propose to benchmark its level at WHO IT-1.

(b) The new national standard for annual nitrogen dioxide (NO2) proposed by the Ministry of Environmental Protection is the same as ours and WHO’s ultimate AQG. In addition, the WHO currently has not established any 24-hour limit for NO2.Our practice is in line with other countries such as EU, USA and Australia.

(c) Following the introduction of the new AQOs, to obtain the environmental impact assessments approval, it will be necessary for designated projects to demonstrate their air quality impacts will meet the new legal standards. When updating the AQOs, the Government has also put forward a basket of 22 new air quality improvement measures to help reduce ambient air pollutant levels. At the same time, when the proposed objectives have become legal standards, designated projects have to implement adequate and appropriate mitigation measures in areas of design, construction and other operation standards, where necessary, to meet the legal requirements.

(d) Implementation of the proposed new AQOs and air quality improvement measures will help alleviate air pollution problems and bring about health benefits, including reduction of number of people admitting to hospitals due to asthma or other respiratory illnesses. According to the Consultant’s study report, implementation of the recommended Phase 1 emission control measures would lead to an anticipated benefit of about $1,228 million annually due to improvement in public health, which is significantly higher than the estimated annualized cost of about $596 million to be incurred by the society. The Consultant also estimated that some 4,200 hospital admissions could be avoided because of the improvement measures. In addition, the average life expectancy of the population would be increased by about one month or around 7,400 “life years” saved each year. In addition, the existing Air Pollution Index (API) has been providing a simple way of describing air pollution levels in Hong Kong. To tie in with the updating of the AQOs, we will correspondingly review and improve the existing API system.

Source: HKSAR Government

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