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May 25th, 2011:

LCQ19: Air quality

Hong Kong, May. 25 — Hong Kong SAR Government issued the following news release:

Following is a question by the Hon Abraham Shek Lai-him and a written reply by the Secretary for the Environment, Mr Edward Yau, at the Legislative Council meeting today (May 25):


It has been reported that Friends of the Earth had analysed the Air Pollution Indexes (API) at 11 general stations set up by the Environmental Protection Department over the 13-month period from January 2010 and found that Sham Shui Po had the worst air quality, with an average API of 44.58, followed by Kwai Chung (43.28) and Kwun Tong (43.08); and that the poor air quality in these areas could be due to a higher number of old diesel vehicles running on the roads, compared to other areas. However, the yearly average API readings of these general stations were within the medium range of air pollution level by the Government’s standard, meaning that air quality was acceptable. In this connection, will the Government inform this Council:

(a) given that roadside stations are set up in Causeway Bay, Central and Mong Kok, whether it will consider setting up roadside stations also in Sham Shui Po, Kwai Chung and Kwun Tong; if it will, of the details with regard to the increase in the estimated expenditure; if not, the reasons for that;

(b) whether it has assessed if the current API standard in Hong Kong meets the World Health Organization (WHO)’s air quality guideline standard; if the API does not meet the WHO standard, whether it has considered tightening the API system to keep it up to par accordingly; if not, of the reasons for that;

(c) as it was reported that there were months during the aforesaid 13-month period in which APIs of Sham Shui Po, Kwai Chung and Kwun Tong exceeded 50, and that it is harmful for people to breathe the air with that API level for long, whether it had implemented any measure in the past three years to improve the air quality in the aforesaid areas; if it had, of the details; and

(d) given that three pilot low-emission zones (LEZs) will be designated in Causeway Bay, Central and Mong Kok;

(i) whether it has considered extending the pilot LEZs to Sham Shui Po, Kwai Chung and Kwun Tong; if it has, whether it will conduct public consultation; if it will, of the timetable; if it has not considered extending the pilot LEZs, the reasons for that;

(ii) whether it will consider issuing a guideline on the suggested ratio of low-emission franchised buses running in these areas; if it will, of the details; and

(iii) of the current progress of the retirement of Euro II and III franchised buses operating in these areas; and whether it has considered providing any financial incentive to the franchised bus companies for the related increase in operation expenses; if it has, of the details; if not, the reasons for that?



(a) Siting of the roadside air quality monitoring stations (AQMSs) in Causeway Bay, Central and Mong Kok has been made to measure the roadside situations in busy urbanised areas of Hong Kong. These three AQMSs are surrounded by a mix of commercial buildings and commercial-cum-residential buildings in the presence of heavy traffic. Such physical environment typifies the air quality in other busy urbanised areas like Sham Shui Po, Kwai Chung and Kwun Tong. As such, we consider that the air quality data collected by these roadside stations are representative of the roadside air quality of busy urbanised areas in other parts of the territory and do not propose to set up additional roadside AQMSs;

(b) The World Health Organization has not issued any standards and guidelines on the calculation and reporting of API values and internationally, there is also no standardised approach on the issue. Our API system is in general similar to those of Singapore and Taipei. It calculates API by making reference to the current Hong Kong Air Quality Objectives (AQOs). In parallel to our current exercise to examine how best the AQOs should be updated, we have already commissioned a team of leading academics including health experts and air scientists from the local universities to review our API system for providing more timely information to the public on the level of air pollution and the associated health effects;

(c) In Hong Kong, air pollution in different districts is caused by common air pollutant emission sources such as power plants, vehicles, etc. Cutting these local emissions, coupled with the joint efforts with the Guangdong Provincial Government to reduce emissions from the Pearl River Delta region, will help improve air quality in all districts including Sham Shui Po, Kwai Chung and Kwun Tong. We implemented the following key measures in the past three years to reduce local emissions –

i. imposed statutory emission caps on power plants since August 2005. The caps have recently been tightened to require power plants to further reduce their emissions by 34-50%, starting from 2015, as compared with the 2010 levels through maximising the use of existing gas-fired generation units and prioritising the use of coal-fired units retrofitted with emission abatement facilities;

ii. introduced on July 1, 2010 a 36-month one-off grant to encourage the early replacement of Euro II diesel commercial vehicles with new commercial vehicles after completing on March 31, 2010 a similar scheme for pre-Euro and Euro I diesel commercial vehicles;

iii. introduced in April 2008 a first registration tax concession scheme for environment-friendly commercial vehicles in addition to the one for environment-friendly petrol private cars;

iv. mandated motor vehicle fuels to comply with Euro V standard from July 1, 2010;

v. mandated the use of ultra low sulphur diesel in industrial and commercial processes from October 2008; and

vi. amended the Air Pollution Control (Volatile Organic Compounds) Regulation in October 2009 to include products such as adhesives, sealants, vehicle refinishing paints, marine vessel paints and pleasure craft paints, to limit their VOC contents in phases from January 2010;

The above measures, together with on-going air quality improvement measures and those implemented in the Pearl River Delta region by the Guangdong Provincial Government, have brought improvements to our air quality in recent years. Between 2008 and 2010, the levels of sulphur dioxide and respirable suspended particulates in Sham Shui Po, Kwai Chung and Kwun Tong reduced by 31% and 8% respectively.

(d) (i)&(ii) The pilot LEZs to be designated in Causeway Bay, Central and Mong Kok seek to restrict the access of franchised buses to low-emission models (i.e. those meeting the emission level of a Euro IV or above bus). We are working with the franchised bus companies to increase as far as practicable the ratio of low-emission buses running in these zones from 2011, with the target of having only low-emission buses in these zones by 2015.

To meet the above target, the franchised bus companies will accord priority to the deployment of low-emission buses to routes serving the pilot LEZs. They are also working with us to undertake a trial of retrofitting on their Euro II and III buses selective catalytic reduction devices (SCRs) which, together with the diesel particulate filters already installed on the buses, could upgrade their emission performance to the Euro IV level. Subject to satisfactory trial results, the Government will fund the full cost of retrofitting all Euro II and Euro III buses with SCR devices.

As many of the franchised buses serving the pilot LEZs will also pass through other districts such as Sham Shui Po, Kwai Chung and Kwun Tong, these districts will also benefit from the designation of the pilot LEZs. Should the trial on SCR retrofit be successful, we expect the majority of the franchised bus fleet would be upgraded to Euro IV level by 2015.

(d) (iii) Franchised bus companies are required to operate their franchised bus services with buses under the age of 18, and have been replacing their serving buses accordingly. This arrangement has taken account of the maintenance, operational and financial capability of the bus operators, and their obligation to provide a proper and efficient service to the public.

Currently, about 70% of franchised buses are Euro II or Euro III vehicles. Given their large numbers, it would be difficult to phase them out in the coming few years. The Government is looking into other options which are more cost-effective than expediting their replacement to reduce emissions from franchised buses. That is why we are working jointly with the franchised bus companies to undertake a trial to retrofit SCRs on Euro II and III franchised buses. As stated above, subject to satisfactory trial results, the Government will fund the full cost of retrofitting Euro II and Euro III buses with SCRs to bring their emission performance on a par with Euro IV level.

Source: Hong Kong SAR Government