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LCQ17: Roadside air quality

     Following is a question by the Hon Kam Nai-wai and a written reply by the Secretary for the Environment, Mr Wong Kam-sing, in the Legislative Council meeting today (July 4):


     It has been reported that the International Agency for Research on Cancer (IARC) under the World Health Organization (WHO) has raised the classification of exhaust from diesel engine exhaust (diesel exhaust) from Group 2A "probably carcinogenic" to Group 1 "carcinogenic", and pointed out that diesel exhaust is a cause of lung cancer and is associated with an increased risk of bladder cancer.  IARC has also pointed out that apart from motor vehicles, trains, ships and power plants powered by diesel also emit harmful exhaust.  Further, some environmental groups have queried that the 11 existing general air quality monitoring stations (AQMSs) are all located on rooftops and far away from roads and cannot reflect the roadside air pollution situation accurately.  Such groups have also pointed out that the index of fine suspended particulates (PM 2.5) adopted by the Environmental Protection Department (EPD) is two times more lenient than the "ultimate objective" set down by WHO.  In this connection, will the Government inform this Council:

(a)  whether it knows the existing numbers of buses of the fleets under each of the franchised bus companies, including hybrid, electric and supercapacitor buses, together with a breakdown of the buses by the emission standards with which they comply;

(b)  whether it knows the numbers of old buses replaced by each of the franchised bus companies in each of the past five years, the cost required to replace each bus and the total cost involved, as well as the estimated changes of such figures in the coming five years; details of the replacement schedules of old buses of the franchised companies; if schedules have not been determined, of the reasons for that;

(c)  of the quantities of the various air pollutants recorded on the roadside in each of the past five years, together with a breakdown by source of pollution (e.g. franchised buses, commercial diesel vehicles and minibuses, etc.);

(d)  given that according to the web site of EPD, "the emission inventory of the Hong Kong Special Administrative Region [compiled annually by EPD] covers five major air pollutants", but the data set out on the web site are figures of 2007, of the reasons why the data have not been updated by the authorities; when they will be updated; together with a breakdown of the relevant figures in the past five years by source of pollution (e.g. public electricity generation, road transport, navigation, civil aviation, combustion of other fuels, non-combustion sources of pollution and machines, etc.);

(e)  of the number of lung cancer and bladder cancer patients in Hong Kong in each of the past five years, and among them, the number of those who are new cases; whether it has compiled statistics on the number of cases involving cancer caused by diesel exhaust; if it has, of a breakdown by year and cancer; further, of the medical cost incurred for patients of these two types of cancer; and the respective numbers of deaths caused by these two types of cancer;

(f)  of the details, expenditure incurred, specific work schedule, current work progress and effectiveness of the various existing measures adopted by the authorities to reduce diesel exhaust and PM 2.5 at present; and

(g)  whether the authorities have planned to set up more AQMSs at present; if so, of the details and specific schedule, and whether the new AQMSs will be set up at locations closer to the road; if not, the reasons for that, and how the authorities can accurately and fully reflect the roadside air pollution situation?



     The Government is committed to improving roadside air quality and has been introducing measures to reduce diesel exhaust emissions. Key measures that we have implemented include promoting the replacement of diesel taxis and light buses with liquefied petroleum gas (LPG) vehicles, introducing an advanced smoke test and increasing the fixed penalty for smoky vehicles, requiring the installation of particulate filters or oxidation catalyst in pre-Euro diesel vehicles, tightening the motor diesel fuel specifications to Euro V, as well as further tightening the emission standards for newly registered heavy duty diesel vehicles to Euro V in June this year.  In addition, the Government has since 2007 provided grants to encourage vehicle owners to use more environment-friendly vehicles.  These include grants for the early replacement of pre-Euro, Euro I and Euro II diesel commercial vehicles, and the provision of first registration tax concession for environment-friendly vehicles.  To further reduce the pollution caused by diesel exhaust, we will mandate control on emissions from non-road mobile machinery and examine how to reduce emissions from vessels.

     The above measures have borne fruits. The levels of respirable suspended particulates (PM 10) and fine suspended particulates (PM 2.5) at local roadsides in 2011 dropped by 33% and 28% respectively as compared with 1999.  In late 2011, the Government completed the installation of PM 2.5 monitors in all 14 air quality monitoring stations (AQMSs) in Hong Kong, including three roadside monitoring stations located at busy traffic corridors in urban areas. We have released online the PM 2.5 data of the 14 AQMSs since March 8 this year.     

Below is the reply to the Hon Kam Nai-wai's question:

(a)  A breakdown of franchised buses according to emission standards as at end April 2012 is in Table 1 of the Annex.  Currently, there are no hybrid, electric or supercapacitor buses in the franchised bus fleet.

(b)  Between 2007 and 2011, the franchised bus companies purchased 821 buses and phased out 870 old buses in total.  At present, a new double-deck bus and a new single-deck bus cost about $3 million and $2 million respectively.  However, the actual cost will vary according to factors such as fluctuation in market prices, the numbers and types of buses purchased, foreign exchange rates, etc.

     According to the five-year forward planning programmes submitted by the franchised bus companies to the Transport Department, it is estimated that a total of 3,073 old buses will be phased out from 2012 to 2016 and 3,070 new buses will be purchased in the same period.  This replacement schedule is drawn up in the light of the age profile of the existing franchised bus fleet and the commitment of the franchised bus companies to operate their services with buses under the age of 18.  The actual number of buses to be replaced may vary, subject to the annual bus route development programme and the operating environment of bus companies, etc.

(c) & (d)  The Environmental Protection Department (EPD) has been keeping abreast of international developments in the methodologies in estimating emissions from pollution sources, and conducting local studies and measurements with a view to adopting the latest methodologies and techniques for improving the accuracy of the emission estimates.  For instance, after reviewing the assessment methods adopted in recent years by the United States Environmental Protection Agency and the Los Angeles Port in preparing vessel emission inventories, we commissioned a local university to collect data on movements of local vessels for a detailed assessment of vessel emissions within the boundary of Hong Kong.  In addition, we have introduced the latest portable emission measuring system used in the United States and European countries to measure the emissions from different types of vehicles in operation.  After concluding the findings of these studies and validating the data, we shall publish the latest emission data.

(e)  Based on the data kept by the Hong Kong Cancer Registry of the Hospital Authority (HA), we have tabulated the number of cases of and deaths caused by lung cancer and bladder cancer in each year from 2005 to 2009 in Table 2 and Table 3 of the Annex respectively.  The HA does not keep the number of new patients or information on the medical cost incurred by patients of these two types of cancer and whether air pollution by diesel exhaust contributed to such cases.  According to data of the Department of Health, smoking is the major cause of lung cancer.

(f)  Regarding the reduction of diesel exhaust and PM 2.5 emissions, we have introduced a package of measures targeting different sources of pollution, which are as follows:

-  mandated in 1998 newly registered diesel private cars to be at an emission level comparable with that of petrol private cars.  Newly registered vehicles (except diesel light goods vehicles of design weight not exceeding 3.5 tonnes) must comply with the Euro V emission standards since June 1, 2012 and diesel light goods vehicles of design weight not exceeding 3.5 tonnes will have to comply with that standard starting from December 31,  2012;

-  introduced an advanced smoke test in 1999 to enhance the maintenance conditions of diesel vehicles for reducing emissions;

-  incentivised vehicle owners to replace their diesel taxis and light buses with LPG taxis and light buses and enacted in 2001 legislation to require newly registered taxis to be LPG or petrol vehicles;

-  incentivised vehicle owners to install in their pre-Euro diesel commercial vehicles particulate reduction devices and mandated in 2003 the installation of such devices as a prerequisite for vehicle licence renewal;

-  launched one-off grant schemes in 2007 and 2010 to encourage the owners of pre-Euro, Euro I and Euro II diesel commercial vehicles respectively to replace their vehicles with those that comply with the prevailing emission standards.  The number of pre-Euro and Euro I diesel commercial vehicles has dropped from about 59,000 in 2007 to about 30,000 at present (a drop by 49%);

-  starting from July 14, 2008, the duty for Euro V diesel was waived entirely to further encourage drivers to use this more environment-friendly fuel.  Since July 2010, the fuel specifications for Euro V vehicles have been adopted as the statutory fuel standards;

-  launched in 2008 a concession scheme to reduce the first registration tax for environment-friendly commercial vehicles to encourage the vehicle owners to use such vehicles; and

-  started in December 2011 the enforcement of the Motor Vehicle Idling (Fixed Penalty) Ordinance requiring drivers to switch off the engines whilst awaiting.

     To implement the new AQOs, we will implement as soon as possible 22 air quality improvement measures.  Those measures targeting diesel exhaust include the following:

-  set up the $300 million Pilot Green Transport Fund in March 2011 to encourage the transport sector to introduce more green and innovative transport technologies and to use low-emission and energy efficient transportation;

-  engaged franchised bus companies to test out retrofitting Euro II and III franchised buses with selective catalytic reduction devices, which could reduce nitrogen oxides emissions by some 60%. Subject to satisfactory trial results, the Government will fund the retrofit of the devices on all Euro II and Euro II franchised buses;

-  adopted an ultimate policy objective to have zero emission buses running in Hong Kong.  To this end, the Government has proposed to the Finance Committee of Legislative Council to earmark $180 million for franchised bus companies to purchase 36 electric buses for trial runs.  Separately, the Committee allocated $33 million in April 2011 to fund the full cost of procuring six hybrid buses for trial by franchised bus companies along busy corridors;

-  to bring emissions of air pollutants from non-road mobile machinery under statutory control;

-  to reduce emissions from vessels.  This includes the new initiative to encourage ocean going vessels to use low sulphur fuel when at berth in Hong Kong waters through reducing by half the port facilities and light dues.  This initiative will span three years.  We will study in collaboration with the relevant trades how to improve the quality of vessel fuels sold locally to reduce emissions from vessels.

     In 2012/2013, the Government allocated a total of $626.7 million to implement various measures to improve air pollution.

(g)  In setting up the air quality monitoring network, the EPD aims mainly to collect data for assessing the impact of air pollution on the public, facilitate the formulation of an air quality management strategy and evaluate its effectiveness.  Apart from adopting the internationally recognised guidelines (such as the guidelines of the United States Environmental Protection Agency) for the design and site selection for the monitoring stations, we also follow strictly a quality control and assurance system to ensure that the data on air quality are highly accurate, reliable and representative.  To collect representative air quality data, we will take into account various factors in determining the locations of the AQMSs, namely, spatial distribution of AQMSs in the network, coverage of different types of development areas (such as urban areas, new towns and rural areas), distribution of local population, traffic flow and distribution of sources of pollution, representativeness in terms of the local air quality, topography and meteorology.

     Hong Kong is a small and highly populous place, with economic activities being mainly commercial and financial.  In urban areas and new towns, the air pollutants come mainly from vehicle emissions.  Given the similar sources of pollution, the levels of air pollution in different districts are mainly determined by their respective types and density of development.  The current air quality monitoring network, comprising 11 general AQMSs, covers the major areas of Hong Kong from east to west and from south to north.  As for land uses, they cover different development categories such as residential, residential/commercial, residential/commercial/industrial, rural and urban areas.  As such, the current general air quality monitoring network can effectively and comprehensively reflect air pollution in districts with different types of development in Hong Kong.

     In addition, we have set up three roadside AQMSs at busy traffic corridors in built-up urban areas with a large number of pedestrians so as to monitor roadside air quality.  These three roadside stations are in Causeway Bay, Central and Mongkok, covering the more densely built-up and most common types of land use in urban areas, including commercial, residential and commercial and financial areas.  The data collected by these roadside AQMSs are representative of the roadside air quality along busy traffic corridors with a heavy pedestrian flow in the most common urban areas in Hong Kong.

     On the whole, the current monitoring network can adequately reflect the level of air quality in Hong Kong and support our formulation of air management strategy and measures while providing the public with representative data on air quality.  At present, we have no plan to increase the number of AQMSs, but we will review from time to time the situation and the need according to the established mechanism.

Ends/Wednesday, July 4, 2012
Issued at HKT 13:55


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