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LCQ19: PM2.5 levels in Hong Kong

     Following is a question by the Hon Chan Hak-kan and a written reply by the Secretary for the Environment, Mr Wong Kam-sing, in the Legislative Council today (June 11):


     Fine suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 2.5 £gm or less (PM2.5). It has been reported that the findings of a medical research reveal that PM2.5 are very active, and harmful or toxic substances can be easily attached to them. It is also difficult to exhale PM2.5 after it has been inhaled into the human body through respiratory tracts. As a result, PM2.5 pose rather serious hazards to human health. On the other hand, while concentrations of PM2.5 in air are closely monitored in some mainland cities in recent years, there is no comprehensive monitoring network for PM2.5 in Hong Kong. In this connection, will the Government inform this Council:

(a) given that at present, some mainland web sites report on a real time basis the data on PM2.5 concentrations in various parts of the Mainland and the air quality across the country, as well as provide information about PM2.5, of the reasons why the data on concentrations of air pollutants at various air quality monitoring stations (AQMSs) published on the web site of the Environmental Protection Department of Hong Kong (EPD) are confined to information (i) for the past 24 hours and (ii) on or before December 31, 2013; whether the authorities can make reference to Mainland web sites in providing more information (such as the health impacts of PM2.5);

(b) given that one of the major sources of PM2.5 in the air of Hong Kong is vehicle emissions, whether the authorities can collect data on PM2.5 concentrations at roadside AQMSs and publish them on a real time basis for reference by the public and for publicity purposes; if they cannot, of the reasons for that;

(c) given that PM2.5 are hazardous to human health, for example, they may induce upper respiratory tract diseases and even cancers, whether the authorities have assessed the impacts of PM2.5 on human health and formulated any countermeasures; if they have, of the details; if not, the reasons for that; whether the authorities will collect data through district-wide health screening exercises for the purpose of studying the impacts of PM2.5 on human health;

(d) given that a PM2.5 monitor has been installed at Wan Po Road in Tseung Kwan O, of the reasons why the relevant data are not published on the EPD's web site; whether it can publish such data on the web site concerned; whether the authorities have studied the sources of PM2.5 on that road and the reasons for the persistently high PM2.5 concentrations there; whether they have formulated any measures to tackle the air pollution problem on that road; and

(e) despite the fact that the Pearl River Delta, which has a close relationship with Hong Kong, has been identified as one of the focal regions for controlling PM2.5 emissions in the "National Environmental Protection Plan under the 12th Five-year Plan", of the reasons why the reports on the monitoring results of the Pearl River Delta Regional Air Quality Monitoring Network published annually have not mentioned any information relating to PM2.5; whether analyses on PM2.5 can be incorporated into future reports; of the measures adopted by the authorities to tie in with the collaboration plan on emission reduction and to educate the public on the health impacts of PM2.5?



     In order to understand the ambient PM2.5 levels in Hong Kong, the Environmental Protection Department (EPD) started monitoring PM2.5 concentration in 1999 at three general air quality monitoring stations (AQMSs), which are in Tap Mun, Tung Chung and Tsuen Wan, respectively, and the Central roadside AQMS. The general AQMS in Yuen Long started monitoring PM2.5 concentration in 2005; and all other AQMSs in Hong Kong started in 2011. Since March 8, 2012, the EPD has been disseminating real time data of PM2.5 for all the AQMSs (including the three roadside AQMSs) in Hong Kong. Our reply to the questions raised by Hon CHAN Hak-kan is as follows:

(a) and (b) The EPD has been releasing via its website the real time concentrations of major air pollutants measured in all AQMSs (including both general and roadside AQMSs). Since March 8, 2012, the release has also included the real time data of PM2.5.

     As the real-time data are raw data which have yet to be validated, the EPD only retains the past 24 hours' data on the website. After validating the data, the EPD will upload the validated data to its website for the public to download or peruse. As the validation process takes time, the uploaded validated data are up to December 31, 2013.

     In addition to the real-time air pollutant data, the EPD's Air Quality Health Index (AQHI) website also provides past validated major air pollutant (including PM2.5) data and information on their major sources and health impacts. For further details, please refer to EPD's AQHI website as below:

(c) The Hong Kong Special Administrative Region Government has all along been very concerned about the impacts of air pollution on public health. Emissions from diesel vehicles are a key source of PM2.5. After the World Health Organisation (WHO) classified particulate matters emitted from diesel vehicles as "probably carcinogenic" to humans, the Government started reducing diesel emissions and has been putting forward since 1999 comprehensive emission controls to reduce vehicular emissions, especially diesel particulate emissions. The key control measures included replacing diesel taxis/light buses with liquefied petroleum gas vehicles, mandating pre-Euro diesel vehicles to be retrofitted with particulate reduction devices, tightening vehicle fuel and vehicle emission standards, and stepping up the control on smoky vehicles by increasing the fixed penalty fine and adopting an advanced smoke test, etc. These measures have borne fruits. From 1999 to 2013, the roadside PM2.5 levels in Hong Kong were reduced by 37 per cent. In response to WHO's classification of diesel exhaust as carcinogenic to humans in June 2012, the Government launched an ex-gratia payment scheme on  March 1 this year to phase out progressively some 82 000 pre-Euro IV diesel commercial vehicles (DCVs) including goods vehicles, light buses and non-franchised buses, to further reduce PM2.5 emissions from diesel vehicles for protecting public health.

     Regarding the impacts of PM2.5 on public health, the EPD has commissioned local health experts to collect data through district-wide health screening exercise or questionnaire to study the impacts. The studies are expected to be completed by the end of 2015.

(d) In response to the concerns and request of residents from Tseung Kwan O (TKO), the EPD has, since September 18, 2013, placed monitoring equipment on the rooftop of Tai Chik Sha Fire Station in TKO to measure the concentration of PM2.5 at Wan Po Road. Results show that the 24-hour average PM2.5 levels measured were similar to those recorded at the general AQMSs elsewhere in Hong Kong. As the monitoring point at Tai Chik Sha Fire Station is specifically designed to measure the PM2.5 levels at Wan Po Road and its nature is different from other AQMSs, we therefore considered it is more appropriate to provide the data to the Sai Kung District Council (SKDC) with relevant information for comparison. The EPD has already provided the monitoring data from September 2013 to March 2014 to the Housing and Environmental Hygiene Committee (HEHC) of the SKDC and relevant papers (SKDC[HEHC] papers no. 20/14 and 68/14) have also been uploaded to the SKDC website for the public's reference. We will continue to provide relevant data to the SKDC. Looking ahead, legislative amendments have been passed and subject to the funding approval for the Southeast New Territories (SENT) Landfill Extension, the reception of only construction waste will be implemented as soon as possible at the SENT Landfill. The number of vehicle loads transported to the landfill will then be reduced from the present level of some 1 000 to 500. This will help improve the air quality in the area.

(e) As for the PM2.5 data monitored by the Pearl River Delta Regional Air Quality Monitoring Network, Guangdong and Hong Kong governments will consider including them in the annual report in due course.

     To achieve the 2015 and 2020 emission reduction targets agreed by the two governments, the EPD is implementing a series of enhanced control measures to further reduce the emissions from major local air pollution sources. These measures include the progressive phasing out of pre-Euro IV DCVs launched in March 2014, tightening the sulphur content of local marine diesel to not more than 0.05 per cent since April 2014, and the drafting of new regulation to mandate ocean-going vessels (OGVs) to switch to low sulphur fuel while at berth, etc. All these control measures could help reduce the PM2.5 levels in Hong Kong.

     As mentioned above, information on major sources of PM2.5 and its impacts on health are provided in the EPD's AQHI website to enhance public's awareness and understanding of PM2.5.

Ends/Wednesday, June 11, 2014
Issued at HKT 14:19


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