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LCQ20: Emission levels of air pollutants from aircrafts at Hong Kong International Airport

     Following is a question by the Hon Albert Chan and a written reply by the Secretary for the Environment, Mr Wong Kam-sing, in the Legislative Council today (February 19):


     At the Council meeting on October 19, 2011, I asked the authorities about the emission levels of various types of air pollutants from aircraft movements and aircraft parking at the Hong Kong International Airport (HKIA) each year between 2009 and 2010, and whether the authorities had taken measures to reduce the emissions from aircraft so as to alleviate the problem of air pollution in Tung Chung and thereby reduce the impact of air pollutants on the health of Tung Chung residents. The authorities indicated in their reply that they had taken measures to reduce emissions of air pollutants and carbon from aircraft. Yet, residents in Tung Chung have still relayed to me that the number of flights operating at HKIA has been growing constantly in the recent three years and aircraft emissions have also increased correspondingly, hence worsening the air quality in Tung Chung and affecting the health of the residents in the district. In this connection, will the Government inform this Council:

(1) whether it knows the emission levels of various types of air pollutants from aircraft movements and aircraft parking at HKIA each year between 2011 and 2013, with a breakdown, by aircraft model in table form, of the emission levels of various types of air pollutants from aircraft, as well as which aircraft model had the highest level of emissions, and what measures currently have been put in place by the authorities to reduce emissions from aircraft of such models;

(2) whether it has assessed if the worsening of the air quality in Tung Chung in recent years is related to the increase in air pollutant emissions from aircraft; if the assessment outcome is in the affirmative, to what extent the increase in emissions from aircraft has led to the worsening of air quality in Tung Chung; if the assessment outcome is in the negative, of the reasons for that; and

(3) whether it will take new measures to reduce the impact of the air pollutants emitted by aircraft on the health of Tung Chung residents; if it will, of the details; if not, the reasons for that?



     The numbers of arrival and departure of aircraft at the Hong Kong International Airport (HKIA) between 2011 and 2013 and the air pollutant emissions in 2011 are set out in Annex 1. As the compilation of air pollutant emissions for 2012 and 2013 is underway, we cannot provide the aircraft emission data for these two years.

     Aircraft emissions of sulphur dioxide, nitrogen oxides, respirable suspended particulates, volatile organic compounds and carbon monoxide accounted for 1 per cent, 4 per cent, 1 per cent, 1 per cent and 3 per cent of Hong Kong's overall emissions respectively in 2011.

     The total quantities of air pollutants emitted from individual model of aircraft depend on various factors including the numbers of their arrivals and departures in a year, the type, size and number of their engines. Even for aircraft of the same model, they may not have engines of the same types or sizes and could have different quantities of emissions. In general, bigger aircraft with higher arrival and departure frequencies will have greater quantities of emissions. Based on the aircraft arrival and departure data of the HKIA in 2011 released by Civil Aviation Department (CAD), the percentage shares of emissions for different types of aircraft are set out in Annex 2.

     Air pollutants emissions from different types of commercial aircraft vary with the engine design, aircraft size and passenger load. The CAD has adopted the standards set out at Annex 16 to the Convention on International Civil Aviation (hereinafter referred to as "the Chicago Convention"), Volume 2, Part III, Chapter 2 (Turbojet and turbofan engines intended for propulsion only at subsonic speeds) to certify engines on commercial aircraft registered in Hong Kong. This document specifies the standards for four types of emissions that an aircraft engine has to meet, namely, smoke, unburned hydrocarbons, carbon monoxide and nitrogen oxides. Commercial aircraft registered elsewhere also meet generally the standards set out at Annex 16 to the Chicago Convention. To reduce their air pollutant emissions, aircraft that use the HKIA are required to meet the international standards for aircraft engine emissions.

(2) Apart from aircraft emissions, air quality in Tung Chung is also influenced by regional air quality and other local emission sources. Over the past three years, the air pollutant concentration data recorded at the Tung Chung general air quality monitoring station did not reveal any apparent change in air quality as a result of the increase in aircraft movements. There was a slight decrease in respirable suspended particulates concentrations in Tung Chung whereas concentrations of sulphur dioxide, nitrogen dioxide and ozone, an air pollutant related to regional photochemical smog problem, were relatively steady. Please refer to Annex 3 for the detailed data.

(3) Since October 22, 2009, the CAD has implemented new air routes which shorten the travelling distance for aircraft approaching from the west and north of Hong Kong. Hence, a flight to Hong Kong from the Mainland, South East Asia and Europe can save up to about 210 km in flight journey, that is about 14 minutes in flight time. The shortened air routes and the reduced flight time can help reduce aircraft's air pollutant emissions. In 2013, a total of over 70,000 flights adopted these shortened routes. Besides, the CAD will continue to implement international standards in certifying aircraft engines, and to closely monitor and follow the international requirements in this respect.

     Since the operation of the HKIA, the Airport Authority (AA) has been providing electricity powered fixed ground power (FGP) and pre-conditioned air (PCA) systems for aircraft at parking stands to reduce the operation time of onboard fuel combustion auxiliary power generation units, and thereby reduce emissions. In 2011, about 80 per cent of passenger flights have adopted the FGP and PCA systems. The AA is going to mandate the use of FGP and PCA at parking stands before end of 2014 with a view to further reducing aircraft emissions.

Ends/Wednesday, February 19, 2014
Issued at HKT 14:41


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