Air Quality

Air Quality

The AA is committed to complying with statutory air quality criteria and monitoring and controlling air emissions associated with airport operations.

As one of the world’s busiest airports, Hong Kong International Airport (HKIA) manages emissions from its daily operations through a range of policies, reduction measures and continuous monitoring with the aim of minimising impact on the community and the surrounding environment.

Our Story

Air Quality Monitoring

The Airport Authority (AA) has been monitoring the air quality at HKIA since 2004 and has made this information available on its website since 2012. The data helps to identify the most cost-effective policies and solutions to reduce emissions at HKIA and also provides useful insights into regional air quality. Ambient air quality at HKIA is monitored through two on-airport air quality monitoring stations and a control site on Sha Chau. Monitored air pollutants include nitrogen dioxide (NO2), sulphur dioxide (SO2), respirable suspended particulates (PM10), fine suspended particulates (PM2.5), carbon monoxide (CO) and ozone (O3). The average hourly concentrations are collected and disclosed in real-time to the public on our website.

In 2016, we upgraded our website to include hourly Air Quality Health Index (AQHI) information, which makes reference to the AQHI published by the HKSAR Government.

Air Quality Management

The AA is committed to reducing air emissions that are under our direct control (e.g., emissions related to the AA’s vehicles), and facilitating emissions reduction of airport business partners and aircraft at parking stands.

Auxiliary Power Units Ban

Aircraft at parking stands normally use their Auxiliary Power Units (APUs), which are small engines located at the rear of aircraft, to provide electrical power when the main engines are switched off. To reduce emissions from burning jet fuel, the AA implemented an APU ban in December 2014 that controls the use of APUs at frontal stands. In order to meet aircraft’ needs for electrical power and cabin cooling when parked, the AA installed fixed ground power (FGP) and pre-conditioned air (PCA) systems - a total of over 405 FGP units and over 153 PCA units (as of November 2022). The AA also worked closely with our airport business partners to organise trials and develop operational procedures for the transition. 

Clean Transportation

The AA is committed to investing in clean transportation to reduce both greenhouse gas (GHG) and air emissions generated from its vehicle fleets.

Airside Vehicles Electrification

The AA has been implementing an Airside Vehicle Electrification Programme since July 2013. Under Phase 1 of the Progamme, the AA has required all newly registered saloons operating in the Airport Restricted Area (ARA) to be electric vehicles (EVs). Phase 1 of the Progamme was successfully completed with all saloon cars replaced with EVs since 2017. The second phase of the Programme began in 2019 and this will require the replacement of all airside private vehicles with a gross weight of less than 3 tonnes with electric models by the end of 2023.

To facilitate vehicles electrification, the AA has installed over 658 EV chargers on the apron (as of October 2022). The network of EV chargers are planned to be increased to over 1,300 to support the Three-Runway System (3RS) operation by 2030. In addition, a Smart-to-Charge (STC) System has been installed on the airside, which has a built-in intelligence feature that allows it to supply electricity to multiple EVs more efficiently by monitoring the battery condition of each vehicle that is being charged. The STC System not only ensures sufficient charging facility and capacity could be provided for the expanding EV fleets at HKIA, but also helps to reduce the installation cost for new charging facilities.

Ground Services Equipment Pooling Scheme

In July 2018, the AA rolled out the On-stand Ground Services Equipment (GSE) Pooling Scheme at the Midfield Apron as a resource-sharing initiative to unleash existing untapped capacity and create new capacity in the ramp handling process. This first phase, covering over 250 units of critical GSE, led to an improvement in air quality and reduction of GHG emissions at HKIA as 95% of the GSE are powered by electricity. The on-stand GSE provided include electric lower deck loaders, electric conveyor belt loaders, electric passenger steps and main deck loaders, etc.

Subsequent phases of the scheme will expand the coverage to other areas of the airport: Terminal 1 Apron and the future Terminal 2 Concourse Apron, ultimately increasing the size of GSE fleet to 580. There are currently over 178 electric GSE chargers (as of November 2022) installed on the apron and these are planned to be increased to more than 400 in 2025 to support the expansion of GSE fleet. 

Autonomous Transportation System

The AA is taking forward the Airportcity Link (ACL) project, a purpose-built bridge on which a vehicular road and a pedestrian walkway will be provided to connect the Hong Kong Port of the Hong Kong-Zhuhai-Macao Bridge and SKYCITY. The ACL will be served by electric vehicles and ultimately an autonomous transportation system supported by zero-emission autonomous vehicles. An extension of the autonomous transportation system linking SKYCITY and Tung Chung town centre has also been planned.

Air Quality Study with HKUST

Air Quality Study with HKUST

Since 2007, the AA has been working with the Hong Kong University of Science and Technology (HKUST) to analyse air quality data and study HKIA’s operational air quality impact. These studies have allowed the AA to gain a better understanding of the air quality performance of different aspects of airport operations and facilitated the development of the above mentioned emissions reduction measures.

Quick Facts  


Since July 2017, all saloon vehicles on the airside are required to be EVs


The AA implemented an APU ban in December 2014


The APU ban policy reduces NOx emissions from APU operations by approximately 20%


95% of HKIA Ground Services Equipment is electrified


By 2030, increase the number of 1,300 charge points to support airside vehicles electrification

Awards & Recognition

ACI Asia-Pacific Green Airports Recognition 2021 - Gold Recognition ("Over 25 million passengers per annum" category)
ACI Asia-Pacific Green Airports Recognition 2021 - Gold Recognition ("Over 25 million passengers per annum" category)
Air Quality Data

Current Pollutant Concentration & AQHI


AQHI 24 Hrs


Past 24 hours Pollutant Concentration & AQHI


AQHI Distribution


Download Pollutant Data