Review of Air Quality Objectives

The Government has set out Hong Kong’s Air Quality Objectives (AQOs) in the Air Pollution Control Ordinance (Cap. 311), and is required to review the AQOs at least once every five years to continuously improve air quality and safeguard public health. The current AQOs took effect from 1 January 2022. The Government has embarked on a new round of review to assess the scope for further tightening the AQOs, with an aim of completing the review by 2023.

Guiding Principles of the Review

The Government’s ultimate goal, in the long run, is for Hong Kong’s air quality to fully meet the ultimate targets set out by the World Health Organisation (WHO). In September 2021, the WHO released a set of new Global Air Quality Guidelines (AQGs), imposing much more stringent limits, and introducing three new parameters, namely the peak season level for ozone (O3), 24-hour level for nitrogen dioxide (NO2) and 24-hour level for carbon monoxide (CO).

As in the past, WHO advises in the new AQGs that while achievement of the AQG levels should be the ultimate goal, this might be a difficult task for many countries and regions. Therefore, gradual progress in improving air quality, marked by the achievement of interim targets, should be considered a critical indicator of improving health conditions for populations. The current review will follow the above principles and guidelines. Of the 12 parameters in our AQOs, five of them are already pegged at the most stringent levels of the new AQGs.

Key tasks

  1. Appraise the latest air quality levels and trends of Hong Kong and the Pearl River Delta (PRD) region;
  2. Examine the progress and effectiveness of on-going and committed air quality improvement measures, and deliberate on new air quality improvement measures with substantial emission reduction impacts by 2025 and 2030;
  3. Evaluate the air quality improvement in 2025 and 2030, and the associated health and economic benefits in 2030 taking into consideration the implementation of air quality improvement measures in Hong Kong and the PRD region; and
  4. Assess the compliance of AQOs for 2025 and the scope for further tightening the AQOs in 2030 with reference to the latest WHO AQGs.

AQOs Review Working Group and Air Science and Health Task Force

A Working Group led by the Under Secretary for Environment and Ecology has been set up to engage stakeholders and gauge their views on the current review. The Working Group will deliberate on air quality improvement measures with substantial emission reduction impacts by 2025 and 2030, and evaluate the scope for tightening the AQOs having regard to the findings of the air quality and health and economic impact assessments.

The Working Group comprises some 20 external members in the fields of air science, environmental groups, professional institutions, business groups and relevant trades, as well as officials representing related Government bureaux and departments. An Air Science and Health Task Force (ASHTF) comprising air scientists and medical experts has been established under the Working Group to advise on the methodologies and findings of the air quality and health and economic impact assessments that will be carried out by a consultant engaged by the Government.

More information on the Working Group and the ASHTF