Announcing an overview of Hong Kong’s air quality in 2024, the Environmental Protection Department said today that the city’s air remained good overall and was broadly in compliance with the Government’s Air Quality Objectives.

In recent years, the Government has promoted electric vehicles, green transport and net-zero electricity generation in an effort to improve air quality in Hong Kong.

The department said that in 2024 the percentages of hourly Air Quality Health Index (AQHI) readings recorded by general and roadside monitoring stations that fell within “low” or “moderate” health risk paramaters were 98.7% and 98.9% respectively. The comparable figures for 2014, the year the index launched, were 96.1% and 92.1%.

From 2004 to 2024, the annual average concentrations of respirable suspended particulates, fine suspended particulates, nitrogen dioxide and sulphur dioxide in the ambient air have fallen by 45% to 88%. The annual average concentrations of these pollutants at the roadside have fallen by 36% to 88%.

The annual average concentration of ozone has also steadied over the past few years. The number of hours of reduced visibility has declined by 82% since 2004.

Despite an increase in regional ozone levels, Hong Kong’s air quality has continued to improve over the past 20 years, resulting in a reduction in long-term health risks of more than 50%.

The department said it will update the risk factors assigned to air pollutants with reference to data derived from hospital admissions associated with air pollutants over the past decade.

It will also update its AQHI compilation methods with reference to the latest guideline levels for air pollutants published by the World Health Organization.

The updated AQHI will be made available online from tomorrow.