According to a report on air quality in 2023 jointly released by Guangdong, Hong Kong and Macau under the Guangdong-Hong Kong-Macao Pearl River Delta Regional Air Quality Monitoring Network, there is a long-term and significant downward trend of air pollutant concentrations for sulphur dioxide, nitrogen dioxide, carbon monoxide, respirable suspended particulates, or PM10, and fine suspended particulates, or PM2.5.

The report reveals that 2023 annual average concentrations for these pollutants have declined between 17% and 86% from their peak levels, the Environmental Protection Department explained, adding that the drop demonstrates the effectiveness of emission reduction measures implemented across the three places in improving air quality in the Pearl River Delta region.

However, the report also revealed that ozone annual average concentrations have remained stagnant in recent years, indicating the need for alleviating regional photochemical pollution.

In response, the study on “Characterization of photochemical ozone formation, regional & super-regional transportation in the Greater Bay Area” was carried out and concluded in early 2024 to provide scientific data for further understanding the causes as well as the regional and super-regional transport characteristics of ozone, the department noted.

Separately, the department pointed out that the Hong Kong Special Administrative Region Government has implemented various air pollutant emission control measures to enhance air quality. Among such initiatives, new registrations of fuel-propelled private cars, including hybrids, will cease in 2035 or earlier, and approximately 700 electric buses and 3,000 electric taxis will be introduced by end-2027.

These efforts have produced early results, with the number of electric vehicles in Hong Kong increasing from about 14,000 in 2019 to over 102,000 in September 2024, the department highlighted.