Assistant Director of Environmental Protection (Air Quality Management) of the Environmental Protection Department, Stephen Siu Chi-wai (center); Principal Environmental Protection Officer (Air Science and Modelling) of the EPD, Eddie Lee (left); and Senior Environmental Protection Officer (Air Science and Modelling) of the EPD, Tony Lee (right) pose for a photo before a press briefing on an overview of Hong Kong's air quality in 2023 in Hong Kong. (PHOTO / HKSAR GOVT)

HONG KONG – The emissions of local air pollutants returned to their normal levels in 2023 with the resumption to normalcy of social and economic activities, the Environmental Protection Department revealed on Wednesday.

There was a 1 to 2μg/m3 rise in levels of certain ambient air pollutants – respirable suspended particulates (PM10), fine suspended particulates (PM2.5), nitrogen dioxide (NO2) and sulphur dioxide (SO2) – as compared to 2022, according to air quality data recorded by the EPD's air quality monitoring stations.

Stephen Siu Chi-wai, assistant director of Environmental Protection (Air Quality Management) of the EPD, hailed the air quality in 2023 as “the second best since 1997”, having shown a continuous improvement despite fluctuation in the concentrations of individual pollutants.

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Compared to 2021, except for PM2.5 which remained at a similar level, the ambient levels of the other air pollutants improved by 7 to 20 percent.

Hong Kong's overall air quality in 2023 complied broadly with Hong Kong's Air Quality Objectives.

Environmental Protection Department, HKSAR 

Due to the influence of COVID-19 in the first half of 2022, which led to the decline in overall activities and emissions, air quality in 2022 was the best since the 1997 handover. While a slight rebound was found in emissions after the resumption of normalcy in 2023, the overall air quality still met the standard, Siu said. 

Siu said he believed that these improvements were the living embodiment of the special administrative region government’s effective regulation and emission reduction measures, and Hong Kong’s air quality will continue to improve in the coming years.

Pointing out that the city’s overall air quality in 2023 complied broadly with Hong Kong's Air Quality Objectives, the EPD said in a statement the annual average concentrations of PM10, PM2.5, NO2, and SO2 in the ambient air have reduced by 40 percent to 69 percent from 2011. 

During the same period, the annual average pollutant concentrations at the roadside have reduced by 46 percent to 58 percent, it added. 

Despite the downward trend of most pollutants, the city has witnessed a growth in ozone. Siu clarified that the ozone concentration had improved and there was only a slight increase at roadside stations. He emphasized that the ozone problem cannot be solved by Hong Kong itself, but needs collaboration with Guangdong province and Macao to improve the overall situation. 

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In the future, the three regions will jointly promote emission reduction, and the authorities have completed a three-year study on photochemical ozone pollution. 

A boat sails through Victoria Harbour of Hong Kong under a hazy sky on Jan 1, 2024. (SHAMIM ASHRAF / CHINA DAILY)

Regarding relatively high levels of nitrogen oxides recorded in some areas such as Mong Kok, Sham Shui Po, and Kwai Chung, an EPD spokesman said, "With the government's continued promotion and implementation of the comprehensive air quality improvement measures put forth in the Hong Kong Roadmap on Popularization of Electric Vehicles, the Clean Air Plan for Hong Kong 2035 and Hong Kong's Climate Action Plan 2050 announced in 2021, including the promotion of electric vehicles, green transport and net-zero electricity generation, local NOx emissions will be further reduced and the overall air quality in Hong Kong will improve continuously."

Following the completion of Air Quality Objectives by the EPD, the HKSAR government will further tighten five prevailing AQOs and include three new parameters introduced in the Global Air Quality Guidelines of the World Health Organization. Among the 15 updated AQOs, seven are set at the most stringent levels specified in the WHO AQGs.