An evening view of Canton Tower in Guangzhou, Guangdong province, on July 30, 2019. (PHOTO / VCG VIA CHINADAILY.COM.CN)

HONG KONG – The air quality in the Pearl River Delta continued to improve, with the average annual concentration levels of sulphur dioxide (SO2) dropping by 86 percent, according to a government report released on Monday.

The Pearl River Delta Regional Air Quality Monitoring Report for Year 2020 showed that air pollutant emission reduction measures implemented by Guangdong province and the Hong Kong and Macao SARs contributed to the gradual improvement of overall air quality in the delta.

Compared with 2006, the average annual concentration levels of sulphur dioxide (SO2), respirable suspended particulates (RSP) and nitrogen dioxide (NO2) in 2020 decreased by 86 percent, 49 percent and 43 percent, respectively, according to the report.

Compared with 2006, the average annual concentration levels of sulphur dioxide (SO2), respirable suspended particulates (RSP) and nitrogen dioxide (NO2) in 2020 decreased by 86 percent, 49 percent and 43 percent, respectively

The average annual concentration levels of carbon monoxide (CO) and fine suspended particulates (FSP) also decreased by 16 percent and 31 percent, respectively, in 2020 when compared with those in 2015.

On the other hand, the 2020 average annual concentration level of ozone (O3) increased by 27 per cent when compared with that in 2006, indicating that further alleviation of regional photochemical pollution is required.

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The Guangdong-Hong Kong-Macao Pearl River Delta Regional Air Quality Monitoring Network, which came up with the report, was launched in November 2005 has 23 stations monitoring air pollution

From 2021 to 2024, Guangdong and the Hong Kong and Macao SARs will conduct a study on Characterisation of photochemical ozone formation and regional and super-regional transportation in the Greater Bay Area.

Results from the study will help better understand the origins of ozone precursors, their formation mechanism and regional and super-regional transportation characteristics in the Greater Bay Area.

The HKSAR has implemented various air pollutant emission control measures on marine and land transport, power plants and non-road mobile machinery to improve air quality.

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It tightened the emission standards for first registered vehicles (except for diesel private cars, motorcycles and tricycles) to Euro VI in phases according to vehicle classes, and will continue to phase out old diesel commercial vehicles.

The HKSAR has also stepped up emission controls against petrol and liquefied petroleum gas vehicles by using roadside remote sensing equipment.

In March 2021, the HKSAR government announced the Hong Kong Roadmap on Popularisation of Electric Vehicles, which guides Hong Kong's future direction to attain zero vehicular emissions before 2050.

The HKSAR government and the Guangdong provincial government have also jointly implemented control measures requiring vessels to use low-sulphur fuel.

Hong Kong will also increase the use of natural gas in power generation, promote the local development of renewable energy and continue to tighten emission caps for power plants progressively.

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Guangdong province also put forward vapour control measures in petrol filling stations, oil depots and tanker trucks, and implemented a target action plan for sensitive areas and chemical industry zones, imposing coal-to-gas switching and an in-depth treatment of coal-fired boilers with capacity of more than 35 tons of steam per hour for some industrial boilers and furnaces in the building ceramic industry.

Macao rolled out a series of air quality improvement measures, including continuously optimizing and improving the emission limits and measurement methods for exhaust gases from vehicles, promoting the use of electric vehicles and continuously putting forward research on controlling and reducing volatile organic compounds.