政策倡議及咨詢

Green Power, a local charitable green group, has been monitoring the Air Quality Health Index (AQHI) and the previous Air Pollution Index (API) data for over two decades. Enclosed with this letter is a brief report produced by Green Power regarding our AQHI analyses, i.e. A Brief Review of AQHI Data of Hong Kong for 2022.

From the past AQHI statistics provided by EPD for 15 General Air Quality Monitoring Stations (General Stations) during 2014-2022 (Table 1), both the total number of HR hours (hourly AQHI ≥7) and HR days (daily maximum AQHI ≥7) decreased from their top levels in 2014 to their lowest records in 2016, and winded upwards to the top level in 2019, then dropped to the second lowest levels in 2020 and rebounded moderately in 2021 and 2022 (Figure 1). Such trend in the past nine years revealed that the health risk of the public associated with air pollution varied but had not been relieved.

The sudden decrease in HR hours and days in 2020 (Figure 1), especially those with AQHI = 10+, (Table 1) was coincident with the community lockdowns in Mainland, strict border passenger and freight control and local quarantine measures (e.g. work-from-home) due to outbreak of pandemic of Covid-19 in early 2020. Therefore, the rebound of HR hours and days figures in 2021 and 2022 may be attributable to the resumed transportation, commercial and industrial activities and energy production in the Pearl River Delta area.

Central/Western ranked the third in 2022 in terms of annual total number of HR hours (hourly AQHI ≥7), which was its highest yearly ranking during the past nine years. As a central business district, Central/Western in this aspect was not particularly high amongst the 15 General Stations in ranking in previous years but a trend of slightly increase has been observed in total number of HR hours (Figure 6). If its ranking or number of HR hours persist high in the following years, implementation of remedial measures, e.g. the proposed electronic road pricing, should be accelerated.

In 2022, the top five districts in terms of total number of HR days (daily maximum AQHI ≥7) were all situated in the northern part of the New Territories (NT), namely Yuen Long, Tuen Mun, Tung Chung, Northern and Tai Po (Table 1). The Administration should study the health risk associated with air quality in New Development Areas (NDAs) in the NT such as the Northern Metropolis during planning stage to maintain the sustainability of NDAs and protect the health of residents. More proactive measures should be introduced in addition to the proposed Environmentally Friendly Transport Services (EFTS).

Regarding the number of hours recorded AQHI reaching 10+, Yuen Long, Tuen Mun and Tung Chung used to the top three in previous years (2014 to 2021). However, in 2022 none of them ranked top three and replaced by Central/Western, Southern and Sham Shui Po which have almost never been amongst top three. Southern, a General Station facing South China Sea, remote from urban and Mainland and without heavy traffic, recorded 12 hours with AQHI of 10+ in 2022 (the second highest) just showed that relatively less polluted areas are also vulnerable to the highest health risk.

Over the period 2014 to 2022, when considering the proportion of an individual General Station to the total HR hours (hourly AQHI ≥7) of all old General Stations (Figure 6), the perceived polluting districts Kwun Tong, Kwai Chung and Tsuen Wan displayed obvious declining trend when comparing with other stations. Contrarily, Tai Po, Yuen Long, Tuen Mun and Central/Western showed a slightly ascending trend while Tai Po was the most obvious one.

For any queries, please contact the undersigned at Green Power (T: 3961 0200, Fax: 2314 2661, Email: lkcheng@greenpower.org.hk

Thank you very much for your kind attention. I look forward to the Administration’s policies to further relieve the health risk of the public associated with air quality.