Welcome to Environmental Protection Department Air Quality Health Index Website


The Annual Air Quality Index (AAQI) is the ratio of the past 12-month rolling average concentration to the annual air quality guidelines (AQG) of the World Health Organization (WHO).

Air Pollutant Concentrations (μg/m3)
Period: July 2021 - June 2022

General Stations

StationNO2PM10PM2.5
Central/Western312214
Southern282312
Eastern342513
Kwun Tong472615
Sham Shui Po442413
Kwai Chung472315
Tsuen Wan422214
Tseung Kwan O232212
Yuen Long402617
Tuen Mun423218
Tung Chung262316
Tai Po292214
Sha Tin292113
North332213
Tap Mun92012
Pollutant concentrations in micrograms per cubic metre (μg/m3)

Roadside Stations

StationNO2 PM10PM2.5
Causeway Bay653421
Central632617
Mong Kok642616
Pollutant concentrations in micrograms per cubic metre (μg/m3)

Annual AQI Values
Period: July 2021 - June 2022

General Station

StationNO2PM10PM2.5
Central/Western0.781.101.40
Southern0.701.151.20
Eastern0.851.251.30
Kwun Tong1.181.301.50
Sham Shui Po1.101.201.30
Kwai Chung1.181.151.50
Tsuen Wan1.051.101.40
Tseung Kwan O0.581.101.20
Yuen Long1.001.301.70
Tuen Mun1.051.601.80
Tung Chung0.651.151.60
Tai Po0.731.101.40
Sha Tin0.731.051.30
North0.831.101.30
Tap Mun0.231.001.20
AAQI = 12-month rolling concentrations/Annual WHO AQG concentration

Roadside

StationNO2PM10PM2.5
Causeway Bay1.631.702.10
Central1.581.301.70
Mong Kok1.601.301.60
AAQI = 12-month rolling concentrations/Annual WHO AQG concentration

Remarks:

(1) The AAQI is updated monthly. The AAQI is calculated based on validated monitoring data.

(2) An AAQI greater than one indicates that the health risk resulted from long-term exposure is higher than that of the WHO's annual AQG, whereas an index below one means a lower risk.

(3) WHO’s annual AQG (2006):


Annual WHO AQG
(μg/m3)
NO2 40
PM10 20
PM2.5 10

Reference: http://www.who.int/phe/health_topics/outdoorair/outdoorair_aqg/en/index.html

For further information about the annual AQI, please visit the FAQ.

(4) NO2 - nitrogen dioxide, PM10 - respirable suspended particulates, PM2.5 - fine suspended particulates

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Last revision date: 02:07 06-10-2022