EPD


Latest Annual AQI

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: February 2023 - January 2024

General Stations

StationNO2PM10PM2.5
Central/Western332315
Southern262513
Eastern322514
Kwun Tong422715
Sham Shui Po442413
Kwai Chung512616
Tsuen Wan402416
Tseung Kwan O222415
Yuen Long382617
Tuen Mun413419
Tung Chung272314
Tai Po272516
Sha Tin272313
North302715
Tap Mun82212
Pollutant concentrations in micrograms per cubic metre (μg/m3)

Roadside Stations

StationNO2 PM10PM2.5
Causeway Bay673924
Central643020
Mong Kok692918
Pollutant concentrations in micrograms per cubic metre (μg/m3)

Annual AQI Values
Period: February 2023 - January 2024

General Station

StationNO2PM10PM2.5
Central/Western0.831.151.50
Southern0.651.251.30
Eastern0.801.251.40
Kwun Tong1.051.351.50
Sham Shui Po1.101.201.30
Kwai Chung1.281.301.60
Tsuen Wan1.001.201.60
Tseung Kwan O0.551.201.50
Yuen Long0.951.301.70
Tuen Mun1.031.701.90
Tung Chung0.681.151.40
Tai Po0.681.251.60
Sha Tin0.681.151.30
North0.751.351.50
Tap Mun0.201.101.20
AAQI = 12-month rolling concentrations/Annual WHO AQG concentration

Roadside

StationNO2PM10PM2.5
Causeway Bay1.681.952.40
Central1.601.502.00
Mong Kok1.731.451.80
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