Health risk category for Air Quality Health Index may reach "Serious" level

     The Environmental Protection Department (EPD) has recorded higher than normal pollution levels since September 1. According to the EPD's forecast, it is expected that the Air Quality Health Index (AQHI) at some general and roadside air quality monitoring stations may reach the "Serious" level later today (September 3).

     Under the influence of the outer circulations of Severe Typhoon Maysak and Typhoon Haishen, a continental air steam is bringing in high background pollution to Hong Kong. The weather in Hong Kong is fine and very hot with light winds. The light wind hinders the effective dispersion of air pollutants. The intense sunshine enhances photochemical smog activity and the formation of ozone and fine particulates in the Pearl River Delta region. The high level of ozone has promoted the formation of nitrogen dioxide in parts of the urban areas and at the roadside.

     According to the Hong Kong Observatory, the weather in Hong Kong will still be fine with light winds in the next couple of days. It will be windier with a few showers early next week. It is expected that pollution levels will remain higher than normal until the wind speed strengthens.

     With a health risk category in the "Very High" range or above, children, the elderly and persons with existing heart or respiratory illnesses are advised to reduce physical exertion and outdoor activities to a minimum or avoid such activities. The general public is advised to reduce, or reduce to a minimum, outdoor physical exertion, and to reduce time staying outdoors, especially in areas with heavy traffic. As health effects of air pollutants may vary for individuals, persons who are in doubt or experience discomfort should seek advice from health-care professionals. The public may visit the Centre for Health Protection's website ( for more information on the health effects of air pollution and relevant health advice.

     The Education Bureau (EDB) urges all schools to visit the EDB's website for appropriate measures to safeguard students' health and take note of changes in the index. The relevant hyperlink is as follows:

     When the AQHI is at the "Very High" level, employers of outdoor workers performing heavy manual work are advised to assess the risk of outdoor work and take appropriate preventive measures to protect the health of their employees, such as reducing outdoor physical exertion and the time of their stay outdoors, especially in areas with heavy traffic. At the "Serious" level, employers of all outdoor workers are advised to assess the risk of outdoor work and take appropriate preventive measures to protect the health of their employees.

     Members of the public can check the current AQHI readings at the EPD's website ( or by calling the hotline 2827 8541.

Ends/Thursday, September 3, 2020
Issued at HKT 14:40