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

     The Environmental Protection Department (EPD) has recorded higher than normal air pollution levels since yesterday (July 23). According to the EPD's forecast, it is expected that the AQHI at some general and roadside air quality monitoring stations may reach the "Serious" level later today (July 24), and the air pollution levels are expected to remain higher in the next two days.

     Under the continuing influence of the outer subsiding air of Tropical Cyclone In-fa, the weather in Hong Kong is very hot with light winds today, which is unfavourable for pollutant dispersion. The intense sunshine enhances photochemical smog activity and the rapid formation of ozone and fine particulates in the Pearl River Delta region. The airstream with high regional background pollutant concentrations is affecting Hong Kong. The high level of ozone has promoted the formation of nitrogen dioxide.

     According to the Hong Kong Observatory, a southwesterly airstream is expected to bring showers to the coast of southern China next week. It is expected that pollution levels will remain higher until then.

     With a health risk category in the "Very High" or "Serious" levels, 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 are 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 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/Saturday, July 24, 2021
Issued at HKT 15:35