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

     The Environmental Protection Department (EPD) has recorded higher than normal pollution levels. At 1pm today (September 11), the Air Quality Health Index (AQHI) at some general stations reached 8, corresponding to the "Very High" health risk category.

     Under the influence of the Tropical Cyclone Barijat, the weather in Hong Kong today is hazy with sunny periods and a moderate northerly wind. Higher than normal levels of particulates have been recorded in the territory since this morning. Hong Kong is being affected by an air mass with higher background pollutant concentrations. The sunshine enhances photochemical smog activity and the formation of ozone and fine particulates, resulting in high pollution in the Pearl River Delta region. The high level of ozone has promoted the formation of nitrogen dioxide, particularly in parts of the urban areas and at the roadside. It is expected that the AQHI at some general and roadside air monitoring stations may reach the "Serious" level later today.

     According to the Hong Kong Observatory, Tropical Cyclone Barijat will move across the northern part of the South China Sea in the next couple of days, bringing unsettled weather to the coastal areas of Guangdong. It is expected that pollution levels will improved by then.

     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 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/Tuesday, September 11, 2018
Issued at HKT 14:50