Air Quality Health Index reaches "Serious" level

     The general and roadside monitoring stations of the Environmental Protection Department (EPD) have recorded higher than normal pollution levels. At 4pm today (September 24), the Air Quality Health Index (AQHI) at Tung Chung, Yuen Long and Tuen Mun reached 10+, while some other stations reached 8 or above. The health risk categories are from "Very High" to "Serious".

     The Pearl River Delta (PRD) region including Hong Kong is under the influence of a continental airstream with sunny periods. In Hong Kong, the wind is light to moderate northerly. The intense sunshine enhanced photochemical smog activities and formation of ozone in the PRD region, resulting in higher pollution levels.

     The EPD expects that the AQHI level at some of the general monitoring stations will reach 10+ in the afternoon later today. In addition, light winds in the urban areas, which hinder the effective dispersion of pollutants at street level, coupled with a high ozone level in the general air, may lead to a higher than normal nitrogen dioxide level.

     According to the Observatory, an anticyclone over southern China is expected to establish itself in the latter part of this week, bringing generally fine weather to the region. It is expected that the pollution due to photochemical smog activities would still be active, resulting in "Very High" or "Serious" health risk categories in the afternoon in that period.

     With an AQHI 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 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 website for appropriate measures to safeguard students' health and take note of changes in the index. The relevant hyperlink is as follows: .

     At "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 "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/Wednesday, September 24, 2014
Issued at HKT 17:01