Tung Chung’s air quality readings again reached ‘very high’ yesterday, with more bad air forecast for later this week.

EPD air monitoring stations in Tung Chung recorded pollution in the ‘high’ and ‘very high’ levels for four hours late yesterday afternoon, peaking at 5pm.

The ozone reading was 162.7 micrograms, more than 50% above the World Health Organization standard of 100 micrograms per cubic meter. The concentration of fine particulates, PM2.5, reached 58.2 micrograms, 25 micrograms higher than the WHO standard.

The outlook for today is moderate, but the World Air Qualty Index website predicts further high levels this week, in particular Wednesday morning and early Saturday morning.

The high pollution levels across Hong Kong and much of Guangdong are the result of a northeast monsoon which is bringing dry sunny weather and light winds – ideal conditions for photochemical smog.

Under the EPD’s Air Quality Health Index (AQHI), a reading of 7 is high, 8-10 is very high, and above 10 is serious.

In ‘very high’ pollution conditions the EPD advises children, the elderly and those with heart or respiratory diseases to reduce outdoor exertion and stay indoors, especially those living in areas with heavy vehicle traffic.