Tung Chung’s air quality yesterday hit dangerous levels, with more bad air on its way.

The government Air Quality Index (AQI) reached 10+ – its highest level – in Tung Chung, Tuen Mun and Yuen Long on Tuesday afternoon, a result of high temperatures and light winds.

The Environmental Protection Department (EPD) says the hot, still conditions are the result of a subtropical ridge which will continue today. It said in a statement:

Hong Kong will remain very hot with sunny periods. Showers will increase gradually in the latter part of this week. It is expected that pollution levels will remain higher than normal until then.

The department warns that when AQI readings reach the 10+ or “serious” level, children, elderly and people with heart or respiratory illnesses are advised to stay indoors.

The general public is advised to reduce to the minimum outdoor physical exertion, and to reduce to the minimum the time of their stay outdoors, especially in areas with heavy traffic.

Islands District Councillor Amy Yung has called on the EPD to explain the “continued deterioration of air quality in Tung Chung.”

In a question tabled prior to yesterday’s readings, Yung asked EPD officials to attend next Monday’s council meeting to advise what measures have been formulated to improve Tung Chung’s air.

Tung Chung historically has had some of the city’s worst air quality, a result of its proximity to the airport and the Pearl River as well as the basin effect of mountains on three sides.

The area is in the throes of a massive expansion in population, from 80,000 today to an estimated 268,000 in the middle of the next decade.

A maximum of 34.3 degrees was recorded at Chek Lap Kok yesterday. At 11:45 today the temperature at Chek Lap Kok was 31.1 degrees.