Air pollution hits new high this year as heat and light wind trap city's smog

Air pollution hit its highest level of the year in parts of the city yesterday.

By midnight, roadside pollution levels measured by the Environmental Protection Department reached 146 in Mong Kok, 133 in Causeway Bay and 121 in Central. Levels are considered 'very high' once they go above 101, and in those conditions, people with heart or respiratory illnesses are advised to avoid areas with heavy traffic.

The previous high this year was 143 in Central on September 16.

Throughout the day, general station levels fluctuated between 70 and 120, with Kwai Chung and Kwun Tong reaching the higher levels.

An Observatory spokesman said: 'Due to a continental airstream and the effects of Typhoon Krosa, the weather over the South China region is sunny and hot, and the wind is light. The sunny and hot weather conditions favour the formation of photochemical smog in the region, and pollutants are trapped under the light wind.'

Air pollution levels are expected to remain high today and tomorrow.