Sharp improvement in Hong Kong’s bad air days attributed to wild weather

Hong Kong breathed a little easier this year as the number of hours of air pollution reaching “high health risk” and beyond fell by half the recent average.

But much of the decline was due to wetter, windier weather in what are traditionally two of the most polluted months, January and October, according to a study by an environmental group.

Hongkongers were exposed to 1,480 hours of air of high health risk this year, meaning “7” or above on the government’s 11-tier Air Quality Health Index (AQHI), when children, the elderly and those with heart or respiratory illnesses are advised to avoid physical exertion outside and areas with heavy traffic.

About 3,559 hours were logged last year and 4,110 hours in 2014. The yearly average from 2014 to December 20 this year was 3,050 hours. There were also fewer days with high-risk air – 65 compared with 96 in 2014 and 79 in 2015.

Green Power analysed data from the Environmental Protection Department’s 13 general air quality monitoring stations and found “major decreases” in hours of high health risk air in the city’s most polluted towns, including Tuen Mun, Kwai Chung, Yuen Long, Kwun Tong and Tung Chung.

Dr Cheng Luk-ki, head of scientific research and conservation at Green Power, said the worst months for pollution were usually August to October in the autumn seasonal transition as well as January.