AN environmental group claims the air quality has gradually improved. After studying the Air Quality Health Index (AQHI,空氣質素健康指數), Green Power said there were 1,480 hours during which the AQHI was at seven or above.
The number of hours at this high danger level has dropped greatly compared to last year. This downward trend has continued for the past three years.
The number of high air pollution days has also been dropping. But Tuen Mun, followed by Yuen Long and Tung Chung, have the highest number of days when the index was at seven or higher.
Cheng Luk-ki (鄭睦奇) of Green Power said though government action has helped improve the air quality, the weather plays an important role, too. Hot weather and heavy sunlight often leads to a rise in ozone levels, worsening the air quality. On the other hand, rainfall makes the air cleaner.
(This article is published on Goodies on 4 January 2017)