Hong Kong air pollution hits highest mark at ‘serious’ level in parts of city, conditions expected to persist for 2 more days
- Air pattern blamed on Typhoon Chanthu in East China Sea and accelerated ozone formation
- Public advised to stay indoors, while elderly and those with chronic respiratory illnesses urged to minimise physical exertion
Air pollution in parts of Hong Kong reached “serious” levels on Wednesday – the most extreme on a five-tier scale – with environmental authorities expecting the same conditions for another two days.
“This is quite a strong typhoon, so I expect it is related, as it has brought quite hot and sunny weather to Hong Kong, which has accelerated the formation of ozone,” said Lau, referring to the pollutant that contributes to smog.
Ozone is formed when nitrogen oxides emitted by vehicles mix with volatile organic compounds from sources such as paint, and react with sunlight.
The Air Quality Health Index (AQHI) reached the “serious” level – the highest on the government scale – at three of the Environmental Protection Department’s 18 monitoring stations, namely those in the north in the New Territories and Tai Po, as well as in Tap Mun, to the east.
Stations in Kwun Tong, Yuen Long and Tai Po had also recorded “very high” readings – the fourth level on the scale – at about 3pm, while nine other facilities, including those in Central and Western district, Sham Shui Po, as well as all three roadside stations in Causeway Bay, Mong Kok and Central registered “high” levels by 4pm.
Ozone concentrations in Hong Kong have been climbing steadily throughout the day, with the mark at 12 stations exceeding the 160-microgram limit laid out in Hong Kong’s Air Quality Objectives, which set limits for pollutants and the number of times these can be exceeded in a year.