Air Quality Health Index may reach "serious" level due to pollutionLocal | 24 Jul 2021 5:42 pm
It is expected that the Air Quality Health Index at some general and roadside air quality monitoring stations may reach the "serious" level later today, according to the Environmental Protection Department's forecast.
The department has recorded higher than normal air pollution levels since yesterday, while the air pollution levels are expected to remain higher in the next two days as well.
Under the continuing influence of the outer subsiding air of Tropical Cyclone In-fa, the weather in Hong Kong is very hot with light winds today, which is unfavorable for pollutant dispersion, the department said.
The intense sunshine enhances photochemical smog activity and the rapid formation of ozone and fine particulates in the Pearl River Delta region. The airstream with high regional background pollutant concentrations is affecting Hong Kong.
The high level of ozone has promoted the formation of nitrogen dioxide.
According to the Hong Kong Observatory, a southwesterly airstream is expected to bring showers to the coast of southern China next week. It is expected that pollution levels will remain higher until then.
Elderly and persons with existing heart or respiratory illnesses are advised to reduce physical exertion and outdoor activities to a minimum or avoid such activities with a health risk category in the "very high" or "serious" levels.