Hong Kong’s air pollution index reached the “severe” level for the third time this year, triggering a government warning, as pollutants from China were trapped by the lack of air flow.
The Air Pollution Index reached 207 in the Central business district and 203 at the Mong Kok roadside-monitoring station as of 2 p.m. local time, according to the Environment Protection Department. The index last registered similar readings in March in the city’s Causeway Bay area.
“Poor dispersion of air pollutants and a high regional background air pollution level” has led to the readings, Hong Kong’s Environmental Protection Department said in a statement on its website today. “The Hong Kong Observatory expects that the wind will pick up tomorrow. In that case, air quality will start to improve gradually later tomorrow.”
Chief Executive Leung Chun-ying has vowed to clean up the city after a government audit last year showed air quality has worsened since 2007. Poor air quality and high rental and living costs are deterring companies from setting up regional headquarters in the city, according to a survey released in November by CPA Australia.
The concentration of fine suspended particulates, or PM2.5, was 101.3 micrograms per cubic meter in Central as of 2 p.m. local time. World Health Organization’s air quality guidelines set as safe an annual level of 10 micrograms of PM2.5 per cubic meter.
The government said the public should avoid prolonged stays in areas with heavy traffic and reduce physical exertion. The Education Bureau asked schools to cut down on physical activities in the next few days, and the Labour Department said employers should assess the risks of outdoor work.
Elevated nitrogen dioxide concentrations are the contributing pollutant for the smog in the city, the government said. The index ranges from zero to 500, with any reading from 201 ranked as the highest level.
Hong Kong will raise its standard for measuring air quality for the first time since 1987, using WHO measures as a reference for its own objectives, Wong Kam-sing, secretary for the environment, said last month.
The government is offering HK$10 billion ($1.3 billion) in subsidies to replace old diesel vehicles, and plans to introduce laws requiring ships berthing at its ports to use cleaner fuel over the next two years.