Hong Kong recorded more than twice as many hours of very high roadside pollution in the first quarter as more sunlight and rising vehicle numbers led to smog in the city’s financial and shopping districts.
Commuters wait at a bus stop in Hong Kong. Emissions from Chinese factories across the border and old vehicles in the former British colony have choked residents this year as slower air flow trapped pollutants. (Bloomberg/Jerome Favre photo)
Roadside monitors recorded 1,372 hours when the pollution index exceeded 100 in the first three months, compared with 580 hours for the same period in 2012, data compiled by the city’s environmental department show. There was 180 hours more of bright sunshine, a 78% gain from a year ago, according to Hong Kong Observatory's data.
"The weather in the first three months of 2013 was drier and with a lot more sunshine, which was more conducive to photochemical smog formation," the Environmental Protection Department said in an e-mail response to queries.
Emissions from Chinese factories across the border and old vehicles in the former British colony have choked residents this year as slower air flow trapped pollutants. Hong Kong Chief Executive Leung Chun-ying is seeking to clean up the city's air after a government audit last year showed that the quality has worsened since 2007.
"Our approach to traffic management and pollution control presumed that most of the time the winds will blow," said Bill Barron, associate professor at the environment division of Hong Kong University of Science and Technology. "When the winds stop, that’s just a reminder of how much we've come to rely on the cleansing effect of the winds."
Roaring Cars
The average wind speed fell 13% in the first three months from the same period a year earlier, data from the Hong Kong Observatory show.
Diesel fumes come out of a tug boat chimney as skyscrapers stand in the Wanchai district of Hong Kong on April 15, 2013. (Bloomberg/Jerome Favre photo)
The rising number of vehicles plying the streets have not helped. Licensed vehicles rose by 4.1% as of January this year, compared with a year ago, the latest data from the Transport Department show.
The roadside monitors were measuring air quality at Central, Mong Kok and Causeway Bay. The index has a range from 0 to 500, with readings above 100 classified as very high pollution.
The government's failure to retire aging buses and trucks is a key cause of pollution that results in more than 3,000 premature deaths a year, according to think tank Civic Exchange.
Leung in January announced a plan offering HK$10 billion ($1.3 billion) in subsidies to replace old diesel vehicles. Hong Kong is also working with the government in Guangdong province, which borders the city, to reduce emissions so as to cut the regional ozone level, the environmental protection department said in its statement.
Hong Kong will raise its standard for measuring air quality for the first time since 1987, using World Health Organisation measures as a reference for its own objectives, Wong Kam-sing, secretary for the environment, said last month.