Hong Kong recorded more than twice as many hours of very high roadside pollution in the first quarter, blaming an increase in sunshine for contributing to the smog in the city’s financial and shopping districts.
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 were 180 more hours of bright sunshine, a 78 percent gain from a year ago, according to Hong Kong Observatory’s data.
“The weather explanation sounds logical, especially given windless days,” said Kwong Sum-yin, chief executive officer of Clean Air Network, a non-profit advocacy group. “Having said that, the problem in Hong Kong is if you can see the pollution from the roadside, it’s coming from the tailpipes of old dirty vehicles. This problem hasn’t been tackled yet.”
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 offering HK$10 billion ($1.3 billion) in subsidies to replace old diesel vehicles after a government audit last year showed that the city’s air quality has worsened since 2007.
“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.
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.
“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.”
The average wind speed fell 13 percent in the first three months from the same period a year earlier, data from the Hong Kong Observatory show.
The rising number of vehicles plying the streets haven’t helped. Licensed vehicles climbed by 4.1 percent as of January this year, compared with a year ago, the latest data from the Transport Department show.
Leung’s plan to replace aging vehicles is a “good sign,” said Kwong. “But it is still under negotiation and we’re still waiting. I would urge the government not to go on with the industry for so long because the people in Hong Kong have already sacrificed their health for long enough.”
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.
The Chinese city will raise its standard for measuring air quality for the first time since 1987, using World Health Organization measures as a reference, it said last month.