But environmental campaigners say pollution cannot be solely blamed on mainland sources
Hong Kong has seen a bigger rise in poisonous ozone pollution than industrial Guangdong – but pollutants from the mainland are not solely to blame, environmental campaigners say.
Environmentalists from Clean Air Network have urged the government to take tougher action on air pollutants through transport planning measures.
Campaigners looked at the data on ozone levels from the Guangdong-Hong Kong-Macau air quality monitoring database. Ozone levels recorded at the 13 monitoring stations in Guangdong province saw a 6.1 per cent increase between 2010 and 2014, compared to the 9.2 per cent increase recorded at the three Hong Kong stations, set up in Tsuen Wan, Tap Mun and Tung Chung.
When data from local general air quality monitoring stations was studied, excluding three included in a regional monitoring scheme, the rise in the level of ozone was even greater, at 17.1 per cent.
Between 2006 and 2014, local stations recorded a 27.2 per cent rise in ozone, in contrast to 19.5 per cent in the neighbouring province.
The Environmental Protection Department said more easterly prevailing winds from the mainland explained greater air pollution in eastern parts of the city, but Clean Air Network said local factors still played a role.
Kwun Tong in Kowloon East experienced a drop in the number of hours defined as having experienced serious pollution between 1992 and 2014 despite its largely northeasterly winds.
“The high level of ozone is not solely a regional issue. We can target ozone pollution both locally and regionally,” said Kwong Sum-yin, chief executive officer of the group.
Hong Kong and Guangdong have set up joint emissions reduction targets, which include four pollutants, two of which are the main sources of ozone production. But the group urged authorities to include targets on ozone.
Locally, Kwong said the rise in the number of vehicles on the roads over the past decade had contributed to the deteriorating air pollution in the city. Between 2005 and 2014, the number of trips by vehicles through the three cross-harbour tunnels daily increased from 228,000 to more than 250,000. Meanwhile, nitrogen dioxide, one of the key air pollutants measured at four roadside stations, increased steadily until 2013.
Kwong said people in Hong Kong were still exposed to significant health risks from air pollution.
According to the Hedley index, an indicator developed by the University of Hong Kong’s public health school to show the public health costs and risks from pollution, as many as 2,196 people died prematurely last year due to air pollution. The cost to the public purse of such health problems amounted to HK$27 billion.
“Although there was a slight improvement in air quality, the health of people could not be guaranteed,” she said.