Ozone pollution in Hong Kong at worst level in a decade: environmental report
Ozone pollution is at its worst in nearly a decade, indicating deteriorating regional air quality, an environmental group found.
This was despite a slight improvement in levels of nitrogen dioxide, sulphur dioxide and particulate matters in the first six months of the year compared with the same period last year, the group Clean Air Network said.
The group's mid-year review found ozone levels far beyond World Health Organisation guidelines at all 15 of the city's air quality monitoring stations.
From January to June, average annual concentrations of the pollutant hit 43 micrograms per cubic metre, nearly double WHO's annual recommended concentration level of 23.5mcg per cubic metre.
Watch: Ozone pollution in Hong Kong at worst level in a decade according to report
It was roughly the same as last year and only slightly lower than the average of 43.33 in 2004, the highest year on record.
The figure has been rising since its lowest recorded level in 2005, at 35mcg per cubic metre.
Network chief executive Kwong Sum-yin said ozone was a secondary pollutant that indicated worsening air quality.
"We would like the government to strengthen collaboration with the mainland and do more studies to find the sources" of ozone, and stop them, she said.
Kwong urged speedier legislation requiring ships to switch to cleaner fuels while berthed, and called for coordination with Guangdong to set up an emissions control area.
Meanwhile, a slight drop in nitrogen dioxide concentrations at both roadside and general stations was recorded in the first half of the year compared with the same period last year.
An Environmental Protection Department spokeswoman said: "To improve the regional air pollution, including the ozone problem, we have reached an agreement with Guangdong to achieve the emission reduction targets by 2015 and 2020."