http://thestandard.com.hk/news_print.asp?art_id=164856&sid=45860273
Vehicle, factory and power plant emissions in the Pearl River Delta have pushed up the ozone level in Hong Kong, although general air quality continued to improve last year compared with 2014, the Environmental Protection Department says.
While preliminary data showed concentrations of all major pollutants, such as sulfur dioxide, nitrogen dioxide and respirable suspended particulates, dropped in 2015 compared with 2014, the level of ambient ozone dropped slightly by 2 percent but was still 32 percent higher than in 1999.
The assistant director of environmental protection, Mok Wai- chuen, said ozone pollution produced from local emissions showed a decreasing trend over the past year.
“But the increase in the regional background, mainly due to PRD-originating emissions, has led to an overall increase in ambient ozone level,” he said.
Mok stressed that collaboration with the mainland is a must when tackling the increasing level of ozone.
But he did not say what actual measures have been or would be taken.
“The two sides of the government will prepare for a mid-term review on the emission reduction results for 2015 so as to finalize the emission reduction targets for 2020 in order to further improve regional air quality,” he said.
Data showed that Tuen Mun had the worst air quality last year, with 416 hours of the Air Quality Health Index at high or above, followed by Tung Chung with 346 hours.
Principal Environmental Protection Officer Shermann Fong Che-ping said the two areas were mainly affected by ozone.
Asked if the smog in China would possibly affect the SAR air quality, Mok said: “The air quality will be worse if the wind is from mainland because it will bring the pollutants from the land and human activities.”
Mok said the government aims to phase out 82,000 pre-Euro IV diesel commercial vehicles by the end of 2019.
Three low emission zones have been set up at busy corridors in Central, Causeway Bay and Mong Kok for franchised buses whose emission performances meet Euro IV or above.
He believed that Hong Kong will reduce carbon intensity by 50 to 60 percent by 2020 compared with the 2005 level by committing to its control measures