Tsang ‘did little’ to improve air

The city’s air quality has improved only slightly during Chief Executive Donald Tsang Yam-kuen’stenure because of his lack of action to tackle pollution, a green group says.

?Improvements? in roadside air quality since the handover were instead due largely to measures worked out by the administration of Tsang’s predecessor, Tung Chee-hwa, Friends of the Earth said.

It urged Tsang’s successor, Leung Chun-ying, to roll out more assertive measures to combat the problem.

“Tung had set clear objectives, such as the retirement of old diesel vehicles and a push for owners of high-emission diesel taxis to use the relatively clean fuel of liquefied petroleum gas, which were effective measures,” Thomas Choi Ka-man, senior environmental affairs officer of the group, said.

“But Mr Tsang seemed to like to play around with trial schemes that achieved only minor improvements during his tenure.”

In Causeway Bay for example, between 1999 and 2002 the annual average concentration of fine particulate matter fell from 74.6 micrograms per cubic metre to 53.5mcg, a drop of 21.1mcg, the group said, citing a study by the University of Science and Technology. Fine particulate, known as PM2.5, refers to respirable hazardous particles of 2.5 microns in diameter. A microgram is one millionth of a gram.

In 2010, the district recorded a PM2.5 concentration of 46.5mcg per cubic metre – a drop of only 7mcg since 2002. Last year it was 45.3mcg. Tsang took over from Tung in 2005.

According to air quality guidelines issued by the World Health Organisation, the annual average concentration of PM2.5 should be 10mcg per cubic metre.

Other studies also showed roadside air improved at a diminishing rate during Tsang’s tenure, Choi said.

The Tsang administration launched a trial for low-emission zones for franchised buses in 2009 and subsidised a trial of six hybrid buses in 2010.

Choi said Tung’s policies were more effective than Tsang’s. “Tsang rolled out more voluntary trials and incentive schemes but lacked clear targets,” he said.

The green group urged the next government to set clear objectives.

“The carrot-and-stick approach should go side by side for policies to be effective,” said Choi, who proposed imposing higher licence fees for vehicles with higher emissions.

The government gives high priority to controlling street-level air pollution, the Environmental Protection Department says. A key strategy is to control emissions from cars, power plants, and industrial and commercial processes locally, it says.

kc.ng@scmp.com