LONG WAY TO GO
Xiao Hang came back from Canada last year and became a researcher at the Institute of Urban Environment under the Chinese Academy of Sciences.
"I think heavy smog will affect China's international image," he said. His friends in Canada regularly discussed this issue. While they care about development opportunities in China, environment and health have come to assume greater important in recent years.
Like Xiao Hang, 40-year-old Fu Yu left Harvard University and returned to China this year.
"My son was taught to conserve energy and protect the environment in an American kindergarten," he said. "But I found in our nation, many people still don't know much about that."
But the government is aiming to correct this ignorance. In September, China announced an action plan to tackle air pollution, aiming to cut the density of inhalable particulate matter by at least 10 percent in major cities nationwide by 2017.
"Xi'an is shutting down high-polluting factories and promoting environmentally friendly energies," according to Yan Hao.
The total number of vehicles in Xi'an is about 1.7 million, consuming 1.35 million tonnes of oil and emitting 300,000 tonnes of key pollutants each year, an amount that is equal to the city's level of industrial discharge.
In response, public security departments have toughened checks on vehicles, including phasing out older ones.
Lin Yanluan also recalled that when he stood in the streets of New York, the smell of vehicle exhausts was not as pungent as in Beijing.
"So improving the quality of gasoline is also very important," Yan observed.
In Xi'an, more than 70 of the city's 600 gas stations have switched to cleaner fuel to meet the national level-IV standard, which allows for the sulphur content of fuel to be no more than 50 parts per million (ppm).
"Experts said this standard might reduce vehicle exhaust fumes by 10 percent compared to the level-III standard with sulphur content as high as 150 ppm," Yan said.
Xiao Hang now lives in China's coastal city of Xiamen. "The air quality is good here, but perhaps these cities will face the same problem someday," he said.
It is a problem which big cities in industrialized countries have repeatedly come up against for decades. China still has a long way to go, Xiao added.
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