Interview: Successful clean air action in Beijing leads to vast improvement in air quality, says UK expert

LONDON, April 7 (Xinhua) -- Successful clean air action has led to a dramatic reduction in air pollution in Beijing over the last few years, according to a new report published by a team of more than 150 British and Chinese scientists.

Roy Harrison, professor of environmental health at the University of Birmingham, was on the team of scientists who spent five years carrying out the research and field work in Beijing. He noted that the Chinese authorities outlawed certain fuel sources to reduce the impact of air pollution, and to improve air quality.

"The local residents were prevented from using solid fuels for heating and cooking within the city itself. So coal and wood are outlawed as fuel sources and cleaner fuels, electricity and gas were made available to them so they could do this. And that's part of the change," Harrison said in an interview with Xinhua.

"New regulations and enforcement of those regulations with regard to admissions from road traffic," he noted. "It's a very heavily traffic city, very congested. But they were very effective in bringing in cleaner vehicles and that's made quite a difference."

Before the research began, the Chinese government had carried out an action plan to clean up the air in Beijing and the surrounding area.

"Our measurements started in the latter part of that plan. And one of our activities was to analyse the data for air quality through the period immediately preceding and during that plan, and afterwards, and to take out effects of the weather.

"We found that they had actually made really big strides in improving air quality with respect to quite a number of the pollutants that they were measuring."

The international group of researchers have spent five years using a range of equipment in Beijing to measure how pollution composition and levels change at different heights above the city.

The scientists have found that sources of key air pollutants in the city center, including fine particles, volatile organic compounds (VOC), and black carbon are much lower than predicted, said a press statement published recently on the website of the University of Birmingham.

Within the wider project, researchers also discovered that cooking oil emissions are a potential source of potentially hazardous fine particles in Beijing -- suggesting that a more stringent control of this local source may be needed within the city.

Furthermore, they showed that road traffic is not a major source of primary PM2.5, but remains a significant source of NOx (Nitrogen oxide).

"For periods of about five weeks, in the summer and winter, we did very intensive, very detailed measurements of conventional air quality parameters, but also lots of other chemical and meteorological features, which helped us to understand the processes that are leading to the concentrations that we measured."

Not only did Harrison and his team collaborate with their Chinese counterparts to identify key areas of growth that China had made in terms of cleaner air, but Harrison also stated that he learned a lot from working with Chinese scientists.

"It was really good because we didn't really understand the extent to which they were already engaged in research in this field, and they've come on hugely rapidly. So they're very much at the same level as us in terms of the research that they do."

"They're personally very good people to work with. They're very highly motivated, they work very hard," Harrison said. "They collaborate very effectively with us, they have done. And so it was great, real pleasure to work with them. they've actually brought a lot of very good science to the program of work as well. So it's not been purely a UK effort it's been very much designed jointly interpreted jointly."

"We would love to continue the collaboration," he added.