Beijing-area air better than before_美文_趣味英语-查字典英语网

Beijing-area air better than before

Visibility in the smog was 2 kilometers, while Wang said the visibility will not be improved unless the PM2.5 concentration falls to below 100 micrograms per cubic meter. In February, it was 230 mg per cubic meter.

Beijing's contingency plan includes forcing nearby plants to cut production.

However, Wang said that only long-term solutions will end the pollution.

"The major PM2.5 source comes from coal power stations," he said. "The overall area of Beijing, Tianjin and Hebei accounts for some 0.05 percent of the world, while this region consumes 11 percent of its coal, so you don't have to use your imagination to understand why we are suffering from air pollution. We are living inside a huge chimney."

He Hong, from the Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, said: "Our research shows that 'second particles' contribute around 60 percent to the formation of PM2.5 in Beijing and Tianjin."

Second particles are pollutants generated by chemical reactions between different pollutants released into the atmosphere.

"As a result, reducing the emissions of oxynitride and oxysulfide from coal fuel and vehicles is necessary," He said.

However, due to the complex chemical reactions, scientists are not sure about the exact contributing factors of smog. To understand better, the Chinese Academy of Sciences will apply for construction in 2016 of a "smog chamber" to simulate pollution conditions.