污染增加形成烟雾天气主因

Authorities in Beijing have now dropped the yellow alert for smog.

The PM 2.5 index in the capital is now sitting at around 100.

While still above the Chinese government's safety standard of 75, the PM 2.5 count is down significantly from the near one-thousand levels reached on Saturday.

A yellow alert still remains in effect for a number of areas outside Beijing.

The Beijing Municipal Environmental Protection Bureau says a spike in emissions is the main cause of the dangerous conditions the past few days.

Zhang Dawei is the director of the Beijing Municipal Environmental Monitoring Center.

"A surge in the emissions of pollutants including that from fire coal, motor vehicle, industrial production as well as dust is the prime cause of the build up of pollution this time. Beijing is a mega city, a large number of pollutants are discharged everyday. Under an unfavorable weather condition, the pollution can be trapped and the air quality will get worse. "

Municipal authorities in Beijing brought in steps to try to deal with the problem, temporarily shutting down 58 high-polluting operations, including automaker Hyundai's manufacturing plant.

At the same time, the authorities ordered 30-percent of government vehicles off the road.

Data released by the Beijing Municipal Environmental Protection Bureau contends around one-fourth of the air pollution in the capital is generated from Beijing's neighbors.

Hao Xiaoxia is the director of the Green Beagle Environment Institute, which is a Beijing-based environmental protection NGO.

"There is a poverty-stricken area and an economic zone around Beijing. To control pollution in the city, Beijing has moved its factories to these places, and pollutants from these factories can be blown back into the capital. I went to a small county of Baoding once; it has a paper mill and a quarry yard. You can even smell the stink in the air."

Zhu Tong is the Dean of College of Environmental Sciences and Engineering at Peking University.

He says the problem of rampant air pollution won't be solved through peace-meal solutions.

"To tackle the problem, authorities need to identify the sources of pollution, be it vehicle exhaust fumes or industrial emissions. The pollution control plan will only be effective when authorities take actions to roll out coordinated response. In the long term, cities need to change their power consumption model. Currently most of cities in the northern region rely on coal for heating and industrial productions, which can lead to heavy pollution."

Vice-Premier Ki Keqiang is on record saying the authorities are planning to strengthen the enforcement of environmental laws and beef up measures to tackle air pollution.

China consumed 3.7 billion tons of coal in 2011, which is almost half of the world's total coal consumption.

The figure is expected to hit 4.3 billion tons by 2015.

For CRI, I'm Qi Zhi