北京发布新规以改善空气质量

Beijing's municipal authorities will issue new regulations to improve air quality by the end of this year.

The smoggy weather has affected a total area of 1.3 million square kilometers in China recently.

The new regulations include higher standards for vehicle fuel, and stricter restrictions on industrial and exhaust gas emissions.

Traffic authorities in Beijing have also ordered 30 percent of official cars in the city to be off road.

Ma Xuekuan is the chief weather forecaster with National Meteorological Center.

"It is a long process to change the situation. It is particularly hard to tackle such a large-scale smog through artificial means. Only strong wind or rainfall can disperse it or reduce its density."

He advises people to take precautionary measures to protect their health.

The smog has also disrupted traffic, with planes grounded and highways closed during the on-going Spring Festival travel rush.

The smog has also led to a surge in respiratory illnesses, particularly among children and the elderly.

Studies show that most of the pollution comes from coal burning, motor vehicles, industrial emissions and dust.

It was the fourth round of heavy smog to hit Beijing in a month.

Beijing's air quality has worsened again since Monday, with a significant thickening of the PM 2.5, or airborne particles measuring less than 2.5 micrometers in diameter.

The average concentration of PM 2.5 has reached hazardous levels.