空气质量标准将进行修订

Foggy weather hit the cities of Beijing, Tianjin, and provinces of Hebei, Henan, Shandong, Anhui and Jiangsu early this week.

Highways in these regions were temporarily shut down, and police urged drivers to reduce their speed in the thick fog.

Hundreds of flights across the country were cancelled or delayed due to low visibility.

The thick fog continues to affect people's health. Ma Yingmin is director of the Respiratory Department at Beijing's Shijitan Hospital.

"Because of the heavy fog, the number of patients coming to the Respiratory Department has increased by about 20 percent. There are more airborne particulates during foggy weather. They may have a noticeable impact on our respiratory system especially for people with chronic respiratory diseases."

In big cities like Beijing, people worry whether the fog is just mist or an indication of air pollution - and if so, how serious it is.

Liu Changfeng, an office worker in downtown Beijing, says many people like him have the same concern.

"Recently, everyday when I got to the office, many of my coworkers posed air quality data both from the American embassy and China's Central Meteorological Bureau. Some of them even downloaded air quality inspection apps to monitor the figure. Topics such as what is PM 2.5 and whether these figures are reliable are very hot. There is huge difference between the two data sources. As for myself, I have already reduced my outdoor exercise time to avoid the unnecessary intake of unhealthy air."

Zou Ji, a professor at the Environment Institute at Renmin University says, human activity plays an important role in the continuous foggy weather.

"The haze is mainly because of the rising number of particulate matter in the air. But the particulates are mainly produced by car emissions and industrial manufacturing. They may cause serious losses to traffic, infrastructure and agriculture as well as the public health system."

China currently uses PM 10, particulate matter with an aerodynamic diameter smaller than 10 micrometers, to evaluate air quality. But PM 2.5, a stricter standard, is widely used by the World Health Organization and many developed countries like the United States. It measures smaller but more harmful particulates. That's why the data from cell phone apps indicates that Beijing is highly polluted, while figures issued by China's Meteorological Bureau says it is slight pollution.

Wang Ruibin, Director of the Atmosphere Department at the China Environment Monitoring Center, says the government is considering revising the existing ambient air quality standards to cope with the changing conditions of ambient air pollution.

"China will gradually adopt the PM 2.5 standard to monitor the air quality in 2012 or 2013. It takes time, so the goal will be achieved step by step."

In late August, the Ministry of Environmental Protection reviewed revisions to the current national ambient air quality standard. The new standard is expected to be released at the end of the year. The ozone-8-hour standard may be added in the new standard, while the PM 2.5 standard may also be listed as reference standard.

For CRI, I am Li Dong.