A Red alert, the highest, will be issued for heavy pollution that is expected to last more than 3-days.

　　An air quality index of over 200 will be defined as "heavy pollution".

　　Orange and red alerts are to be issued 24-hours before heavy pollution days to give people in Beijing advanced warning.

　　Sun Feng with the Beijing Municipal Environmental Monitoring Center says issuing alerts before heavy pollution days should help authorities deal with air pollution.

　　北京新空气污染应急预案

　　"If we try to control air pollution before it happens, the accumulation of pollutants may be reduced. Accordingly, air pollutant concentrations will be much lower."

　　Authorities contend the move should help give government departments enough time to take emergency steps to limit heavy-pollution days.

　　Sun Feng says this will require more accuracy and promptness in predicting the air condition.

　　"That is to say, we have to make a very accurate prediction of the air quality in the coming week. We will refresh the data every day to guarantee the accuracy of the prediction of what the pollution is likely to be like. The data will then be reported to various environmental administration departments for further analysis and research."

　　A Red alert for air pollution will prompt an alternate-day driving system for odd- and even-numbered license plates.

　　At the same time, 30 percent of all municipal vehicles will also be pulled from the streets on an odd and even basis.

　　Liu Jianjun with Beijing Municipal Commission of Transportation says improvements to the public transport system will also be made, with additional buses put on the roads to meet people's public transport needs.

　　"It's estimated that the public transport system will have 2 million more passengers on an emergency day."

　　When an orange or red alert is issued, construction vehicles will be banned from the streets and construction sites will be shut down.

　　Heavy polluting factories will also be shut down or forced to limit their production, except those necessary to maintain the operation of the city.

　　Last year saw Beijing Municipal authorities issue 2 Orange alerts, 5-yellow alerts, 11-blue alerts, but no Red Alerts.

　　For CRI, I'm Qian Shanming.