国内英语新闻: Another round of smog hits Beijing, yellow alert issued

BEIJING, Jan. 15 (Xinhua) -- Beijing issued a yellow alert for air pollution at mid-night Sunday as a new bout of smog will hang over the city until Tuesday night.

According to the municipal environmental protection bureau, Beijing's air quality will plunge from "fairly good" on Sunday to "seriously polluted" on Monday.

Air quality will improve on Tuesday night with the arrival of cold air.

According to the National Meteorological Center, the smog will also hit northern and central China provinces of Hebei, Shandong, and Henan.

Beijing has a four-tier alert system for air pollution, with red being the highest, followed by orange, yellow and blue.

When a yellow alert is issued, it means the Air Quality Index will exceed 200 for 48 hours. Outdoor construction will be limited while more road cleaning will be conducted.