Smog blankets Beijing and Shanghai a day after Christmas alert

[SHANGHAI] Dense smog continued to blanket China's largest cities on Saturday, a day after Beijing raised an air pollution alert that forced the cancellation of more than 200 flights from the nation's capital.

Beijing's air was "severely" polluted while Shanghai was "heavily" polluted, environmental authorities said. The concentration of PM2.5 - particles that pose the greatest health risks - reached 340 micrograms per cubic meter near Tiananmen Square as of 8 a.m., according to the Beijing Municipal Environmental Monitoring Center That's lower than the peak of 647 on Christmas morning, when officials in the capital raised pollution alert levels to orange, the second-highest on a four-grade scale. The World Health Organization recommends PM2.5 exposure of no more than 25 over 24 hours. The reading was 157 for Shanghai as of 7 a.m., that city's government said.

Chronic air pollution has spurred renewed calls for the government to make better forecasts and act faster to clear the skies. Beijing this year has imposed two red alerts, the highest on the scale, prompting measures including school closures, traffic restrictions and factory operation limits.

The government has shut down 17,000 companies for pollution offenses and another 28,600 were ordered to halt operations as of October, according to the environmental protection ministry. In all, about 50 cities in northern and eastern China have issued air pollution alerts, the China Daily reported on Friday.

BLOOMBERG