The concentration of PM2.5 -- the particles that pose the greatest health risks -- was 503 micrograms per cubic meter near Tiananmen Square at 2 p.m. after reaching 647 in the morning, according to the municipal air-monitoring website. The World Health Organization recommends PM2.5 exposure of no more than 25 over 24-hours. Beijing Capital International Airport, the world’s second- busiest by passengers, reported the cancellations on its website Friday and said another 12 departures were delayed as of 4 p.m. local time because of poor visibility. The canceled flights accounted for about 12 percent of scheduled departures Friday, according to the site.
The chronic air pollution has renewed calls for the government to make better forecasts and act faster to help clear the skies over the city of 21.5 million. 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 latest ended Tuesday. Smog also blanketed China’s eastern and central regions Friday. PM2.5 levels were as high as 260 micrograms per cubic meter in Zibo and 322 in Jinan of Shandong province, data from the China National Environment Monitoring Center showed. The readings were 277 in Wuhan and 255 in Huanggang of Hubei province. Shanghai issued a yellow alert for air pollution, the third-highest of four levels. Children and the elderly were warned to avoid outdoor activities, with the Shanghai Environmental Monitoring Center reporting PM2.5 levels of 154 micrograms per cubic meter as of 2 p.m. About 50 cities in northern and eastern China have issued air pollution alerts, the China Daily reported on Friday. Smog across the eastern, northern and central parts of the country will weaken or disperse from north to south from Saturday, the China Meteorological Administration said.