Air Pollution Shrouds Eastern China Eastern China is suffering from some of the most severe air pollution in recent memory, forcing schools to cancel classes in the city of Nanjing and shrouding Shanghai's famous skyline in an acrid haze. Nanjing called off classes for all of the city's kindergartens, elementary and middle schools Thursday, although schools remained open to watch over children who had no one to care for them during the day, the Nanjing-based Modern Express reported. In Shanghai, education officials told schools to call off outdoor activities due to the hazardous conditions. Shanghai has reported air quality at levels deemed "heavily polluted" for much of the week. On Monday, the city's air quality index was over 301 - the threshold for "severely polluted," the most dangerous level according to China's national standards - for more than 10 hours, the official Shanghai Daily newspaper reported. That made it the worst air quality the city had experienced since the new index was put in place one year ago, the newspaper said. By early evening Thursday, the pollution level in Shanghai was hovering at 340. At least 16 other cities in four provinces in eastern China were also reporting pollution levels over 300. In Zaozhuang, a city of nearly four million in Shandong Province, the pollution index hit 500, the maximum reading on the Chinese scale. The pollution prompted the prominent property developer Zhang Xin to recommend on her microblog that all real estate developers install air filtration systems "to keep the smog from getting indoors." Shanghai's pollution is really bad. I've rarely seen it like this," Yang Hongxu, vice president of the Shanghai-based E-house China Research and Development Institute, wrote on his Sina Weibo account Monday. It's not the lack of clarity, it's that it's really hard to breathe. In 10 years I've never been this sensitive to it. Such conditions are more familiar to northern Chinese cities. Harbin, in far northeastern China, had an episode of "airpocalypse" in October with readings hitting the 500 maximum and residents complaining they could not see across traffic intersections. In January, a pollution monitor at the U.S. Embassy in Beijing, which uses an American air-quality index slightly different than China's, hit 755, above the normal 0-500 scale. This week though the Chinese capital is experiencing much clearer skies thanks to strong winter winds blowing from the north. Factors such as central heating systems dependent on coal mean that northern China experiences frequent bouts of toxic air, the latest episode of serious pollution in eastern China is a reminder that the rest of the country is not immune to the dangers. Environmental officials blamed the poor conditions on the lack of strong winds to flush out bad air and the growing number of vehicles pumping out pollutants, according to the Shanghai-based Oriental Morning Post. The newspaper said more favorable weather conditions that could help reduce pollution are expected to begin Sunday.