Smog cancels and delays flights in Beijing

Thousands of passengers were stranded Tuesday morning after dozens of early morning flights were either canceled or delayed due to a thick, dark cloud of smog that rolled through the Chinese capital.

The haze prompted 34 flight cancellations and delayed 98 others after visibility dropped to less than 200 meters in the airspace surrounding Beijing, state media reported.

Air carriers resumed normal flight schedules as of 10 a.m. (local), according to Xinhua. But the city’s air quality continued to be listed as “fair.”

The U.S. Embassy, which reports pollution levels on its Twitter feed, said the accumulation of air particles was “beyond index” for most of the morning, which means the pollution exceeded the scale used to measure it.

The U.S. Embassy and Chinese officials use different systems to measure air pollution. The U.S. Embassy’s air quality monitor includes smaller particles that are less than 2.5 micrometers in diameter. The U.S. Consulate General in Guangzhou, China, explains that these smaller particles “are believed to pose the largest health risks” and “are small enough to get into the lungs and even the blood stream.”

Last month, Beijing’s Capital International Airport canceled more than 200 incoming and outgoing flights and delayed more than 125 others because of smog.

Analysts have blamed the thick haze on rapid urbanization and industrialization.

Beijing, for instance, burned some 27 million tons of coal in 2010, according to state-run media.

Despite efforts to limit the number cars with an auto-plate lottery, it’s estimated that Beijing now has over 5 million cars, up from about 3.5 million in 2008.

Pollution is more acute because of the sheer size of the city’s population (17 million) and the rapid speed of its economic growth, experts say.

CNN’s Haolan Hong contributed to this report