China to Release More Data on Air Pollution in Beijing SHANGHAI - China said on Friday that it would begin to publish more detailed air quality data on Beijing later this month, following a public outcry over official government readings that critics said underestimated the severity of the air pollution problem in the smog-filled capital. Beijing plans to publish hourly air quality reports based on an international standard known as PM 2.5, which measures tiny particles that are 2.5 microns or less in diameter, according to an announcement on the Web site of the Beijing municipal government. Those are the particles that are considered the most serious health hazard. Big cities in China, including Beijing, generally publish air quality data that measure particles that are up to 10 microns in diameter. Using that standard has allowed Beijing to record more than 250 "blue sky days" during each of the past two years. China's Ministry of Environmental Protection also said early Saturday that monitoring pollution levels using the PM 2.5 standard would be included in a newly amended draft of national air quality standards, suggesting other cities may also publish air quality readings using the more stringent standards this year, according to Xinhua, the state news agency. The public's anger over declining air quality has been intensified by hourly readings released by the United States Embassy in Beijing. Those reports, released on a Twitter feed, use the 2.5 standard and paint a far grimmer picture of the city's air problems, annoying Chinese officials and alarming residents who are aware of the feeds. Beijing's "blue sky days" have often turned up in United States Embassy readings as "unhealthy." In 2009, a Chinese Foreign Ministry official pressed the United States Embassy to stop reporting the data, saying the information was "confusing" and "insulting," according to a State Department cable published by WikiLeaks. The embassy continues to release the readings via Twitter. Twitter is blocked by the Chinese government, but some Chinese are able to access the site, and republish the data. During the past year, smog has forced the city to periodically close highways, cancel flights and even cope with state-run media assaults on health problems caused by poor air quality. Public anger over traffic jams and smog in the capital is doing economic and political damage to the city's leaders. Some prominent bloggers, including the real estate tycoon Pan Shiyi, have sharply criticized the government's official readings on microblogs and encouraged others to vote online about whether Beijing should publish more detailed air quality readings.