City reaches annual 'blue sky days' target

Updated: 2011-12-19 07:48

(China Daily)

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BEIJING - As of Saturday, Beijing had enjoyed 274 days of "blue sky" in 2011, fulfilling its annual target ahead of schedule, an official at the city's environmental protection bureau said on Saturday.

Beijing experienced an overall decline in the concentration of various pollutants in 2011, said Zhuang Zhidong, deputy director of the bureau.

The concentration of PM10, or particulate matter of less than 10 micrometers, decreased to 114 micrograms a cubic meter this year, the lowest in four years, according to the bureau.

The city's overall air quality was better than last year, with 22 more days of Grade I air quality, Zhuang said.

Beijing uses a five-grade classification of air quality on the basis of pollution indices, with Grade I being the best and Grade V the worst.

Days with Grade I or II air quality are considered "blue sky days."

However, Beijing also experienced several days of poor air quality as a result of adverse weather. Factors such as weaker winds and a rise in humidity are unsuitable for the dispersal of atmospheric pollutants, according to the bureau.

The bureau has been closely monitoring construction sites and coal-fired boilers in order to reduce emissions of pollutants since the city began supplying heat in mid-November.

Air quality monitoring in Beijing made headlines recently due to public debate over different standards of measurement.

China currently uses PM10 to measure air quality, but the public has urged government authorities to apply the tighter PM2.5 standard, which measures finer matter that is considered more hazardous to human health as it can go deeper into the lungs.

The Ministry of Environmental Protection said it has been reviewing the standards.

It said that a new index standard, which would include PM2.5 and ozone density, is scheduled to be fully implemented nationwide in 2016, with pilot projects in certain regions ahead of the national deadline.

Zhuang said the Beijing Environment Monitoring Center is making preparations to monitor PM2.5 levels, including buying equipment, establishing monitoring posts and training staff.

Xinhua

(China Daily 12/19/2011 page3)