Weather: a lot better, apparently

No sooner had the sumptuous curtain fallen on the 2008 Beijing Olympics than locals began bidding goodbye to beautiful blue skies and assuming a return to choking blankets of smog.

One year later, Beijing citizen Jiang Nan has something rather unexpected to say about that.

��he temperature felt comfortable this year. You don�� have to use air conditioning at night when a breeze blows through the whole room,��Jiang said.

According to the Beijing Municipal Environmental Protection Bureau, the overall Beijing air quality has generally progressed one year after the 2008 Olympic Games. Statistics provided by the local environmental bureau suggests on some days, the air quality was even better than last year.

The Air Pollution Index (API), also known as the Air Quality Index (AQI), is a number used by government agencies to characterize the quality of the air at a given location, provided by the Ministry of Environmental Protection between July and August 2007-2009. The API fluctuation this year is more drastic than in 2008. Pollution in Beijing is becoming less serious one year after the Olympic Games. The API, though, was far higher in 2007 before the Olympics were held.

The delightful statistics provided by the Chinese government have been unintentionally challenged by the hourly updated API provided by the US Embassy in Beijing.

The Global Times examined the API provided by the Chinese Ministry of Environmental Protection and the US Embassy at 12 noon every day for the past month. The chart below shows similar curves, with the figures from the US embassy stunningly higher.

Embassy spokeswoman Susan Stevenson explained the difference.

��he US Embassy has an air quality monitor to measure PM (Particulate Matter) 2.5 particulates on the Embassy compound as an indication of air quality,��she said.

��his monitor is a resource for the health of the Mission community. Citywide analyses cannot be done, however, on data from a lone machine.

��he data from the embassy monitor is not comparable to Chinese air quality monitors. Since we have only one machine measuring a different parameter, the embassy monitor�� data cannot be compared to Chinese data.��br>

Customers in Beijing buy Olympic merchandise on March 19. (CFP Photo)

Stevenson said the embassy monitors for PM 2.5 rather than the Chinese parameter of PM 10. Particles less than 2.5 micrometers in diameter are referred to as ��ine��particles and are believed to pose the largest health risks.

PM 2.5 is the standard recognized by the US Environmental Protection Agency and allows the embassy to compare against US standard measures.

��he PM 2.5 particulates are of concern since they are small enough to get into the lungs and even the bloodstream,��she said.

The Beijing Municipal Bureau of Environmental Protection asserts air quality will continue to improve in coming months. It has something to do with the recent rainy weather and is the result of pollution controls and measures, the bureau spokesman has said.

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