Independent sensor readings and photographs taken in Beijing both tell the same story: the Chinese government's olympian efforts to clean up the city's air aren't working.

With the Olympics slated to start Friday, Wired.com took a careful look at the raw air pollution numbers taken by air pollution sensors set up by the BBC's Beijing bureau. Graphed over a period of almost four weeks, the analysis shows that the Chinese authorities' anti-smog efforts are not making the city's air better.

On most days, Beijing's air clearly remains poor, rarely dropping below

50 micrograms of particulate matter per cubic meter of air. The World

Health Organization considers any concentration of particulate higher than 50 to be unhealthy. While the BBC sensor has a large margin of error (20 percent), on most days the readings have been far above the threshold. The pollution levels have been clearly reflected in daily photographs taken from the same location by the news agency's reporters.

The Chinese government has been working on an ambitious plan to improve the air quality in Beijing for the games including traffic bans, factory shutdowns, cloud seeding, and construction slowdowns.

But the city's air quality has not varied in response to the city's anti-smog efforts, according to the BBC's readings. Pollution levels are changing, however, but only in response with meteorological conditions, i.e. rain. That's exactly what University of Rhode Island professor Kenneth Rahn predicted would happen in a Wired.com story last month.

"They are trying every conceivable thing and that is the right approach," Rahn said. "But when the air is worst in Beijing, it's the hardest to control."

On July 20th, the Chinese government put into effect the full package of anti-smog efforts (indicated by the first gray bar), but as can be clearly seen, air pollution levels actually went up. Only after heavy rain fell on July 29th (indicated by the second gray bar) did air pollution levels decrease.

In addition, if the anti-smog efforts were keeping particulate matter out of the air, air pollution levels should have stayed low after the July 29th storm, but as the graph shows, pollution immediately climbed back to previous levels.

And yet Chinese government officials continue to recite the party line that the anti-smog efforts will result in a "blue-sky" Olympics. For example, they deny that the lack of visibility in the city is due to smog.

"Clouds and haze are not pollution. This kind of weather is a natural phenomenon. It has nothing to do with pollution," Du Shaozhong, deputy director of the Beijing municipal bureau of environmental protection, told Xinhua last week, the official government news outlet.

He explicitly criticized the use of photographs as an indication of pollution levels.

"Such photographs 'don't tell the truth,'" Du Shaozhong said. "We don't approve of their use to pass judgment on the air quality... you have to look at the complete monitoring system, and analyze the data scientifically."

The problem, however, is that there is compelling evidence that the Chinese government is cooking the pollution accounting books. As laid out by Steven Andrews, an environmental consultant, in an op-ed earlier this year in the Wall Street Journal, he describes three number manipulations:

Seven sensors were used from 1998-2005, but after that, as international scrutiny was increasing, the government dropped two sensor stations from polluted areas of the city and added three in less polluted areas. These changes had a very significant impact in showing air quality increases. The government subbed nitrogen oxides out and nitrogen dioxide in to its air pollution index calculations. Of the various substances that the sensors measure, nitrogen oxides were the most likely to exceed air pollution standards. The Chinese government considers an air pollution index rating of under 100 to be a "blue sky day." In 2006, 49 days were reported to have an air pollution index between 96 and 105. 47 of those days were – what "luck"! – reported under 100, a near statistical impossibility. 2007 data shows "a similar bias."

The end result of the system is that the Chinese government gave August 4, seen above, an air pollution index rating in its "Good" category.

Given these problems with the "complete monitoring system," photos and independent sensors are the best indications available about how bad the air in Beijing really is.

In fact, even the Chinese government doesn't seem to believe that its efforts are working. There is word in China Daily, a government mouthpiece, that officials are considering an even more drastic plan that could take 90 percent of the city's cars off the road, if the pollution readings don't cooperate.

Images and PM readings: The BBC.

See Also:

Pic: Beijing's Air After 4 Days of Anti-Smog Measures

Why China's Olympian Efforts to Clean Beijing's Air Won't Work

The Wall Street Journal's tracking of official air pollution statistics.

BeijingAirBlog.com, an independent air quality tracking site

WiSci 2.0: Alexis Madrigal's Twitter , Google Reader feed, and webpage; Wired Science on Facebook.