As it struggles with hosting duties in advance of next month's important Party Plenum, smoggy Beijing may have been trying to artificially improve its air quality after an anti-smog truck was curiously discovered pointed at a city air monitoring station.

Weibo user @张宏杰 posted an eight-second-long video Tuesday afternoon that showed the "giant cannon" mounted on the back of an anti-smog truck aimed toward what appears to be an air-monitoring station located in Beijing's Changying Park.

"It's such a nice day outside, but (there's a machine) spraying water beside the atmospheric particle detector at Changying Park," Zhang wrote. "What a waste of water and electricity."

Zhang also provided a close-up photograph of a sign on the air monitoring device that reads: "Chaoyang District Department of Environmental Protection" (shown below).

Later the same day that Zhang made the post, a reporter with the Beijing Youth Report went to the park and independently verified Zhang's claim. The reporter said the anti-smog truck was parked by itself in an enclosed courtyard with its equipment pointed at the air-monitoring station located just beyond the courtyard's wall, but was turned off after the reporter arrived. By the next day, it was gone.

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Although a worker at the scene was very forthcoming, explaining that the anti-smog truck was trying to reduce dust at Changying Park, other answers were harder to come by.

On Tuesday, the reporter for the Beijing Youth Report visited the petitioner's office of the Chaoyang Detachment for the Ministry of Environmental Protection, as well as the Law Enforcement Brigade of Chaoyang Environmental Protection Bureau; both offices denied any knowledge of or responsibility for the incident.

Anti-smog trucks help improve air quality in urban centers by spraying a fine mist of water into the air that weighs down larger-sized airborne contaminants. They usually accomplish this task by driving around a city instead of being parked in one place.

Netizens reacted with cold cynicism to the news that authorities may be misleading them. "As it turns out, burying your head in the sand is a useful tactic," wrote one person, while another satirically said: "Your micro-blog has been exploited by foreign reactionary forces. Please delete it as soon as possible."

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A member of the Atmospheric Department for the Ministry of Environmental Protection was quoted by Beijing Youth Report as saying he didn't think an anti-smog truck could influence the results of an air monitoring station, but didn't explain further. "As for why, I cannot provide you with a specific answer," he said.

Regardless of its efficiency, Beijing has been caught doing this same thing before.

Last May during a severe smog attack in which the local AQI level spiked at around 900, an anti-smog truck was found parked beside an air-monitoring station at Beijing's Olympic Sports Center, possibly causing it to have an AQI level rated 170 less than the city average.

Other attempts to tamper with air quality-monitoring equipment around China have included plugging up sensors with cotton gauze as well as previous similar water spraying incidents.

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Tentatively scheduled for October 18, the 19th Party Plenum is the most important Communist Party gathering in five years. As pressure mounts on Beijing officials to ensure local air quality, the upcoming plenum will also impact life in the city with strict controls expected on everything ranging from internet access to commuting.

Meanwhile, Beijing experienced its latest smog attack Thursday – one that is expected to last until Saturday.

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Twitter: @Sinopath

E-mail: charlesliu1@qq.com

Images: Weibo, Weibo