While smog is a problem in many of the world's urban cities, few have it as bad as China. Most of last year, the air around Beijing was so polluted that on certain days it went beyond what was once considered the worst possible level. The residents of Harbin, in northeast China, have not had it easy either. On days when the haze is really bad, residents are unable to even see across streets and airplanes have a hard time landing.

The problem is so acute that it has spawned a whole new cottage industry, with local innovators conjuring up all kinds of solutions. The most commonly seen of course are the face masks that almost no city resident leaves home without. There are also a myriad of air purifiers that range from simple duct-taped contraptions to mini air filters designed to fit inside nostrils. Then there is the bicycle that purifies air when ridden, cans filled with fresh air . . . and the list goes on.

While the best way to curb smog would be by cutting emissions, the government of China has so far been a little reluctant to impose any rules simply, because the leaders have been worried that it may impact the country's economic growth.

But that may finally change. Late last year, the officials finally pledged to take action to combat the pollution that is fast becoming a health hazard for its residents. Among the measures passed are mandatory factory closures and bans on cars entering cities like Beijing, on days when the smog levels are extremely high. Fully realizing that these alone will not be enough to solve the problem, the leaders also announced a plan to spend as much as 3 trillion Yuan ($494 billion) towards a feasible long-term solution.

Among the top contenders being contemplated, is cleaning the air using artificial rain. Thanks to a chronic water shortage China has one of the world's most robust and active programs to create man-made precipitation. Over the years, it has been deployed numerous times to make rain by seeding clouds with catalysts like dry ice, silver iodide and salt powder. In 2008, the officials even stopped rain to ensure clear skies for the opening ceremony of the Beijing Olympics.

The one thing that it has never been used for, is to clean out the smog. Though this seems like a feasible solution, it may not always be possible given that the moisture conditions have to be just right for cloud-seeding programs to work. Not only that, the clouds have to be above the area that requires the cleansing. There is also the issue of the heavy pollutants used for seeding mixing in with the groundwater and causing further health issues for the country's residents.

These issues have led a scientist to suggest an alternative - Washing down the smog using giant sprinklers, similar to shower heads. Shaocai Yu, who formerly worked for the U.S. Environmental Protection Agency, believes that since pollution tends to hang at low levels, giant shower head like devices fitted onto the country's numerous skyscrapers, would work just as well as 'artificial rain'. The added advantage is that they could be turned on whenever required. Of course, in a country already strapped for water, this may not be a viable solution. There is also the issue of retrofitting the buildings with pumps and sprinklers that can sustain all kinds of weather.

That is probably why the officials have agreed to meet with Dutch artist Daan Roosegaarde and test his giant electrostatic 'vacuum cleaner'. The device that resembles a giant hula hoop uses a weak electromagnetic field to draw the smog components down to the ground, where they can be cleaned. Since the coils are buried underground, there is no danger of toxic residues being released. However, while it has the capability to suck up enough smog to create holes of clean air as big as 60 meters (196 feet), it cannot clean up the entire sky.

But the fact that is effective enough to cut patches big enough to allow residents to experience a bright sun, may be enough to convince the officials to do the right thing - Clean up China's cities the old fashioned way - By curbing emissions drastically!

Resources: theguardian.com,saratogian.com,ajc.com,gizmodo.com,cnn.com