- Dutch designer Daan Roosegaarde unveiled his Smog Free Tower at Beijing Design Week
- The tower attracts pollution particles and expels clean air
- According to WHO, China has the world's "deadliest" air
Beijing, China (CNN)One of the 21st century's bleakest problems, air pollution leads to the premature death of 3 million people every year, according to a study published in the journal Nature last year. That number is set to double by 2050.