This article is from the archive of our partner .
The latest market opportunity for entrepreneurs in China? Polluted air. For nearly as long as pollution has been a salient, public issue in the country, foreigners and locals have been devising ways to help residents avoid the worst of smog—and in some cases make a little money in the process. Here are some of the most notable ones.
DIY filters:
As we’ve reported, American graduate student Thomas Talhelm has designed his own air filter made up of a high-efficiency particulate air (HEPA) filter strapped to a box fan. “It’s pretty ghetto,” he told Quartz. It costs just $27 to assemble, but does reduce the amount of PM2.5 particles (pollutants that can enter one’s bloodstream. In Beijing, the Beijing Energy Network hosts workshops to teach people how to make their own air filters.

A smog vacuum:
Last month, Dutch designer Daan Roosegaarde introduced an electronic vacuum cleaner, or the “sky vacuum,” which creates an electrostatic field that draws particles in the air to the ground where they can be captured and cleaned. He’s currently working Beijing’s mayor to conduct a pilot test of the vacuum in a new park.