For four years, I lived on 58th street in Manhattan. My apartment was basically on the Queensborough Bridge, right where cars enter and exit. I know what you’re thinking—”How loud was that?”—and you’d have a point. In all honesty, it was pretty noisy. But as it would turn out, that was only the most obvious problem, not the most important one.

I turned my A/C to the “fan” setting each night to cover up the noise and kept my double windows closed pretty much at all times. While it was annoying, I didn’t really mind, since leaving them open meant that, within a day, the glass itself, the windowsill, and everything around it would be covered in black dirt. We’re not talking about your normal dust—this was straight soot and pollution from the constant flow of motors outside. So keeping them closed meant less cleaning up, which was OK with me.

Read More: http://www.self.com/wellness/2016/05/i-got-an-air-purifier-and-it-literally-changed-my-life/