Toyota Mirai billboard actually purifies the air around it

Billboards don't really do anything -- except for Toyota's new Mirai billboards, which are actually engineered to clean the air around them.From April 3 to May 28, Toyota will put up 37 billboards around Los Angeles and San Francisco, touting the Mirai hydrogen fuel cell vehicle. In order to reinforce how clean a hydrogen-powered electric car can be, the billboards are built to scrub pollution from the air.