 says a researcher with Washington Physicians for Social Responsibility. Research shows that creating clean air spaces with an air purifier or filter is one adaptation people should try and take. At a smoke-ready communities workshop at the Rainier Beach Community Center, the Puget Sound Clean Air Agency demonstrates how to create your own filter with a box fan and a furnace filter attached to the back. They recommend a MERV 13 filter or better. Joanna Ganji.