Indoor HEPA filters significantly reduce pollution indoors when outside air unhealthy, study finds

Source: Science Daily

Outdoor air pollution is a major contributor to indoor air pollution — but high-efficiency particulate air (HEPA) filters used in the home significantly reduce fine-particulate matter in the air compared with non-HEPA air filters, according to a new study.

https://www.sciencedaily.com/releases/2018/09/180925110030.htm