Using high-quality air filters (MERV 13-16) and HEPA filters can reduce indoor PM2.5 levels by 40% and decrease inflammation markers like CRP.

“Using a high-quality air filter in your HVAC system is the most effective measure to reduce indoor PM 2.5 levels. Look for a MERV filter rated at 13-16. Supplement with Efficiency Particulate Air HEPA filters to further purify your indoor air from fine particles to protect you from the hazards of polluted outside air. In a study with participants living in highly polluted areas, the use of HEPA filtration reduced levels of indoors PM2.5 by 40% (12). Moreover, the levels of inflammation marker CRP went down with reduced levels of fine particles, especially those coming from combustion engines (12).”