On March 26, 2008, EHP-in-Press posted an article entitled “Recirculating Air Filtration Significantly Reduces Exposure to Airborne Nanoparticles.” The authors investigated the effectiveness of recirculating air filtration to reduce exposure to incidental and intentionally produced airborne nanoparticles while driving in traffic, and while generating nanomaterials using gas-phase synthesis. The authors state that “use of inexpensive low-efficiency filters in recirculation systems is shown to reduce nanoparticle concentrations to below levels found in a typical office within three minutes while driving through heavy traffic, and within twenty minutes in a simulated nanomaterial production facility.”