David Y.H. Pui, Chaolong Qi, Nick Stanley, Günter Oberdörster, and Andrew Maynard
doi:10.1289/ehp.11169 (available at http://dx.doi.org/) Online 26 March 2008
BACKGROUND: Airborne nanoparticles from vehicle emissions have been associated with adverse effects in people with pulmonary and cardiovascular disease, and toxicological studies have shown that nanoparticles can be more hazardous than their larger scale counterparts. Re-circulating air filtration in automobiles and houses may provide a low-cost solution to reducing exposures in many cases, thus reducing possible health risks.
OBJECTIVES: We investigated the effectiveness of re-circulating air filtration on reducing exposure to incidental and intentionally produced airborne nanoparticles under two scenarios: while driving in traffic, and while generating nanomaterials using gas phase synthesis.
METHODS: We tested the re-circulating air filtration in two commercial vehicles when driving in traffic, as well as in a non-ventilation room with a nanoparticle generator, simulating a nanomaterial production facility. We also measured the time-resolved aerosol size distribution during the in-car recirculation to investigate how re-circulating air filtration impacts on particles of different sizes. A recirculation model was developed to describe the aerosol concentration change during recirculation.
RESULTS: The 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.
CONCLUSIONS: Development and application of this technology could lead to significant reductions in airborne nanoparticle exposure, reducing possible risks to health and providing solutions to generating nanomaterials safely.