Analysis of the Results of Air Filtration Experiments to Reduce Indoor Exposure to Ultrafine Particles.
Samy, Liza A.
- Exposure to ultrafine particles (UFP; <100 nanometers in diameter) is associated with systemic inflammation, adverse effects on blood pressure, blood coagulation and respiratory mortality. Exhaust from motor vehicles is a significant source of UFP, and as a result UFP concentrations are higher near highways and major roadways. Indoor air filtration is needed to reduce exposure for people living ... read morenear highways and major roadways. HEPA (High Efficiency Particle Arrestance) filtration is one option. While HEPA proved to be effective in removing particulate matter due to tobacco smoke in homes, there is no evidence in the literature that HEPA removes UFP to a degree where there are noticeable positive health effects. Data collected inside and outside of 24 homes of Puerto Rican adults in Boston and Chelsea as part of the Boston Puerto Rican Health Study (BPRHS) was analyzed. HEPA PNC reductions ranged from 8% to 86% with an average of 59%. No trends connecting indoor PNC, outdoor PNC, indoor:outdoor concentration ratios, outdoor PNC differences, wind directions or wind speeds to HEPA PNC reductions were observed. Indoor PNC levels were higher during waking hours (between 6 AM and 11 PM). Outdoor PNC levels were higher during the same time period during weekdays. Outdoor PNC was also higher when wind came from the direction of Logan Airport, Interstate 93, and Interstate 90 suggesting that homes might be subject to increased indoor PNC when wind blows from these impact sectors. A more controlled study design is suggested to better investigate factors that can affect HEPA PNC reductions.read less