Temporal Variations of Airborne Ultrafine Particles Inside and Outside of Homes in an Urban Area.
particles are particles with aerodynamic diameter less than 0.1 micrometers. These
particles have many origins including outdoor and indoor sources. Infiltration of
outdoor particles may influence the particle number concentration (PNC) indoors;
however, indoor sources such as cooking and smoking may also have a significant
contribution to the particle number concentration ... read moreindoors. Our study area was focused on
two cities of Boston and Chelsea, MA. TSI model 3783 was employed to measure PNC for 24
homes for six weeks, switching between HEPA and sham filtration for three weeks. Our
results show that median hourly indoor PNC variations for each week during HEPA have
spikes higher than 100,000 (#/cm3). These spikes are mostly during the evening; this may
be due to cooking as the trend is common for many days in every week. Monthly PNC
variations during sham measurements show that there are higher median concentrations
during cold seasons compared to warm ones; however, various factors may have effect on
these results including different home types, number of data points for each cluster of
homes included in the season. There is an increase in median outdoor and indoor PNC
during sham filtration for colder seasons compared to warmer seasons. Moreover, the
effect of HEPA filtration was noticeable in the weekly indoor variations for HEPA
compared to sham filtration. HEPA indoor variations were associated with lower baseline
levels and higher spikes compared to sham indoor
Thesis (M.S.)--Tufts University, 2015.
Submitted to the Dept. of Civil Engineering.
Advisor: John Durant.
Committee: John Durant, Doug Brugge, and Mark Woodin.
Keyword: Environmental engineering.read less