Real time monitoring of indoor aerosols

This study investigated the effects of different indoor air pollutants such as smoking,cooking and incense burning on indoor air quality. Before the experiments, the indoorparticulate concentration was evaluated using two types of aerosol monitoring devices,the TSI, Inc. Model 8520 DustTrak Aerosol Monitor (DustTrak), and the MSP Corp.,Mode 200, Personal Environmental Monitor (PEM). These two instruments werecollocated indoors simultaneously to assess the comparability of the sampling methods.The results show that PM₁₀ and PM_2.5 concentrations measured by PEM sampler wereless than that of DustTrak sampler. The difference between PM₁₀ and PM_2.5concentrations measured by PEM and DustTrak increase with increasing particulateconcentrations. Whereas the DustTrak sampler is well correlated with PEM sampler inmeasuring PM₁₀ and PM_2.5 concentration for a R² value of 0.92 and 0.89, respectively. Asa consequence, real-time motoring of PM₁₀ and PM_2.5 concentrations by DustTraksampler is applicable and was used to evaluate indoor air quality. When there is no indoorpollutant, the PM_2.5/PM₁₀ ratio is 0.78 ± 0.04 indoors. It means that most indoorparticulates are less than 2.5 μm in aerodynamic diameter. If there exists indoor pollutantsources, the monitored particulates are less than 2.5 μm mostly, especially in smokingand incense burning experiments where the PM_2.5/PM₁₀ ratio is above 0.90, while theratio is 0.77 in cooking experiment. Furthermore, it was found that the PM₁₀concentration indoors is less than that outdoors. The average I/O ratio (indoor to outdoorPM₁₀ concentrations) of 24-hour PM₁₀ concentration is 0.58.