TRACING THE SOURCES OF INDOOR AEROSOLS USING EVOLVED GAS-ANALYSIS

An exploratory study was conducted to determine whether microanalytical evolved gas analysis for measuring carbon and nitrogen could be used to distinguish aerosols from different indoor sources. The method requires < 20-mu-g of particulate matter and it is rapid and inexpensive. Thermograms (rate of evolution of CO2 and NO(x) versus temperature) were determined for samples of environmental tobacco smoke (ETS), kerosene soot, indoor aerosol from woodburning homes, and outdoor aerosol from New Jersey. The thermograms were used to calculate the amounts of carbon and nitrogen for five temperature intervals from 50 to 600-degrees-C normalized to particle mass. The thermograms from different sources showed distinct differences. ETS and kerosene soot had the highest mass percentages of carbon and nitrogen (37% C, 4% N and 27% C, 10% N, respectively), although their nitrogen thermograms differed substantially. Organic nitrogen dominated the ETS samples while most of the nitrogen in kerosene soot was (NH4)2SO4. The kerosene soot samples also had the highest percentages of black (elemental) carbon and could thus be distinguished from woodsmoke: These results on a limited number of samples suggest that, with additional research, this method may be useful for distinguishing the contributions of ETS, kerosene soot, and woodsmoke in indoor atmospheres.