Source using measured ambient particulate

Receptor models are used to determine the source contributions to ambient particulate matter loadings at a sampling site based on common properties between source and receptor. This is in contrast to a source model which starts with emission rates and meteorological measurements to predict an ambient concentration. 

If the nature of the major sources influencing a particular receptor is unknown, statistical factor analysis methods can be combined with ambient measurements to estimate the source composition. Assuming that for a particular location several ambient particulate samples are collected and analyzed for several elements, the resulting data will probably include information about the fingerprints of the sources affecting the location. Principal-component analysis (PCA) is one of the factor analysis methods used to unravel the hidden source information from a rich ambient measurement data set. Factor analysis models are mathematically complex, and their results are often difficult to interpret. 

We identify the benefits of reducing SOj emissions (SOjBEN) from a given source with the change in mortality risk from exposure to ambient particulate concentrations caused by those SOj emissions. These health benefits are measured using a simplified linear damage function, based on estimated parameters from the appropriate literature ... 

The relation between ambient levels and precursor emissions is somewhat easier to identify for particulates than for ozone, because the chemical composition of individual particulates provides evidence for their origin sulfate particulates are associated with sulfur dioxide emissions organic particulates with specific VOCs, and so on. A variety of statistical methods have been used to identify source types for particulates based on chemical composition, especially in terms of trace metal components (e.g., Henry, 1992 Seinfeld and Pandis, 1998). This type of analysis requires sophisticated measurements of the chemical composition of individual particulates, rather than the more common measurement of summed concentrations. Statistical methods have also been used to gain information about ozone and ozone precursors (e.g., Buhr et al., 1995 Stehr et al., 2000). 

The characteristics of several QCM instruments for aerosol measurement have been reviewed (ll). Particles are collected by impaction, electrostatic precipitation or both. The mass sensitivity is reported to be affected by the location of deposited particles on the crystal, the size of the particles, and the type of coating. In addition, the sensitivity changes as the crystal becomes loaded. Despite some limitations, most of the studies Indicated that QCMs can be successfully used for aerosol measurement with good correlation coefficient with the reference filtration method. Applications included measurement of aerosol in ambient air, particulate emission from automobiles and diesel engines, smoke plume from a coal-fired power plant, solid fueled rocket plvune, and particulate matter in the effluents in combustion sources. 

A method for determining the existence and nature of non-automotive lead sources in a given area from ambient air particulate samples has been developed. The method consists of first measuring the diurnal variations of the Br/Pb ratio using x-ray fluorescence to determine those days on which the non-automotive lead source is operating. For the episodal days the diurnal concentration patterns of about 20 metals are measured using neutron activation analysis. 

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