Review of the Department of Defense Enhanced Particulate Matter Surveillance Program Report (2010) / Chapter Skim
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3 Evaluation of Analytic Results
3 Evaluation of Analytic Results
Pages 38-47
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From page 38... ...
This chapter will review the analytic methods used and the evaluation of the resulting data on chemical composition. The objective of the EPMSP was to identify the general chemical characteristics of PM at 15 sites in the Middle East with methods that were similar to those used for ambient-air monitoring networks in the United States, including the Environmental Protection Agency's Chemical Speciation Network and the Interagency Monitoring of Protected Visual Environments network.
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From page 39... ...
The mass concentrations observed in the EPMSP are much higher than those currently measured in the United States. However, they are comparable with values observed 30-40 years ago when studies of airborne-particle composition began to use XRF as an analytic tool (Jaklevic et al.
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From page 40... ...
Although problems with sample collection outlined in the previous chapter may be applicable to the XRF analyses, there would not be a problem in analyzing heavily loaded samples with methods in which samples are leached or solubilized, such as ICP-MS. In those cases, a combination of nitric acid and hydrochloric acid was used to solubilize selected elements, including antimony, arsenic, beryllium, cadmium, chromium, lead, manganese, nickel, vanadium, zinc, mercury, and strontium.
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From page 41... ...
The evolved compounds were oxidized to carbon dioxide, the carbon dioxide was converted to methane, and the methane was quantitatively measured with a flame ionization detector. After the organic compounds were evolved at the highest temperature, the gas was changed to a mixture of a few percent oxygen in helium, and the refractory carbon, EC, was oxidized.
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From page 42... ...
Some elements are not measured but can be estimated. For example, silicon would typically be found in airborne particles as SiO2, and the mass of SiO2 can be estimated from the silicon concentration and the appropriate gravimetric factor (molecular weight of SiO2 divided by the molecular weight of silicon)
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From page 43... ...
SITE-SPECIFIC DIFFERENCES IN PARTICULATE-MATTER CONCENTRATIONS BETWEEN THE MIDDLE EAST AND THE UNITED STATES The EPMSP attempted to compare data gathered from 15 Middle Eastern sites with data gathered in the United States. The committee surmised that the comparison was probably performed to demonstrate that there are no substantial differences in PM composition between the Middle East and the United States despite higher mass concentrations in the Middle East.
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From page 44... ...
Comparison of Particulate-Matter Data with Air Quality and Health Standards The MiniVol sampler is not a Federal Reference Method sampler, nor has it been designated as a Federal Equivalent Method. Thus, the results of these measurements are not fully comparable with the results of samples collected in the regulatory monitoring network for determining attainment of the PM2.5 or PM10 National Ambient Air Quality Standards.
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From page 45... ...
regions that are substantially affected by geologic material. There were higher proportions of lead than are currently seen in the United States, presumably from smelters and the use of leaded gasoline.
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From page 46... ...
Future efforts may omit total suspended particulates if the goal is to understand potential health effects from exposures. The comparisons of PM composition in the EPMSP report should be interpreted with caution because they may not fully represent the true underlying distribution of PM concentrations.
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From page 47... ...
1994. Airborne particle classification with a combi nation of chemical composition and shape index utilizing an adaptive resonance artificial neural network.
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