Project at a Glance

Title: Colloquium on particulate air pollution and human mortality and morbidity. proceedings January 24-25, 1994.

Principal Investigator / Author(s): Phalen, Robert

Contractor: UC Irvine

Contract Number: 92-341

Research Program Area: Health & Exposure

Topic Areas: Ambient Air Quality Stds, Health Effects of Air Pollution


The organic fraction of urban aerosol contains hundreds to thousands of chemical species, many of which contribute to human mortality and morbidity. The identity and concentration of individual hydrocarbons which contribute to these adverse health effects can generally only be identified by performing mass spectroscopy on the extracts of aerosol collected on filters. Such analytical techniques are time consuming, expensive and are only able to identify a small fraction of the organic species present. Consenquently, detailed analyses of aerosol composition are rare. For routine work, the analysis of organic aerosol has typically been limited to a determination of volatile (organic) carbon and non-volatile (elemental) carbon. Unfortunately, if the analysis of aerosol organics is confined to organic and elemental carbon, detailed resolution of sources, atmospheric reaction pathways and potential mortality and morbidity becomes impossible.

The search for a compromise between mass spectrometric methods, in which individual organic species are identified, and thermogravimetric methods, where only organic and elemental carbon are measured, has led to the development of compound class methods for characterizing ambient aerosol. These methods rely on infrared spectroscopy to determine the concentrations of groups of compounds, such as organonitrates, nitroaromatics and compounds containing carbonyl groups. This paper will briefly review the results obtained using organic compound classes anlyses during the Southern California Air Quality Study. The results will include average functional group loadings and loadings as a function of aerosol size. The measured loadings will be compared to predictions based on the emissions inventory of the Southern California Air Basin.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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