CaltechAUTHORS
  A Caltech Library Service

Physical and Chemical Characterization of Atmospheric Ultrafine Particles in the Los Angeles Area

Hughes, Lara S. and Cass, Glen R. and Gone, Jec and Ames, Michael and Olmez, Ilhan (1998) Physical and Chemical Characterization of Atmospheric Ultrafine Particles in the Los Angeles Area. Environmental Science and Technology, 32 (9). pp. 1153-1161. ISSN 0013-936X. http://resolver.caltech.edu/CaltechAUTHORS:20160613-112922976

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20160613-112922976

Abstract

Atmospheric ultrafine particles (diameter < 0.1 μm) are under study by inhalation toxicologists to determine whether they pose a threat to public health, yet, little is known about the chemical composition of ultrafine particles in the atmosphere of cities. In the present work, the number concentration, size distribution, and chemical composition of atmospheric ultrafine particles is determined under wintertime conditions in Pasadena, CA, near Los Angeles. These experiments are conducted using a scanning differential mobility analyzer, laser optical counter, and two micro-orifice impactors. Samples are analyzed to create a material balance on the chemical composition of the ultrafine particles. The number concentration of ultrafine particles in the size range 0.017 < d_p < 0.1 μm, analyzed over 24-h periods, is found to be consistently in the range 1.3 × 10^4 ± 8.9 × 10^3 particles cm^(-3) air. Ultrafine particle mass concentrations are in the range 0.80−1.58 μg m^(-3). Organic compounds are the largest contributors to the ultrafine particle mass concentration. A small amount of sulfate is present in these particles, at concentrations too low to tell whether it exists as unneutralized sulfuric acid. Iron is the most prominent transition metal found in the ultrafine particles. These data may assist the health effects research community in constructing realistic animal or human exposure studies involving ultrafine particles.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/es970280rDOIArticle
http://pubs.acs.org/doi/abs/10.1021/es970280rPublisherArticle
Additional Information:© 1999 American Chemical Society. Received for review March 26, 1997. Revised manuscript received December 18, 1997. Accepted January 6, 1998. This work was supported by the Center for Air Quality Analysis at Caltech. Thanks are due to Drs. Kent Hoekman and Steve Ziman of Chevron for assistance with this research. Aerosol carbon analyses were performed by Bob Cary at Sunset Labs, Forest Grove, OR.
Funders:
Funding AgencyGrant Number
Caltech Center for Air Quality AnalysisUNSPECIFIED
Record Number:CaltechAUTHORS:20160613-112922976
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20160613-112922976
Official Citation:Physical and Chemical Characterization of Atmospheric Ultrafine Particles in the Los Angeles Area Lara S. Hughes, Glen R. Cass, Jec Gone, Michael Ames,and Ilhan Olmez Environmental Science & Technology 1998 32 (9), 1153-1161 DOI: 10.1021/es970280r
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:67875
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:13 Jun 2016 20:06
Last Modified:13 Jun 2016 20:06

Repository Staff Only: item control page