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Human Cell Mutagens in Los Angeles Air

Hannigan, Michael P. and Cass, Glen R. and Penman, Bruce W. and Crespi, Charles L. and Lafleur, Arthur L. and Busby, William F. and Thilly, William G. (1997) Human Cell Mutagens in Los Angeles Air. Environmental Science and Technology, 31 (2). pp. 438-447. ISSN 0013-936X. doi:10.1021/es960266z.

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The human cell mutagenicity of particulate air pollution samples collected in southern California is measured. The human cell mutation assay used in this study tests mutagenic activity at the thymidine kinase locus in h1A1v2 cells using a 72-h exposure. Throughout 1993, airborne fine particle samples were taken at a regional background site on San Nicolas Island upwind of Los Angeles and at four urban sites:  Long Beach, central Los Angeles, Azusa, and Rubidoux. The Long Beach site is in close proximity to direct emissions from industrialized sources including power plants, petroleum refineries, and the Los Angeles−Long Beach harbor complex. Central Los Angeles was chosen because of its dense vehicle traffic, railroad yards, and proximity to the central business district. Azusa and Rubidoux are photochemical smog receptor sites located generally downwind of the highest density of primary emissions sources. No systematic seasonal variation of the mutagenic potency (mutagenicity per unit organic aerosol mass) is observed at any of the urban sites. This suggests that the important human cell mutagens are not dominated by a seasonal emission source such as wood combustion and that if the atmospheric transformation products of photochemical air pollution are involved, then these reactions must occur during the winter as well as during the summer photochemical smog season. No significant spatial variation of annual average mutagenic potency of the aerosol was observed between three of the four urban sites; while the average mutagenic potency of the Long Beach aerosol was slightly higher than elsewhere in the air basin. This similarity of mutagenic potency values across widely separated monitoring sites suggests that the mutagenicity of the aerosol is due largely to ubiquitous emission sources (e.g., motor vehicle traffic or stationary source fuel combustion) rather than to proximity to isolated point sources of unusual mutagenic organics. The mutagen concentration per cubic meter of ambient air was computed by weighting the mutagenic potency values of the aerosol according to the mass concentration of organics present at each monitoring site. The human cell mutagen concentration in Los Angeles urban air was found to be 1 order of magnitude greater than at the background site studied upwind of the city, showing that the city is indeed a source of human cell mutagens.

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Additional Information:© 1997 American Chemical Society. Received for review March 21, 1996. Revised manuscript received August 30, 1996. Accepted September 13, 1996. Publication Date (Web): January 30, 1997. We thank Lawrence Donhoffner and Lita Doza-Corpus at Gentest Corporation for performing the human cell mutation assays. We would also like to thank all those involved with establishing and maintaining the ambient particulate matter sampling network, specifically Matt Fraser and Lynn Salmon at Caltech and Bill Bope at the South Coast Air Quality Management District. John Durant provided valuable guid ance in bioassay data reduction. The assistance of the U.S. Navy meteorological office at Pt. Magu was critical to our ambient sampling activities on San Nicolas Island, and we especially thank Jay Rosenthall and Ken Fesperman. This research has been supported by Center Grant P30-ES02109 and Program Grant P01-ES07168 from the National Institute of Environmental Health Sciences.
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National Institute of Environmental Health SciencesP30-ES02109
National Institute of Environmental Health SciencesP01-ES07168
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Official Citation:Human Cell Mutagens in Los Angeles Air Michael P. Hannigan, Glen R. Cass, Bruce W. Penman, Charles L. Crespi, Arthur L. Lafleur, William F. Busby, Jr., and William G. Thilly Environmental Science & Technology 1997 31 (2), 438-447 DOI: 10.1021/es960266z
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:67918
Deposited By: George Porter
Deposited On:14 Jun 2016 23:08
Last Modified:11 Nov 2021 03:56

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