The Influence of Asian and Regional Atmospheric Transport on the Genotoxicity of Air Masses in the Pacific Northwest

EPA Grant Number: F07D40790
Title: The Influence of Asian and Regional Atmospheric Transport on the Genotoxicity of Air Masses in the Pacific Northwest
Investigators: Layshock, Julie Anna
Institution: Oregon State University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2007 through September 1, 2010
RFA: STAR Graduate Fellowships (2007) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Academic Fellowships , Fellowship - Analytical Chemistry , Fellowship - Environmental Toxicology , Fellowship - Genotoxicity Testing


Intercontinental atmospheric transport of pollutants can impact local air quality in places far from the original source regions. Because China has become the largest coal consumer and one of the top petroleum users in the world, the outflow of incomplete combustion products makes China an important emitter of carcinogenic PM-bound polycyclic aromatic hydrocarbons (PAHs). Transport of Asian PM to the US West coast increases the potential to form more toxic products such as the nitro- and oxy-PAHs. Our laboratory measures enhanced PM-bound PAHs associated with trans-Pacific Asian air masses. Inclusion of more toxic PAHs derivatives and toxicity testing greatly aides in assessment of human health concerns associated with particulate matter.

The objective of this research is to evaluate the relative genotoxicities and chemical composition of PM from trans-Pacific and regional air masses collected in the Pacific NW United States.


Air masses will be collected in urban, rural, and remote sites in the Pacific Northwest to compare trans- Pacific atmospheric transport from Asia to regional atmospheric transport from the United States. The mutagenic and DNA-damaging potential of size segregated particulate matter (PM) will be evaluated using the Ames Salmonella mutagenicity assay using TA98 and TA98NR strains and the Comet (Single Cell Gel Electrophoresis) assay using ATCC human lung cells. An extensive collection of parent PAHs and substituted oxy- and nitro-PAHs will be measured in the PM samples using GC-MS.

Expected Results:

Since nitro- and oxy-PAHs can directly interact with DNA, enhanced concentrations on PM could be more harmful to human health than the parent carcinogenic PAHs. Consequently, it is expected that concentrations of substituted and parent PAHs will be correlated with the mutagenic and genotoxic potency of air masses. Asian air masses are likely to contain elevated concentrations of specific oxy- and nitro- PAH isomers, as well as mutagenicity, compared to regional U.S. air masses. This research will demonstrate that air pollution is a global concern and advance both public and administrative decision-making on such issues as emission controls, liabilities, and human exposure standards.

Supplemental Keywords:

Long Range Transport, combustion by-products, PM, Nitro-PAH, Oxy-PAH, Air Pollution, China, Genotoxicity, Mutagenicity, Comet, Ames test, Human Toxicology,

Progress and Final Reports:

  • 2008
  • 2009
  • Final