Superfund Research Program

Identification of Remediation Technologies and Conditions that Minimize Formation of Hazardous PAH Breakdown Products at Superfund Sites

Project Leader: Lewis Semprini
Co-Investigators: Staci L. Simonich, Ha-Yeon (Paul) Cheong
Grant Number: P42ES016465
Funding Period: 2009-2025

Project-Specific Links

Final Progress Reports

Year:   2019  2012 

Studies and Results

The following studies were conducted and results obtained in the funding year:

Specific Aim 1: Measure the PM-bound PAH composition and exposure to nonsmoking Chinese and American Indian men and women.

In 2012, the research team published a manuscript in Environmental Science and Technology describing the novel GCxGC/ToF-MS method they developed for the analysis of complex PAH mixtures in samples collected from Superfund Sites. They also published manuscripts on the emission of PAHs from cooking fuels in China in Environmental Science and Technology. In addition, the researchers published manuscripts on human exposure to PAHs in China, including an electronic waste recycling area, in Environmental Science and Technology, Environmental Engineering Science, and Environmental Pollution.

Specific Aim 2: Measure the effect of atmospheric aging on the PAH composition of Asian PM in situ to the U.S. West Coast and in the laboratory.

The research team continued their collaboration with UC-Riverside to measure the photochemical aging of PAHs on Beijing particulate matter (PM) in the laboratory by reacting it with ozone, hydroxyl radicals, and nitrogen oxide species. In addition, the researchers continued to calculate the thermodynamic stability of possible nitro-PAH photochemical products in order to predict which nitro-PAH products may be present in the atmosphere and result in human exposure. They have completed the measurement of the 2011 size fractionated PM samples collected from Beijing, at Mt. Bachelor Observatory, and on the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) for parent PAH, nitro-PAH, oxy-PAH, and high molecular weight PAHs and are comparing modeling, laboratory and field results.

Specific Aim 3: Determine the relative mutagenicity of the different forms of PM.

The research team tested the extracts from the photochemical aging experiments (with and without photochemical reaction) for mutagenicity (Ames Assay using the TA98 strain and TA98 NR strain) and they are in the process of correlating these data with the formation of nitro-PAH products.

Significance

The results to date indicate that the Chinese and Native American populations are exposed to high, and toxicologically significant, PAH concentrations via inhalation. The results also indicate that photochemical transformations occur on Chinese particulate matter under laboratory conditions similar to trans-Pacific atmospheric transport.