The McCormick and Baxter Superfund Site is located on the Willamette River in Portland, Oregon and has PAH contaminated soils and sediments from historical creosote operations. As part of an Oregon Department of Environmental Quality (ODEQ) ten year study to assess the effectiveness of the sediment cap, passive sampling devices from Kim Anderson’s lab were deployed by U.S. EPA Region 10 divers in both sediment and water at the site. Included in this study was a newly designed passive sampling sediment probe which allowed for deployment in the rocky armoring of the sediment cap. Based on data from this study, the ODEQ reported that the sediment cap appears to be effective in meeting its remedial objectives. The full results of the study, used to inform ODEQ regulatory decision making, is available here (https://semspub.epa.gov/work/10/100031136.pdf), beginning on page 20.
Dr. Staci Simonich led the study team. Photo by Lynn Ketchum, OSUCORVALLIS, Ore. – Air pollution controls installed at an Oregon coal-fired power plant to curb mercury emissions are unexpectedly reducing another class of harmful emissions as well, an Oregon State University study has found.
Portland General Electric added emission control systems at its generating plant in Boardman, Oregon, in 2011 to capture and remove mercury from the exhaust.
Before-and-after measurements by a team of OSU scientists found that concentrations of two major groups of air pollutants went down by 40 and 72 percent, respectively, after the plant was upgraded. The study was published in the journal Environmental Science & Technology this month.
The Boardman plant, on the Oregon side of the Columbia River about 165 miles east of Portland, has historically been a major regional source of air pollution, said Staci Simonich, environmental chemist in OSU’s College of Agricultural Sciences and leader of the study team (OSU SRP Project 5).
“PGE put control measures in to reduce mercury emissions, and as a side benefit, these other pollutants were also reduced,” she said.
The pollutants in question are from a family of chemicals called polycyclic aromatic hydrocarbons (PAHs), which are formed from incomplete combustion of fossil fuels and organic matter. PAHs are a health concern because some are toxic, and some trigger cell mutations that lead to cancer and other ailments.
Simonich and her team tracked concentrations of airborne PAHs during 2010 and 2011 at Cabbage Hill, Oregon (elevation 3,130 feet), about 60 miles east of the Boardman plant, and also at the 9,065-foot summit of Mount Bachelor 200 miles to the southwest.
They sampled approximately weekly from March through October of 2010, and again from March through September of 2011. They analyzed the samples for three major groups of PAHs: the parent chemicals and two “derivatives”— groups of PAH chemicals resulting from the decomposition of the parent PAHs.
The 2011 measurements at Cabbage Hill showed significantly reduced concentrations of the parent PAHs and also of one of the derivative groups, called oxy-PAHs (OPAHs). The other derivative group, called nitro-PAHs (NPAHs), did not show significant reduction. The NPAHs were more likely to have come from diesel exhaust associated with Interstate Highway 84, Simonich said.
Some of the individual PAH chemicals were reduced so much after the upgrade that the researchers couldn’t tell from the data whether the plant was running or not, she added.
“The upgrades reduced the PAH emissions to the point where we could hardly distinguish between air we sampled along the Gorge and at the top of Mount Bachelor.” While Oregon’s mountaintops typically have less air pollution than lower-lying areas, Simonich’s previous work has shown that they are not pristine.
Scott Lafontaine
She and her student Scott Lafontaine stumbled upon the Boardman findings while studying PAHs that originate in Asia and ride high-level air currents across the Pacific Ocean. They were measuring how much of each PAH type was coming from Asia, and how much from within the Northwest or elsewhere.
“We wanted to see if there was the same level of trans-Pacific transport at lower elevations—where people actually live—as we’ve previously found at Mount Bachelor,” Simonich said.
When the researchers analyzed the Cabbage Hill data for 2010, they found high levels of the chemicals they were studying, but the pollutants did not have an Asian signature.
Then in 2011, they found that the Cabbage Hill concentrations of the parent PAHs and OPAHs were much lower than they’d been in 2010.
“We looked at the data and said, ‘Wow! 2010 is different from 2011, and why should that be?’” Simonich said. “We had trouble understanding it from a trans-Pacific standpoint. So we started thinking about regional sources, and that’s what led us to look at emissions from Boardman.”
They got in touch with officials at PGE and learned about the April 2011 upgrade. Their review of PGE’s emission records revealed correlations with their own measurements. They concluded that the reductions in PAH concentrations at the Cabbage Hill site were caused by the 2011 upgrade.
The upgrade may also aid her research, Simonich said. “When you have a major point source of pollution nearby, it’s hard to pick out the signal of the Asian source coming from farther away. Now that these emissions are reduced, we may be able to pick up that signal much better.”
More important, she said, the air is cleaner.
“Boardman used to be a major source of PAH pollution in the Columbia River Gorge, and now it’s not,” she said. “That’s a good thing for PGE and a good thing for the people living in the Gorge.”
The study was funded by the OSU Superfund Research Program, a multidisciplinary center administered by the National Institute of Environmental Health Sciences. Pacific Northwest National Laboratory and the Confederated Tribes of the Umatilla Indian Reservation collaborated on the research.
Scott Lafontaine received his MS in Chemistry at OSU and is now pursing a Ph.D. in Food Science with Dr. Thomas Shellhammer in the Food Science Department.
I am focusing on brewing science and specifically on advancing the understanding of the chemical behavior of hop flavor and aroma in beer. I am very excited to have the opportunity to continue my graduate studies at OSU, within a program that has been analyzing hops since 1932. I look forward to using my unique background and education to bridge some of the concepts I learned while working on my master’s thesis. I want to be able to bring a new perspective to some of the key questions in this field.
This is an Oregon State University press release from 5-8-15 that shares about the collaborative research project of Project 1 and Core C – Biostatistics and Modeling.
– By Gail Wells, 541-737-1386, gail.wells@oregonstate.edu, on Twitter @OregonStateExt
Source: Susan Tilton, 541-737-1740, susan.tilton@oregonstate.edu http://bit.ly/OSU_AgNews1542
CORVALLIS, Ore. – Scientists at Oregon State University have developed a faster, more accurate method to assess cancer risk from certain common environmental pollutants.
Researchers found that they could analyze the immediate genetic responses of the skin cells of exposed mice and apply statistical approaches to determine whether or not those cells would eventually become cancerous.
The study focused on an important class of pollutants known as polycyclic aromatic hydrocarbons, or PAHs, that commonly occur in the environment as mixtures such as diesel exhaust and cigarette smoke.
Dr. Susan Tilton
“After only 12 hours, we could predict the ability of certain PAH mixtures to cause cancer, rather than waiting 25 weeks for tumors to develop,” said Susan Tilton, an environmental toxicologist with OSU’s College of Agricultural Sciences.
For at least some PAH mixtures, the new method is not only quicker but produces more accurate cancer-risk assessments than are currently possible, she said.
“Our work was intended as a proof of concept,” said Tilton, who is also affiliated with the OSU’s multidisciplinary Superfund Research Program, a center funded by the National Institute of Environmental Health Sciences (NIEHS).
“The method needs to be tested with a larger group of chemicals and mixtures. But we now have a model that we can use to develop larger-scale screening tests with human cells in a laboratory dish.”
Such a method will be particularly useful for screening PAHs, a large class of pollutants that result from combustion of organic matter and fossil fuels. PAHs are widespread contaminants of air, water and soil. There are hundreds of different kinds, and some are known carcinogens, but many have not been tested.
Humans are primarily exposed to PAHs in the environment as mixtures, which makes it harder to assess their cancer risk. The standard calculation, Tilton said, is to identify the risk of each element in the mix – if it’s known – and add them together.
But this method doesn’t work with most PAH mixes. It assumes the risk for each component is known, as well as which components are in a given mix. Often that information is not available.
This study examined three PAH mixtures that are common in the environment – coal tar, diesel exhaust and cigarette smoke – and various mixtures of them.
They found that each substance touched off a rapid and distinctive cascade of biological and metabolic changes in the skin cells of a mouse. The response amounted to a unique “fingerprint” of the genetic changes that occur as cells reacted to exposure to each chemical.
By matching patterns of genetic changes known to occur as cells become cancerous, they found that some of the cellular responses were early indicators of developing cancers. They also found that the standard method to calculate carcinogenic material underestimated the cancer risk of some mixtures and overestimated the combined risk of others.
“Our study is a first step in moving away from risk assessments based on individual components of these PAH mixtures and developing more accurate methods that look at the mixture as a whole,” Tilton said. “We’re hoping to bring the methodology to the point where we no longer need to use tumors as our endpoint.”
Tilton collaborated on the research with Katrina Waters of the Pacific Northwest National Laboratory, and others. Their findings appeared in a recent edition of Toxicological Sciences.
The study was funded by NIEHS, which supports the Superfund Research Program, a multi-partner collaboration that includes OSU and PNNL.
SRP Trainee Blair Paulik photo credit: Tyler Moss, Oregon State University
Oregon State University Superfund Research Program trainees Blair Paulik and Lane Tidwell were selected to represent the College of Agricultural Science at the annual State of the University Address 2015 held in Portland Oregon on January 30th.
Only one department from each college was selected to represent important work and trainee development that occurs in the college. PhD candidates Paulik and Tidwell highlighted the research the Food Safety and Environmental Stewardship Program in the Department of Environmental and Molecular Toxicology has been conducting for last 15 years in the Portland Harbor Superfund site.
SRP Trainee Lane Tidwell photo credit: Hannah O’Leary, Oregon State University
While at the event the trainees were able to talk with many OSU alumni, stakeholders and supporters. Conversation topics ranged from current research occurring in the EMT department, the FSES program and the College of Agricultural Sciences to what the individual trainees hoped to do after graduation. Trainees Paulik and Tidwell were proud to represent the FSES program, the EMT Department and the College of Agriculture at this important outreach and engagement event with about 800 attendees.
State of the University Address Ballroom photo credit: Tyler Moss, Oregon State University
Erin will receive $2500 for travel and lodging to work with Ulrike Luderer MD, PhD, a Reproductive Toxicologist and expert in polycyclic aromatic hydrocarbon (PAH) Benzo(a)pyrene (BaP) induced female infertility at UC Irvine.
Dr. Luderer will train Erin on methods to histologically analyze ovaries and testes from mice treated prenatally with the PAH, dibenzo[def,p]chrysene (DBC), in a Project 1 study. This unique training opportunity will help further research exploring how exposure of pregnant mothers to PAHs induces reproductive effects in their offspring.
This area of research is valuable as several individual PAHs are well documented to cause reproductive effects that include abnormal morphology, reduced fertility, infertility, and cancers. DBC has not previously been studied as a reproductive toxicant.
A comparison of BaP and DBC reproductive effects could be useful for risk assessors and modelers as PAHs occur in dynamic mixtures.
This is an exciting new collaboration with the Luderer Lab.
