Holly
Holly Dixon

My name is Holly Dixon, and I am a new PhD student in the Dept. of Environmental and Molecular Toxicology (EMT) at Oregon State University (OSU). I grew up in Lake Oswego, Oregon and completed my undergraduate degree in Biology at the University of Puget Sound in Tacoma, Washington in 2014.

During my undergraduate career, I had the opportunity to complete a nuclear forensics internship at the Los Alamos National Laboratory (LANL) and a chemical mixtures internship at the Pacific Northwest National Laboratory (PNNL) through the U.S. Department of Homeland Security. By completing summer internships, I not only discovered that the field of toxicology is the perfect blend of my biology, chemistry, and research interests, but also that one of my career goals is to better understand people’s environmental exposure to toxicants.

I am excited by all of the opportunities I have had at OSU so far – both in my classes and research. I cannot wait to gain more specialized knowledge in toxicology and take part in a long-term research project.  Through the EMT program’s supportive and motivated environment, I know I will grow as a student, researcher, and collaborator.   I am currently working in Dr. Kim Anderson’s lab and learning about her different SRP projects (Project 4).

Recently I had the privilege of being recognized as an OSU ARCS Scholar. This award is for a new PhD student in the College of Agricultural Sciences. As an ARCS Scholar, I receive a stipend for three years to support my graduate studies.

Outside of studying and conducting research, I enjoy playing tennis and exploring the Pacific Northwest. I look forward to spending the next few years in Corvallis.

The SRP Training Core is pleased to support externship opportunities for SRP trainees to provide added experiential training specifically benefiting the trainee’s career goals. This new funding opportunity began in 2014.

Blair Paulik, a Trainee with Project 4, is the first to receive an Externship Award. Blair is receiving travel and lodging support to attend SETAC Europe 25th Annual Meeting, which will be held in Barcelona, Catalonia, Spain, from May 3-7 2015.  

Blair Paulik
Blair Paulik

Attending this meeting will build her leadership and networking skills. She will also have the opportunity to present a part of her PhD research at this international meeting. Blair will be presenting about the impact of unconventional natural gas extraction on air quality.

Blair was elected to be the Vice Chair of the Society of Environmental Toxicology and Chemistry (SETAC) North America Student Advisory Council (NASAC) for a 3-year term beginning fall 2014. She will be one of only a few students from North America to formally represent NASAC and SETAC North America on this global stage.

Blair will come back and share her experience with other SRP Trainees through the upcoming OSU SRP-led quarterly “brown-bag” web conferences with other SRP programs. She also plans to write about her experience to support other students. This opportunity will help Blair become a stronger mentor and bring visibility to our NIEHS SRP Trainee network.

Blair Paulik photo credit: Tyler Moss, Oregon State University
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.

Lane Tidwell photo credit: Hannah O’Leary, Oregon State University
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 Ballroom photo credit: Tyler Moss, Oregon State University
State of the University Address Ballroom
photo credit: Tyler Moss, Oregon State University
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Erin Madeen, Project 1 Trainee

Congratulations to Erin Madeen from Project 1, the first recipient of a Trainee-Initiated Collaboration (TrIC) grant.

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.

OSU Press Release:  http://bit.ly/1sjfefn

MEDIA CONTACT:  David Stauth, 541-737-0787

David Williams, 541-737-3277 or david.williams@oregonstate.edu

12/10/2014

CORVALLIS, Ore. – Researchers for the first time have developed a method to track through the human body the movement of polycyclic aromatic hydrocarbons, or PAHs, as extraordinarily tiny amounts of these potential carcinogens are biologically processed and eliminated.

PAHs, which are the product of the incomplete combustion of carbon, have been a part of everyday human life since cave dwellers first roasted meat on an open fire. More sophisticated forms of exposure now range from smoked cheese to automobile air pollution, cigarettes, a ham sandwich and public drinking water. PAHs are part of the food we eat, the air we breathe and the water we drink.

However, these same compounds have gained increasing interest and scientific study in recent years due to their role as carcinogens. PAHs or PAH mixtures have been named as three of the top 10 chemicals of concern by the Agency for Toxic Substances Disease Registry.

With this new technology, scientists have an opportunity to study, in a way never before possible, potential cancer-causing compounds as they move through the human body. The findings were just published by researchers from Oregon State University and other institutions in Chemical Research in Toxicology, in work supported by the National Institute of Environmental Health Sciences (NIEHS)

The pioneering work has been the focus of Ph.D. research by Erin Madeen at Oregon State, whose studies were supported in part by an award from the Superfund Research Program at NIEHS for her work at Lawrence Livermore National Laboratory.

“We’ve proven that this technology will work, and it’s going to change the way we’re able to study carcinogenic PAHs,” said David Williams, director of the Superfund Research Program at OSU, a professor in the College of Agricultural Sciences and principal investigator with the Linus Pauling Institute.

“Almost everything we know so far about PAH toxicity is based on giving animals high doses of the compounds and then seeing what happens,” Williams said. “No one before this has ever been able to study these probable carcinogens at normal dietary levels and then see how they move through the body and are changed by various biological processes.”

The technology allowing this to happen is a new application of accelerator mass spectrometry, which as a biological tracking tool is extraordinarily more sensitive than something like radioactivity measuring. Scientists can measure PAH levels in blood down to infinitesimal ratios – comparable to a single drop of water in 4,000 Olympic swimming pools, or to a one-inch increment on a 3-billion mile measuring tape.

As a result, microdoses of a compound, even less than one might find in a normal diet or environmental exposure, can be traced as they are processed by humans. The implications are profound.

“Knowing how people metabolize PAHs may verify a number of animal and cell studies, as well as provide a better understanding of how PAHs work, identifying their mechanism or mechanisms of action,” said Bill Suk, director of the NIEHS Superfund Research Program.

One PAH compound studied in this research, dibenzo (def,p)-chrysene, is fairly potent and defined as a probable human carcinogen. It was administered to volunteers in the study in a capsule equivalent to the level of PAH found in a 5-ounce serving of smoked meat, which provided about 28 percent of the average daily dietary PAH intake. There was a fairly rapid takeup of the compound, reaching a peak metabolic level within about two hours, and then rapid elimination. The researchers were able to study not only the parent compound but also individual metabolites as it was changed.

“Part of what’s so interesting is that we’re able to administer possible carcinogens to people in scientific research and then study the results,” Williams said. “By conventional scientific ethics, that simply would not be allowed. But from a different perspective, we’re not giving these people toxins, we’re giving them dinner. That’s how much PAHs are a part of our everyday lives, and for once we’re able to study these compounds at normal levels of human exposure.”

What a scientist might see as a carcinogen, in other words, is what most of us would see as a nice grilled steak. There are many unexpected forms of PAH exposure. The compounds are found in polluted air, cigarettes, and smoked food, of course, but also in cereal grains, potatoes and at surprisingly high levels in leafy green vegetables.

“It’s clear from our research that PAHs can be toxic, but it’s also clear that there’s more to the equation than just the source of the PAH,” Williams said. “We get most of the more toxic PAHs from our food, rather than inhalation. And some fairly high doses can come from foods like leafy vegetables that we know to be healthy. That’s why we need a better understanding of what’s going on in the human body as these compounds are processed.”

The Williams-led OSU laboratory is recruiting volunteers for a follow-up study that will also employ smoked salmon as a source of a PAH mixture and relate results to an individual’s genetic makeup.

Some of the early findings from the study actually back up previous research fairly well, Williams said, which was done with high-dose studies in laboratory animals. It’s possible, he said, that exposure to dietary PAHs over a lifetime may turn out to be less of a health risk that previously believed at normal levels of exposure, but more work will need to be done with this technology before such conclusions could be reached.

Collaborators on the study were from the Pacific Northwest National Laboratory, Lawrence Livermore National Laboratory, and the OSU Environmental Health Sciences Center.

“Further development and application of this technology could have a major impact in the arena of human environmental health,” the researchers wrote in their conclusion.

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