Understanding How Pollutants Change During Remediation

Staci Simonich, Ph.D.

June 14, 2018

Staci Simonich, Ph.D., a professor in the Department of Environmental & Molecular Toxicology and Associate Vice President for Research at Oregon State University (OSU), has been passionate about environmental health since she was a child.

Simonich grew up in Green Bay, Wisconsin near paper mills where her father worked. She says that the beauty of the Great Lakes and an early awareness of how pollution from paper mills and power plants could potentially harm human health set her on a path towards environmental science at a young age.

The first in her family to attend college, Simonich excelled in math and chemistry. She was intrigued by where chemicals in the environment originate, how they move and change, and where they end up. “I’ve always been fascinated by environmental chemistry because I see it as an interesting puzzle, and because it has real world impacts on people and their health,” Simonich noted.

Studying the Behavior of PAHs in Air

In graduate school, Simonich began studying polycyclic aromatic hydrocarbons (PAHs), a group of more than 100 different potentially harmful chemicals that are released during combustion. In fact, some of her early graduate work on PAHs was published in Nature.

“PAHs are really challenging to study because they’re everywhere, and as a group of chemicals they are very diverse and exist in complex mixtures,” she said. “In the real world, PAHs are combined with other contaminants, like metals or polychlorinated biphenyls, and it makes the puzzle even more complex.”

By combining small scale lab experiments, field measurements, and sophisticated models, Simonich and her colleagues have made important discoveries about how PAHs move across great distances and persist in the atmosphere. They have shed light on how PAHs age and react with other chemicals, and how different transport pathways contribute to PAH concentrations they have measured in the field.

Translating PAH Research to Soil

Interestingly, Simonich and her team have found that many of their discoveries and observations about how PAHs move and behave in air can also be applied to understanding PAHs in soil.

Through the OSU Superfund Research Program (SRP) Center, Simonich and her team are working to understand how traditional approaches used to clean up, or remediate, PAHs in soil at Superfund sites can create toxic breakdown products. They have teamed up with environmental engineers at other SRP Centers around the country to study how PAHs in soil change when different common remediation methods are used, including using microbes to remove contaminants, called bioremediation.

“The SRP provides an exciting opportunity to conduct transdisciplinary research not only within each Center, but it also promotes collaboration between Centers,” she noted. “The fact that we have the entire SRP network with diverse expertise to leverage makes our research even stronger. Through these partnerships we can combine our partners’ expertise in environmental engineering and different remediation approaches with our expertise in analytical fate and transport to study PAHs in soil before and after remediation.”

Through this work, Simonich and her team discovered polar transformation products, which are known to be toxic, and high molecular weight PAHs, which are known to damage DNA, in contaminated soil following bioremediation. These findings shed light on the behavior of PAHs in realistic conditions that could inform risk assessment of bioremediated soils, which typically do not consider polar or high molecular weight PAHs, to better protect human health.

In addition to studying how remediation alters PAH chemistry in soil, Simonich and her team have been working to understand how these changes might influence their toxicity. In collaboration with Robert Tanguay, Ph.D., Simonich and her team have found that bioremediation of PAHs leads to breakdown products that are more toxic to zebrafish than the original compounds. Their collaboration has also shed light on the developmental toxicity of PAHs.

Moving forward, Simonich and her team will study whether the PAHs formed during traditional remediation approaches could potentially harm human health. Through this work Simonich and her team aim to identify the PAH breakdown products formed during remediation that are driving toxicity so that remediation approaches can be designed to minimize the formation of these harmful compounds.

Training the Next Generation of Leaders

Simonich understands the importance of training and mentorship to develop the next generation of scientific leaders. In fact, she was recognized by OSU with the Excellence in Graduate Mentoring Award in 2015.

She notes that SRP trainees often do laboratory rotations where they are exposed to interdisciplinary research projects. “The SRP’s strong commitment to training provides trainees from all of the SRP Centers with a variety of career-building activities and experiences.” Some of these experiences include traveling to collaborating institutions, to other SRP Centers, or other labs through the SRP KC Donnelly Externship Award.

“Training and mentorship are not only part of the SRP’s key mission, they are important to me personally,” Simonich noted. “These students truly are the future. I know that the trainees who come in to my lab are going to be at the front lines to make the world a better place in the future.”

A Lifelong Learner

Simonich notes that many of the great opportunities her students have for training and mentorship were not available early in her academic career, but that hasn’t stopped her from continuing to learn. For example, she recently began working towards her Master of Business Administration at OSU, which she says will help her in managing her laboratory, as well as in her new role as Associate Vice President for Research.

In addition, Simonich credits the SRP with adding solutions-oriented research to her agenda. “The SRP has helped my research move from pure environmental and analytical chemistry to including toxicology and risk assessment and really connecting the dots with real-world implications,” she noted. “This focus has been instrumental in guiding the direction of my research and making sure it makes a difference.”

Recently, she was awarded a Clare Boothe Luce Scholarship that provides funds to women in science, technology, engineering, and math higher education to attend the Higher Education Resource Services (HERS) Institute at the University of Denver. Simonich will join a group of approximately 65 women leaders from across the United States as part of the HERS Institute, six of whom were awarded the Luce Scholarship.