Ivan Titaley
Ivan Titaley

By Ivan Titaley, Project 5 Trainee

Back in April, I was awarded the SRP Trainee Externship Award through OSU’s SRP Training Core to help support my training opportunity at the Pacific Northwest National Laboratory (PNNL) as an Alternate Sponsored Fellow. The aim of this internship was to predict the formation of hydroxy- and oxygenated‑PAHs (OHPAHs and OPAHs, respectively) in the environment using a computational chemistry approach. OPAHs and OHPAHs can be formed from the degradation of PAHs. OPAHs in air samples have been found to be more mutagenic than the unsubstituted PAHs.

To achieve this objective, I used the NWChem software, which is a high performance computational chemistry software developed by PNNL scientists. Through a collaboration set-up by Dr. Dayle Smith (previously in Core C), I spent two months learning how to use NWChem under the supervision of Dr. Kurt Glaesemann.

The Environmental and Molecular Science Laboratory (EMSL) is a national user facility that houses multiple instruments and laboratories. My office was located inside this building at PNNL in Richland, WA.
The Environmental and Molecular Science Laboratory (EMSL) is a national user facility that houses multiple instruments and laboratories. My office was located inside this building at PNNL in Richland, WA.

Using this approach, my goal was to be able to predict which OHPAHs and OPAHs are likely to form in the environment based on their thermodynamic properties, specifically the reaction Gibbs free energy. There were three main areas related to Project 5’s focus where this predictive capability will be helpful. First, the results could assist in explaining why toxicity in remediated soils increased, even after PAHs’ concentrations went down (e.g. Chibwe et al., 2015). Secondly, prior data of OHPAHs found in human urine, (e.g. Motorykin et al., 2015) can be compared with computational results to see if I can formulate a prediction of which OHPAHs are likely to form in human urine. Finally, continuing on prior work that has predicted the formation of NPAHs in ambient air (e.g. Jariyasopit et al., 2013), I could then apply similar approach, but for OHPAHs and OPAHs.

The learning curve during my externship was quite steep. Although I was able to understand how to use NWChem, I also learned that a one-size-fits-all approach was not possible and I would need to tailor my modeling approach to successfully predict formation of OHPAHs and OPAHs. It was during this time that I found out how valuable it was for me to be able to spend time at PNNL. Being in a facility where there were experts in almost every imaginable field, I was able to talk to many experts about issues that I faced. These conversations led me to the field of chemometrics which helped me tailor the computational chemistry approach accordingly. One of the online programs that I found to be useful was XenoSite, which can predict CYP450 inhibition sites on a given compound. This program can potentially be useful when narrowing down potential OHPAHs that might form through bioactivation.

In addition, the myriad instruments and facilities that are available at PNNL have also assisted me greatly during my internship. For example, the NWChem software that I used was connected to the supercomputing facility, which helped speed up the calculation, resulting in faster computational time. Another perk of being in Richland, was that I managed to tour the Hanford B Reactor—coincidentally a couple of days before the anniversary of the atomic bomb being dropped in Japan.

All in all, the externship challenged me to get me out of my comfort zone, but also rewarded me with a new skill and unique

Constance, my "instrument" over the summer. Constance is one of several supercomputers available at PNNL.
Constance, my “instrument” over the summer. Constance is one of several supercomputers available at PNNL.

experience. In a way, the internship at PNNL served as a preview of what may come once I am finished with my Ph.D. More importantly, I found the networking opportunity and exposure to a possible career path while at PNNL to be invaluable. Currently, I am excited to combine the in silico approach that I learned at PNNL with the analytical chemistry approach at the Simonich lab into my research projects. The chemical analysis component will verify how accurate the prediction capabilities are. If this approach is proven to be reliable, I hope that this perspective can offer a different insight in predicting the formation of OHPAHs and OPAHs.

 

 

By Lisandra Santiago-Delgado, Project 5 Trainee

Lisandra Santiago-Delgado
Lisandra Santiago-Delgado

Earlier this summer I conducted research at the USEPA Robert S. Kerr Research Laboratory in Ada, Oklahoma under the guidance of Dr. Eva L. Davis. This experience was made possible through the KC Donnelly Externship Award Supplement that I received in late April.

Research Benefits

The main objective of my externship was to collaborate and learn from Dr. Davis, an expert in the field of thermal remediation of contaminated soils and groundwater. I focused on utilizing steam injections on a laboratory scale to thermally remediate creosote-contaminated Superfund soils.

Another goal of this externship was to understand the chemical processes that occur during and after remediation. I looked at measurements of polycyclic aromatic hydrocarbons (PAHs) and their transformation to oxygenated PAHs (oxy- and hydroxy-PAHs) in soils, as well as their potential developmental toxicity and mutagenicity.

This partnership was a great fit, because it combined the expertise of Dr. Davis, involving thermal remediation of soil, with our expertise in soil analysis for PAHs and oxygenated PAHs, and toxicity assays in our SRP Project 3, directed by Dr. Robyn L. Tanguay.

Career Impact

The experimental setup used for one-dimensional steam injections.  It consists of two ISCO syringe pumps (left), steam generator (upper middle), column with soil sample (middle), and the computer to collect temperature data in the right.
The experimental setup used for one-dimensional steam injections. It consists of two ISCO syringe pumps (left), steam generator (upper middle), column with soil sample (middle), and the computer to collect temperature data in the right.

I have always considered a career path with the federal government.   This experience allowed me to experience first-hand what it would be like. Preparing to work in a federal facility was probably, and surprisingly, one of the greatest initial challenges of the project. It included paperwork, security clearance procedures, and training, among many other things.

Having the opportunity to meet, collaborate, and have one-on-one conversations with Dr. Davis was a fulfilling experience, especially since she is a female scientist. I also met other scientists working in the same facility, but base their research here in the Willamette Valley. Other experiences included participating in their weekly seminars, where they present trending topics of importance to the environment and the USEPA, as well as their own research updates.

Outside of research, weather was a big challenge, especially since my externship began in the middle of tornado season. One afternoon I had to spend over a half hour in a closet while the sirens were blaring. My next visit will be before May, for sure!

Summary

The externship was definitely an incredible experience, and it provided me with better understanding of thermal remediation and new knowledge about soil and how chemicals behave underneath the surface. I encourage other SRP trainees to apply for the KC Donnelly Externship Award Supplement. You will not regret it, and the outcome will be very valuable for your current research and future work as well.

The EPA provided a welcoming atmosphere and the OSU beaver was a nice touch.
The EPA provided a welcoming atmosphere and the OSU beaver was a nice touch.

SRP Trainee Mitra Geier was able to attend The International Neurotoxicology Association and Neurobehavioral Teratology Society joint meeting last month with her Externship Award from the SRP Training Core. The aim of the Externship Award is to support opportunities for SRP trainees that will provide enhanced experiential learning activities that benefit the trainee’s career goals.

Networking and face-time with peers and scientists is an essential part of an Externship opportunity.  At the conference, Mitra was able to interact and formalize her connections with other trainees from five different SRP centers across the country, including students whose work involved epidemiology, cell culture, fish, and mammalian model systems.  She will be reporting back to the OSU SRP trainees at their monthly meeting about what she learned from the other trainees at the conference related to their Superfund Centers, their activities, and their interests.

Mitra was also able to attend sessions and interact with leading scientists. She attended sessions to learn about different methods for assessing neurotoxicity, including mechanistic and behavioral effects, especially in the context of how the different models can be used to approach similar questions.   Mitra attended the sessions on neurotoxicants in air pollutants and inhaled particles, which are particularly relevant to her research. There was also sessions related to neurotoxicology screening studies and non-mammalian models of neurotoxicity including fish studies that were highly applicable to her screening work in zebrafish. The sessions on epigenetics and the microbiome were not directly related to her work, but she found them very useful in her long-term research interest development.

Mitra Geier
Mitra Geier

Mitra Geier is a PhD student working under Dr. Robyn Tanguay with Project 3: Systems Approach to Define Toxicity of Complex PAH Mixtures.

Mitra received her B.S. in Environmental Science from Western Washington University.  Her current research is focused on defining the developmental toxicity of parent and methylated PAHs, the neurobehavioral effects of these compounds during the embryonic stage and in adulthood, and the molecular pathways involved in these effects using the embryonic zebrafish model.

Chemistry graduate student Ivan Titaley has been immersed in polycyclic aromatic hydrocarbon (PAH) research within SRP Project 5 – Formation of Hazardous PAH Breakdown Products in Complex Environmental Mixtures at Superfund Sites under Dr. Staci Simonich.

Ivan Titaley
Ivan Titaley

Recently, Ivan was selected by Dr. Dayle Smith as a sponsored fellow at the Pacific Northwest National Laboratory (PNNL) to get hands-on training in modeling of polycyclic aromatic hydrocarbons. This program is through the Office of Science and Engineering Education (SEE) at PNNL. The selection is commendable, and will allow Ivan to apply new modeling techniquesl in his own research on OPAHs and OHPAHs transformation processes.

To financially support Ivan on this unique training opportunity, he has been awarded an SRP Trainee Externship Award through the SRP Training Core. This activity provides important synergy between Project 5 and Core C – Biostatistics and Modeling.

Dr. Smith will provide mentoring for Ivan to perform computational chemistry work to predict the formation of oxygenated-PAHs (OPAHs) and hydroxy-PAHs (OHPAHs) from higher molecular weight parent PAHs. More specifically, Ivan will be working using the NWChem 6.5 computational chemistry software. Using thermodynamic data on potential OH-PAH-adduct, he will be able to show which compounds will form based on thermodynamic stability.

Congratulations, Ivan!

 

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.