The objective of my time at UNC was to learn the DT40 bioassay based on chicken cell lines and use it asses the toxicity of Polycyclic Aromatic Hydrocarbon (PAH)-contaminated soil after bioremediation. Though I was quite excited about the opportunity, I was initially intimidated about leaving the familiarity of the chemistry lab at Oregon State University (OSU) and flying cross country to immerse myself in the unfamiliar (and very sterile!) world of cells and assays. It was a definite humbling learning experience; working with living cells taught me just how much of a virtue patience is –something that has helped me develop personally and as a researcher.
The KC Donnelly Externship created a platform on which we were able to combine analytical chemistry, biological and environmental engineering, and toxicology to address a shared concern. I was really inspired by the integration of the different ideas and mindsets from the various fields as we developed this project.
Before the externship, I was analyzing PAHs in remediated soil samples. At UNC, I learned about the DT40 assay and actually got to see how a lab-scale bioreactor (meant to simulate ex situ bioremediation) operated. I feel I now have a better understanding of how bioremediation works and the toxicity concerns often associated with PAHs. The experience has really added more depth to my research at OSU.
The externship was a very intense three months, but I really believe it was a pivotal moment in my development as an environmental health scientist; and has made me more appreciative of my research project. I also just had a great time interacting with everyone at the UNC Superfund Research Program (SRP).
A very powerful and sensitive instrument used to study trace amounts of chemicals is a gas chromatograph connected to a mass spectrometer, or GCMS. GCMS is especially useful for air samples, but it is also used to detect, quantify, and identify chemicals in water, soil, plant and animal tissue, and many other substances.
The GCMS can detect chemicals in amounts as small as a picogram. That is 0.000000000001 gram. One picogram is the equivalent of one drop of detergent in enough dishwater to fill a trainload of railroad tank cars ten miles long. Many of the pollutants found in air are present at concentrations lower than one picogram in a cubic meter of air. It is important for an the instrument to be able to detect these low concentrations.
The GCMS instrument is made up of two parts.
The gas chromatography (GC) portion separates the chemical mixture into pulses of pure chemicals
The mass spectrometer (MS) identifies and quantifies the chemicals.
The GC separates chemicals based on their volatility, or ease with which they evaporate into a gas. It is similar to a running race where a group of people begin at the starting line, but as the race proceeds, the runners separate based on their speed. The chemicals in the mixture separate based on their volatility. In general, small molecules travel more quickly than larger molecules.
The MS is used to identify chemicals based on their structure. Let’s say after completing a puzzle, you accidentally drop it on the floor. Some parts of the puzzle remain attached together and some individual pieces break off completely. By looking at these various pieces, you are still able to get an idea of what the original puzzle looked like. This is very similar to the way that the mass spectrometer works.
Gas chromatography (GC)
Injection port – One microliter (1 µl, or 0.000001 L) of solvent containing the mixture of molecules is injected into the GC and the sample is carried by inert (non-reactive) gas through the instrument, usually helium. The inject port is heated to 300° C to cause the chemicals to become gases.
Oven – The outer part of the GC is a very specialized oven. The column is heated to move the molecules through the column. Typical oven temperatures range from 40° C to 320° C.
Column – Inside the oven is the column which is a 30 meter thin tube with a special polymer coating on the inside. Chemical mixtures are separated based on their votality and are carried through the column by helium. Chemicals with high volatility travel through the column more quickly than chemicals with low volatility.
Mass Spectrometer (MS)
Ion Source – After passing through the GC, the chemical pulses continue to the MS. The molecules are blasted with electrons, which cause them to break into pieces and turn into positively charged particles called ions. This is important because the particles must be charged to pass through the filter.
Filter – As the ions continue through the MS, they travel through an electromagnetic field that filters the ions based on mass. The scientist using the instrument chooses what range of masses should be allowed through the filter. The filter continuously scans through the range of masses as the stream of ions come from the ion source.
Detector – A detector counts the number of ions with a specific mass. This information is sent to a computer and a mass spectrum is created. The mass spectrum is a graph of the number of ions with different masses that traveled through the filter.
The data from the mass spectrometer is sent to a computer and plotted on a graph called a mass spectrum.
The Unsolved Mysteries of Human Health web site was developed by the Environmental Health Sciences Center, another NIEHS-funded Center at OSU. The GCMS section of the web site was developed in collaboration with Dr. Staci Simonich, Superfund Center Project 5 leader. The interactive image above received about 37,000 pageviews this past year (up about 10,000 from the previous year). It is the most popular page coming out of our Centers.
Unfortunately, the interactive image does not currently work on an iPhone or iPad.
On Oct. 16th, Dr. Paul Slovic visited Oregon State University to share and discuss issues related to risk communication with graduate students enrolled in the TOX 507/607 seminar. This term the seminar is co-lead by the Superfund Research Center’s Research Translation Core and Training Core.
Dr. Slovic, a founder and President of Decision Research, studies human judgment, decision making, and risk analysis. His research and expertise fit nicely with this term’s seminar focus on training students to communicate science and risk effectively to audiences outside of academia.
Some key points came out of the Q and A session with Dr. Slovic.
1) The importance of message framing.
After you publish a scientific paper, focus on how you will frame that information to the public.How can you help your audience conceptualize the bottom line of the research? The facts never speak for themselves, which is why scientists need to “frame” their messages to the public.
All information is conveyed with a frame. Framing in science and risk communication can be viewed as positive or negative depending on who the audience is and what kind of information is
being presented. There is rarely neutral framing. For that reason, it is important to have a clear message thoughtfully framed to invoke a desirable response by your audience.
Create messages that resonate with your audience.
2) The role of emotions and uncertainty.
Understand that risk perception comes from our gut feelings. How you share information makes a difference, creates an image, and impacts a person’s perception of risk.
Our emotions are often tied to our motivation, positive or negative. Information will lack meaning if it does not invoke emotion.
If something is uncertain, people can interpret it the way that they want. (Example: When scientists began sharing studies that cigarette smoking caused cancer, the tobacco industry wanted to cultivate doubt, so they could keep their profits.). With certain topics, industry and others want to emphasize the unknowns and cast doubt.
When research studies are not definitive, help the public understand the strengths and limitations of that study. Frame the information so it is not biased, focusing on what the science predicts and the implications of that prediction.
Be sure to present the data the best you can if you think people are distorting the data.
3) Visuals make research real and relevant.
Visual images are more powerful than statistics. Visuals help the mind process information. Make your research real and relevant by using visuals that invoke emotion and foster scientific understanding.
Find and share this seminar’s highlights and related articles on Twitter with hashtag#TOX607
Andy Larkin is working with David Williams and William Baird at OSU and just started his fourth year as a Ph.D. student. Larkin is doing great work and we look forward to his presentation on atmospheric pollutant models and smartphones in an upcoming Risk e Learning webinar.
Larkin’s Ph.D. research involves several different projects, all of which are designed to bridge the gap between basic research and risk assessment. Larkin is working on computational modeling for predicting biological responses to PAH mixtures, real time forecasts of atmospheric PM2.5, PM10, and ozone for the state of Oregon, and smartphone programs to predict and prevent atmospheric pollutant exposures.
While he has won an impressive seven awards* as a graduate student, he was most proud of winning second place in the Oregon State three-minute thesis competition. Although not the most prestigious of his awards, Larkin explains that, “Creating a summary of a thesis designed to be understood by the public and less than three minutes in length was by far the most challenging presentation of my graduate studies, and it was thoroughly rewarding to have so many members of the general public understand and enjoy the presentation.”
When he isn’t busy working on his outstanding graduate research projects, he enjoys community volunteer work and ultramarathon running. Larkin just ran the Portland Marathon on October 6 and his next ultramarathon is the Florida Keys 100 mile run in May!
After Larkin finishes his Ph.D., he hopes to work for a research group or regulatory agency to develop technologies for reporting real-time risk assessment and risk communication information. He also hopes these technologies will help to prevent unwanted exposures in sensitive populations.
*Note: The Training Core web site shares more specifics about Larkin’s recent awards.
The UC Davis Entrepreneurship Academy was a unique learning experience that teaches the basics of intellectual property as well as marketing and launching a new business. While I am not currently interested in launching a company, this experience provided valuable information on how to maintain flexibility with intellectual property.
As scientists, especially in the SRP, we are always developing new methods and systems to answer our specific questions. Many of those techniques or systems are patentable. Our goal as a federally funded program supported by tax payers is to provide accurate data that can be used to develop environmental policy for a better society. I was not aware that technology used to generate that data is patentable, only in the instance that it was not described in the public domain prior to applying for a patent. Additionally, once a patent has been applied for, the specifics of the technology can be presented in the public domain as a paper, or a presentation.
Also attending the academy were several prior SRP students from UC Davis and UC Berkeley who were able to patent technologies with their respective universities as students and are now launching companies with the technology licensed through the university.
It was an interesting experience to see the traditional binary of industry or academic lines blurred.
The Superfund Research Program is federally funded and administered by the National Institute of Environmental Health Sciences (NIEHS grant #P42 ES016465), an institute of the National Institutes of Health.