Notre Dame 2019 - Physics Excellence

Researchers study presence of fluorinated chemicals in firefighter clothing

National QuarkNet physics program to continue educating high school teachers

The Search for Heavy Metals

Researchers study presence of fluorinated chemicals in firefighter clothing

By Jessica Sieff

Graham Peaslee 300x350Graham Peaslee

Scientists at the University of Notre Dame will begin an independent study of turnout gear worn by firefighters after initial samples tested positive for fluorine.

Graham Peaslee, a professor of experimental nuclear physics at the University of Notre Dame, and his lab tested fabric swatches taken from unused personal protective gear for the presence of perfluorinated alkyl substances (PFASs).

“The results were phenomenal — off the scale in parts per million of fluorine in all but one of the samples,” Peaslee said. “Everything was just loaded with fluorine.” Following the initial tests, Peaslee is leading a study of new and used turnout and personal protective gear issued throughout the 2000s, including jackets, pants and undershirts — all of which are either new or have been in service for more than a decade.  

Various forms of PFASs have been linked to prostate, kidney and testicular cancers, as well as thyroid disease and low birthweight. The chemicals are commonly associated with stain-resistant products and the manufacture of nonstick cookware. In 2017, Peaslee was one of several researchers who uncovered the presence of PFASs in fast-food wrappers.

The chemicals are also a component of aqueous film-forming foams. These foam fire suppressants have been linked to incidents of contaminated drinking water. In Michigan, where a number of communities have traced water contamination to the use of the foam, some fire officials are working to limit its use or to use alternative, PFAS-free formulas when possible. The United States Air Force began phasing out PFAS-based foam for an environmentally safer alternative in 2016, and finished replacing its stock in 2017.

To test for PFASs, Peaslee’s lab uses particle-induced gamma-ray emission spectroscopy, a novel and specialized method he developed as an efficient and cost-effective way to analyze for total fluorine content. For this study, Peaslee said he and his students plan to test for content and how much — if any — is coming off the fabric with time and use.

“We’re going to measure each piece of gear and look at the difference in fluorine content over time and extensive use, including after the fabric has been washed, and look at how much of the chemical can transfer off the fabric,” he said. “The obvious thing is, if you take the new gear and wash it — do the measurements match the old gear? I can also then take the water from the wash and test the liquid. We can expose swatches of this fabric to heat and light and see if the fluorine content is affected. Will the chemical bonds break down?”

The breakdown of those chemical bonds in textiles and the transfer of PFASs is what concerns Peaslee the most. PFASs don’t degrade easily, and have an especially long half-life, meaning that those chemicals remain in the environment for many years, whether accumulating in the ground or the body.

Though scientists have not yet learned if PFASs can transfer to the human body simply by coming in contact with the skin, Peaslee co-authored a study in 2017 describing a method to track certain PFASs in mouse models. The results of that study suggest certain PFASs, such as short-chain PFAS compounds, can accumulate in various organs such as the brain and stomach.

“If I can see a measurable decrease from our tests, that means the PFAS has gone into the environment,” Peaslee said. “That environment is in the workplace where these firefighters work, and where these firefighters live. That would be a pretty significant finding. I think it’s a study that needs to be done.”

National QuarkNet physics program to continue educating high school teachers

By Deanna Csomo McCool

QuarkNet, a program founded at Notre Dame that brings university-level physics research opportunities to high school teachers and students across the country, has been granted funding through 2023 by the National Science Foundation (NSF). The NSF has funded the program since its inception in 1998.


Mitchell Wayne

In addition to $3 million in direct NSF funding, QuarkNet will receive another $1.25 million over five years via NSF support of two collaborative particle detector experiment groups at the European Organization for Nuclear Research (CERN), which operates the Large Hadron Collider, the world's largest particle collider, in Geneva, Switzerland. The two experiments, ATLAS and CMS, benefit from work generated by teachers at the 52 QuarkNet centers across the United States.


“It’s greatly satisfying to receive this funding,” said Mitchell Wayne, a professor in the Department of Physics who has been lead principal investigator for the QuarkNet program since 2004. In addition to Wayne, the other co-principal investigators for the program include Marjorie Bardeen, of Fermilab, and Morris Swartz, of Johns Hopkins University.   “QuarkNet is a wonderful program, and is very well known in the particle physics community. It’s done great things for teachers and students over the past two decades, and I believe that QuarkNet has played an important role in U.S. particle physics during that time.”


Randal Ruchti

The program was the brainchild of Randal Ruchti, professor of physics, and three other co-founders, who wanted to resurrect interest and investment in the field in the 1990s after federal funding dried up for a planned particle collider in Texas. When that project, known as the Superconducting Super Collider, was abandoned, hundreds of physicists who had dedicated years of research to the project lost their jobs and left the field. Ruchti saw a need to rebuild public support for long-term physics research, as well as to develop a pool of future particle physicists.


Engaging high school teachers was his solution. With the support of Fermilab, the particle physics and accelerator laboratory located in Batavia, Illinois, and two other universities, the first four QuarkNet centers were launched in 1998 with short-term funding from the NSF. The agency began funding QuarkNet in five-year cycles the following year.


Nationally, more than 400 teachers each year gain scientific experience by working with university professors and laboratory scientists, according to Wayne. The teachers and their students have created components that have been installed in the detectors at the LHC, which in 2012 discovered the Higgs boson, a particle that bridged the gap in the understanding of the Standard Model of Physics. At Notre Dame’s center, 929 Eddy Street, an average of 15 teachers from schools within a 50-mile radius participate annually.


During previous funding cycles, enough money was granted so each QuarkNet center could also fund high school researchers. However, that component was dropped for this cycle, Wayne said, so the centers will need to seek internal funding to support students. Fermilab is continuing to support the program by funding a half-time staff teacher and providing computing and technical support for the entire program, Wayne noted, and is also designating a neutrino physicist to assist with projects.


With support from Notre Dame International, Wayne and QuarkNet national staff teacher Ken Cecire have brought QuarkNet activities to Santiago, Chile, and Mexico City, and they are exploring other international opportunities. 


The Notre Dame QuarkNet center will move from the Eddy street location to a larger facility on Douglas Road, north of campus, in spring 2019. The planned move had been in the works before the most recent NSF grant was finalized.


The Search for Heavy Metals

By Jessica Sieff

Heavy Metals: The search for rare stars that could unlock a mystery of the universe