Using AI to Assess Veterans’ Exposure to Harmful Forever Chemicals

By: Carrie McDonough and Olexandr Isayev

Service members and first responders are disproportionately exposed to low levels of harmful chemicals throughout their careers such as per/polyfluoroalkyl substances (PFASs). CMU has developed new techniques to rapidly identify these chemicals and predict the long-term consequences, with enough time to mitigate the harm.

Why it matters: The groundwater and/or drinking water of more than 700 U.S. military bases have confirmed or suspected PFAS contamination. PFASs are known as “forever chemicals” due to their persistence, and they can stick around and accumulate in the human body over time. Coming investments in energy infrastructure, such as lithium ion batteries, may exacerbate PFASs exposure.

• Long-term exposure can have significant health consequences later in life, including higher risk of testicular and kidney cancer. There are thousands of “forever chemicals,” and most aren’t screened for by available commercial and clinical blood tests, so they go undetected until the harm is irreversible.
• PFASs are very useful for many applications in energy technologies, including their use as electrolytes in lithium-ion batteries, so we expect their production and usage to increase as energy demands grow.

Catch up quick: Thousands of chemical substances are synthesized for many different applications, including chemicals used as food additives, pesticides, dyes, plastic additives, cosmetics and fragrances, industrial products, medicines, and on and on. But the rapid pace of invention and production far outpaces the safety assessments for these chemicals. 

• This is particularly worrisome for military service members and veterans who have been exposed to various chemicals at low levels continuously throughout their careers, including hundreds of forever chemicals ) in aqueous film-forming foams (AFFFs), turnout gear, and other equipment.
• Veterans and military service members are at an increased risk for certain cancers, likely due to chemical exposures during their service. We know very little about how to assess the risks of these exposures with respect to long-term health outcomes.
• Rapid, high-throughput, and predictive methods are rapidly needed to identify PFASs that persist in the blood of service members for years after exposure.

What we’re doing: We are pairing AI techniques with laboratory experimentation and advanced mass spectrometry instrumentation to better understand how these chemicals persist and accumulate in the human body over time, and predict the risks of chemicals based only on their structure.

• This work will lead to tools that will inform improved protective measures going forward.
• These tools will spur the development of more sustainable chemicals and inform the next generation of synthetic chemists, helping to integrate considerations of sustainability into everything we do in the CMU Department of Chemistry.

Key insight: Traditional models used for chemical risk assessment don’t work for “forever chemicals.” We are using chromatographic techniques in our laboratory to separate PFASs from complex mixtures based on their affinities for biological molecules like phospholipids and serum albumin to rapidly learn about the potential of these chemicals to remain in the body long term. Thus far, our work with animal models has demonstrated that in some cases, PFASs we didn’t initially detect in a complex mixture are only discoverable after the undetectable PFASs accumulate in the body — these chemicals wouldn’t be detected or studied if we didn’t have ways to pick them out and identify them as accumulative. 

Policy takeaways: Our work could help pave the way for more rapid risk assessment so that chemical regulations can be shaped on a shorter timescale. In the future, the potential for accumulation and persistence in the body over time can be incorporated for a wider range of new poorly understood “forever chemicals” based on this study.

What’s next: There are many other jobs where chemical exposures are of concern. In addition to assessing chemical exposures among military service members, we are particularly concerned with understanding chemical usage and potential exposures in semiconductor and lithium-ion battery production.