Are Numbers Enough? The PFAS Issue

This question is what led me to begin my PhD in Environmental Studies.

In water quality science, numbers are often treated as the whole story. Engineers model contaminant distribution and quantify concentrations with precision. There is a quiet assumption underneath all of this that if we collect enough data, the conclusions will speak for themselves. I have never been convinced that this method captured all the dimensions of chemical contamination.

During my PhD interviews, I explained that I wanted to study how people perceive PFAS risk and who carries the burden of contamination. I was told directly that this was not important research. The reasoning was that PFAS is everywhere, universally distributed, and therefore affects everyone equally. That framing ignores the nuance of contamination and inequality in our society. Ubiquity is not the same as equity.

Alarming PFAS facts and statistics

PFAS, or per- and polyfluoroalkyl substances, are a class of synthetic chemicals used in products like nonstick cookware, stain-resistant fabrics, and firefighting foam. They are often referred to as “forever chemicals” because they persist in the environment and bioaccumulate in the human body, and 99 percent of Americans have detectable PFAS levels in their blood.

But exposure is not uniform, and more importantly, neither is the ability to respond. That is where the idea that numbers are enough begins to fall apart. Concentration data cannot tell us who is most affected, who is most vulnerable, or who has the capacity to do something about it.

A number does not determine behavior. It does not tell us whether someone trusts institutions. It does not capture whether someone feels capable of understanding or addressing the problem. It does not account for the structural inequalities that shape access to time, money, and decision-making power. I have seen this firsthand, working with a rural community dealing with PFAS contamination from a nearby military base. They have access to data and institutional support, which already puts them in a different position than many. Compare that to a community without those resources, and the response will look very different.

Data is powerful, but it does not act on its own. Scientific knowledge is often communicated in ways that are difficult to interpret and disconnected from lived experience. If people do not see themselves in the science, or do not have the time and resources to engage with it, then having the data does not lead to action. Even when information is available, trust in institutions plays a central role. If systems are perceived as broken, individuals are less likely to rely on them for solutions. Even if exposure were equal, which it is not, responses would still differ, and social systems shape outcomes. Economic constraints, competing priorities, and historical relationships with institutions all influence what actions people take. If someone is struggling to feed their family, of course, PFAS contamination may not be top of mind. If someone lacks time, financial resources, or social support, their ability to respond is limited.

Molecular Structure of a PFAS molecule

PFAS contamination is also uniquely challenging because it is invisible and long-lasting. It does not present immediate, obvious effects, yet it carries long-term consequences that can span generations. This makes it even more important to move beyond purely quantitative assessments. As we consider the future of PFAS policy, we need to ask not only where contamination is highest, but who is able to respond and who is being left behind.

Only 8 states have numerical PFAS limits

In the scientific community broadly, there is an overreliance on quantitative data as the primary form of evidence, often at the expense of qualitative methods that capture lived experience, perception, and context. If we are serious about understanding real-world impacts, then qualitative approaches are not supplementary; they are imperative. Numbers can describe patterns, but they cannot fully explain them. At the same time, we are seeing limited progress in regulation. Despite growing datasets and increasing awareness, meaningful policy action often lags. If numbers alone were enough, would we still be here?

As regulatory progress stalls, academia has a responsibility to step in and present fuller stories. This means integrating quantitative data with qualitative insight, and recognizing that evidence is not only what can be measured, but also what can be experienced. If we continue to rely on numbers alone, we will continue to miss critical dimensions of the problems we are trying to solve. Numbers are not enough. Not in the case of PFAS, and not in science more broadly. If we want policy that actually works, we need to start telling the whole story.

Rachel Carson National Environmental Leadership Fellow Symone Franks

Symone is a first-year Master’s student at the University of Colorado Boulder where she is a member of the Equal Water Lab conducting research at the intersection of environmental justice, water quality, and emerging contaminants. She earned her Bachelor’s degree in Earth and Environmental Science with a minor in Sustainability from the University of Missouri Kansas City. As an undergraduate, she was recognized as Honors Student of the Year for her graduating class and was awarded both the Marion Bloch Scholar and KC Scholar distinctions for her academic excellence and leadership.