Shira Joudan

Trifluoroacetic acid is a contaminant that likes to move around. Scientists have found the chemical, known as TFA, in the deep ocean, in the Arctic, in plants, and in our blood. TFA also doesn’t biodegrade, so it persists in the environment. But unlike many other persistent pollutants, TFA has few direct sources. Most comes from reactions involving other contaminants. Shira Joudan identifies and studies these reactions to find out exactly where TFA is coming from.Joudan is interested in how contaminants get where they are “and how we can understand chemical reactions to better understand their fate,” she says. This information can help scientists estimate our exposure to contaminants, guide policymakers as they design regulations, and teach chemists how to build molecules that don’t break down into something problematic.Currently, scientists have limited data on TFA’s toxicity in humans and other organisms. But TFA is the most abundant per- and polyfluoroalkyl substance (PFAS) found in the environment—although not everyone groups TFA with PFAS—and its levels are growing. Levels of TFA in different environments are as much as 10 times as high as levels measured a few decades ago. Joudan thinks that persistent chemicals like TFA are worth studying because, as they stick around, they can reach concentrations that might be toxic. Policymakers in the US and elsewhere haven’t yet tried to regulate TFA, in part because of a prevailing narrative that there are large natural sources of it, Joudan says. As a postdoctoral researcher at York University in Ontario, Joudan published, with