On a virtually cloudless May morning, Daniele Miranda, assistant research professor in the Department of Biological Sciences, hops out of a white extended-cab pickup that’s parked at the east end of Turner Park in Hammond, Indiana.
It’s a relatively minimal recreational space with a soccer field that’s been maintained, but not much else.
Three of Miranda’s students hop out with her. They move quickly, stepping out of their casual shoes into tall rubber boots, slip-on reflective jackets, and nitrile gloves. They grab supplies from the back of the truck, water and sediment samplers, plastic bags and bottles, carrying them off in a storage tote toward the banks of the Grand Calumet River.
Miranda’s research focuses on tracking organic contaminants in the environment. She has managed several research projects through Gary Lamberti’s Stream and Wetland Ecology Laboratory studying PFAS in aquatic systems.
With funding from the Indiana Department of Natural Resources’ Lake Michigan Coastal Program, a part of the National Oceanic and Atmospheric Administration's (NOAA) National Sea Grant College Program, Miranda has been leading a team of researchers to the Indiana coastal zone region of Lake Michigan to study PFAS contamination along the lake’s southern corridor and the disproportionate burden on underserved communities in the area.
“We are looking at the range of PFAS concentrations in different streams in northern Indiana,” Miranda said. “It’s an important area for us to investigate because we don’t have much data or information about the waterways in that region, and we know that there are several communities living there that could be exposed to those contaminants when fishing or in contact with those streams.”
The study will examine samples from approximately 60 different sites including the Grand Calumet River, the Deep River–Portage Burns watershed, Salt Creek watershed, Little Calumet River, Dunes Creek watershed, Trail Creek watershed, and the upper part of the White Ditch watershed.
“We’re focusing on major tributaries that flow into Lake Michigan, through areas with underserved communities, and in areas of significant outdoor recreation and fishing,” Lamberti said. “We know from data that there is disproportionately more fishing and more consumption of fish by underserved communities in that area. If you have a specific community that’s disproportionately using that resource, putting it on the dinner table and eating it regularly, then you have the potential for some real inequities.
“There are no current PFAS restrictions on fish consumption from the Great Lakes,” Lamberti said. “There are advisories, but no guidelines like what we see with the EPA’s recent development of drinking water standards when it comes to PFAS.”
Stepping through a break in the fence at the edge of Turner Park, the group follows a rocky, overgrown path, littered with weeds, broken glass, plastic bottles, and even a semi-deflated volleyball, to the riverbank. Traffic moves steadily along the overpass nearby.
There’s something poignant about watching Miranda and her students. Research takes many forms. Some days it’s firing proton beams from a nuclear accelerator, or watching materials break down in the deep orange glow of an incinerator. Other days, it’s meticulous, repetitive sampling, connecting plastic containers to a long pole, collecting countless amounts of river water, breaking up sediment with a PVC pipe and scooping it into containers.
“A water sample is like a photograph of that moment,” Miranda said. “I can see what is being inserted into that system. And with sediment samples, we’re going to see what’s accumulated. The sediment acts as a sink for organic compounds like PFAS.”
Before piling back into the truck and heading off to their next stop—where Miranda and her team will drop samplers from a bridge in East Chicago—the water from Turner Park is treated to remove any potential microbes. This will ensure accurate measurements of organic content that may compete for PFAS compounds in the chemical analysis.
Miranda and Lamberti have already identified PFAS hotspots along the corridor based on water samples alone. The study will include samples from heavy industrial sites in East Chicago, as well as parks and residential areas.
“This project will shed light on the risks underserved communities face from ‘invisible’ sources of PFAS in the environment,” Miranda said.
The hope is studies like Miranda’s will result in more public education, making individuals aware of what they could be consuming when they bring home their daily catch.
But there are still a lot of unanswered questions when it comes to how PFAS affects the biological systems of humans, fish, and wildlife. And that is the subject of yet another study on Lamberti’s plate, this one a collaboration with Michael Pfrender, professor of evolutionary and ecological genomics and director of Notre Dame's Genomics and Bioinformatics Core Facility.
Pfrender and Lamberti have begun an analysis of how PFAS impacts gene expression in Lake Michigan fish.
“The overall idea is to see what genes turn on and off when fish are exposed to PFAS,” Lamberti said. “What’s unique about this study is we are analyzing samples from fish in the field—so you can measure varied levels of exposure to PFAS and look for molecular triggers to see what’s happening in actual, real-world environments to support controlled model experiments in the lab.”
Pfrender is an expert in evolutionary and ecological genomics with a particular interest in the relationship between short-term organismal responses and environmental stresses. His research focuses on genomic structure, patterns of gene expression in response to stress, and the way that organisms adapt to changing environments.
“With PFAS you’re talking about a huge group of related chemical compounds,” Pfrender said. “The pressing issues are how these chemicals are transported through the food web, and what are the effects on aquatic organisms. We know from previous research that exposure to PFAS affects a wide variety of different physiological and developmental pathways. Liver function, the pancreas, the nervous and sensory system, heart function, and the immune system can all be adversely affected. There is evidence growing from laboratory experiments that PFAS exposure can cause genes to behave in an abnormal way. This is referred to as genetic dysregulation and it can cause a wide variety of problems in affected organisms. Part of what we’re lacking is a relationship between studies based on model species in the laboratory and what’s happening to organisms out in the actual biological system.”
To understand which genes are turning on and off, Pfrender will collect RNA sequence data from fish samples collected for Lamberti’s lab and compare results to existing models of genetic impacts of PFAS in other biological systems, such as the laboratory model zebrafish.
“We can look at the signature we’re seeing from the Lake Michigan fish and compare it to what we have observed in zebrafish and other laboratory systems to analyze the overlap. There is a lot of information we can get from those comparisons,” Pfrender said. “It’s all really important if we’re going to think about the effects of these chemicals on real biological systems—and I’m optimistic that by doing this, we’ll be able to connect it to what is a rapidly expanding body of work that’s being done in labs and real-world systems.”
The study reflects one of “the big outstanding questions about PFAS in the aquatic world,” Lamberti said.
PFAS has forever impacted our environment, with an endless effect on fish, wildlife, and humans alike. The ruthless persistence and pervasive effects of fluorinated compounds have seeped into every aspect of life on this planet. It is a problem that scientists will be studying for years to come.
But hope lies in the research and in the tireless efforts of faculty such as Miranda, Lamberti, Pfrender, Kyle Doudrick, and Graham Peaslee, who are working with policymakers, public health officials, and environmental organizations to find solutions and create change.
“We have a huge responsibility,” Miranda said. “We need attention to this problem. We need action and we need education—because informed people can make a huge difference.”
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