For the first time, scientists have detected per- and polyfluoroalkyl substances, or PFAS, in the surface waters of the Miccosukee Indian Reservation, a sovereign territory in the heart of the Florida Everglades. A preliminary analysis by researchers at Florida International University (FIU), conducted in partnership with the Miccosukee Tribe of Indians of Florida, confirmed the presence of 12 distinct PFAS compounds in dozens of samples collected from the reservation’s canals and marshlands, raising new concerns for the ecologically sensitive region. The discovery introduces a new variable into the long-term health of the Everglades and the massive federal project aimed at its restoration.
Known as “forever chemicals” because they do not naturally degrade, PFAS are a class of thousands of man-made compounds used for decades in everything from non-stick cookware to firefighting foam. Their persistence allows them to accumulate in water, soil, wildlife, and human tissue. While the concentrations found on the reservation are considered relatively low and do not exceed current surface water screening standards, the study’s authors caution that the long-term effects of chronic, low-level exposure on the unique Everglades ecosystem and the people who depend on it remain uncertain. The findings, published in the journal Environmental Research, suggest multiple sources are likely responsible for introducing the pollutants into the environment.
A Dozen Contaminants Uncovered
The joint investigation between FIU’s environmental chemists and the Miccosukee Tribe identified a dozen types of PFAS across the reservation’s waterways. The research team collected numerous samples from both the flowing water of canals and the still, shallow water of marshlands, finding the chemicals to be widespread. Surface water concentrations of total PFAS ranged from 3.94 to 40.1 parts per trillion (ppt). This measurement provides the first-ever baseline data for PFAS contamination in this part of the Everglades, a crucial step in monitoring the future health of the ecosystem.
Among the chemicals detected, three were most predominant: PFBA, PFOS, and PFOA. PFBA, a shorter-chain PFAS, has been associated in lab studies with negative effects on the liver and thyroid. PFOS and PFOA are two of the most well-known and historically ubiquitous forever chemicals. Though they have been largely phased out of production in many countries, their extreme persistence means they remain a significant environmental concern. Past exposure to PFOS and PFOA has been linked to developmental problems, thyroid disease, and cancer.
Gauging the Health and Ecosystem Risks
Lead study author Natalia Soares Quinete, an environmental chemist who heads FIU’s initiative on local PFAS prevalence, noted that the observed contamination levels are not yet alarming when compared to more developed areas. For instance, major canals in Miami have registered PFAS concentrations several times higher, ranging from 30.1 to 153 ppt, with a large majority of samples there exceeding safe surface water screening levels. The levels on the reservation did not surpass these official thresholds.
Low Levels, Lingering Questions
Despite the lower concentrations, Quinete emphasized that the discovery is far from reassuring. The primary danger of forever chemicals lies in their ability to accumulate over time, a process known as bioaccumulation. As smaller organisms absorb the chemicals from the water, the contaminants become more concentrated at each step up the food chain. This can lead to potentially harmful levels in fish, birds, and other wildlife, as well as the people who may consume them.
“Whether lower concentrations automatically mean ‘safe’ for this ecosystem and the people and wildlife it supports isn’t something that has been determined with certainty yet,” Quinete stated. “Especially considering how these chemicals tend to accumulate and build up over time in the environment.” Her research group at FIU has been at the forefront of tracking PFAS in South Florida, previously identifying the chemicals in rainwater, drinking water, and marine life in Biscayne Bay.
A Proactive Tribal Collaboration
The investigation began when the Miccosukee Tribe of Indians of Florida, prioritizing the safety of their water, approached Quinete’s team with concerns about potential contamination. Lacking their own data, the tribe sought a scientific partner to determine if these pervasive modern pollutants had reached their ancestral lands. The FIU researchers agreed to assist, collecting and analyzing water samples from locations the tribe identified as important. This collaboration underscores the tribe’s proactive approach to environmental stewardship and the protection of its sovereign lands and resources.
New Questions for Everglades Restoration
The presence of forever chemicals within the reservation has significant implications for the Comprehensive Everglades Restoration Plan (CERP), a multi-billion-dollar federal and state effort to revitalize the vast wetland. According to Quinete, the current restoration framework does not account for the presence or potential impact of contaminants like PFAS. The plan primarily focuses on restoring the natural flow, quality, and quantity of water, with specific limits on nutrients like phosphorus.
PFAS are known endocrine disruptors, meaning they can interfere with the hormonal systems of animals, potentially affecting reproduction and development in the region’s diverse wildlife. The discovery of these chemicals introduces a complex new challenge to the restoration effort. Quinete argues that understanding the prevalence of PFAS is a critical first step toward safeguarding the fragile ecosystem from this invisible threat. “Understanding their presence is the first step toward protecting this fragile ecosystem,” she said.
The Search for a Source
A definitive source for the PFAS contamination has not been identified, and researchers believe the chemicals likely originate from multiple locations. The pollutants can travel long distances through atmospheric deposition in rainfall and are carried through interconnected waterways. Without a single point of origin, tracing the contamination pathways is a complex task that will require further investigation. For now, this initial study serves as a seminal moment, providing the Miccosukee Tribe and environmental scientists with the foundational data needed to address a growing chemical threat in one of America’s most vital natural landscapes.
