From food systems to recreation, the relationship between humans and our natural environment influences our societies and health. Throughout my time as an undergraduate student at the University of Nebraska–Lincoln, I’ve had the privilege of studying these interactions through a variety of projects, including the development of climate models in the Great Plains region and the exploration of conservation strategies in coastal environments. Additionally, my first project at the Daugherty Water for Food Global Institute (DWFI) allowed me to investigate the impact of nitrate contamination on human health and on Nebraska’s economy. This project directed my current interest in connecting human and planetary well-being through public health.
Whether through the clothes we wear or the food we consume, there are a variety of interactions with certain environmental contaminants that can influence our health outcomes. One such instance is per- and polyfluoroalkyl substances (PFAS).
Per- and polyfluoroalkyl substances (PFAS) encompass thousands of compounds characterized by the repellent properties of their strong carbon-fluorine bonds
Found in consumer and industrial products since the 1940s, PFAS include thousands of compounds [1-2]. Their physical and chemical properties allow the substances to repel oil, water, stains, and soil [3]. For this reason, PFAS have been used in an array of products, including carpets, textiles, firefighting foam, and food packaging products [2]. As a result, their global presence has manifested in soil, water, air, and food, as well as human and animal bloodstreams [4].
While the extent of health impacts PFAS may have in their various forms is not fully understood, studies have identified them as a threat to human and environmental health [4-5]. A few adverse human health impacts include decreased birthweight [4,6], changes in liver enzymes [6], high blood pressure during pregnancy [6], hormone interference [7], and certain cancers [4,6]. Further studies are needed to understand the impact of exposure to multiple forms of PFAS and the mechanisms they use to disrupt bodily functions.
But how do PFAS enter our bodies?
Drinking water remains one of the dominant studied pathways for PFAS exposure [8-10], but food systems are also known to be impacted. Due to their ability to bioaccumulate in plants and animals, exposure to PFAS via food consumption has been of increasing concern, especially with certain fish species [11-17]. Additionally, the uptake of PFAS in plants from contaminated irrigation water and air pollution has been estimated to adversely influence the quality of impacted produce [11,17-19]. Though the amount of PFAS transferred varies and may be independently harmless, the presence of PFAS in our ecosystems has the potential to travel up the food chain. Thus, understanding PFAS uptake and the associated risks can be imperative to ensuring food safety.
Current efforts to reduce PFAS presence
Policy
As evidence of adverse health effects and widespread presence of PFAS builds in research, policy initiatives have expanded largely in developed countries. Global actions have included updating water quality standards and implementing manufacturing limitations, for example. Previously, the U.S. federal limit of PFAS concentration in drinking water was 70 parts per trillion (ppt), although several states, such as Wisconsin, New Jersey, and Alaska, have implemented their own stricter standards [20]. However, in April of 2024, the U.S. Environmental Protection Agency (EPA) announced updated PFAS concentration limits through the National Public Drinking Water Regulation (NPDWR) [21]. These federal standards target six common types of PFAS and limit their maximum concentration from 4 ppt to 10 ppt depending upon the compound [21]. By 2029, public water systems are expected to attain and enforce these standards.
In complement, the U.S. federal government has allocated $1 billion to cover the cost of updates within public water systems and provide support for private well users through the Bipartisan Infrastructure Deal [21]. An additional $2 billion has been set aside for research and remediation (i.e. clean up) of emerging contaminants, like PFAS, through the same bill [22]. Major manufacturers, though, have also provided funding for treatment of PFAS in drinking water. Thus far, a handful of companies will contribute roughly $11 billion in settlements over claims of their alleged role in drinking water contamination [23].
While cleaning our drinking water is important, certain policies are looking upstream to reduce the introduction of PFAS into the environment. In the manufacturing process, the two most common forms of PFAS, PFOA and PFOS, have been the focus. In 2006, the EPA started the PFOA Stewardship Program, which encouraged eight major manufacturing companies to eliminate PFOA from emissions and products by 2015 [24]. In accordance with their PFAS roadmap, the EPA is working to classify PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) [25]. Designation under CERCLA, the nation’s Superfund law, would allow for greater enforcement of PFAS disposal regulations on manufacturers.
Updates to water quality and manufacturing standards, in tandem with their associated funding, may greatly benefit drinking water quality and human health in the United States. However, concerns remain regarding the lack of international standards, as well as the lack of support for private well users who must independently test and treat their water.
Research
Throughout the 21st century, research on PFAS has accelerated rapidly, incorporating diverse environments and methods of remediation [20]. In the biology field, labs have focused on identifying and recording certain bacterium’s ability to biotransform PFAS. Biotransformation describes the alteration of a chemical’s structure using microorganisms or enzymes. This differs from biodegradation because the chemical does not necessarily reach a benign form [26], yet biotransformation still provides hope for PFAS remediation. In 2015, a lab at Princeton University received a high volume of attention for their successful observation of the process by the bacteria named Acidimicrobium sp. Strain A6. The study focused on PFOA and PFOS and recorded a 63% and 47% reduction in their respective samples [27]. Similar iterations of this study are currently being conducted with different bacterium, such as the work of DWFI Faculty Fellow Xu Li, PhD at the University of Nebraska–Lincoln.
In addition, some researchers hope to achieve similar PFAS reductions through chemical methods, like electrochemical oxidation, which are faster but more costly and energy-intensive [28-29]. However, propositions have been made to combine multiple treatment processes as a ‘treatment train,’ which could be powered by solar panels to improve effectiveness of PFAS removal while reducing costs [29].
Both approaches, biological and chemical, are often directed for application to wastewater treatment plants, which are known sources of PFAS contamination [20,30]. Despite the lengthy timeline, scaling up the prospective treatment processes to industry-sized operations provides promise to remediating PFAS from our environment.
Complementary to the extraction of PFAS from our environment is the reduction of human exposure to this class of chemicals. In the public health arena, researchers have aimed to understand the extent of specific health impacts of PFAS, particularly in children, those who are pregnant, and those occupationally exposed [10, 31-32]. One prominent concern of PFAS presence in the human body is reduced vaccine antibody response, which has been observed for certain vaccines, like Tetanus and Rubella [33, 5]. To date, the majority of PFAS research has revolved around PFOA and PFOS. Therefore, the physiological impact of other forms of PFAS has been of increasing interest to researchers who are using improved detection methods to better understand the role of all PFAS in various health conditions.
Research on our environment and personal health can idle without the ability for the public to understand its gravity. Social scientists are studying the public risk perception of PFAS. One approach seeks to understand the influences of messaging to develop and improve communication methods, like personalization, that bolster meaningful engagement with information on PFAS [34]. Meanwhile, other studies aim to gauge public perception and acceptance of PFAS in consumer products [35]. The goal of this work is often to educate the public about how environmental contaminants are significant to them. Such public knowledge can improve mobilization, initiate important policy advancements, and increase execution of effective remediation and mitigative solutions.
Conclusion
From what we drink to what we eat for dinner, the health of our environment influences our own. PFAS, though once viewed as an extraordinary breakthrough, have come to be known for their pervasiveness, prevalence, and adverse impacts on humans and the environment. Though much remains unknown about PFAS, and certain populations continue to be disproportionately exposed, collaborations among researchers and policymakers are helping to carve a path forward. Globally, PFAS remediation efforts provide hope for our capacity to restore our ecosystems’ integrity, improve our food and drinking water quality, and reduce threats to human health.
Interested in learning more about PFAS research? Watch this video to see the important work researchers at the University of Nebraska are doing to address PFAS contamination.
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