Forever Chemicals Research Articles

Photocatalytic low-temperature defluorination of PFASs.

Polyfluoroalkyl and perfluoroalkyl substances (PFASs) are found in many everyday consumer products, often because of their high thermal and chemical stabilities, as well as theirhydrophobic and oleophobic properties1. However, the inert carbon-fluorine (C-F) bonds that give PFASs their properties also provide resistance to decomposition through defluorination, leading to long-term persistence in the environment, as well as in the human body, raising substantial safety and health concerns1-5. Despite recent advances in non-incineration approaches for the destruction of functionalized PFASs, processes for the recycling of perfluorocarbons (PFCs) as well as polymeric PFASs such as polytetrafluoroethylene (PTFE) are limited to methods that use either elevated temperatures or strong reducing reagents. Here we report the defluorination of PFASs with a highly twisted carbazole-cored super-photoreductant KQGZ. A series of PFASs could be defluorinated photocatalytically at 40-60 °C. PTFE gave amorphous carbon and fluoride salts as the major products. Oligomeric PFASs such as PFCs, perfluorooctane sulfonic acid (PFOS), polyfluorooctanoic acid (PFOA) and derivatives give carbonate, formate, oxalate and trifluoroacetate as the defluorinated products. This allows for the recycling of fluorine in PFASs as inorganic fluoride salt. The mechanistic investigation reveals the difference in reaction behaviour and product components for PTFE and oligomeric PFASs. This work opens a window for the low-temperature photoreductive defluorination of the 'forever chemicals' PFASs, especially for PTFE, as well as the discovery of new super-photoreductants.

Toxic-Free Environment: Forever Chemicals Removal from Water and Wastewater

Per- and polyfluoroalkyl substances (PFAS), commonly known as "forever chemicals," are persistent synthetic compounds that have been widely utilized since the mid-20th century across various industries. Due to their environmental persistence and potential health risks, PFAS has become a significant concern, particularly in relation to water and wastewater contamination. This paper investigates the complex challenges associated with PFAS, focusing on existing regulatory frameworks, treatment strategies, and innovative clean technologies that aim to reduce or eliminate these harmful substances. The study emphasizes the importance of advanced treatment methods such as electrochemical degradation, nanofiltration, adsorption, and biodegradation, each offering varying degrees of success. Despite advancements in treatment technologies, prevention remains the most effective strategy to minimize PFAS pollution. The paper calls for collaborative efforts from regulatory bodies, industries, and communities to implement more sustainable practices, ensuring a toxic-free environment and aligning with circular economy principles. Continuous research and international cooperation are crucial for developing effective long-term solutions to address PFAS contamination and safeguard both public health and the environment.

PFAS: The Journey from Wonder Chemicals to Environmental Nightmares and the Search for Solutions

Per- and polyfluoroalkyl substances (PFAS) are diverse synthetic chemicals manufactured over seven decades. It is an aliphatic molecule with a basic hydrophobic structure of carbon and fluorine linked to a hydrophilic end group. Due to their physicochemical properties associated with the unique structure, PFAS has been used in a wide variety of applications including aqueous film-forming foams (AFFF), paper, carpets, non-stick cookware, etc. as they make products resistant to water, heat, and stains. These molecules have drawn great attention recently for their unique properties, high stability and low degradability, and so-called “Forever Chemicals”. PFAS has the strongest carbon-fluorine bond which makes them persistent in the environment. Hence it contaminates natural resources and endangers public health. This review discusses the discovery, development, and evolution of PFAS from the wonder chemical era to a nightmare chemical era, exposure and its impacts on human health and the environment, current remediation techniques, and future trends of PFAS molecules and related products. The primary objective of this review is to identify knowledge gaps on PFAS contamination, remediation methods, and possible PFAS alternatives.

Comparing occurrence of per- and polyfluoroalkyl substances (PFAS) in municipal biosolids and industrial wastewater sludge: A City of Los Angeles study

Biosolids and sludge are what remain after the liquid fraction of wastewater is separated during wastewater treatment. These high organic content matrices are known to contain organic contaminants, a few of which are the hazardous and environmentally persistent per- and polyfluoroalkyl substances (PFAS). The current study investigates whether sludge from a treatment facility serving mostly industrial establishments and biosolids from a facility serving mostly domestic dwellings retain these ‘forever chemicals’ similarly. Using 31 markers covering different classes of PFAS, the sludge was found to contain higher levels of PFAS (869 ± 791 ng/g; 21 of 31) than biosolids (31 ± 7 ng/g, 11 of 31). The most abundant overall was perfluorooctane sulfonic acid (PFOS), mostly in sludge (range: 71–1300 ng/g versus 0–18 ng/g in biosolids). The large PFAS concentration variability in sludge was seasonal and sinusoidal. Sludge, additionally, contained all long chain PFAS, precursors (mostly surfactant ingredients and their transformation byproducts) and short chain PFAS (perhaps because of higher moisture content). By regression, the sludge is shown to consistently contain twice as much PFAS as biosolids when the same amounts are exposed to increasing levels of PFAS. Factors observed to cause differential PFAS retention between sludge and biosolids were moisture (98.6 % and 72.1 %, respectively), chain length, input quality (industrial versus residential) and functional group. Sulfonic acids for instance are one C atom shorter than carboxylates with similar occurrence in sludge and biosolids. More studies are needed to define the roles that organic carbon of sludge/biosolids, water chemistry, temperature and factors not considered here play in partitioning PFAS between the two matrices with respect to inputs. Existing Koc values could not help in explaining observed trends, but the ratio of biosolids-to-influent concentrations was found to correlate positively with PFAS size. Using influent in the ratio, and not effluent, is novel. SynopsisSludge and biosolids are soil amendments; they contain hazardous and persistent PFAS. Methods of decoupling PFAS from these matrices start with understanding matrix-driven PFAS partitioning as shown here.

P05-28 Developing an open-source harmonized Physiologically Based Kinetic (PBK) model for 4 PFAS (PFOS, PFOA, PFNA, and PFHxS) to assess the toxicological profile of forever chemicals

P05-28 Developing an open-source harmonized Physiologically Based Kinetic (PBK) model for 4 PFAS (PFOS, PFOA, PFNA, and PFHxS) to assess the toxicological profile of forever chemicals

'Forever Chemicals' in Water Supply More Widespread Than Previously Thought.

The compounds are associated with numerous health risks.

Clinical Implications of New Drinking Water Regulation for “Forever Chemicals”

This Viewpoint describes new maximum contaminant levels set by the Environmental Protection Agency for specific perfluoroalkyl and polyfluoroalkyl substances (PFASs) and discusses the role clinicians can play in addressing their patients’ PFAS health concerns.

“Forever chemicals”: a sticky environmental problem

“Forever chemicals”: a sticky environmental problem

Methylimidazolium ionic liquids - A new class of forever chemicals with endocrine disrupting potential

A class of chemical with a potentially important perceived future contribution to the net zero carbon goal (as “green” solvents) is the methylimidazolium ionic liquids (MILs). These solvents are used in industrial processes such as biofuel production yet little is known about their environmental stability or toxicity in man although one MIL – 1-octyl-3-methylimidazolium (M8OI) – has been shown to activate the human estrogen receptor alpha (ERα). The stabilities of the chloride unsubstituted methylimidazolium (MI) and MILs possessing increasing alkyl chain lengths (2C, 1-ethyl-3-methylimidazolium (EMI); 4C, 1-butyl-3-methylimidazolium (BMI); 6C; 1-hexyl-3-methylimidazolium (HMI), 8C, M8OI; 10C, 1-decyl-3-methylimidazolium (DMI)) were examined in river water and a human liver model system. The MILs were also screened for their abilities to activate the human ERα in vitro and induce uterine growth in pre-pubertal rats in vivo. Short chain MILs (EMI, BMI and HMI) underwent negligible metabolism and mineralisation in river water; were not metabolised in a model of human liver metabolism; activated the human ERα in vitro and were estrogenic in vivo in rats. A structure-based computational approach predicted short chain MIL binding to both the estrogen binding site and an additional site on the human estrogen receptor alpha. Longer chain MILs (M8OI and DMI) were metabolised in river water and partially mineralised. Based on structure-activity considerations, some of these environmentally-derived metabolites may however, remain a hazard to the population. MILs therefore have the potential to become forever chemicals with adverse effects to both man, other animals and the environment in general.

Genotoxicity and cytotoxicity assessment of 'forever chemicals' in zebrafish (Danio rerio)

Per- and polyfluoroalkyl substances (PFAS) comprise many chemicals with strong carbon-carbon and carbon-fluorine bonds and have extensive industrial applications in manufacturing several consumer products. The solid covalent bonding makes them more persistent in the environment and stays away from all types of degradation, naming them 'forever chemicals.' Zebrafish (Danio rerio) was used to evaluate the genotoxic and cytotoxic effects of legacy PFAS, Perfluorooctane sulfonate (PFOS), and its alternatives, such as Perfluoro-2-methyl-3-oxahexanoic acid ammonium (GenX) and 7H-Perfluoro-3,6-dioxa-4-methyl-octane-1-sulfonic acid (Nafion by-product 2 [NBP2]) upon single and combined exposure at an environmental concentration of 10 µg/L for 48-h. Erythrocyte micronucleus cytome assay (EMNCA) revealed an increased frequency of micronuclei (MN) in fish erythrocytes with a significant increase in NBP2-treated fish. The order of genotoxicity noticed was NBP2 > PFOS > Mixture > GenX in D. rerio. Fish exposed to PFOS and its alternatives in single and combined experiments did not cause any significant difference in nuclear abnormalities. However, PFOS and combined exposure positively inhibit cytokinesis, resulting in an 8.16 and 7.44-fold-change increase of binucleated cells. Besides, statistically, increased levels of reactive oxygen species (ROS) and malondialdehyde (MDA) content indicate oxidative stress in D. rerio. In addition, 'forever chemicals' resulted in cytotoxicity, as evident through changes in nucleus width to the erythrocyte length in NBP2 and mixture exposure groups. The findings revealed that PFAS alternative NBP2 is more toxic than PFOS in inducing DNA damage and cytotoxicity. In addition, all three tested 'forever chemicals' induced ROS and lipid peroxidation after individual and combined exposure. The present work is the first to concern the genotoxicity and cytotoxicity of 'forever chemicals' in the aquatic vertebrate D. rerio.

Machine learning-enhanced molecular network reveals global exposure to hundreds of unknown PFAS.

Unknown forever chemicals like per- and polyfluoroalkyl substances (PFASs) are difficult to identify. Current platforms designed for metabolites and natural products cannot capture the diverse structural characteristics of PFAS. Here, we report an automatic PFAS identification platform (APP-ID) that screens for PFAS in environmental samples using an enhanced molecular network and identifies unknown PFAS structures using machine learning. Our networking algorithm, which enhances characteristic fragment matches, has lower false-positive rate (0.7%) than current algorithms (2.4 to 46%). Our support vector machine model identified unknown PFAS in test set with 58.3% accuracy, surpassing current software. Further, APP-ID detected 733 PFASs in real fluorochemical wastewater, 39 of which are previously unreported in environmental media. Retrospective screening of 126 PFASs against public data repository from 20 countries show PFAS substitutes are prevalent worldwide.

‘Forever chemicals’ found to rain down on all five Great Lakes

‘Forever chemicals’ found to rain down on all five Great Lakes

Ocean Waves Mist Decades-Old PFAS into the Atmosphere

“Forever chemicals” enter the air as sea spray aerosols, polluting coastlines and beyond.

Spontaneous Degradation of the "Forever Chemicals" Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) on Water Droplet Surfaces.

Because of their innate chemical stability, the ubiquitous perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been dubbed "forever chemicals" and have attracted considerable attention. However, their stability under environmental conditions has not been widely verified. Herein, perfluorooctanoic acid (PFOA), a widely used and detected PFAS, was found to be spontaneously degraded in aqueous microdroplets under room temperature and atmospheric pressure conditions. This unexpected fast degradation occurred via a unique multicycle redox reaction of PFOA with interfacial reactive species on the droplet surface. Similar degradation was observed for other PFASs. This study extends the current understanding of the environmental fate and chemistry of PFASs and provides insight into aid in the development of effective methods for removing PFASs.

Forever Chemicals, Per-and Polyfluoroalkyl Substances (PFAS), in Lubrication

Per- and polyfluoroalkyl substances (PFAS), also known as forever chemicals, exhibit exceptional chemical stability and resistance to environmental degradation thanks to their strong C-F bonds and nonpolar nature. However, their widespread use and persistence have a devastating impact on the environment. This review examines the roles of PFAS in tribological applications, specifically in lubricants and lubricating systems. This article focuses on conventional and advanced lubricants, including ionic liquids (ILs) and their use in modern automotive vehicles. The objective of this paper is to provide a comprehensive overview of the adverse impacts of PFAS whilst acknowledging their outstanding performance in surface coatings, composite materials, and as additives in oils and greases. The pathways through which PFAS are introduced into the environment via lubricating systems such as in seals and O-rings are identified, alongside their subsequent dispersion routes and the interfaces across which they interact. Furthermore, we examine the toxicological implications of PFAS exposure on terrestrial and aquatic life forms, including plants, animals, and humans, along with the ecological consequences of bioaccumulation and biomagnification across trophic levels and ecosystems. This article ends with potential remediation strategies for PFAS use, including advanced treatment technologies, biodegradation, recovery and recycling methods, and the search for more environmentally benign alternatives.

Occurrence of forever chemicals in Chennai waters, India

BackgroundPer- and polyfluoroalkyl substances (PFAS) are considered ‘contaminants of emerging concern’ due to their environmental persistence, bio-accumulative potential, and adverse effects on human health. They are widely employed in producing various goods used in daily life, such as non-stick cookware, cleaning agents, and many industrial applications in aerospace, automotive, construction, electronics, and military, all of which ultimately end up in different environmental matrices. India’s rapid economic growth necessitates a comprehensive understanding of its PFAS contamination levels and potential human and ecological exposure.ResultsThe present study reports the quantification of one long-chain and two short-chain perfluoroalkyl acids and three long-chain and two short-chain perfluorosulfonic acids and qualitative analysis using suspect screening in the waters of Chennai, Tamil Nadu, India. Samples were collected from surface and groundwater sources, including the Adyar river, Buckingham canal, Chembarambakkam lake, and the water treatment plant. The concentrations analyzed in all the samples ranged from 0.10 ng/L to 136.27 ng/L. Groundwater had some of the highest concentrations of PFAS. L-PFBS (up to 136.27 ng/L) and PFOA (up to 77.61 ng/L) are present in all the samples. The concentrations of all the target PFAS increased in the 5 to 103% range in the final treated water compared to the raw water of the water treatment plant. This treated water is distributed as a source of drinking water for the residents of Chennai. Additionally, the dominance of short-chain compounds (4–7 carbons) over long-chain compounds (> 7 carbons) was observed. Suspect screening revealed numerous precursors and other fluorinated compounds abundantly present in the samples.ConclusionsOur study revealed PFAS levels up to 136.27 ng/L in both surface and groundwater samples from Chennai. These findings raise concerns about potential risks to ecosystems and human well-being. The dominance of short-chain PFAS coupled with abundant precursors and unidentified fluorinated compounds indicates an ongoing shift toward alternatives. Conventional water treatment is ineffective in eliminating these chemicals from the water system; rather, increasing the PFAS concentrations from raw water to treated water necessitates advanced polishing steps. Industrial emissions, untreated domestic wastewater discharge, and open dump sites have been suspected as the significant sources of contamination, highlighting the need for further investigation to fully assess the extent of PFAS contamination in Chennai.Graphical

The Discovery and Analysis of PFAS (‘Forever Chemicals’) in Human Blood and Biological Materials

This paper reviews the development of analytical techniques used prior to the early 1980s in the identification of organofluorine compounds in human blood. The compounds of interest are industrial products, the so-called Forever Chemicals, which are stable long-chain per- and polyfluoroalkyl substances (PFAS) that are highly resistant to breakdown. Because of their special properties they have been used since the 1950s in a wide range of commercial and domestic products. Academic research in the 1960s and 1970s that originally focused on fluoride in dentistry and human health led to the finding that PFAS were present in the blood of residents of several cities in the United States. This, and concerns over their toxic properties, encouraged industrial research into analytical methods for their detection. Notably, and because long-chain PFAS are nonvolatile, special techniques were developed for analysis by gas chromatography.

Research on the Neurotoxic Effects of ‘Forever Chemicals’ Is Just Emerging

Research on the Neurotoxic Effects of ‘Forever Chemicals’ Is Just Emerging

Removal of Forever Chemicals from Aqueous Solutions through Adsorption on Swellable Organically Modified Silicas

Removal of Forever Chemicals from Aqueous Solutions through Adsorption on Swellable Organically Modified Silicas

Edukasi Masyarakat Mengenai Toksikan Abadi (Forever Chemicals) dalam Kosmetik Bersifat Waterproof

Per- and poly-fluoroalkyl substances (PFAS) are synthetic chemicals added to cosmetics for their waterproof property to obtain a long-lasting application. PFAS is highly persistent, hence called the forever chemicals. This community outreach was aimed to educate the public on PFAS exposure through waterproof cosmetics and its health implications. Our webinar was attended by 84 people, 50 of whom responded to the pre-and post-test. An expert delivered the presentation of the educational content. There was an increase in attendees’ test scores from 56.4±21.3 to 88.4±19.0 (mean±SD; paired t-test, p<0.05). The webinar improved attendees’ knowledge of PFAS exposure from waterproof cosmetics and its potential effects on health.