Validation of a low-cost lead hazard screening kit for the home environment.

The main sources of lead exposure for children occur in the home environment, yet no low-cost analytical methods exist to screen homes for lead hazards. Previously, an inexpensive (~$20), quantitative lead screening kit was developed in which residents collect soil, paint, and dust samples that are returned to a laboratory for lead analysis using X-ray fluorescence spectroscopy (XRF). This screening kit was initially validated in 2020; it was determined that in situ and ex situ XRF lead measurements on the same samples exhibited strong sensitivity, specificity, and accuracy. As a follow-up to the initial validation, an implementation study and further statistical analyses were conducted. Correlation analysis using the results from nearly 400 screening kits identified an overall lack of correlation between sample types, reinforcing the utility of all eight sample locations. Principal component analysis searched for underlying correlations in sample types and provided evidence that both interior and exterior paint are major sources of lead hazards for Indiana homes. The implementation study compared the results of the government-standard lead inspection and risk assessment (LIRA) and the lead screening kit in 107 Indiana homes. In the United States, the LIRA is a thorough inspection of paint, dust, and soil that is usually state mandated in response to a child's elevated blood level and is used to identify where remediation efforts should be focused. The lead screening kit and LIRA agreed on the presence of lead in 79 of the 107 homes tested (74%). Discrepancies in agreement are likely the result of differences in the sample location and number of samples collected by each method. Overall, these results suggest that the lead screening kit is an acceptable resource that could be used to expand the services health departments provide for lead prevention. Integr Environ Assess Manag 2024;20:1504-1513. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Per- and Polyfluoroalkyl Substances in Canadian Fast Food Packaging.

A suite of analytical techniques was used to obtain a comprehensive picture of per- and polyfluoroalkyl substances (PFAS) in selected Canadian food packaging used for fast foods (n = 42). Particle-induced gamma ray emission spectroscopy revealed that 55% of the samples contained <3580, 19% contained 3580-10 800, and 26% > 10 800 µg F/m2. The highest total F (1 010 000-1 300 000 µg F/m2) was measured in molded "compostable" bowls. Targeted analysis of 8 samples with high total F revealed 4-15 individual PFAS in each sample, with 6:2 fluorotelomer methacrylate (FTMAc) and 6:2 fluorotelomer alcohol (FTOH) typically dominating. Up to 34% of the total fluorine was released from samples after hydrolysis, indicating the presence of unknown precursors. Nontargeted analysis detected 22 PFAS from 6 different groups, including degradation products of FTOH. Results indicate the use of side-chain fluorinated polymers and suggest that these products can release short-chain compounds that ultimately can be transformed to compounds of toxicological concern. Analysis after 2 years of storage showed overall decreases in PFAS consistent with the loss of volatile compounds such as 6:2 FTMAc and FTOH. The use of PFAS in food packaging such as "compostable" bowls represents a regrettable substitution of single-use plastic food packaging.

Occurrence and biomagnification of perfluoroalkyl substances (PFAS) in Lake Michigan fishes.

We measured perfluoroalkyl substances (PFAS) in prey and predator fish from Lake Michigan (USA) to investigate the occurrence and biomagnification of these compounds in this important ecosystem. Twenty-one PFAS were analyzed in 117 prey fish obtained from sites across Lake Michigan and in 87 salmonids collected in four lake quadrants. The mean concentration of sum (∑) PFAS above the method detection limit was 12.7 ± 6.96 ng g-1 wet weight in predator fish (all of which were salmonids) and 10.7 ± 10.4 ng g-1 in prey fish, with outlier levels found in slimy sculpin, Cottus cognatus (187 ± 12.2 ng g-1 ww). Perfluorooctanoic sulfonic acid (PFOS) was the most frequently detected and most abundant compound of the 21 PFAS, occurring in 98 % of individuals with a mean concentration of 9.86 ± 6.36 ng g-1 ww without outliers. Perfluoroalkyl carboxylates (PFCA) concentrations were higher in prey fish than in predators, with some compounds such as perfluorooctanoic acid (PFOA) being detected in higher frequency in prey fish. Besides PFOS, detection of several long-chain (C8-C12) PFCAs were observed in >80 % of the prey fish. Overall, the observed concentrations in Lake Michigan fish were lower than those reported in other Laurentian Great Lakes except for Lake Superior. Biomagnification factors (BMFs) for PFOS exceeded 1.0 (range, 1.80 to 5.12) in all predator-prey relationships analyzed, indicating biomagnification of these compounds, whereas BMFs of other long-chain PFCAs varied according to the fish species. PFAS were found in all fish species measured from Lake Michigan and commonly biomagnified from prey to predator fish, strongly suggesting a dietary connection.

Use and release of per- and polyfluoroalkyl substances (PFASs) in consumer food packaging in U.S. and Canada.

Numerous per- and polyfluoroalkyl substances (PFASs) occur in consumer food packaging due to intentional and unintentional addition, despite increasing concern about their health and environmental hazards. We present a substance flow analysis framework to assess the flows of PFASs contained in plant fiber-based and plastic food packaging to the waste stream and environment. Each year between 2018 and 2020, an estimated 9000 (range 1100-25 000) and 940 (range 120-2600) tonnes per year of polymeric PFASs were used in 2% of food packaging in the U.S. and Canada, respectively. At least 11 tonnes per year of non-polymeric PFASs also moved through the food packaging life cycle. Approximately 6100 (range 690-13 000) and 700 (range 70-1600) tonnes per year of these PFASs were landfilled or entered composting facilities in the U.S. and Canada, respectively, with the potential to contaminate the environment. The results suggest that minimal food packaging contains intentionally added PFASs which, nonetheless, has the potential to contaminate the entire waste stream. Further, this indicates that PFASs are not needed for most food packaging. These results serve as a benchmark to judge the effectiveness of future industry and government initiatives to limit PFAS use in food packaging.

Per- and Polyfluoroalkyl Substances in North American School Uniforms.

We analyzed 72 children's textile products marketed as stain-resistant from US and Canadian stores, particularly school uniforms, to assess if clothing represents a significant route of exposure to per- and polyfluoroalkyl substances (PFAS). Products were first screened for total fluorine (total F) using particle-induced γ-ray emission (PIGE) spectroscopy (n = 72), followed by targeted analysis of 49 neutral and ionic PFAS (n = 57). PFAS were detected in all products from both markets, with the most abundant compound being 6:2 fluorotelomer alcohol (6:2 FTOH). Total targeted PFAS concentrations for all products collected from both countries ranged from 0.250 to 153 000 ng/g with a median of 117 ng/g (0.0281-38 100 µg/m2, median: 24.0 µg/m2). Total targeted PFAS levels in school uniforms were significantly higher than in other items such as bibs, hats, stroller covers, and swimsuits, but comparable to outdoor wear. Higher total targeted PFAS concentrations were found in school uniforms made of 100% cotton than synthetic blends. Perfluoroalkyl acids (PFAAs) precursors were abundant in school uniforms based on the results of hydrolysis and total oxidizable precursor assay. The estimated median potential children's exposure to PFAS via dermal exposure through school uniforms was 1.03 ng/kg bw/day. Substance flow analysis estimated that ∼3 tonnes/year (ranging from 0.05 to 33 tonnes/year) of PFAS are used in US children's uniforms, mostly of polymeric PFAS but with ∼0.1 tonne/year of mobile, nonpolymeric PFAS.

Excitation function of 54Fe(p,α)51Mn from 9.5 MeV to 18 MeV.

Excitation function of the 54Fe(p,α)51Mn reaction was measured from 9.5 to 18 MeV E 0 , p + by activating a foil stack of 54Fe electrodeposited on copper substrates. Residual radionuclides were quantified by HPGe gamma ray spectrometry. Both 51Mn (t 1/2 = 46.2 min, 〈 E ß + 〉 = 963.7 keV , I ß + = 97 % ; E γ = 749.1 keV, I γ = 0.265%) and its radioactive daughter, 51Cr (t 1/2 = 27.704d, E γ = 320.1 keV, I γ = 9.91%), were used to indirectly quantify formation of 51Mn. Results agree within uncertainty to the only other measurement in literature and predictions of default TALYS theoretical code. Final relative uncertainties are within ±12%.

A worldwide evaluation of trophic magnification of per- and polyfluoroalkyl substances in aquatic ecosystems.

A review of the published literature on the trophic magnification factor (TMF) for per- and polyfluoroalkyl substances (PFAS) was conducted to assess how biomagnification varies across aquatic systems worldwide. Although the TMF has been recognized as the most reliable tool for assessing the biomagnification of organic contaminants, peer-reviewed studies reporting TMFs for PFAS are few and with limited geographical distribution. We found 25 published studies of the biomagnification of 35 specific PFAS, for which the TMF was generated through linear regression of individual log-PFAS concentration and the δ15 N-based trophic position of each organism in the food webs. Studies were concentrated mainly in China, North America, and Europe, and the most investigated compound was perfluorooctane sulfonate (PFOS), which was frequently shown to be biomagnified in the food web (TMFs ranging from 0.8 to 20). Other long-chain carboxylates displayed substantial variation in trophic magnification. Observed differences in the TMF were associated with length of the food web, geographic location, sampling methodologies, tissue analyzed, and distance from known direct PFAS inputs. In addition to biomagnification of legacy PFAS, precursor substances were observed to bioaccumulate in the food web, which suggests they may biotransform to more persistent PFAS compounds in upper trophic levels. This review discusses the variability of environmental characteristics driving PFAS biomagnification in natural ecosystems and highlights the different approaches used by each study, which can make comparisons among studies challenging. Suggestions on how to standardize TMFs for PFAS are also provided in this review. Integr Environ Assess Manag 2022;18:1500-1512. © 2022 SETAC.

Per- and Polyfluoroalkyl Substances (PFAS) in Facemasks: Potential Source of Human Exposure to PFAS with Implications for Disposal to Landfills.

Facemasks are important tools for fighting against disease spread, including Covid-19 and its variants, and some may be treated with per- and polyfluoroalkyl substances (PFAS). Nine facemasks over a range of prices were analyzed for total fluorine and PFAS. The PFAS compositions of the masks were then used to estimate exposure and the mass of PFAS discharged to landfill leachate. Fluorine from PFAS accounted only for a small fraction of total fluorine. Homologous series of linear perfluoroalkyl carboxylates and the 6:2 fluorotelomer alcohol indicated a fluorotelomer origin. Inhalation was estimated to be the dominant exposure route (40%-50%), followed by incidental ingestion (15%-40%) and dermal (11%-20%). Exposure and risk estimates were higher for children than adults, and high physical activity substantially increased inhalation exposure. These preliminary findings indicate that wearing masks treated with high levels of PFAS for extended periods of time can be a notable source of exposure and have the potential to pose a health risk. Despite modeled annual disposal of ~29-91 billion masks, and an assuming 100% leaching of individual PFAS into landfill leachate, mask disposal would contribute only an additional 6% of annual PFAS mass loads and less than 11 kg of PFAS discharged to U.S. wastewater.

Disposition of Fluorine on New Firefighter Turnout Gear.

Firefighter turnout gear is essential for reducing occupational exposure to hazardous chemicals during training and fire events. Per-and polyfluoroalkyl substances (PFASs) are observed in firefighter serum, and possible occupational sources include the air and dust of fires, aqueous film-forming foam, and turnout gear. Limited data exist for nonvolatile and volatile PFASs on firefighter turnout gear and the disposition of fluorine on the individual layers of turnout gear. Further implications for exposure to fluorine on turnout gear are not well understood. Three unused turnout garments purchased in 2019 and one purchased in 2008, were analyzed for 50 nonvolatile and 15 volatile PFASs by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-qTOF-MS) and gas chromatography-mass spectrometry (GC-MS), respectively. Particle-induced gamma ray emission (PIGE), a surface technique, and instrumental neutron activation analysis (INAA), a bulk technique, were used to measure total fluorine. Bulk characterization of the layers by pyrolysis-GC/MS (py-GC/MS) was used to differentiate fluoropolymer (e.g., PTFE) films from textile layers finished with side-chain polymers. The outer layer, moisture barrier, and thermal layers of the turnout gear all yielded measured concentrations of volatile PFASs that exceeded nonvolatile PFAS concentrations, but the summed molar concentrations made up only a small fraction of total fluorine (0.0016-6.7%). Moisture barrier layers comprised a PTFE film, as determined by py-GC-MS, and gave the highest individual nonvolatile (0.159 mg F/kg) and volatile PFAS (20.7 mg F/kg) as well as total fluorine (122,000 mg F/kg) concentrations. Outer and thermal layers comprised aromatic polyamide-based fibers (aramid) treated with side-chain fluoropolymers and had lower levels of individual nonvolatile and volatile PFASs. Equal concentrations of total fluorine by both PIGE and INAA on the outer and thermal layers is consistent with treatment with a side-chain fluoropolymer coating. New turnout gear should be examined as a potential source of firefighter occupational exposure to nonvolatile and volatile PFASs in future assessments.

A heavy-ion production channel of 149Tb via 63Cu bombardment of 89Y.

The radionuclide 149Tb (t1/2 = 4.1 h) is a potential theranostic isotope which can simultaneously be used for targeted-alpha-particle therapy and positron-emission tomography. Feasibility experiments were performed to test a near-symmetric heavy-ion reaction of 63Cu bombardment on monoisotopic 89Y. The indirect reaction was studied to avoid isomer production. Offline gamma spectroscopy was used to quantify thick-target physical yields and experimental results show modest agreement to the fusion-evaporation code PACE4. A near-symmetric fission yield was also observed.

Heavy-ion production of 77Br and 76Br.

Many radioisotopes with potential medical applications are difficult to produce routinely, especially those on the proton-rich side of the valley of stability. Current production methods typically use light-ion (protons or deuteron) reactions on materials of similar mass to the target radioisotope, which limits the elemental target material available and may require the use of targets with poor thermal properties (as is the case for the production of radiobromine). These reactions may also create significant amounts of proton-rich decay products which require chemical separation from the desired product in a highly radioactive environment. A promising alternative method using heavy-ion fusion-evaporation reactions for the production of the medically relevant bromine radioisotopes 76Br (t1/2 = 16.2 h) and 77Br (t1/2 = 57.0 h) is presented. Heavy-ion beams of 28Si and 16O were used to bombard natural chromium and copper targets just above the Coulomb barrier at the University of Notre Dame's Nuclear Science Laboratory to produce these bromine and precursor radioisotopes by fusion-evaporation reactions. Production yields for these reactions were measured and compared to PACE4 calculations. In addition to using more robust targets for irradiation, a simple physical-chemical separation method is proposed that will lead to very high radiopurity yields. A summary of accelerator facility requirements needed for routine production of these radioisotopes is also presented.

The large bat Helitron DNA transposase forms a compact monomeric assembly that buries and protects its covalently bound 5'-transposon end.

Helitrons are widespread eukaryotic DNA transposons that have significantly contributed to genome variability and evolution, in part because of their distinctive, replicative rolling-circle mechanism, which often mobilizes adjacent genes. Although most eukaryotic transposases form oligomers and use RNase H-like domains to break and rejoin double-stranded DNA (dsDNA), Helitron transposases contain a single-stranded DNA (ssDNA)-specific HUH endonuclease domain. Here, we report the cryo-electron microscopy structure of a Helitron transposase bound to the 5'-transposon end, providing insight into its multidomain architecture and function. The monomeric transposase forms a tightly packed assembly that buries the covalently attached cleaved end, protecting it until the second end becomes available. The structure reveals unexpected architectural similarity to TraI, a bacterial relaxase that also catalyzes ssDNA movement. The HUH active site suggests how two juxtaposed tyrosines, a feature of many replication initiators that use HUH nucleases, couple the conformational shift of an α-helix to control strand cleavage and ligation reactions.

Per- and polyfluoroalkyl substances (PFAS) and total fluorine in fire station dust.

Per- and polyfluoroalkyl substances (PFAS) are a class of over 4700 fluorinated compounds used in industry and consumer products. Studies have highlighted the use of aqueous film-forming foams (AFFFs) as an exposure source for firefighters, but little is known about PFAS occurrence inside fire stations, where firefighters spend most of their shifts. In this study, we aimed to characterize PFAS concentrations and sources inside fire stations. We measured 24 PFAS (using LC-MS/MS) and total fluorine (using particle-induced gamma ray emission) in dust from multiple rooms of 15 Massachusetts stations, many of which (60%) no longer use PFAS-containing AFFF at all and the rest of which only use it very rarely. Compared to station living rooms, turnout gear locker rooms had higher dust levels of total fluorine (p < 0.0001) and three PFAS: perfluorohexanoate (PFHxA), perfluoroheptanoate (PFHpA), and perfluorodecanoate (PFDoDA) (p < 0.05). These PFAS were also found on six wipes of station turnout gear. By contrast, the dominant PFAS in living rooms was N-ethyl perfluorooctane sulfonamidoacetic acid (N-MeFOSAA), a precursor to perfluorooctane sulfonate (PFOS) that still persists despite phase-outs almost two decades ago. The Σ24 PFAS accounted for less than 2% of fluorine in dust (n = 39), suggesting the potential presence of unknown PFAS. Turnout gear may be an important PFAS source in stations due to intentional additives and/or contamination from firefighting activities.

Characterization and within-site variation of environmental metal concentrations around a contaminated site using a community-engaged approach.

Historic industrial activity led to extensive lead and arsenic contamination within residential areas of East Chicago, Indiana, United States. Although remediation is underway, community concerns about this contamination remain. Therefore, the goal for this analysis was to characterize environmental contamination in soil within and around these areas. A total of 228 samples from 32 different sites (addresses) were collected by community members or study staff. These were analyzed for metals using portable x-ray fluorescence or inductively coupled plasma ̶ optical emission spectroscopy. Concentrations exceeding EPA screening levels were found for 42% of the soil arsenic samples, 35% of the soil lead samples, and 79% of the soil manganese samples; a few samples also contained elevated copper or zinc. Concentrations above EPA screening levels were identified both within and outside of the formally designated contaminated area. Roughly 30% of all sites had at least one sample above and one sample below the screening level for arsenic, lead, and manganese. For sites within the contaminated area, more than 90% (arsenic), 60% (lead) and 60% (manganese) of the samples exceeded EPA screening levels. There was a significant association of proximity to the historic industrial site with elevated soil concentrations of arsenic and lead; a similar association was present for manganese. These results are consistent with existing data for lead and arsenic and we additionally report elevated concentrations of manganese and a high within-site variability of all metal concentrations. These findings should be considered in future remediation efforts.

Flows, Stock, and Emissions of Poly- and Perfluoroalkyl Substances in California Carpet in 2000-2030 under Different Scenarios.

In this study, we present a holistic analysis of the stock and emissions of poly- and perfluoroalkyl substances (PFAS) in California carpet in 2000-2030. Our high estimate is that, in 2017, the total PFAS accumulated in in-use carpet stock and landfilled carpet are ∼60 and ∼120 tonnes, respectively, and the resultant PFAS emissions are ∼800 and ∼100 kg, respectively. Among the three subclasses (side-chain polymers, PFAA, and nonpolymeric precursors), side-chain polymers dominate the in-use stock and landfill accumulation, while nonpolymeric precursors dominate the resultant emissions. Our low estimate is typically 8-15% of the high estimate and follows similar trends and subclass breakdowns as the high estimate. California's new Carpet Stewardship Regulations (24% recycling of end-of-life carpet) will reduce the landfilled PFAS by 6% (7 tonnes) at the cost of increasing the in-use stock by 2% (2 tonnes) in 2030. Aggressive PFAS phase-out by carpet manufacturers (i.e., reduce PFAS use by 15% annually starting 2020) could reduce the in-use PFAS stock by 50% by 2030, but its impact on the total landfilled PFAS is limited. The shift toward short-chain PFAS will also significantly reduce the in-use stock of long-chain PFAS in carpet by 2030 (only 25% of the total PFAS will be long-chain). Among the data gaps identified, a key one is the current area-based PFAS emission reporting (i.e., g PFAS emitted/area carpet/time), which leads to the counterintuitive result that reducing the PFAS use in carpet production has no impact on the PFAS emissions from in-use stock and landfills. Future technical studies should either confirm this or consider a mass-based unit (e.g., g PFAS emitted/g PFAS used/time) for better integration into regional substance flow analysis. Other noticeable data gaps include the lack of time-series data on emissions from the in-use stock and on leaching of side-chain polymers from landfills.

A Sensitive XRF Screening Method for Lead in Drinking Water.

A novel method for quickly and quantitatively measuring aqueous lead in drinking water has been developed. A commercially available activated carbon felt has been found to effectively capture lead from tap water, and partnered with X-ray fluorescence (XRF) spectrometry, it provides quantitative measurement of aqueous lead in drinking water. Specifically, for a 2 L volume of tap water, the linear range of detection was found to be from 1-150 ppb, encompassing the current EPA limit for lead in drinking water (15 ppb). To make a reproducible and easy to use method for filtering, a 2 L bottle cap with a 1.25 cm diameter hole was used for filtering. Utilizing this filtration method, 75 solutions from 0 to 150 ppb lead gave a 91% sensitivity, 97% specificity, and 93% accuracy, and all the misclassified samples fell between 10 and 15 ppb. This method has also proved reliable for detecting calcium as well as several other divalent metals in drinking water including copper, zinc, iron, and manganese.

Harvesting 48V at the National Superconducting Cyclotron Laboratory.

As part of an effort to develop aqueous isotope harvesting techniques at radioactive beam facilities, 48V and a cocktail of primary- and secondary-beam ions created by the fragmentation reaction of a 160 MeV/nucleon 58Ni beam were stopped in an aqueous target cell. After collection, 48V was separated from the mixture of beam ions using cation-exchange chromatography. The extraction efficiency from the aqueous solution was (47.0 ± 2.5)%, and the isolated 48V had a radiochemical purity of 95.8%. This proof-of-concept work shows that aqueous isotope harvesting could provide significant quantities of rare isotopes which are currently unavailable at conventional facilities.

Risky bismuth: Distinguishing between lead contamination sources in soils.

In a broad environmental study in St. Joseph County, Indiana, elemental data from ∼2000 soil samples and ∼800 paint samples were collected with X-ray Fluorescence (XRF) spectroscopy. The observed lead concentrations were compared to other elemental concentrations in these data. A strong correlation between lead and bismuth concentrations was observed in a subset of the soil samples and in nearly all of the paint samples, with lead levels approximately 150 times higher than bismuth. However, some soil samples contained lead with no bismuth present. Since most lead sources likely contain bismuth as an impurity from refining of native lead ore, but leaded gasoline does not contain any bismuth impurities due to the manufacturing process of tetraethyl lead, it may be possible to distinguish environmental lead sources by XRF. To test if leaded gasoline could be the source of lead in the subset of soil samples containing no bismuth, leaded paint samples were analyzed with Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES), which confirmed the presence of bismuth in leaded paint. Aviation gasoline, which contains tetraethyl lead, was also analyzed by ICP-OES to confirm the absence of bismuth in leaded gasoline. This discovery suggests that XRF can be used to rapidly distinguish different legacy lead contamination sources from one another. For low lead concentrations, elemental measurements of bismuth by ICP-OES can be used in environmental forensics to distinguish leaded gasoline contamination from other sources of lead.

Serum concentrations of PFASs and exposure-related behaviors in African American and non-Hispanic white women.

Per- and polyfluoroalkyl substances (PFASs) are used in a wide range of consumer products for their water- and grease-resistant properties, but few studies have explored this exposure route. We used multiple regression to investigate associations between six self-reported behaviors hypothesized to influence PFAS exposure and serum concentrations of six PFAS chemicals in 178 middle-aged women enrolled in the Child Health and Development Studies, about half of whom are African American. Blood samples were collected in 2010-2013, and participants were interviewed about behavior in 2015-2016. Results showed that African American women had lower levels of perfluorooctanoic acid (PFOA) and perfluorohexanesulfonic acid (PFHxS) compared with non-Hispanic white women. In African Americans, but not others, frequent consumption of prepared food in coated cardboard containers was associated with higher levels of four PFASs. Flossing with Oral-B Glide, having stain-resistant carpet or furniture, and living in a city served by a PFAS-contaminated water supply were also associated with higher levels of some PFASs. Product testing using particle-induced γ-ray emission (PIGE) spectroscopy confirmed that Oral-B Glide and competitor flosses contained detectable fluorine. Despite the delay between blood collection and interview, these results strengthen the evidence for exposure to PFASs from food packaging and implicate exposure from polytetrafluoroethylene (PTFE)-based dental floss for the first time.

Fluorinated Compounds in U.S. Fast Food Packaging.

Per- and polyfluoroalkyl substances (PFASs) are highly persistent synthetic chemicals, some of which have been associated with cancer, developmental toxicity, immunotoxicity, and other health effects. PFASs in grease-resistant food packaging can leach into food and increase dietary exposure. We collected ~400 samples of food contact papers, paperboard containers, and beverage containers from fast food restaurants throughout the United States and measured total fluorine using particle-induced γ-ray emission (PIGE) spectroscopy. PIGE can rapidly and inexpensively measure total fluorine in solid-phase samples. We found that 46% of food contact papers and 20% of paperboard samples contained detectable fluorine (>16 nmol/cm2). Liquid chromatography/high-resolution mass spectrometry analysis of a subset of 20 samples found perfluorocarboxylates, perfluorosulfonates, and other known PFASs and/or unidentified polyfluorinated compounds (based on nontargeted analysis). The total peak area for PFASs was higher in 70% of samples (10 of 14) with a total fluorine level of >200 nmol/cm2 compared to six samples with a total fluorine level of <16 nmol/cm2. Samples with high total fluorine levels but low levels of measured PFASs may contain volatile PFASs, PFAS polymers, newer replacement PFASs, or other fluorinated compounds. The prevalence of fluorinated chemicals in fast food packaging demonstrates their potentially significant contribution to dietary PFAS exposure and environmental contamination during production and disposal.