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We analyzed 72 children's textile products marketed as stain-resistant from US and Canadian stores, particularly school uniforms, to assess if dothing represents a significant route of exposure to per- and polyfluoroalkyl substances (PFAS). Products were first screened for total fluorine (total F) using particle-induced gamma-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 mu g/m(2), median: 24.0 mu g/m(2)). Total targeted PEAS 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 similar to 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 similar to 0.1 tonne/year of mobile, nonpolymeric PFAS., Environmental Science & Technology, 56 (19), ISSN:0013-936X, ISSN:1520-5851

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., Environmental Science: Processes & Impacts, 24 (11), ISSN:2050-7887, ISSN:2050-7895

Per- and polyfluoroalkyl substances (PFAS), a highly persistent and potentially toxic class of chemicals, are added to cosmetics to increase their durability and water resistance. To assess this potential health and environmental risk, 231 cosmetic products purchased in the U.S. and Canada were screened for total fluorine using particle-induced gamma-ray emission spectroscopy. Of the eight categories tested, foundations, mascaras, and lip products had the highest proportion of products with high total fluorine ≥0.384 μg F/cm2. Twenty-nine products including 20 with high total fluorine concentrations were analyzed using targeted LC-MS/MS and GC-MS. PFAS concentrations ranged from 22–10,500 ng/g product weight, with an average and a median of 264 and 1050 ng/g product weights, respectively. Here, 6:2 and 8:2 fluorotelomer compounds, including alcohols, methacrylates, and phosphate esters, were most commonly detected. These compounds are precursors to PFCAs that are known to be harmful. The ingredient lists of most products tested did not disclose the presence of fluorinated compounds exposing a gap in U.S. and Canadian labeling laws. The manufacture, use, and disposal of cosmetics containing PFAS are all potential opportunities for health and ecosystem harm. Given their direct exposure routes into people, better regulation is needed to limit the widespread use of PFAS in cosmetics., Environmental Science & Technology Letters, 8 (7), ISSN:2328-8930

Excitation function of the (54)Fe(p,α)51Mn reaction was measured from 9.5 to 18 MeV [Formula: see text] by activating a foil stack of (54)Fe electrodeposited on copper substrates. Residual radionuclides were quantified by HPGe gamma ray spectrometry. Both (51)Mn (t(1/2) = 46.2 min, [Formula: see text] , [Formula: see text]; E(γ) = 749.1 keV, I(γ) = 0.265%) and its radioactive daughter, (51)Cr (t(1/2) = 27.704d, E(γ) = 320.1 keV, I(γ) = 9.91%), were used to indirectly quantify formation of (51)Mn. 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 promising method for the production and extraction of 52Fe utilizing near-symmetric, heavy-ion fusion-evaporation reactions is presented. A 28Si beam was used to bombard a 27Al target, producing 52Fe through the reaction: 27Al (28Si, p2n)52Fe. After irradiation, the aluminum target was dissolved, and the 52Fe was separated from the aluminum matrix and other reaction products through the use of a cationic-exchange column. It was possible to recover the 52Fe (t1/2 = 8.3 h) with high specific activity, higher than can be achieved with the high energy proton spallation reactions currently used to produce this isotope, which has significance in medical research. The production yields for this reaction were measured and compared to PACE4 calculations. These results demonstrate the potential for dedicated accelerator production of 52Fe using heavy-ion beams, which will result in higher specific activities with robust radiochemical purification techniques.

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

Particle-induced gamma-ray emission spectroscopy is a quantitative, sensitive technique that measures light element abundance in materials using external reference standards with known beam energy and intensity. When the ion beam is used ex vacuo, gamma-ray spectroscopy on targets in air greatly increases sample throughput. However, for most targets the accuracy of these measurements is limited by the uncertainty of the collected charge. An indirect beam current measurement technique has been developed using an ion beam reaction on atmospheric argon, the only atmospheric component with sufficient abundance (~1%) that produces abundant gamma rays with low-energy proton beams. The 40Ar(p,nγ)40K reaction has been studied here, and the characteristic 770 keV gamma ray is observed to serve as a reliable monitor for proton flux. This method allows a real-time calibration of beam intensity on target to measured upstream currents for ion beam analysis at beam energies above 3.5 MeV.

Elevated blood sera concentrations of perfluorinated and polyfluorinated alkyl substances (PFAS) are associated with many adverse human health effects, including lower birth weight children. Yet th...

The widespread detection of per- and polyfluoroalkyl substances (PFAS) throughout the world and the ongoing proliferation of environmental regulations has prompted the need for a forensic approach ...

Occupational exposure to aqueous film-forming foams (AFFF) can lead to elevated concentrations of per- and polyfluorinated alkyl substances (PFAS) in firefighter blood sera. AFFF are also one expos...

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.

It is important that sample collection and shipping for monitoring perfluoroalkyl and polyfluoroalkyl substances (PFAS) in groundwater and soil do not contribute to PFAS concentrations in samples. ...

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.

This work presents results of macro, micro, and nanoscale surface characterization for a set of Roman denarii, ranging from 136 BCE to 240 CE, using large-scale X-ray fluorescence (XRF) mapping, particle-induced X-ray emission (PIXE) spectroscopy, focused-ion-beam-assisted scanning electron microscopy (FIB-SEM) with energy dispersive spectroscopy (EDS). The combination of XRF and PIXE, with varying beam energies, allowed for visualization and quantification of individual elements as a function of the surface distribution. These results helped to select suitable areas for FIB-SEM-EDS analysis. The edges of selected coins were polished to image the inner composition and surface morphology of the coins using a backscattering electron (BSE) imaging method and EDS mapping. Nanosized lamellas extracted from the coins were investigated by transmission electron microscopy (TEM) as well. The combination of these methods enabled the surface, the subsurface, and volume composition of these coins to be probed to better understand their production methods, their surface treatment methods, and their corrosion. The results also provide evidence that a particular surface treatment method, amalgam silvering, had been used to make authentic Roman coins as early as the third century CE.

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.

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.

The use of atmospheric fallout radionuclides as sediment tracers can provide valuable information on sediment transport processes within watersheds. Research was conducted in cropland and mixed land use subwatersheds of the Pleasant Valley watershed (50 km2) in south-central Wisconsin to identify sources of suspended sediment using cesium-137 (137Cs) and excess lead-210 (210Pbxs). In the cropland-dominated subwatershed, contributions to suspended sediment from in-stream and agricultural sources ranged from 36% to 81% and from 19% to 64%, respectively. In the mixed land use subwatershed, contributions to suspended sediment from in-stream and agricultural sources ranged from 68% to 100% and from 0% to 32%, respectively. The relative contribution to suspended sediment from agricultural sources was greater in the cropland subwatershed compared to the mixed land use subwatershed. The phosphorus (P) concentration in suspended sediment and fine sediment deposited on the streambed varied from 601 to 1545 mg kg-1, and cropland areas were the dominant sources of P-enriched sediment in streams. The legacy P and sediment in this watershed can result in a lag time between implementation of best management practices and attainment of desired water quality improvement. Depending on the fingerprinting properties considered (metals vs. fallout radionuclides) and suspended sediment source considerations, the source apportionment results may vary. Keywords: Fallout radionuclides, Legacy sediment, Phosphorus, Sediment fingerprinting, Soil erosion, Streambanks.

Isotope harvesting is a method of collecting the long-lived radioisotopes that build up during the operation of ion-beam facilities in a way that is useful for subsequent research. As a demonstration of this method for the collection of a group IV metal at a fragmentation facility, the high-energy $^{88}\mathrm{Zr}$ secondary beam produced from a 140-MeV/u $^{92}\mathrm{Mo}$ primary beam at the National Superconducting Cyclotron Laboratory (NSCL) was stopped in a water target. The setup aimed to mimic the aqueous beam dump that will be implemented at the Facility for Rare Isotope Beams (FRIB). The collected $^{88}\mathrm{Zr}$ and accompanying $^{88}\mathrm{Y}$ decay daughter were radiochemically extracted from the solution and made into target samples suitable for neutron-capture cross-section measurements. These samples were then irradiated at two reactor facilities, and the $^{88}\mathrm{Zr}$ average thermal-neutron-capture cross section (${\ensuremath{\sigma}}_{T}$) and resonance integral ($I$) were determined to be ${\ensuremath{\sigma}}_{T}=(8.04\ifmmode\pm\else\textpm\fi{}0.63)\ifmmode\times\else\texttimes\fi{}{10}^{5}$ b and $I=(2.53\ifmmode\pm\else\textpm\fi{}0.28)\ifmmode\times\else\texttimes\fi{}{10}^{6}$ b. The ${\ensuremath{\sigma}}_{T}$ value agrees well with previous results and $I$, determined for the first time here, was found to be the largest measured resonance integral by two orders of magnitude. The $^{88}\mathrm{Y}$ thermal-neutron-capture cross section was determined to be less than $1.8\ifmmode\times\else\texttimes\fi{}{10}^{4}$ b. This work demonstrates the steps needed to make cross-section measurements with samples produced via aqueous isotope harvesting.

The radionuclide

Fabric and foam samples from popular children car seats marketed in the United States during 2018 were tested for fluorine content by particle-included gamma ray emission spectroscopy (PIGE, n = 93) and X-ray photoelectron spectroscopy (XPS, n = 36), as well as for per- and polyfluoroalkyl substances (PFAS) by liquid and gas chromatography mass spectrometry (LC/MS and GC/MS, n = 36). PFAS were detected in 97% of the car seat samples analyzed with MS, with total concentrations of 43 PFAS (∑PFAS) up to 268 ng/g. Fabric samples generally had greater ∑PFAS levels than foam and laminated composites of foam and fabric. The three fabric samples with the highest total fluorine content as represented by the highest PIGE signal were also subjected to ultraviolet (UV) irradiation and the total oxidizable precursor (TOP) assay. Results from these treatments, as well as the much higher organofluorine levels measured by PIGE compared to LC/MS and GC/MS, suggested the presence of side-chain fluorotelomer-based polymers (FTPs), which have the potential to readily degrade into perfluoroalkyl acids (PFAAs) under UV light. Furthermore, fluorotelomer (meth)acrylates were found to be indicators for the presence of (meth)acrylate-linked FTPs in consumer products, and thus confirmed that at least half of the tested car seats had FTP-treated fabrics. Finally, extraction of selected samples with synthetic sweat showed that ionic PFAS, particularly those with fluorinated carbons ≤8, can migrate from fabric to sweat, suggesting a potential dermal route of exposure.

Carbon and oxygen burning reactions, in particular, $^{12}\mathrm{C}+^{12}\mathrm{C}$ fusion, are important for the understanding and interpretation of the late phases of stellar evolution as well as the ignition and nucleosynthesis in cataclysmic binary systems such as type Ia supernovae and x-ray superbursts. A new measurement of this reaction has been performed at the University of Notre Dame using particle-$\ensuremath{\gamma}$ coincidence techniques with SAND (a silicon detector array) at the high-intensity 5U Pelletron accelerator. New results for $^{12}\mathrm{C}+^{12}\mathrm{C}$ fusion at low energies relevant to nuclear astrophysics are reported. They show strong disagreement with a recent measurement using the indirect Trojan Horse method. The impact on the carbon burning process under astrophysical scenarios will be discussed.

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.

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.

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.

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.

Per- and polyfluoroalkyl substances (PFASs) comprise a large array of man-made fluorinated chemicals. It is an emerging chemical class of concern because many PFASs are environmentally persistent and some have known ecological and human toxicity. Consumer products treated with PFASs result in human exposure to PFASs through inhalation, ingestion, and environmental exposure to emissions from wastewater or from landfills. A rapid screening method based on total fluorine was developed and applied to quantify PFASs on consumer papers and textiles. Particle-Induced Gamma Ray Emission (PIGE) spectroscopy provides a non-destructive and quantitative measurement of total fluorine on papers and textiles. This technique is both rapid and sensitive, with a limit of detection (LOD) of 13 nmol F/cm2 for papers and 24–45 nmol F/cm2 for textiles, with reproducibility of ±12% RSD for both. PIGE is a high throughput (>20 samples/hr typically) method that was applied to 50 papers and 50 textiles in commerce to demonstrate the method.

A novel method for radiolabeling perfluorinated alkyl substances (PFAS) with fluorine 18 has been developed, and after purification, the stability and biological distribution in healthy mice were evaluated. Three PFAS, [18F]PFOA (C8), [18F]PFHxA (C6), and [18F]PFBA (C4), were readily labeled and isolated in average yields between 12 and 31%. The stability of each compound was monitored in 0.1% ammonium hydroxide (NH4OH) in methanol, in saline, and in human, mouse, and rat sera. The amount of intact, radiolabeled PFAS was determined by radiometric instant thin layer chromatography and was calculated by the amount of free fluorine 18 observed over time. All compounds were highly stable in 0.1% NH4OH in methanol and saline, with

While the practice of tattooing has existed for thousands of years, it has recently begun growing in popularity in the US. With the increasing prevalence of tattoos, the methods and inks involved in the tattooing process have also developed. Tattoos now use many brightly colored inks, often made using metal-based pigments. There is concern that chemicals may be present in tattoo inks in concentrations that may lead to human health concerns either during application or removal of tattoos. Since exposure to metals has been linked to tremors, liver damage, memory loss, cognitive loss, and even death, there is concern about the prevalence of metals in tattoo inks in general. To this end, a survey of 226 commercial tattoo inks was performed and each ink was analyzed for the presence of heavy metals using two different x-ray methods: Particle Induced X-Ray Emission and Scanning Electron Microscopy/ Energy Dispersive Spectroscopy. Fifteen metals were identified in various tattoo inks by these rapid x-ray methods, including chromium, manganese, nickel, copper, barium, and lead. Conclusions can be drawn about the prevalence of metals in some pigment colors and from some brands.

As part of an effort to develop aqueous isotope harvesting techniques at radioactive beam facilities

In many states, environmental lead hazards are evaluated only after a lead-poisoned child has been identified. This passive approach is problematic because only a small fraction of children are tested for lead and those with elevated blood lead levels may have irreversible developmental damage. In order to reverse this paradigm, a new lead screening kit was developed. In this study, we validated the accuracy of the kit compared to the conventional methods. Forty-five participants used the kit to collect 3 dust, 3 soil and 2 paint samples in their homes. A researcher performed an in-situ analysis of the lead content in the paint and soil using a portable X-ray fluorescence (XRF) spectrometer. The soil, paint, and dust samples collected by the participants were then analyzed by XRF ex-situ. A strong linear correlation was found between the in-situ and ex-situ measurements for soil and dust samples, and a reasonable correlation was obtained for lead content of paint samples. The kit had very high degrees of specificity (true negative rate) and sensitivity (true positive rate) for detecting hazardous levels of lead in soil and dust samples. The agreement was more moderate for paint samples because some of the paint chips provided gave different readings from the front or back surface, but in-situ XRF only reads from the front surface. Overall, the kit gave a sensitivity of 87%, a specificity of 98% and an accuracy of 96% for detection of environmental lead hazards in samples collected from the home by untrained citizens. This suggests that widespread and inexpensive lead screening could be used to successfully identify hazards and ultimately decrease environmental lead exposure in children.

Background There is no safe level of lead in children's bodies. The US Centers for Disease Control and Prevention (CDC) estimate that more than half a million children under the age of 6 years are affected by low-level lead exposure in the USA. Low levels of lead can cause irreversible neurological and physiological damage in children. Currently, lead is investigated in the home and environment after a child has been identified as having elevated concentrations of lead in their blood; the source of lead exposure is then sought and removed. However, we seek to reverse this paradigm and allow families to engage in prevention by testing their home and environment before their child is exposed to lead. The aim of this study was to design and pilot a screening device to allow families to test their homes for lead. Methods We recruited participants for this blinded case-control study in Saint Joseph County, Indiana, USA, through community partnerships, a community lead testing event, and flyers. Participants were divided into three groups based on the age of their home: homes built before 1950; homes built between 1951 and 1978; and homes built after 1978. The post-1978 group acted as a control because lead paint was banned in 1978. Participants collected eight samples from their homes, including from soil, dust, and paint. The field team measured the concentration of lead levels in each of the eight samples at the site of collection using an X-ray fluorescence analyser. Samples were then tested at the laboratory where all identifying information was removed and workers were unaware of the age of the home the samples came from. Results from the field were then correlated with results from the laboratory using Bland-Altman plots, linear regression, and ROC curves. Informed consent was obtained and this study was approved by the University of Notre Dame Institutional Review Board. Findings We included results from 45 homes in the analysis: 17 from pre-1950 homes, 11 from 1951–78 homes; and 17 from post-1978 houses. Of the 17 pre-1950 homes, 94% had at least one finding of a lead concentration that exceeded the action level laid out by the US Environmental Protection Agency. Of the 11 1951–78 homes, 36% (4) had at least one elevated lead result, and none of the 1978 homes had an elevated lead result. Bland-Altman plot analysis showed good agreement between onsite and laboratory measurement with biases very close to zero. Correlation coefficients between field and laboratory measurements were 0·97, 0·89, and 0·92 for the soil, dust, and paint samples, respectively. The ROC curves show high sensitivity (87%), specificity (98%), and accuracy (96%). At the time of the study, the cost of the kit was approximately US$7.00, excluding laboratory fees. Interpretation This study lays the foundation for the creation of a lead sample collection kit model that can be implemented in homes, day-care centres, and schools. Although this model will not provide the participant with an in-depth lead risk assessment, it has the potential to be a tool to allow proactive screening of homes for environmental lead hazards. Our team will now work to scale up implementation with our community partners. Our goal is to distribute and test 500 kits in 2019. Funding A local private donor.

A refurbished 3 MV tandem Pelletron® accelerator has been installed in the University of Notre Dame’s Nuclear Science Laboratory for the purpose of ion beam analysis applications. A modified Alphatross® ion source provides microAmps of H, He or both ions into the accelerator. Several high-energy beam lines are operational, which allow for internal and ex vacuo ion beam analyses. The external beam capability allows for gamma-ray (PIGE) and x-ray (PIXE) analyses to be conducted simultaneously on targets in atmosphere. Rutherford backscattering (RBS) analysis as well as PIXE can also be performed in a 30” scattering chamber. An overview of the new facility, its commissioning experiments and routine operating procedures will be presented together with some examples of ion beam analysis applications performed to date.

Background: The Center for Disease Control recommends case management begin at a blood lead level of 5 μg/dL, yet Indiana does not take action until a blood lead level of 10 μg/dL. Low levels of lead can cause irreversible neurological damage in children. The goal of this study was to design a scalable, low-cost Home Lead Test Kit to proactively find lead in homes. Methods: Individuals were recruited through community partnerships, community lead testing events, and flyers. Qualitative data was recorded during home visits as participants used the kit. An x-ray fluorescence analyzer was used in the field and laboratory to analyze lead levels of samples. Results were blinded during the analysis. Results: To date, 40 homes have been recruited, and 20 have been completed. The average completion time of the kit was 23.45 minutes. Of the 8 pre-1950 homes 100% had elevated lead results, of the 7 1950-1978 homes 43% had elevated lead results, and of the 5 post 1978 homes 0% had elevated lead results. Conclusion and Potential Impact: The study is ongoing. Preliminary results support the hypothesis that pre-1950 homes have a high risk of lead exposure, and post 1978 homes have minimal to no levels of lead. Feedback from study participants regarding kit usability has been positive. Future plans are to produce a kit to be scaled up in St. Joseph County with the goal of a statewide model. This kit may allow citizens to identify lead hazards to prevent children from lead exposure.

Hydroxyapatite is an inorganic mineral closely resembling the mineral phase in bone. However, as a biological mineral, it is highly disordered, and its composition and atomistic structure remain poorly understood. Here, synchrotron X-ray total scattering and pair distribution function analysis methods provide insight into the nature of atomistic disorder in a synthetic bone mineral analogue, chemically substituted hydroxyapatite. By varying the effective hydrolysis rate and/or carbonate concentration during growth of the mineral, compounds with varied degrees of paracrystallinity are prepared. From advanced simulations constrained by the experimental pair distribution function and density functional theory, the paracrystalline disorder prevalent in these materials appears to result from accommodation of carbonate in the lattice through random displacement of the phosphate groups. Though many substitution modalities are likely to occur in concert, the most predominant substitution places carbonate into the mirror plane of an ideal phosphate site. Understanding the mineralogical imperfections of a biologically analogous hydroxyapatite is important not only to potential bone grafting applications but also to biological mineralization processes themselves.

Discarded carpet and clothing are potential sources of per- and polyfluoroalkyl substances (PFASs) in landfill leachate, but little is known about their release when disposed in landfills. The concentrations of 70 PFASs in the aqueous phase of anaerobic model landfill reactors filled with carpet or clothing were monitored under biologically active and abiotic conditions. For carpet, total PFAS release was greater in live than abiotic reactors, with an average of 8.5 nmol/L and 0.62 nmol/L after 552 days, respectively. Release in live carpet reactors was primarily due to 5:3 fluorotelomer carboxylic acid (FTCA - 3.9 nmol/L) and perfluorohexanoic carboxylic acid (PFHxA - 2.9 nmol/L). For clothing, release was more dependent on sample heterogeneity than the presence of biological activity, with 0.63, 21.7, 2.6, and 6.3 nmol/L for two live and two abiotic reactors after 519 days, respectively. Release in the clothing reactors was largely due to perfluorooctatonic carboxylic acid (PFOA), with low relative concentrations of measured biotransformation precursors (FTCAs). For carpet and clothing reactors, the majority of PFAS release was not measured until after day 100. Results demonstrate that carpet and clothing are likely sources of PFASs in landfill leachate.

Hazardous chemicals used in electronic and electrical consumer products can re-enter commerce when these products are recycled. The objectives of this study were to 1) identify the possible sources of unexpected chemicals and elements in consumer products, including the use of recycled E-waste plastics and 2) demonstrate bromine detection with nondestructive spectroscopy as an indicator of brominated flame retardants contaminating new products via recycled waste streams. More than 1500 consumer products of diverse types purchased in 2012-2014 were examined using X-ray fluorescence spectroscopy for correlations between bromine and other elements. New electronic products were much more likely than new non-electronics to contain greater than 1000 ppm bromine, consistent with intentionally added flame retardants, while non- electronic products were more likely to contain between 5 and 100 ppm bromine, suggesting unintentional contamination. A typical suite of elements present in E-waste was found in a majority of plastic products. Two product categories, vinyl floor tiles and beaded necklaces/garlands, were explored in more detail. Specific flame retardant chemicals in bead samples were identified by mass spectrometry and their distribution in beads was studied using scanning electron microscopy and energy dispersive spectroscopy. Five brominated chemicals typically used as flame retardants, including BDE-209, were identified in 50 of 50 Mardi Gras beads analyzed.

In this study we examined whether a Gram-positive and a Gram-negative bacterial species have the capability to remove perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) from solution through sorption reactions under two different pH conditions. We developed a novel approach for quantifying PFAS in solution using particle-induced gamma-ray emission (PIGE) spectroscopy, and we used the results to constrain the important PFAS-bacterial sorption mechanisms. A mass balance experiment measuring PFOS in the aqueous phase and solid phase confirmed that PIGE spectroscopy measurements can account for all PFOS in the system, demonstrating for the first time how PIGE spectroscopy can be used to quantify the extent of PFAS sorption in experimental systems. Significant sorption occurred under most conditions studied, with up to 40 ± 5% and 67 ± 11% sorption of PFOA and PFOS, respectively. PFOA and PFOS sorption were both rapid, with steady-state being attained within minutes. PFOS sorption was pH dependent while PFOA sorption was pH independent, and greater sorption occurred onto Bacillus subtilis biomass compared to Pseudomonas putida biomass for both PFAS types. This sorption behavior suggests that pH, the PFAS head molecule, and cell wall structure all have a significant effect on the extent and mechanisms of bacterial sorption of PFAS. The observed sorption behaviors suggest that sorption of both molecules involves electrostatic and hydrophobic components. PFOS desorption was rapid and exhibited complete reversibility for both bacterial species, indicating that sorption is likely a cell surface phenomenon with no internalization occurring on the timescale of these experiments, and that the process can be modeled as an equilibrium reaction. Our work demonstrates that different PFAS molecules react to bacteria differently, and thus likely have markedly different mobilities in the environment. PFAS sorption in geologic systems is strongly influenced by organic matter, and our results suggest that biosorption may represent an inexpensive and effective PFAS remediation technique.

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.

Introduction: Poly- and perfluoroalkyl substances (PFAS) are used to provide water- and oil-repellency in consumer products, including food packaging. Some PFAS are persistent and toxic, and can mi...