In this study, we measured the effects of sample type and storage temperature on the stability of 29 per- and polyfluorinated alkyl substances (PFAS) in water. Spiked bottled water, surface water, ...and two types of effluent samples were stored in HDPE containers at +20, 4, and −20 °C over a period of up to 180 days. The analytes studied included C4 through C14 perfluorinated carboxylates (PFCAs); C4 through C10 and C12 perfluorinated sulfonates (PFSAs); 4:2, 6:2, and 8:2 fluorotelomer sulfonates (FTS); three perfluorooctane sulfonamides (PFOSA, N-MeFOSA, and N-EtFOSA); two perfluorooctane sulfonamide ethanols (N-MeFOSE and N-EtFOSE); and two perfluorooctane sulfonamide acetic acids (N-MeFOSAA and EtFOSAA). Overall, 10 analytes, PFOA, PFNA, 8:2 FTS, PFOSA, N-MeFOSA, NEtFOSA, N-MeFOSAA, N-EtFOSAA, N-MeFOSE, and N-EtFOSE, showed increasing or decreasing concentration trends under at least one of the experimental conditions investigated. Increases in concentrations of N-MeFOSAA and N-EtFOSAA in surface water and effluent samples at +20 and 4 °C correlated with the decreases in the concentrations of N-MeFOSE and N-EtFOSE, respectively, suggesting analyte interconversion during sample storage. This is the first time such analyte conversion is reported in samples under storage, and this work demonstrates the importance of assessing stability of PFAS in environmentally relevant matrices. The significance of this study extends beyond sample storage for analysis, as toxicological and exposure studies conducted at room temperature also need to consider the significance of analyte degradation through the exposure process.
Per- and polyfluoroalkyl substances (PFAS) are considered chemicals of emerging concern, in part due to their environmental and biological persistence and the potential for widespread human exposure. ...In 2007, a PFAS manufacturer near Decatur, Alabama notified the United States Environmental Protection Agency (EPA) it had discharged PFAS into a wastewater treatment plant, resulting in environmental contamination and potential exposures to the local community.
To characterize PFAS exposure over time, the Agency for Toxic Substances and Disease Registry (ATSDR) collected blood and urine samples from local residents.
Eight PFAS were measured in serum in 2010 (n=153). Eleven PFAS were measured in serum, and five PFAS were measured in urine (n=45) from some of the same residents in 2016. Serum concentrations were compared to nationally representative data and change in serum concentration over time was evaluated. Biological half-lives were estimated for perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and perfluorohexane sulfonic acid (PFHxS) using a one-compartment pharmacokinetic model.
In 2010 and 2016, geometric mean PFOA and PFOS serum concentrations were elevated in participants compared to the general U.S. population. In 2016, the geometric mean PFHxS serum concentration was elevated compared to the general U.S. population. Geometric mean serum concentrations of PFOA, PFOS, and perfluorononanoic acid (PFNA) were significantly (p≤0.0001) lower (49%, 53%, and 58%, respectively) in 2016 compared to 2010. Half-lives for PFOA, PFOS, and PFHxS were estimated to be 3.9, 3.3, and 15.5years, respectively. Concentrations of PFOA in serum and urine were highly correlated (r=0.75) in males.
Serum concentrations of some PFAS are decreasing in this residentially exposed community, but remain elevated compared to the U.S. general population.
•Serum PFAS concentrations are decreasing in a residentially exposed community.•PFOS and PFOA concentrations are elevated compared to the U.S. general population.•Reductions in the use of long-chain PFAS have led to declines in serum concentrations.
To examine the spatial, and temporal variation and potential sources of pesticide concentrations, primarily neonicotinoid insecticides, in hummingbirds in western Canada, we sampled their cloacal ...fluid from sites in British Columbia and Saskatchewan, Canada in 2017–2018. At a sub-sample of those sites, we also measured pesticides in honey bee (Apis mellifera) nectar, water, and sediment. We collected cloacal fluid from 5 species of hummingbirds (n = 26 sites) in British Columbia (BC) and Saskatchewan, Canada, and nectar from honey bee hives (n = 4 sites), water and sediment (n = 18 sites) in the Fraser Valley, BC. Among those, multiple types of samples were collected at 6 sites. We report the first measurement of flupyradifurone, a relatively new butenolide insecticide, in wildlife which was detected at 4.58 ng/mL in hummingbird cloacal fluid and 2.18 ng/g in honey bee nectar. We also detected three other neonicotinoids (imidacloprid, clothianidin, acetamiprid) and one metabolite desnitro-imidacloprid, and MGK264, a pesticide synergist, in our samples. Among 49 samples of cloacal fluid from rufous (Selasphorus rufus), Anna's (Calypte anna), calliope (Selasphorus calliope) black-chinned (Archilocus alexandri) and ruby-throated hummingbirds (Archilocus colubris), 26.5% (n = 13) contained neonicotinoids. Maximum pesticide concentrations in hummingbirds, water and sediment were found in samples collected in the Fraser Valley, BC within 0.5 km of conventionally sprayed blueberry fields (CSBF) but highest levels in honey bee nectar were detected at a site 1.5 km from a CSBF. Imidacloprid in honey bee nectar at one site exceeded concentrations (>1 ng/g) that can sublethally affect worker bee foraging efficiency. In water, imidacloprid concentrations at another site exceeded Canadian guidelines (230 ng/mL) for the protection of aquatic invertebrates.
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•In western Canada (2017, 2018; n=39 sites), neonicotinoid concentrations were the highest in hummingbird, honey bee nectar, water and sediment from sites closest to sprayed blueberry fields.•We report the first measurement of flupyradifurone, a new butenolide insecticide, in wildlife at concentrations of 4.58 ng/mL in hummingbird cloacal fluid and 2.18 ng/g in honey bee nectar.•Imidacloprid in honey bee nectar at one of four sites exceeded concentrations (>1 ng/g) which sublethally affect worker bee foraging efficiency.•Imidacloprid in water at one of 18 sites exceeded Canadian guidelines (230 ng/mL) for the protection of aquatic invertebrates.
Investigations into the biodegradation potential of perfluorooctane sulfonate (PFOS)-precursor candidates have focused on low molecular weight substances (e.g., N-ethyl perfluorooctane sulfonamido ...ethanol (EtFOSE)) in wastewater treatment plant sludge. Few data are available on PFOS-precursor biodegradation in other environmental compartments, and nothing is known about the stability of high-molecular-weight perfluorooctane sulfonamide-based substances such as the EtFOSE-based phosphate diester (SAmPAP diester) in any environmental compartment. In the present work, the biodegradation potential of SAmPAP diester and EtFOSE by bacteria in marine sediments was evaluated over 120 days at 4 and 25 °C. At both temperatures, EtFOSE was transformed to a suite of products, including N-ethyl perfluorooctane sulfonamidoacetate, perfluorooctane sulfonamidoacetate, N-ethyl perfluorooctane sulfonamide, perfluorooctane sulfonamide, and perfluorooctane sulfonate. Transformation was significantly more rapid at 25 °C (t 1/2 = 44 ± 3.4 days; error represents standard error of the mean (SEM)) compared to 4 °C (t 1/2 = 160 ± 17 days), but much longer than previous biodegradation studies involving EtFOSE in sludge (t 1/2 ∼0.7–4.2 days). In contrast, SAmPAP diester was highly recalcitrant to microbial degradation, with negligible loss and/or associated product formation observed after 120 days at both temperatures, and an estimated half-life of >380 days at 25 °C (estimated using the lower bounds 95% confidence interval of the slope). We hypothesize that the hydrophobicity of SAmPAP diester reduces its bioavailability, thus limiting biotransformation by bacteria in sediments. The lengthy biodegradation half-life of EtFOSE and recalcitrant nature of SAmPAP diester in part explains the elevated concentrations of PFOS-precursors observed in urban marine sediments from Canada, Japan, and the U.S, over a decade after phase-out of their production and commercial application in these countries.
•A new HRGC–HRMS method was developed for determination of 4 OH-PAHs.•The causes of OH-PAHs instability were identified as photo induced oxidation.•The current method controlled OH-PAH analyte ...degradation during analysis.•Conjugated OH-PAHs are more stable than non-conjugated OH-PAHs.•Accuracy and precision were 77.4–117% (<15% RSD) in synthetic and human urine samples.
A high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) method was developed for quantitative analysis of hydroxy polycyclic aromatic hydrocarbons (OH-PAHs). Four hydroxy metabolites of known and suspected carcinogenic PAHs (benzoapyrene (BaP), benzaanthracene (BaA), and chrysene (CRY)) were selected as suitable biomarkers of PAH exposure and associated risks to human health. The analytical method included enzymatic deconjugation, liquid − liquid extraction, followed by derivatization with methyl-N-(trimethylsilyl) trifluoroacetamide and instrumental analysis. Photo-induced oxidation of target analytes − which has plagued previously published methods − was controlled by a combination of minimizing exposure to light, employing an antioxidant (2-mercaptoethanol) and utilizing a nitrogen atmosphere. Stability investigations also indicated that conjugated forms of the analytes are more stable than the non-conjugated forms. Accuracy and precision of the method were 77.4–101% (<4.9% RSD) in synthetic urine and 92.3–117% (<15% RSD) in human urine, respectively. Method detection limits, determined using eight replicates of low-level spiked human urine, ranged from 13 to 24pg/mL. The method was successfully applied for analysis of a pooled human urine sample and 78 mouse urine samples collected from mice fed with PAH-contaminated diets. In mouse urine, greater than 94% of each analyte was present in its conjugated form.
•A new HPLC-MS/MS was developed for determination of 13 OPs in WWTP samples.•The method displayed good accuracy (70–132%) and precision (<19%RSD) in all matrices.•∑OPs ranged from 2328 to 5764ng/L ...and 2128 to 3167ng/g, in liquid and solid waste streams, respectively.•V6, TPrP, and TDBPP are reported for the first time in a WWTP system.
A method for quantitative determination of 13 organophosphorous compounds (OPs) was developed and applied to influent, primary sludge, activated sludge, biosolids, primary effluent and final effluent from a wastewater treatment plant (WWTP). The method involved solvent extraction followed by solid phase clean-up and analysis by high performance liquid chromatography positive electrospray ionization-tandem mass spectrometry (HPLC(+ESI)MS/MS). Replicate spike/recovery experiments revealed the method to have good accuracy (70–132%) and precision (<19% RSD) in all matrices. Detection limits of 0.1–5ng/L for aqueous samples and 0.01–0.5ng/g for solid samples were achieved. In the liquid waste stream ∑OP concentrations were highest in influent (5764ng/L) followed by primary effluent (4642ng/L), and final effluent (2328ng/L). In the solid waste stream, the highest ∑OP concentrations were observed in biosolids (3167ng/g dw), followed by waste activated sludge (2294ng/g dw), and primary sludge (2128ng/g dw). These concentrations are nearly 30-fold higher than ∑polybrominated diphenyl ether (BDE) concentrations in influents and nearly 200-fold higher than ∑BDE concentrations in effluents from other sites in Canada. Tetrekis(2-chlorethyl)dichloroisopentyldiphosphate (V6), tripropylphosphate (TnPrP), and Tris(2,3-dibromopropyl)phosphate (TDBPP) are investigated for the first time in a WWTP. While TnPrP and TDBB were not detected, V6 was observed at concentrations up to 7.9ng/g in solid waste streams and up to 40.7ng/L in liquid waste streams. The lack of removal of OPs during wastewater treatment is a concern due to their release into the aquatic environment.
The decay of the 21.47-MeV stretched resonance in 13C, arising from p3/2→d5/2 nucleon excitation coupled to maximum spin, was investigated in a (p,p′) experiment at 135 MeV proton bombarding energy, ...performed at the Cyclotron Centre Bronowice (CCB) at IFJ PAN in Krakow. First experimental information on the proton and neutron decay branches from this state was obtained by using coincidence measurement of protons inelastically scattered on a 13C target and γ rays from daughter nuclei, namely, 12B (proton decay) and 12C (neutron decay). The main branches lead to the Jπ=2+, first-excited state at 0.953 MeV in 12B, and to the Jπ=1+, T=1 level at 15.110 MeV in 12C. The results were compared with predictions from the Gamow Shell Model (GSM), which was used to describe the stretched resonance in terms of its energy, width, electromagnetic transition strengths and decay pattern. A very good agreement was obtained between the measured and calculated properties of the 21.47-MeV stretched resonance in 13C, demonstrating the high-quality and precision of the GSM wave function calculations, which include coupling to the resonant and non-resonant particle continuum.
Very high levels of industrial contaminants in St. Lawrence Estuary (SLE) beluga whales represent one of the major threats to this population classified as endangered under the Species at Risk Act in ...Canada. Elevated concentrations of short-chained chlorinated paraffins (SCCPs) were recently reported in blubber of adult male SLE belugas. Recent regulations for SCCPs in North America, combined with their replacement by medium- (MCCPs) and long-chained chlorinated paraffins (LCCPs), highlight the importance of tracking this toxic chemical class. The objectives of this study were to evaluate (1) levels and profiles of chlorinated paraffins (CPs) in samples obtained from carcasses of adult male, adult female, juvenile, newborn, and fetus beluga, and (2) trends in adult male belugas between 1997 and 2018. Factors potentially influencing CP temporal trends such as age, feeding ecology and sampling year were also explored. SCCPs dominated (64 to 100%) total CP concentrations across all age and sex classes, MCCPs accounted for the remaining proportion of total CPs, and LCCPs were not detected in any sample. The chlorinated paraffin homolog that dominated the most in beluga blubber was C12Cl8. Adult male SCCP concentrations from this study were considerably lower (> 2000-fold) than those recently reported in Simond et al. (2020), likely reflecting a previously erroneous overestimate due to the lack of a suitable analytical method for SCCPs at the time. Both SCCPs and total CPs declined over time in adult males in our study (rate of 1.67 and 1.33% per year, respectively), presumably due in part to the implementation of regulations in 2012. However, there is a need to better understand the possible contribution of a changing diet to contaminant exposure, as stable isotopic ratios of carbon also changed over time.
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•SCCPs dominated the blubber of St. Lawrence Estuary belugas.•The CP homolog that dominated beluga blubber was C12Cl8.•SCCPs appear to be mainly transferred via lactation to calves.•Total CPs in belugas declined by 28 % over two decades ending 2018.•Our study corrects a previous report of very high SCCP levels in this population.
The environmental occurrence of perfluorooctane sulfonate (PFOS) can arise from its direct use as well as from transformation of precursors ((N-alkyl substituted) perfluorooctane sulfonamides; ...FOSAMs). Perfluorooctane sulfonamidoethanol-based phosphate (SAmPAP) esters are among numerous potential PFOS-precursors which have not been previously detected in the environment and for which little is known about their stability. Based on their high production volume during the 1970s–2002 and widespread use in food contact paper and packaging, SAmPAP esters may be potentially significant sources of PFOS. Here we report for the first time on the environmental occurrence of SAmPAP diester in marine sediments from an urbanized marine harbor in Vancouver, Canada. SAmPAP diester concentrations in sediment (40–200 pg/g dry weight) were similar to those of PFOS (71–180 pg/g). A significant (p < 0.05) correlation was observed between SAmPAP diester and N-ethyl perfluorooctane sulfonamido acetate (an anticipated degradation product of SAmPAP diester). ∑PFOS-precursor (FOSAM) concentrations in sediment (120–1100 pg/g) were 1.6–24 times greater than those of PFOS in sediment. Although SAmPAP diester was not detected in water, PFOS was observed at concentrations up to 710 pg/L. Among the per- and polyfluoroalkyl substances monitored in the present work, mean log-transformed sediment/water distribution coefficients ranged from 2.3 to 4.3 and increased with number of CF2 units and N-alkyl substitution (in the case of FOSAMs). Overall, these results highlight the importance of FOSAMs as potentially significant sources of PFOS, in particular for urban marine environments.
New physics opportunities are opening up by the Advanced Gamma Tracking Array, AGATA, as it evolves to the full 4
π
instrument. AGATA is a high-resolution
γ
-ray spectrometer, solely built from ...highly segmented high-purity Ge detectors, capable of measuring
γ
rays from a few tens of keV to beyond 10 MeV, with unprecedented efficiency, excellent position resolution for individual
γ
-ray interactions, and very high count-rate capability. As a travelling detector AGATA will be employed at all major current and near-future European research facilities delivering stable and radioactive ion beams.
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