Long-term outcomes following impedance-controlled radiofrequency ablation for the treatment of chronic rhinitis.

Objective: To assess long-term safety and effectiveness of a multipoint, impedance-controlled, RF ablation device for treatment of chronic rhinitis through 12-month follow-up. Methods: A prospective, multicenter study. Bilateral posterior nasal nerve (PNN) ablation was performed on all participants. Assessments at 6-, 9-, and 12-month visits included Visual Analog Scale Nasal Symptom Score (VAS NSS), reflective Total Nasal Symptom Score (rTNSS), mini-Rhinoconjunctivitis Quality of Life Questionnaire (mini RQLQ), and adverse events. Results: Thirty-six participants were enrolled and 35 completed the 12-month follow-up. All 5 VAS NSS items demonstrated statistically significant improvement (p < .0001) over baseline at all 3 time points. The total rTNSS improved from 7.9 ± 1.8 at baseline to 4.3 ± 2.1 at 6-months, 3.8 ± 2.4 at 9-months, and 4.0 ± 2.1 at 12-months (all p < .0001). At 12-months, 91% (31/35) of participants had achieved the minimum clinically important difference (MCID) of a reduction from baseline of ≥1 point and 80% (28/35) of the participants met the responder criteria of ≥30% reduction from baseline. The total mean mini RQLQ was reduced from 3.0 ± 1.0 at baseline to 1.4 ± 0.8 at 6-months, 1.4 ± 1.0 at 9-months, and 1.3 ± 0.8 at 12-months (all p < .0001). At 12-months, 86% (30/35) of participants achieved the MCID of a reduction from baseline of ≥0.4 points for the mini RQLQ. No related serious adverse events occurred during the study. Conclusions: Impedance-controlled RF ablation of the PNN is safe and resulted in durable, significant improvement in rhinitis symptoms and quality of life through 12-month follow-up. Trial Registration: The study is registered at www.clinicaltrials.gov with the unique identifier of NCT05324397. Level of Evidence: 4.

Advective and diffusive gas phase transport in vadose zones: Importance for defining vapour risks and natural source zone depletion of petroleum hydrocarbons.

Quantifying the interlinked behaviour of the soil microbiome, fluid flow, multi-component transport and partitioning, and biodegradation is key to characterising vapour risks and natural source zone depletion (NSZD) of light non-aqueous phase liquid (LNAPL) petroleum hydrocarbons. Critical to vapour transport and NSZD is transport of gases through the vadose zone (oxygen from the atmosphere, volatile organic compounds (VOCs), methane and carbon dioxide from the zone of LNAPL biodegradation). Volatilisation of VOCs from LNAPL, aerobic biodegradation, methanogenesis and heat production all generate gas pressure changes that may lead to enhanced gas fluxes apart from diffusion. Despite the importance of the gaseous phase dynamics in the vadose zone processes, the relative pressure changes and consequent scales of advective (buoyancy and pressure driven) / diffusive transport is less studied. We use a validated multi-phase multi-component non-isothermal modelling framework to differentiate gas transport mechanisms. We simulate a multicomponent unweathered gasoline LNAPL with high VOC content to maximise the potential for pressure changes due to volatilisation and to enable the joint effects of methanogenesis and shallower aerobic biodegradation of vapours to be assessed, along with heat production. Considering a uniform fine sand profile with LNAPL resident in the water table capillary zone, results suggest that biodegradation plays the key role in gas phase formation and consequent pressure build-up. Results suggest that advection is the main transport mechanism over a thin zone inside the LNAPL/capillary region, where the effective gaseous diffusion is very low. In the bulk of the vadose zone above the LNAPL region, the pressure change is minimal, and gaseous diffusion is dominant. Even for high biodegradation rate cases, pressure build-up due to heat generation (inducing buoyancy effects) is smaller than the contribution of gas formation due to biodegradation. The findings are critical to support broader assumptions of diffusive transport being dominant in vapour transport and NSZD assessments.

The Dynamics of Per- and Polyfluoroalkyl Substances (PFAS) at Interfaces in Porous Media: A Computational Roadmap from Nanoscale Molecular Dynamics Simulation to Macroscale Modeling.

Managing and remediating perfluoroalkyl and polyfluoroalkyl substance (PFAS) contaminated sites remains challenging. The major reasons are the complexity of geological media, partly unknown dynamics of the PFAS in different phases and at fluid-fluid and fluid-solid interfaces, and the presence of cocontaminants such as nonaqueous phase liquids (NAPLs). Critical knowledge gaps exist in understanding the behavior and fate of PFAS in vadose and saturated zones and in other porous media such as concrete and asphalt. The complexity of PFAS-surface interactions warrants the use of advanced characterization and computational tools to understand and quantify nanoscale behavior of the molecules. This can then be upscaled to the microscale to develop a constitutive relationship, in particular to distinguish between surface and bulk diffusion. The dominance of surface diffusion compared to bulk diffusion results in the solutocapillary Marangoni effect, which has not been considered while investigating the fate of PFAS. Without a deep understanding of these phenomena, derivation of constitutive relationships is challenging. The current Darcy scale mass-transfer models use constitutive relationships derived from either experiments or field measurements, which makes their applicability potentially limited. Here we review current efforts and propose a roadmap for developing Darcy scale transport equations for PFAS. We find that this needs to be based on systematic upscaling of both experimental and computational studies from nano- to microscales. We highlight recent efforts to undertake molecular dynamics simulations on problems with similar levels of complexity and explore the feasibility of conducting nanoscale simulations on PFAS dynamics at the interface of fluid pairs.

Efficacy of EDS-FLU for Chronic Rhinosinusitis: Two Randomized Controlled Trials (ReOpen1 and ReOpen2).

BACKGROUND: Chronic rhinosinusitis (CRS) is a prevalent inflammatory disease. No medications are Food and Drug Administration-approved for the most common form, CRS without nasal polyps (also called "chronic sinusitis"). Novel biomechanics of the exhalation delivery system deliver fluticasone (EDS-FLU; XHANCE) to sinonasal areas above the inferior turbinate, especially sinus drainage pathways not reached by standard-delivery nasal sprays. OBJECTIVE: Assess EDS-FLU efficacy for CRS (irrespective of nasal polyps). METHODS: Two randomized, EDS-placebo-controlled trials in adults with CRS irrespective of polyps (ReOpen1) or exclusively without polyps (ReOpen2) were conducted at 120 sites in 13 countries. Patients received EDS-FLU 1 or 2 sprays/nostril, or EDS-placebo, twice daily for 24 weeks. Coprimary measures were composite symptom score through week 4 and ethmoid/maxillary sinus percent opacification by computed tomography at week 24. RESULTS: ReOpen1 (N = 332) composite symptom score least-squares mean change for EDS-FLU 1 or 2 sprays/nostril versus EDS-placebo was -1.58 and -1.60 versus -0.62 (P < .001, P < .001); ReOpen2 (N = 223), -1.54 and -1.74 versus -0.81 (P = .011, P = .001). In ReOpen1, sinus opacification least-squares mean change for EDS-FLU 1 or 2 sprays/nostril versus EDS-placebo was -5.58 and -6.20 versus -1.60 (P = .045, P = .018), and in ReOpen2, -7.00 and -5.14 versus +1.19 (P < .001, P = .009). Acute disease exacerbations were reduced by 56% to 66% with EDS-FLU versus EDS-placebo (P = .001). There were significant, and similar magnitude, symptom reductions in patients using standard-delivery nasal steroid products just before entering the study (P < .001). Adverse events were similar to standard-delivery intranasal steroids. CONCLUSIONS: EDS-FLU is the first nonsurgical treatment demonstrated to reduce symptoms, intrasinus opacification, and exacerbations in replicate randomized clinical trials in CRS, regardless of polyp status.

Childhood growth outcomes 2 years after hypertensive versus normotensive pregnancy: a P4 study.

BACKGROUND: Intrauterine exposure to hypertensive disorders of pregnancy, including gestational hypertension (GH) and preeclampsia (PE), may influence infant growth and have long-term health implications. This study aimed to compare growth outcomes of infants exposed to a normotensive pregnancy (NTP), GH, or PE from birth to 2 years. METHODS: Infants were children of women enroled in the prospective Postpartum Physiology, Psychology and Paediatric (P4) cohort study who had NTP, GH or PE. Birth, 6-month (age-corrected) and 2-year (age-corrected) weight z-scores, change in weight z-scores, rapid weight gain (≥0.67 increase in weight z-score) and conditional weight gain z-scores were calculated to assess infant growth (NTP = 240, GH = 19, PE = 66). RESULTS: Infants exposed to PE compared to NTP or GH had significantly lower birth weight and length z-scores, but there were no differences in growth outcomes at 6 months or 2 years. GH and PE-exposed infants had significantly greater weight z-score gain [95% CI] (PE = 0.93 [0.66-1.18], GH = 1.03 [0.37-1.68], NTP = 0.45 [0.31-0.58], p < 0.01) and rapid weight gain (GH = 63%, PE = 59%, NTP = 42%, p = 0.02) from birth to 2 years, which remained significant for PE-exposed infants after confounder adjustment. CONCLUSION: In this cohort, GH and PE were associated with accelerated infant weight gain that may increase future cardiometabolic disease risk. IMPACT: Preeclampsia exposed infants were smaller at birth, compared with normotensive pregnancy and gestational hypertension exposed infants, but caught up in growth by 2 years of age. Both preeclampsia and gestational hypertension exposed infants had significantly accelerated weight gain from birth to 2 years, which remained significant for preeclampsia exposed infants after adjustment for confounders including small for gestational age. Monitoring of growth patterns in infants born following exposure to a hypertensive disorder of pregnancy may be indicated to prevent accelerated weight gain trajectories and obesity.

Reviewing the Bioremediation of Contaminants in Groundwater: Investigations over 40 Years Provide Insights into What's Achievable.

Biodegradation and biotransformation of contaminants in groundwater commonly occurs naturally. However, natural biodegradation rates can be slow leading to elongated contaminant plumes and prolonged risks that demand greater remedial intervention. Enhancement of the biodegradation of contaminants in groundwater can be induced by the addition of amendments to change the geochemical conditions to those that are more favorable for indigenous or added biota. Enhancing biodegradation requires collocation of the contaminant of concern with the 'right' microbial communities under the 'right' geochemical conditions, so that the microbiota thrive and bio-transform, degrade or lock up the contaminant of interest. This is most easily achievable at laboratory or bench scale where mixing is easily performed, and mass transfer limitations are minimized. However, inducing such changes at field scale in aquifers is non-trivial - amendments do not easily mix into groundwater because it is a laminar (non-turbulent) and low-energy flow environment. Bioaugmentation of cultured or genetically modified organisms have also been considered to add to groundwater to enhance contaminant degradation rates. Here we provide an overview of research studies over approximately 40 years that highlight the progression of understanding from natural biodegradation of plumes in groundwater to active bioremediation efforts that have been variably successful at field scale. Investigated contaminants providing insights include petroleum hydrocarbons, chlorinated and brominated hydrocarbons, ammonium, metals, munition compounds, atrazine and per- and polyfluorinated alkyl substances. The redox and electron acceptor/donor conditions that are inducive to biodegradation for a range of contaminants are highlighted. Biodegradation is challenged by the availability of electron donors/acceptors in the core of plumes and on plume fringes. Cases for bioaugmentation are identified. A long history of investigations provides examples of the importance of amendment delivery mechanisms, scale-up from laboratory to field, and field-scale demonstration of the effectiveness of groundwater bioremediation technologies. Advantages and disadvantages of remedial approaches are tabulated. The value and contributions of integrative modelling advances are identified. The literature review and example cases provide a deep understanding of what scale of bioremediation might be achievable for groundwater plumes. Limitations to bioremediation strategies outlined here will help direct future efforts. Addressing the sources of groundwater plumes as well as bioremediation of the plume itself will achieve more effective outcomes. Twelve 'lessons learnt' are synthesized from the review.

Quantification of the variability and penetration of per- and poly-fluoroalkyl substances through a concrete pad.

Historical use of aqueous film forming foams (AFFF) containing per- and poly-fluoroalkyl substances (PFAS) for fire-fighting activities has contributed to widespread contamination of infrastructure which can represent an ongoing source of PFAS to the surrounding environment. A concrete fire training pad with historical use of Ansulite and Lightwater AFFF formulations had PFAS concentrations measured to quantify spatial variability of PFAS within the pad. Surface chips and whole cores of concrete through to the underlying aggregate base were collected over the 24 × 9 m concrete pad and depth profiles of PFAS concentrations in nine cores were analysed. PFOS and PFHxS dominated the PFAS for surface samples, along the depth profile of cores and in the underlying plastic and aggregate material, with substantial variability in the concentrations of PFAS in the samples. Although there was variability of individual PFAS along the depth profile, higher surface concentrations of PFAS generally followed the designed movement of water across the pad. Total oxidisable precursor (TOP) assessments of one core indicated additional PFAS were present along the entire length of the core. This study highlights concentrations of PFAS (up to low µg/kg) from historical use of AFFF can occur throughout concrete, with the variable concentrations throughout the profile.

Clinical evaluation of a novel multipoint radiofrequency ablation device to treat chronic rhinitis.

Objective: Safety and efficacy of the NEUROMARK® system for treating chronic rhinitis. Methods: A prospective, single-arm, multicenter study was performed on adults with chronic rhinitis who underwent radiofrequency ablation to the posterior nasal nerves. Primary endpoints were device-related serious adverse events (SAEs) at 1 month and change from baseline in visual analog scale nasal symptom scale (VAS NSS) for rhinorrhea and nasal congestion at 3 months. Total nasal symptom score (rTNSS) and mini Rhinoconjunctivitis Quality of Life Questionnaire (mini RQLQ) score were also evaluated. Results: Thirty-six participants were enrolled and completed follow-up at 1 and 3 months. Mean VAS NSS scores for rhinorrhea and nasal congestion demonstrated significant improvement at 3 months (both p < .0001). The mean percent changes from baseline in VAS rhinorrhea and nasal congestion were 53% and 55%, respectively. Total scores and all individual rTNSS items significantly improved (all p < .001) over the measured interval. Percent responder rate (≥30% reduction from baseline in total rTNSS) at 3 months was 78%. The total mean mini RQLQ scores, as well as all subdomains, improved significantly (all p < .0001). At 3 months, 89% of participants reported a minimal clinically important difference of ≥0.4 point improvement in the mini RQLQ score. No SAEs occurred during the study. Conclusions: The NEUROMARK System is a novel radiofrequency ablation device that provides safe and effective treatment to the posterior nasal nerves for patients with chronic rhinitis. Study participants experienced statistically significant and clinically meaningful improvement in symptoms and quality of life assessments at 3 months post-procedure. Trial Registration: The study is registered at www.clinicaltrials.gov with the unique identifier of NCT05324397. Level of Evidence: 4.

Stabilisation of PFAS in soils: Long-term effectiveness of carbon-based soil amendments.

Immobilisation/stabilisation is one of the most developed and studied approaches for treating soils contaminated with per- and poly-fluoroalkyl substances (PFAS). However, its application has been inhibited by insufficient understanding of the effectiveness of added soil sorbents over time. Herein, we present results on the effectiveness of select carbon-based sorbents, over 4 years (longevity) and multiple laboratory leaching conditions (durability). Standard batch leaching tests simulating aggressive, worst-case scenario conditions for leaching (i.e., shaking for 24-48 h at high liquid/solid ratios) were employed to test longevity and durability of stabilisation in clay-loam and sandy-loam soils historically contaminated with PFAS (2 and 14 mg/kg ∑28 PFAS). The different sorbents, which were applied at 1-6% (w/w), reduced leaching of PFAS from the soils to varying degrees. Among the 5 sorbents tested, initial assessments completed 1 week after treatment revealed that 2 powdered activated carbon (PAC) sorbents and 1 biochar were able to reduce leaching of PFAS in the soil by at least 95%. Four years after treatment, the performance of the PAC sorbents did not significantly change, whilst colloidal AC improved and was able to reduce leaching of PFAS by at least 94%. The AC-treated soils also appeared to be durable and achieved at least 95% reduction in PFAS leaching under repetitive leaching events (5 times extraction) and with minimal effect of pH (pH 4-10.5). In contrast, the biochars were affected by aging and were at least 22% less effective in reducing PFAS leaching across a range of leaching conditions. Sorbent performance was generally consistent with the sorbent's physical and chemical characteristics. Overall, the AC sorbents used in this study appeared to be better than the biochars in stabilising PFAS in the long term.

Advancing "Autonomous" sensing and prediction of the subsurface environment: a review and exploration of the challenges for soil and groundwater contamination.

Can we hope for autonomous (self-contained in situ) sensing of subsurface soil and groundwater pollutants to satisfy relevant regulatory criteria? Global advances in sensors, communications, digital technologies, and computational capacity offer this potential. Here we review past efforts to advance subsurface investigation techniques and technologies, and computational efforts to create a digital twin (representation) of subsurface processes. In the context of the potential to link measurement and sensing to a digital twin computation platform, we outline five criteria that might make it possible. Significant advances in sensors based on passive measurement devices are proposed. As an example of what might be achievable, using the five criteria, we describe the deployment of online real-time sensors and simulations for a case study of a petroleum site where natural source zone depletion (NSZD) is underway as a potential biodegradation management option, and where a high-quality conceptual site model is available. Multiple sensors targeting parameters (major gases and temperature influenced by soil moisture) relevant to the subsurface NSZD biodegradation processes are shown to offer the potential to map subsurface processes spatially and temporally and provide continuous estimates of degradation rates for management decisions, constrained by a computational platform of the key processes. Current limitations and gaps in technologies and knowledge are highlighted specific to the case study. More generally, additional key advances required to achieve autonomous sensing of subsurface soil and groundwater pollutants are outlined.

Model-based identification of vadose zone controls on PFAS mobility under semi-arid climate conditions.

Contamination through per-and poly-fluoroalkyl substances (PFAS) have occurred globally in soil and groundwater systems at military, airport and industrial sites due to the often decades-long periodic application of firefighting foams. At PFAS contaminated sites, the unsaturated soil horizon often serves as a long-term source for sustained PFAS contamination for both groundwater and surface water runoff. An understanding of the processes controlling future mass loading rates to the saturated zone from these source zones is imperative to design efficient remediation measures. In the present study, hydrochemical data from a site where PFAS transport was observed as a result of the decades-long application of AFFF were used to develop and evaluate conceptual and numerical models that determine PFAS mobility across the vadose zone under realistic field-scale conditions. The simulation results demonstrate that the climate-driven physical flow processes within the vadose zone exert a dominating control on the retention of PFAS. Prolonged periods of evapotranspiration exceeding rainfall under the semi-arid conditions trigger periods of upward flux and evapoconcentration, leading to the observed persistence of PFAS compounds in the upper ca. 2 metres of the vadose zone, despite cessation of AFFF application to soils since more than a decade. Physico-chemical retention mechanisms, namely sorption to the air-water interface (AWI) and sediment surfaces, contribute further to PFAS retention. The simulations demonstrate how PFAS downward transport is effectively confined to short periods following discrete rain events when soils display a high degree of saturation. During these periods, AWI sorption is at a minimum. In addition, high PFAS concentrations measured and simulated below the source zone reduce the effect of the AWI further due to a decrease in surface tension associated with elevated PFAS concentrations. Consequently, time-integrated PFAS migration and retardation illuminates that the field-relevant PFAS transport rates are predominantly controlled by the physical flow processes with a lower relative importance of AWI and sediment sorption adding to PFAS retention.

Clinical and economic burden of chronic rhinosinusitis with nasal polyposis: A U.S. administrative claims analysis.

Background: Limited data exist on the clinical and economic burden of chronic rhinosinusitis with nasal polyposis (CRSwNP). Objective: To describe patient characteristics, health-care resource utilization (HCRU), and health-care costs among patients with CRSwNP with and without comorbid asthma (primary analysis) and with surgical management of nasal polyps (secondary analysis). Methods: This was a retrospective study of patients diagnosed with CRSwNP conducted using administrative claims data from January 1, 2013, through March 31, 2019. Study outcomes were assessed over a 2-year follow-up. Results were stratified by baseline asthma status (primary analysis) and presented separately for patients with surgically managed CRSwNP (secondary analysis). Results: The primary analysis included 10,999 patients with CRSwNP (2649 with asthma, 8350 without asthma). Patients with versus without asthma had higher medication use, HCRU, and all-cause medical costs (mean ± standard deviation $34,667 ± $42,234 versus $27,122 ± $45,573; p < 0.001) across the full follow-up period. CRSwNP-related medical costs were significantly higher for patients with versus without asthma in year 2 of follow-up. In the surgical management analysis (n = 4943), most categories of medication use and CRSwNP-related HCRU declined from baseline levels during follow-up, and CRSwNP-related pharmacy costs in year 2 were less than half of baseline levels. Conclusion: Patients diagnosed with CRSwNP and asthma had a greater burden of illness than those without asthma. Higher CRSwNP-related medical costs in year 2 of follow-up for patients with asthma may indicate worsening symptoms over time. Among patients with surgically managed CRSwNP, HCRU and costs increased in year 1 of follow-up but decreased below baseline levels in year 2, potentially reflecting improved symptom severity.

Systemic Corticosteroid-related Adverse Outcomes and Health Care Resource Utilization and Costs Among Patients with Chronic Rhinosinusitis with Nasal Polyposis.

PURPOSE: Nasal polyps (NPs) develop in 20% to 30% of patients with chronic rhinosinusitis. Severe forms of chronic rhinosinusitis with nasal polyposis (CRSwNP) may be treated with systemic corticosteroids (SCSs), which increase the risk for adverse clinical outcomes. This study compared the incidence of SCS-related adverse outcomes and health care resource utilization and costs between patients with CRSwNP who had SCS exposure and those who did not have SCS exposure. METHODS: This retrospective cohort study used health care claims data from adult patients with CRSwNP identified in the IBMⓇ MarketScanⓇ Databases between January 2003 and June 2019. The first SCS prescription date in SCS users or a matched date in SCS nonusers (controls) represented the index date. Enrollment for ≥1 year before and after the index date was required. SCS-related adverse outcomes and costs were compared between all SCS users and controls, and among subgroups of patients who had claims for 1-3 and ≥4 SCS prescriptions in the 12-month postindex period. Comparisons were also made among SCS users and controls who previously had and did not have NP surgery, and those with and without comorbid asthma. Inverse probability of treatment weights was applied to all comparisons, which were evaluated for a variable-length follow-up period. FINDINGS: SCS users (n = 37,740) had a greater risk for any adverse outcome than controls (n = 7032) (incidence rate ratio [IRR] = 1.10; 95% CI, 1.05-1.16). The risk for adverse outcomes was highest in the subgroups that did not have NP surgery and that had ≥4 SCS claims (n = 2993) versus controls who did not have NP surgery (n = 5078) (IRR = 1.30; 95% CI, 1.18-1.44). Similarly, patients with asthma and ≥4 SCS claims (n = 4195) had a greater risk for SCS-related outcomes versus controls with asthma (n = 1226) (IRR = 1.36; 95% CI, 1.19-1.55). SCS users incurred 60% higher all-cause costs versus non-SCS users (P < 0.001). IMPLICATIONS: In patients with CRSwNP, SCS use was associated with a higher risk for adverse outcomes and with increased health care costs compared with controls without SCS exposure. Alternative treatment strategies that avoid and/or reduce SCS use may decrease health care costs and the risk for adverse outcomes among patients with CRSwNP.

Attenuating the 'attentional white bear' effect enhances suppressive attention.

Trying to ignore an object can bias attention towards it - a phenomenon referred to as the 'attentional white bear' (AWB) effect. The mechanisms behind this effect remain unclear. On one hand, the AWB may reflect reactive, 'search and destroy' distractor suppression, which directs attention toward irrelevant objects in order to suppress further attention to them. However, another possibility is that the AWB results from failed proactive distractor suppression - attempting to suppress attention to an irrelevant object from the outset may inadvertently result in an attentional shift towards it. To distinguish these two possibilities, we developed a categorical visual search task that addresses limitations present in prior studies. In five experiments (Ntotal = 96), participants searched displays of naturalistic stimuli cued only with distractor categories (targets were unknown and unpredictable). We observed an AWB and later attenuated it by presenting a pre-search stimulus, likely disrupting guidance from distractor templates in working memory. We conclude that the AWB resulted from a failure of proactive suppression rather than a search and destroy process.

Correction: Method for extraction and analysis of per- and poly-fluoroalkyl substances in contaminated asphalt.

Correction for 'Method for extraction and analysis of per- and poly-fluoroalkyl substances in contaminated asphalt' by Prashant Srivastava et al., Anal. Methods, 2022, 14, 1678-1689, https://doi.org/10.1039/D2AY00221C.

Volatilization Potential of Per- and Poly-fluoroalkyl Substances from Airfield Pavements and during Recycling of Asphalt.

Per- and poly-fluoroalkyl substances (PFAS) in water are typically present in their ionic (nonvolatile) forms; however, these can transition to their nonionic (volatile) forms when in contact with organic solvents and organic matrices. In particular, when PFAS are dissolved in organic solvents such as residues left from firefighting foams, fuels, and bitumen present in asphalt, the equilibrium between ionic and nonionic forms can trend toward more volatile nonionic forms of PFAS. We assessed the volatility of common PFAS based on calculated and available experimental data across ambient temperature ranges experienced by airfield pavements and at elevated temperatures associated with reworking asphalts for reuse. Volatilities are shown to be comparable to hydrocarbons in the semivolatile range, suggesting that volatilization is a viable loss mechanism for some PFAS that are nonvolatile in water. The present study points to future investigative needs for this unexplored mass loss mechanism and potential exposure pathway. Environ Toxicol Chem 2022;41:2202-2208. © 2022 Commonwealth of Australia. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Enhanced threat detection in three dimensions: An image-matched comparison of computed tomography and dual-view X-ray baggage screening.

Computed Tomography (CT) is increasingly used in screening of cabin baggage in airports. The current study aimed to establish whether screening with CT confers a detection advantage over dual-view (DV) X-ray when resolution is controlled. We also evaluated whether a 'targetless' search strategy - in which screeners identify and reject safe items - improved detection relative to target-based methods. In an online study, 104 novice screeners were trained with either CT or DV, and either a targetless or a target-based search strategy. Screeners were then tested in a simulated cabin baggage screening task. CT screeners performed with greater sensitivity than DV screeners. Search strategy did not affect sensitivity, although the target-based strategy resulted in a more liberal criterion. We conclude that CT imaging confers a benefit to screening performance over DV when image resolution is controlled. This is likely due to the ability to rotate the image to resolve occlusions.

Laboratory batch representation of PFAS leaching from aged field soils: Intercomparison across new and standard approaches.

Relating laboratory leaching methods to partitioning and transport of per- and poly-fluoroalkyl substances (PFAS) in field soils is challenging, making estimation of fluxes to groundwater and surface water uncertain. Existing laboratory leaching methods have limitations when assessing field leaching. For 37 aged field soils from five sites historically contaminated with PFAS over decades, we assess PFAS leaching using new and existing laboratory leaching methods to provide alternative methods better reflecting PFAS risks posed by its leaching and movement. Dominant PFAS in the soils were perfluorooctane sulfonic acid, perfluorohexane sulfonic acid, and perfluorohexanoic acid and to a lesser extent perfluorooctanoic acid. Leaching from intact soil cores (Exp 1) was taken to reflect field conditions. These were compared to two new laboratory batch tests, saturate-spin (Exp 2) and saturate-tumble-spin (Exp 3), and two standard approaches; Australian Standard Leaching Procedure (ASLP, Exp 4) and the Leaching Environmental Assessment Framework (LEAF, Exp 5). The tests varied in terms of liquid:soil ratio, tumbling time and pH of the starting solution, with LEAF-1313 conducted across seven pHs (2-12). Correlations between leachate and soil concentrations were highest for Exp 4 and Exp 5 (R2 = 0.72-0.98) and lowest for Exp 3 (R2 = 0.53). The PFAS mass leached as a fraction of the total increased such that: soil core leaching (27 %) < saturate-spin (30 %) < saturate-tumble-spin (65 %) ≤ LEAF-1313 (65 to 88 % at pH 5-9) < ASLP (90 %). As a fraction of individual PFAS compounds in leachate compared with soil, the shorter chain PFAS (e.g., perfluorobutanoic acid) were higher in the leachate in all tests. Across all tests, the saturate-spin batch test most closely represented intact soil core leaching and therefore potentially provides a measure more analogous of in situ soil leaching at field sites. Other methods would apply to broader applications such as landfill disposal.

The role of predicted chemotactic and hydrocarbon degrading taxa in natural source zone depletion at a legacy petroleum hydrocarbon site.

Petroleum hydrocarbon contamination is a global problem which can cause long-term environmental damage and impacts water security. Natural source zone depletion (NSZD) is the natural degradation of such contaminants. Chemotaxis is an aspect of NSZD which is not fully understood, but one that grants microorganisms the ability to alter their motion in response to a chemical concentration gradient potentially enhancing petroleum NSZD mass removal rates. This study investigates the distribution of potentially chemotactic and hydrocarbon degrading microbes (CD) across the water table of a legacy petroleum hydrocarbon site near Perth, Western Australia in areas impacted by crude oil, diesel and jet fuel. Core samples were recovered and analysed for hydrocarbon contamination using gas chromatography. Predictive metagenomic profiling was undertaken to infer functionality using a combination of 16 S rRNA sequencing and PICRUSt2 analysis. Naphthalene contamination was found to significantly increase the occurrence of potential CD microbes, including members of the Comamonadaceae and Geobacteraceae families, which may enhance NSZD. Further work to explore and define this link is important for reliable estimation of biodegradation of petroleum hydrocarbon fuels. Furthermore, the outcomes suggest that the chemotactic parameter within existing NSZD models should be reviewed to accommodate CD accumulation in areas of naphthalene contamination, thereby providing a more accurate quantification of risk from petroleum impacts in subsurface environments, and the scale of risk mitigation due to NSZD.