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The quality of chemical analysis is an important aspect of passive sampling-based environmental assessments. The present study reports on a proficiency testing program for the chemical analysis of hydrophobic organic compounds in silicone and low-density polyethylene (LDPE) passive samplers and hydrophilic compounds in polar organic chemical integrative samplers. The median between-laboratory coefficients of variation (CVs) of hydrophobic compound concentrations in the polymer phase were 33% (silicone) and 38% (LDPE), similar to the CVs obtained in four earlier rounds of this program. The median CV over all rounds was 32%. Much higher variabilities were observed for hydrophilic compound concentrations in the sorbent: 50% for the untransformed data and a factor of 1.6 after log transformation. Limiting the data to the best performing laboratories did not result in less variability. Data quality for hydrophilic compounds was only weakly related to the use of structurally identical internal standards and was unrelated to the choice of extraction solvent and extraction time. Standard deviations of the aqueous concentration estimates for hydrophobic compound sampling by the best performing laboratories were 0.21 log units for silicone and 0.27 log units for LDPE (factors of 1.6 to 1.9). The implications are that proficiency testing programs may give more realistic estimates of uncertainties in chemical analysis than within-laboratory quality control programs and that these high uncertainties should be taken into account in environmental assessments.
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Polietileno , Contaminantes Químicos del Agua , Polietileno/análisis , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , Compuestos Orgánicos , SiliconasRESUMEN
Wastewater treatment plants (WWTPs) have been recognized as secondary sources of per- and polyfluoroalkyl substances (PFAS) released into the environment. In this study, PFAS concentrations were measured in effluent and biosolids samples collected from 75 WWTPs across Australia during the 2016 Census period, which covers more than half of the Australian population. Twelve PFAS compounds, including six C5-C10 perfluoroalkyl carboxylic acids (PFCAs), four perfluoro sulfonic acids (PFSAs) such as perfluorobutane sulfonate (PFBS), perfuorohexane sulfonic (PFHxS), perfluorooctane sulfonic acid (PFOS), and perfluorodecane sulfonic acid (PFDS), and one fluorotelomer sulfonic acid (6:2 FTS), were detected in the effluent, with concentrations up to 504 ng/L (PFHxS). Among these, perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA), and perfluoropentanic acid (PFPeA) exhibited the highest median concentrations. In the biosolids, a total of 21 PFAS compounds were detected, encompassing ten C4-C14 PFCAs, four PFSAs, two FTS (6:2 and 8:2 FTS), perfluorooctane sulfonamide (PFOSA), two perfluorooctane sulfonamido acetic acid (NMethyl FOSAA and NEthyl FOSAA), and two perfluorooctane sulfonamido ethanol (FOSE), with dry weight (dw) concentrations approaching 235 ng/g (PFOS). The highest median and mean concentrations were observed for perfluorodecanoic acid (PFDA) and PFOS. An annual discharge of approximately 250 kg of the total 21 PFAS compounds was estimated through the effluent and biosolids of the participating WWTPs. Notably, PFOS and 6:2 FTS constituted the largest proportion of total PFAS in the WWTPs' output. While PFCAs were higher in effluent concentrations compared to influent levels across most WWTPs (92% of WWTPs for ∑8PFCAs), the concentrations of PFSAs either decreased or remained relatively stable (in 80% of WWTPs for ∑4PFSAs) throughout the wastewater treatment process.
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Fluorocarburos , Eliminación de Residuos Líquidos , Aguas Residuales , Contaminantes Químicos del Agua , Australia , Fluorocarburos/análisis , Contaminantes Químicos del Agua/análisis , Aguas Residuales/química , Monitoreo del Ambiente , Aguas del Alcantarillado/análisis , Ácidos Alcanesulfónicos/análisisRESUMEN
Monitoring contamination from per- and polyfluoroalkyl substances (PFASs) in water systems impacted by aqueous film-forming foams (AFFFs) typically addresses a few known PFAS groups. Given the diversity of PFASs present in AFFFs, current analytical approaches do not comprehensively address the range of PFASs present in these systems. A suspect-screening and nontarget analysis (NTA) approach was developed and applied to identify novel PFASs in groundwater samples contaminated from historic AFFF use. A total of 88 PFASs were identified in both passive samplers and grab samples, and these were dominated by sulfonate derivatives and sulfonamide-derived precursors. Several ultrashort-chain (USC) PFASs (≤C3) were detected, 11 reported for the first time in Australian groundwater. Several transformation products were identified, including perfluoroalkane sulfonamides (FASAs) and perfluoroalkane sulfinates (PFASis). Two new PFASs were reported (((perfluorohexyl)sulfonyl)sulfamic acid; m/z 477.9068 and (E)-1,1,2,2,3,3,4,5,6,7,8,8,8-tridecafluorooct-6-ene-1-sulfonic acid; m/z 424.9482). This study highlights that several PFASs are overlooked using standard target analysis, and therefore, the potential risk from all PFASs present is likely to be underestimated.
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Fluorocarburos , Agua Subterránea , Contaminantes Químicos del Agua , Fluorocarburos/análisis , Contaminantes Químicos del Agua/análisis , Australia , AguaRESUMEN
Non-target analysis (NTA) using high-resolution mass spectrometry is becoming a useful approach to screen for suspect and unknown chemicals. For comprehensive analyses, data-independent acquisition (DIA), like Sequential Windowed Acquisition of all THeoretical Mass Spectra (SWATH-MS) on Sciex instruments, is necessary, usually followed by library matching for feature annotation. The choice of parameters, such as acquisition window number and size, may influence the comprehensiveness of the suspect features detected. The goal of this study was to assess how mass spectrometric DIA settings may influence the ability to obtain confident annotations and identifications of features in environmental (river water, passive sample extract (PSE)), wastewater (unpreserved and acidified) and biological (urine) sample matrices. Each matrix was analysed using 11 different MS methods, with 5-15 variable size acquisition windows. True positive (TP) annotation (i.e., matching experimental and library spectra) rates were constant for PSE (40%) and highest for urine (18%), wastewater (34% and 36%, unpreserved and acidified, respectively) and river water (8%) when using higher numbers of windows (15). The number of annotated features was highest for PSE (12%) and urine (8.5%) when using more acquisition windows (9 and 14, respectively). Less complex matrices (based on average total ion chromatogram intensities) like river water, unpreserved and acidified wastewater have higher annotation rates (7.5%, 8% and 13.2%, respectively) when using less acquisition windows (5-6), indicating matrix dependency of optimum settings. Library scores varied widely for correct (scores between 6 and 100) as well as incorrect annotations (scores between 2 and 100), making it hard to define specific ideal cut-off values. Results highlight the need for properly curated libraries and careful optimization of SWATH-MS and other DIA methods for each individual matrix, finding the best ratio of total annotations to true positive, (i.e., correct) annotations to achieve best NTA results.
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Aguas Residuales , Agua , Espectrometría de MasasRESUMEN
The use of peak-picking algorithms is an essential step in all nontarget analysis (NTA) workflows. However, algorithm choice may influence reliability and reproducibility of results. Using a real-world data set, the aim of this study was to investigate how different peak-picking algorithms influence NTA results when exploring temporal and/or spatial trends. For this, drinking water catchment monitoring data, using passive samplers collected twice per year across Southeast Queensland, Australia (n = 18 sites) between 2014 and 2019, was investigated. Data were acquired using liquid chromatography coupled to high-resolution mass spectrometry. Peak picking was performed using five different programs/algorithms (SCIEX OS, MSDial, self-adjusting-feature-detection, two algorithms within MarkerView), keeping parameters identical whenever possible. The resulting feature lists revealed low overlap: 7.2% of features were picked by >3 algorithms, while 74% of features were only picked by a single algorithm. Trend evaluation of the data, using principal component analysis, showed significant variability between the approaches, with only one temporal and no spatial trend being identified by all algorithms. Manual evaluation of features of interest (p-value <0.01, log fold change >2) for one sampling site revealed high rates of incorrectly picked peaks (>70%) for three algorithms. Lower rates (<30%) were observed for the other algorithms, but with the caveat of not successfully picking all internal standards used as quality control. The choice is therefore currently between comprehensive and strict peak picking, either resulting in increased noise or missed peaks, respectively. Reproducibility of NTA results remains challenging when applied for regulatory frameworks.
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Algoritmos , Análisis de Datos , Reproducibilidad de los Resultados , Espectrometría de Masas/métodos , Cromatografía Liquida/métodosRESUMEN
Wastewater-based epidemiology (WBE) relies on representative sampling that is typically achieved with autosamplers that collect time, flow, or volume proportional samples. The expense, resources and operational know-how associated with autosampler operation means they are only typically available at major wastewater treatment plants (WWTPs). This results in a lack of data on consumption levels in regional and remote areas, or in countries that lack the financial means. The aim of this study was to estimate and investigate trends in drug consumption across varying levels of remoteness in Australia. Field-calibrated, microporous polyethylene passive samplers were deployed over 2 periods (Aug/Sept 2019 and 2020) at 43 treatment plants covering all five categories of remoteness, as per Australian Bureau of Statistics definitions (Major cities, Inner regional, Outer regional, Remote, and Very remote). The per capita consumption of cocaine, methylamphetamine, nicotine, oxycodone and MDMA were estimated. No spatial trends between remoteness and drug consumption were observed, except for cocaine, where Major cities had a 5-to-10-fold higher consumption compared to the other levels of remoteness in 2019 and 2020, respectively. Outer regional sites had the highest and lowest methylamphetamine consumption. The variance in drug use among sites was much higher in Remote (and Inner/Outer regional) sites when compared with Major cities. A significant and consistent decrease in oxycodone consumption was observed at all sites between 2019 and 2020, possibly related to regulatory changes and the COVID-19 pandemic where elective surgeries were suspended. The majority of sites experienced a decrease in cocaine and methylamphetamine consumption, possibly due to border restrictions or changes in supply and demand dynamics. This was the first extensive passive sampling study to assess drug consumption in urban, regional, and remote locations, demonstrating that passive samplers can facilitate extension of wastewater-based drug monitoring programs to sites where other representative sampling options are very difficult to implement.
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The leaching of per- and polyfluoroalkyl substances (PFASs) from Australian firefighting training grounds has resulted in extensive contamination of groundwater and nearby farmlands. Humans, farm animals, and wildlife in these areas may have been exposed to complex mixtures of PFASs from aqueous film-forming foams (AFFFs). This study aimed to identify PFAS classes in pooled whole blood (n = 4) and serum (n = 4) from cattle exposed to AFFF-impacted groundwater and potentially discover new PFASs in blood. Thirty PFASs were identified at various levels of confidence (levels 1a-5a), including three novel compounds: (i) perfluorohexanesulfonamido 2-hydroxypropanoic acid (FHxSA-HOPrA), (ii) methyl((perfluorohexyl)sulfonyl)sulfuramidous acid, and (iii) methyl((perfluorooctyl)sulfonyl)sulfuramidous acid, belonging to two different classes. Biotransformation intermediate, perfluorohexanesulfonamido propanoic acid (FHxSA-PrA), hitherto unreported in biological samples, was detected in both whole blood and serum. Furthermore, perfluoroalkyl sulfonamides, including perfluoropropane sulfonamide (FPrSA), perfluorobutane sulfonamide (FBSA), and perfluorohexane sulfonamide (FHxSA) were predominantly detected in whole blood, suggesting that these accumulate in the cell fraction of blood. The suspect screening revealed several fluoroalkyl chain-substituted PFAS. The results suggest that targeting only the major PFASs in the plasma or serum of AFFF-exposed mammals likely underestimates the toxicological risks associated with exposure. Future studies of AFFF-exposed populations should include whole-blood analysis with high-resolution mass spectrometry to understand the true extent of PFAS exposure.
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Fluorocarburos , Agua Subterránea , Humanos , Animales , Bovinos , Australia , Animales Salvajes , Plasma , MamíferosRESUMEN
L'Albufera Natural Park (Valencia, Spain) is a protected wetland of international significance that provides critical habitats to endemic and threatened bird and plant species. This study aims to use multiple cross-validation techniques to generate an accurate estimation of the environmental risk of organic contaminants (OCs) in an internationally important coastal wetland, to identify compounds of concern and their potential sources and risk factors. Microporous polyethylene tube (MPT) passive samplers were deployed at 12 locations across L'Albufera Natural Park with concurrent grab samples collected. A subset of MPT samplers were also analysed by an additional laboratory in Australia to widen the range of contaminants and assess interlaboratory reproducibility of results. Forty-three pesticides, 20 pharmaceuticals and personal care products (PPCPs), 20 per-and polyfluoroalkyl substances (PFAS) and 4 organophosphorus flame retardants (OPFRs) were detected in the MPT samplers. The fungicides tebuconazole and difenoconazole were detected at the highest concentrations in passive samplers (maximum concentrations, 153 ng sampler-1 and 106 ng sampler-1, respectively). Several other pesticides were detected in all locations (mean concentrations >1 ng sampler-1). The compounds fenamiphos, propyzamide, difenoconazole, propiconazole, metsulfuron methyl, sodium bis (perfluorohexyl) phosphinate (6:6 PFPiA), 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), 6:2 fluorotelomersulfonate (6:2 FTS), citalopram desmethyl and citalopram were reported in the wetland for the first time. Spatial distribution analysis revealed higher pesticide concentrations in the North of L'Albufera. A risk quotient (RQ) analysis showed that ibuprofen is of concern in the area. Overall, the MPT sampling approach is promising as a risk assessment tool for better understanding the transport and fate of OCs in protected areas.
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As Europe's second longest river, the Danube is an important water source for drinking water and irrigation for many countries, before discharging into the Black Sea in the East. Per- and poly-fluoroalkyl substances (PFAS) have been observed over the last two decades in concentrations exceeding the European Union's drinking water guidelines for total sum of 20 select PFAS of 0.1 µg L-1. Their presence is a result of current and historical use and high environmental persistence, necessitating their monitoring for human risk assessments. The aim of this study is to use recently developed passive sampling technology to calculate time-integrated water concentrations and mass loads of 11 select PFAS at 9 sites along the Danube River. Results indicate ∑11 PFAS concentrations in the range of 9.3-29.6 ng L-1 were not in exceedance of EU drinking water guidelines, but perfluorooctanesulfonic acid (PFOS) was in exceedance of the environmental quality standard (0.65 ng L-1) at all sampling locations. The highest ∑11 PFAS mass loads were observed at Ruse (9.5 kg day-1) and Budapest (6.3 kg day-1), believed to be driven by proximity to industrial facilities and large populations (urban runoff). Finally, we estimate 4.9 kg of total PFAS (∑11 PFAS) were delivered to the Black Sea daily over Summer 2019.
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Ácidos Alcanesulfónicos , Agua Potable , Fluorocarburos , Contaminantes Químicos del Agua , Humanos , Ríos , Agua Potable/análisis , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , Ácidos Alcanesulfónicos/análisis , Fluorocarburos/análisis , Estaciones del AñoRESUMEN
Water resources are vulnerable to contamination from polar organic compounds (POCs) originating from sources such as wastewater effluent. Two configurations of a microporous polyethylene tube (MPT) passive sampler were investigated for the time-integrative detection and quantification of POCs in effluent. One configuration contained the polymeric reversed phase sorbent Strata-X (SX) and the other Strata-X suspended in agarose gel (SX-Gel). These were deployed for up to 29 days and analysed for forty-nine POCs including pesticides, pharmaceuticals and personal care products (PPCPs) together with illicit drugs. Complementary composite samples were collected on days 6, 12, 20 and 26 representing the previous 24 h. Thirty-eight contaminants were detected in composite samples and MPT extracts, with MPT sampling rates (Rs) for 11 pesticides and 9 PPCPs/drugs ranging from 0.81 to 10.32 mL d-1 in SX and 1.35-32.83 mL d-1 in SX-Gel. Half-times to equilibrium of contaminants with the SX and SX-Gel equipped samplers ranged from two days to >29 days. MPT (SX) samplers were also deployed at 10 wastewater treatment effluent discharge sites across Australia for 7 days (again with complementary composite samples), to validate the sampler performance under varying conditions. Extracts from these MPTs detected 48 contaminants in comparison with 46 in composite samples, with concentrations ranging from 0.1 to 138 ng mL-1. An advantage of the MPT was preconcentration of contaminants, resulting in extract levels often markedly above instrument analytical detection limits. The validation study demonstrated a high correlation between accumulated contaminant mass in the MPTs and wastewater concentrations from composite samples (r2 > 0.70, where concentrations in composite samples were > 3× LOD). The MPT sampler shows promise as a sensitive tool for detecting POCs at trace levels in wastewater effluent and also quantifying these levels if temporal concentration variations are not significant.
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This study investigated the mobilization of a wide range of per- and polyfluoroalkyl substances (PFASs) present in aqueous film-forming foams (AFFFs) in water-saturated soils through one-dimensional (1-D) column experiments with a view to assessing the feasibility of their remediation by soil desorption and washing. Results indicated that sorption/desorption of most of the shorter-carbon-chain PFASs (C ≤ 6) in soil reached greater than 99% rapidlyâafter approximately two pore volumes (PVs) and were well predicted by an equilibrium transport model, indicating that they will be readily removed by soil washing technologies. In contrast, the equilibrium model failed to predict the mobilization of longer-chain PFASs (C ≥ 7), indicating the presence of nonequilibrium sorption/desorption (confirmed by a flow interruption experiment). The actual time taken to attain 99% sorption/desorption was up to 5 times longer than predicted by the equilibrium model (e.g., â¼62 PVs versus â¼12 PVs predicted for perfluorooctane sulfonate (PFOS) in loamy sand). The increasing contribution of hydrophobic interactions over the electrostatic interactions is suggested as the main driving factor of the nonequilibrium processes. The inverse linear relationship (R2 = 0.6, p < 0.0001) between the nonequilibrium mass transfer rate coefficient and the Freundlich sorption coefficient could potentially be a useful means for preliminary evaluation of potential nonequilibrium sorption/desorption of PFASs in soils.
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Fluorocarburos , Contaminantes del Suelo , Contaminantes Químicos del Agua , Fluorocarburos/análisis , Suelo/química , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
Monitoring SARS-CoV-2 RNA in sewer systems, upstream of a wastewater treatment plant, is an effective approach for understanding potential COVID-19 transmission in communities with higher spatial resolutions. Passive sampling devices provide a practical solution for frequent sampling within sewer networks where the use of autosamplers is not feasible. Currently, the design of upstream sampling is impeded by limited understanding of the fate of SARS-CoV-2 RNA in sewers and the sensitivity of passive samplers for the number of infected individuals in a catchment. In this study, passive samplers containing electronegative membranes were applied for at least 24-h continuous sampling in sewer systems. When monitoring SARS-CoV-2 along a trunk sewer pipe, we found RNA signals decreased proportionally to increasing dilutions, with non-detects occurring at the end of pipe. The passive sampling membranes were able to detect SARS-CoV-2 shed by >2 COVID-19 infection cases in 10,000 people. Moreover, upstream monitoring in multiple sewersheds using passive samplers identified the emergence of SARS-CoV-2 in wastewater one week ahead of clinical reporting and reflected the spatiotemporal spread of a COVID-19 cluster within a city. This study provides important information to guide the development of wastewater surveillance strategies at catchment and subcatchment levels using different sampling techniques.
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COVID-19 , SARS-CoV-2 , Humanos , ARN Viral , Aguas Residuales , Monitoreo Epidemiológico Basado en Aguas ResidualesRESUMEN
Passive sampling approaches to monitor licit and illicit drugs of concern in wastewater shows promise as a supplementary sampling technique to grab sampling when conventional composite autosampling may not be possible. Recent studies have assessed the applicability of passive sampling at a single wastewater treatment plant (WWTP). However, it remains unknown whether a single-site calibration can be applied to other WWTPs. This study evaluated the in situ calibration of microporous polyethylene tube passive samplers (MPTs) against simultaneously collected composite samples for 22 different WWTPs. Samples were analyzed for methylamphetamine, amphetamine, hydroxycotinine, cotinine, benzoylecgonine, 3,4-methylenedioxymethamphetamine, and noroxycodone. Estimated rates of chemical uptake (sampling rates) were calculated using the mass accumulated in the samplers, the concentration measured in composite samples, and the duration of deployment. The estimated sampling rates were consistent between WWTPs (>90% within a factor of two) and ranged from 5 mL day-1 (amphetamine) to 9 mL day-1 (noroxycodone). The samplers were effective at estimating analyte concentrations, with 77% of results having a normalized difference to 24 h composite samples of below 30%. Our study suggests that MPT passive samplers provide a tool for the spatiotemporal monitoring of drug use where automated integrative sampling techniques may not be feasible.
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Drogas Ilícitas , Contaminantes Químicos del Agua , Calibración , Monitoreo del Ambiente , Polietileno , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
Hexa(methoxymethyl)melamine (HMMM) is commonly used as a cross-linking agent in coatings and as a vulcaniser in tyre production to increase the durability of tyres. Early reports of elevated aquatic concentrations of HMMM and a range of co-occurring cyclic amines have been linked to toxicity and mortality events of aquatic organisms. There are currently only few studies reporting environmental concentrations of HMMM and the co-occurring cyclic amines, and this study reports the first environmental assessment in Australian surface waters. Archive passive water samples from 40 rivers, creeks and lakes in South East Queensland, Australia, and covering five years of biannual sampling, were analysed to determine spatial and temporal trends. Concentrations of HMMM and cyclic amines in Australian surface waters (<5-46 and
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New Zealand uses more than a ton of pesticides each year; many of these are mobile, relatively persistent, and can make their way into waterways. While considerable effort goes into monitoring nutrients in agricultural streams and programs exist to monitor pesticides in groundwater, very little is known about pesticide detection frequencies, concentrations, or their potential impacts in New Zealand streams. We used the 'Polar Organic Chemical Integrative Sampler' (POCIS) approach and grab water sampling to survey pesticide concentrations in 36 agricultural streams in Waikato, Canterbury, Otago and Southland during a period of stable stream flows in Austral summer 2017/18. We employed a new approach for calculating site-specific POCIS sampling rates. We also tested two novel passive samplers designed to reduce the effects of hydrodynamic conditions on sampling rates: the 'Organic-Diffusive Gradients in Thin Films' (o-DGT) aquatic passive sampler and microporous polyethylene tubes (MPTs) filled with Strata-X sorbent. Multiple pesticides were found at most sites; two or more were detected at 78% of sites, three or more at 69% of sites, and four or more at 39% of sites. Chlorpyrifos concentrations were the highest, with a maximum concentration of 180â¯ng/L. Concentrations of the other pesticides were generally below 20â¯ng/L. Mean concentrations of individual pesticides were not correlated with in-stream nutrient concentrations. The majority of pesticides were detected most frequently in POCIS, presumably due to its higher sampling rate and the relatively low concentrations of these pesticides. In contrast, chlorpyrifos was most frequently detected in grab samples. Chlorpyrifos concentrations at two sites were above the 21-day chronic 'No Observable Effect Concentration' (NOEC) values for fish and another two sites had concentrations greater than 50% of the NOEC. Otherwise, concentrations were well-below NOEC values, but close to the New Zealand Environmental Exposure Limits in several cases.
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Cloropirifos/análisis , Monitoreo del Ambiente/métodos , Agua Subterránea/química , Plaguicidas/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Agricultura , Nueva Zelanda , Estaciones del AñoRESUMEN
Untargeted analysis of a composite house dust sample has been performed as part of a collaborative effort to evaluate the progress in the field of suspect and nontarget screening and build an extensive database of organic indoor environment contaminants. Twenty-one participants reported results that were curated by the organizers of the collaborative trial. In total, nearly 2350 compounds were identified (18%) or tentatively identified (25% at confidence level 2 and 58% at confidence level 3), making the collaborative trial a success. However, a relatively small share (37%) of all compounds were reported by more than one participant, which shows that there is plenty of room for improvement in the field of suspect and nontarget screening. An even a smaller share (5%) of the total number of compounds were detected using both liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). Thus, the two MS techniques are highly complementary. Most of the compounds were detected using LC with electrospray ionization (ESI) MS and comprehensive 2D GC (GC×GC) with atmospheric pressure chemical ionization (APCI) and electron ionization (EI), respectively. Collectively, the three techniques accounted for more than 75% of the reported compounds. Glycols, pharmaceuticals, pesticides, and various biogenic compounds dominated among the compounds reported by LC-MS participants, while hydrocarbons, hydrocarbon derivatives, and chlorinated paraffins and chlorinated biphenyls were primarily reported by GC-MS participants. Plastics additives, flavor and fragrances, and personal care products were reported by both LC-MS and GC-MS participants. It was concluded that the use of multiple analytical techniques was required for a comprehensive characterization of house dust contaminants. Further, several recommendations are given for improved suspect and nontarget screening of house dust and other indoor environment samples, including the use of open-source data processing tools. One of the tools allowed provisional identification of almost 500 compounds that had not been reported by participants.
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Per-and polyfluoroalkyl substances (PFASs) as key components in aqueous film forming foams (AFFF) have led to growing incidences of environmental contamination. The aim of this study was to investigate a novel diffusion based passive sampling device comprising of microporous polyethylene (PE) for the long-term time-integrative monitoring of PFASs in groundwater systems. PE passive samplers (PEs) were deployed for 83 d and calibrated at five AFFF impacted groundwater sites representing different PFASs concentration levels (ΣPFAS 0.001 to 0.1 ng mL-1). Grab samples were collected simultaneously. Linear accumulation of 12 PFASs (r2 ≥ 0.84) were observed in the PEs over 83 d and PFASs sampling rates were 2-5 mL d-1. Estimated mean half-times to equilibrium for PFASs ranged between 122 and 490 d. A separate validation study compared PEs and grab sampling during a 93 d field deployment, at seven groundwater sites near a fire fighting training ground. Seventeen PFASs were detected in PEs and fifteen in grab samples. PEs showed higher sensitivity for precursors (i.e. 4:2 FTS and FOSA). Time-weighted-average water concentrations across all validation sites for all PFASs determined from PEs were strongly correlated (r2 = 0.98) with grab samples, (within range 0.3-60 ng mL-1 PFOS). Results represent the first application of passive sampling technology for the quantitative assessment of PFASs in groundwater systems.
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Wastewater samples were collected at the influent and effluent of two wastewater treatment plants (WWTPs) in Ho Chi Minh City, Vietnam and then pooled to daily samples over multiple days using 6 hourly grab samples. The aim was to provide a first assessment of the occurrence, consumption, removal and release of a range of organic chemicals including pharmaceuticals and personal care products (PPCPs), illicit drugs, an artificial sweetener, tobacco and its metabolites and alcohol biomarkers (referred to here as DPCPBs). Nineteen DPCPBs were detected via direct measurement of filtered wastewater on LC-MS/MS with a concentration range of 0.05-38µg/L. Caffeine and paracetamol were the most prominent compounds detected in the influent, while acesulfame was found at the highest concentration in the effluent of both WWTPs. Mean concentrations of metabolites of tobacco (nicotine: 7.6µg/L, cotinine: 1.4µg/L and hydroxycotinine: 1.7µg/L) and alcohol (ethyl sulphate: 3.3µg/L) were lower than those of European countries. Consumption rates based on daily mass loads and catchment population data obtained from the WWTPs were <10g/d/1000 pp for the majority of selected PPCPs, except for caffeine (300g/d/1000 pp) and paracetamol (320g/d/1000 pp). Consumption rates for codeine and methamphetamine were 0.05g/d/1000 pp and 0.17g/d/1000 pp, respectively. Consistently across the two WWTPs most of the chemicals (10) showed >80% apparent removal rate from the wastewater, three chemicals showed apparent removal efficiency of approximately 50%; and the removal efficiency could not be assessed for 5 compounds due to their low concentrations in the influent. Based on the fraction of treated and untreated wastewater (10:90) that is released into the receiving environment we estimated a total discharge of approximately 170kg per day of DPCPBs in Ho Chi Minh City.
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Glyphosate (PMG) is one of the most widely used herbicides with a reported 8.6 million tons applied globally in 2016. Due to widespread use and limited understanding of long-term environmental impacts, it is expected that future monitoring requirements for PMG and its primary metabolite aminomethyl phosphonic acid (AMPA) in aquatic environments will increase, along with the need for low cost monitoring and risk assessment strategies. The aim of this study was to investigate a microporous polyethylene tube (MPT; 2-mm thickness, 17.6 cm2 surface area, 35% porosity, 2.5 µm pore size) as a diffusive layer for the passive sampling of PMG and AMPA. Levels of PMG and AMPA sorbed to MPT were low (Kmw close to 1 mL g-1), validating MPT as a diffusive layer. Uptake experiments were conducted first under controlled laboratory conditions (pH = 6.8, 6 days), followed by an in situ freshwater lake system deployment (pH = 7.3, 11 days). PMG and AMPA accumulated linearly (slope relative standard deviation < 6%) under laboratory conditions with sampling rates (Rs) of 18 and 25 mL d-1, respectively. PMG in situ Rs was 28 mL d-1, and was not different from the one found in the laboratory. AMPA was below the limit of quantification (LOQ, 1 ng mL-1) in grab water samples, but was detected (>LOQ) in all passive samplers. Results illustrate the gain in sensitivity provided by the passive sampling technique, and the applicability of the device developed for the passive sampling of PMG and AMPA.