Workflow to facilitate the detection of new psychoactive substances and drugs of abuse in influent urban wastewater

The complexity around the dynamic markets for new psychoactive substances (NPS) forces researchers to develop and apply innovative analytical strategies to detect and identify them in influent urban wastewater. In this work a comprehensive suspect screening workflow following liquid chromatography - high resolution mass spectrometry analysis was established utilising the open-source InSpectra data processing platform and the HighResNPS library. In total, 278 urban influent wastewater samples from 47 sites in 16 countries were collected to investigate the presence of NPS and other drugs of abuse. A total of 50 compounds were detected in samples from at least one site. Most compounds found were prescription drugs such as gabapentin (detection frequency 79%), codeine (40%) and pregabalin (15%). However, cocaine was the most found illicit drug (83%), in all countries where samples were collected apart from the Republic of Korea and China. Eight NPS were also identified with this protocol: 3-methylmethcathinone 11%), eutylone (6%), etizolam (2%), 3-chloromethcathinone (4%), mitragynine (6%), phenibut (2%), 25I-NBOH (2%) and trimethoxyamphetamine (2%). The latter three have not previously been reported in municipal wastewater samples. The workflow employed allowed the prioritisation of features to be further investigated, reducing processing time and gaining in confidence in their identification.

Risk assessment of pesticides used in the eastern Avocado Belt of Michoacan, Mexico: A survey and water monitoring approach

Pesticides use raises concerns regarding environmental sustainability, as pesticides are closely linked to the decline of biodiversity and adverse human health outcomes. This study proposed a holistic approach for assessing the potential risks posed by pesticides for human health and the environment in the eastern region of Michoacan, where extensive agricultural lands, especially corn and avocado fields, surround the Monarch Butterfly Biosphere Reserve. We used a combination of qualitative (semi-structured interviews) and quantitative (chemical analysis) data. Fifty-five interviews with smallholder farmers allowed us to identify pesticide types, quantities, frequencies, and application methods. A robust and precise analytical method based on solid-phase extraction and LC-MS/MS was developed and validated to quantify 21 different pesticides in 16 water samples (rivers, wells, runoff areas). We assessed environmental and human health risks based on the pesticides detected in the water samples and reported in the interviews. The interviews revealed the use of 28 active ingredients, including glyphosate (29 % of respondents), imidacloprid (27 %), and benomyl (24 %). The pesticide analysis showed the presence of 13 different pesticides and degradation products in the water samples. The highest concentrations were found for imidacloprid (1195 ngL-1) and carbendazim (a degradation product of benomyl; 932 ngL-1), along with the metabolite of pyrethroid insecticides, 3-PBA (494 ngL-1). The risk assessment indicates that among the most used pesticides, the fungicide benomyl and carbendazim pose the highest risk to human health and aquatic ecosystems, respectively. This study unveils novel insights on agricultural practices for the avocado, a globally consumed crop that is undergoing rapid production expansion. It calls for the harmonisation of crop protection with environmental responsibility, safeguarding the health of the people involved and the surrounding ecosystems.

Catchment-scale rapid transfer of livestock pharmaceuticals under Mediterranean climate

Various pharmaceuticals are essential for livestock farming, but some are highly toxic to aquatic life if they reach surface water bodies. Mediterranean Climate is characterized by dry summers followed by intense autumn storms. We studied the effect of these climatic conditions on the risk of pharmaceutical residues transfer to streams at the catchment-scale. Pharmaceutical products routinely used in the study area, as well as their application frequency and season, were identified through interviews with farmers. As a proof a concept, three veterinary pharmaceuticals (Fenbendazole (FBZ), Mebendazole (MBZ) and Ivermectin (IVM)) were chosen as model chemicals based on their relatively high usage, their specificity to represent different types of livestock (swine, sheep and cattle), and their ability to be analyzed using the same analytical method. Stream water was analyzed during low flow periods and at high frequency (up to 2 h-1) during flood events. The selected veterinary pharmaceuticals were not detected during low flow, but FBZ and MBZ reached high concentrations for short periods during floods. Due to the event-driven nature of their transfer, a significant load of veterinary pharmaceuticals can reach the river and cause temporary but significant degradation of water quality (e.g. for FBZ, the water concentration reached up to 355 times the predicted no effect concentration (PNEC)). This indicates that special care should be taken to avoid keeping freshly treated livestock on pastures that may become hydrologically connected under wet conditions. In addition, it suggests that low-frequency monitoring is not sufficient to detect those high concentration levels that exist during very short periods.

Optimization and validation of an extraction method for the analysis of multi-class emerging contaminants in soil and sediment

Analytical methods for the determination of multi-class emerging contaminants are limited for soil and sediment while they are essential to provide a more complete picture of their distribution in the environment and to understand their fate in different environmental compartments. In this paper, we present the development and optimization of an analytical strategy that combines reliable extraction, purification and the analysis using ultra-pressure liquid chromatography triple quadrupole mass spectrometry (UPLC-MS/MS) of 90 emerging organic contaminants including pesticides, pharmaceuticals and personal care products, flame retardants, per- and polyfluoroalkyl substances (PFASs) and plasticizers in soil and sediment. To extract a wide range of chemicals, the extraction strategy is based on the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach. A number of different options were investigated (buffer, acidification, addition of EDTA, different types and combinations of dispersive SPE etc.) and the effectiveness of the chemical extraction procedure and the clean-up was assessed for two matrices: soil (organic matter content of 9%) and sediment (organic matter content of 1.9%). The method was fully validated for both matrices, in terms of accuracy, linearity, repeatability (intra-day), reproducibility (inter-day), method limits of detection and quantification (LODs and MLOQs, respectively). The final performance showed good accuracy and precision (mean recoveries were between 70 and 120% with relative standard deviations (RSD) less than 20% in most cases), low matrix effects, good linearity for the matrix-matched calibration curve (R2≥0.991) and MLOQs ranged from 0.25 and 10 µg/kg. To demonstrate the applicability and suitability of the validated method, soil and sediment samples from Vietnam, France, Sweden and Mexico were analyzed. The results showed that of the 90 target compounds, a total of 33 were quantified in the sediment and soil samples analyzed. In addition to multi-target analysis, this strategy could be suitable for non-target screening, to provide a more comprehensive view of the contaminants present in the samples.

Antimicrobial Transformation Products in the Aquatic Environment: Global Occurrence, Ecotoxicological Risks, and Potential of Antibiotic Resistance

The global spread of antimicrobial resistance (AMR) is concerning for the health of humans, animals, and the environment in a One Health perspective. Assessments of AMR and associated environmental hazards mostly focus on antimicrobial parent compounds, while largely overlooking their transformation products (TPs). This review lists antimicrobial TPs identified in surface water environments and examines their potential for AMR promotion, ecological risk, as well as human health and environmental hazards using in silico models. Our review also summarizes the key transformation compartments of TPs, related pathways for TPs reaching surface waters and methodologies for studying the fate of TPs. The 56 antimicrobial TPs covered by the review were prioritized via scoring and ranking of various risk and hazard parameters. Most data on occurrences to date have been reported in Europe, while little is known about antibiotic TPs in Africa, Central and South America, Asia, and Oceania. Occurrence data on antiviral TPs and other antibacterial TPs are even scarcer. We propose evaluation of structural similarity between parent compounds and TPs for TP risk assessment. We predicted a risk of AMR for 13 TPs, especially TPs of tetracyclines and macrolides. We estimated the ecotoxicological effect concentrations of TPs from the experimental effect data of the parent chemical for bacteria, algae and water fleas, scaled by potency differences predicted by quantitative structure-activity relationships (QSARs) for baseline toxicity and a scaling factor for structural similarity. Inclusion of TPs in mixtures with their parent increased the ecological risk quotient over the threshold of one for 7 of the 24 antimicrobials included in this analysis, while only one parent had a risk quotient above one. Thirteen TPs, from which 6 were macrolide TPs, posed a risk to at least one of the three tested species. There were 12/21 TPs identified that are likely to exhibit a similar or higher level of mutagenicity/carcinogenicity, respectively, than their parent compound, with tetracycline TPs often showing increased mutagenicity. Most TPs with increased carcinogenicity belonged to sulfonamides. Most of the TPs were predicted to be mobile but not bioaccumulative, and 14 were predicted to be persistent. The six highest-priority TPs originated from the tetracycline antibiotic family and antivirals. This review, and in particular our ranking of antimicrobial TPs of concern, can support authorities in planning related intervention strategies and source mitigation of antimicrobials toward a sustainable future.

Impact of a megacity on the water quality of a tropical estuary assessed by a combination of chemical analysis and in-vitro bioassays

Tropical estuaries are threatened by rapid urbanization, which leads to the spread of thousands of micropollutants and poses an environmental risk to such sensitive aqueous ecosystems. In the present study, a combination of chemical and bioanalytical water characterization was applied to investigate the impact of Ho Chi Minh megacity (HCMC, 9.2 million inhabitants in 2021) on the Saigon River and its estuary and provide a comprehensive water quality assessment. Water samples were collected along a 140-km stretch integrating the river-estuary continuum from upstream HCMC down to the estuary mouth in the East Sea. Additional water samples were collected at the mouth of the four main canals of the city center. Chemical analysis was performed targeting up to 217 micropollutants (pharmaceuticals, plasticizers, PFASs, flame retardants, hormones, pesticides). Bioanalysis was performed using six in-vitro bioassays for hormone receptor-mediated effects, xenobiotic metabolism pathways and oxidative stress response, respectively, all accompanied by cytotoxicity measurement. A total of 120 micropollutants were detected and displayed high variability along the river continuum with total concentration ranging from 0.25 to 78 μg L^-1. Among them, 59 micropollutants were ubiquitous (detection frequency ≥ 80 %). An attenuation was observed in concentration and effect profiles towards the estuary. The urban canals were identified as major sources of micropollutants and bioactivity to the river, and one canal (Bến Nghé) exceeded the effect-based trigger values derived for estrogenicity and xenobiotic metabolism. Iceberg modelling apportioned the contribution of the quantified and the unknown chemicals to the measured effects. Diuron, metolachlor, chlorpyrifos, daidzein, genistein, climbazole, mebendazole and telmisartan were identified as main risk drivers of the oxidative stress response and xenobiotic metabolism pathway activation. Our study reinforced the need for improved wastewater management and deeper evaluations of the occurrence and fate of micropollutants in urbanized tropical estuarine environments.

Three years of wastewater surveillance for new psychoactive substances from 16 countries

The proliferation of new psychoactive substances (NPS) over recent years has made their surveillance complex. The analysis of raw municipal influent wastewater can allow a broader insight into community consumption patterns of NPS. This study examines data from an international wastewater surveillance program that collected and analysed influent wastewater samples from up to 47 sites in 16 countries between 2019 and 2022. Influent wastewater samples were collected over the New Year period and analysed using validated liquid chromatography - mass spectrometry methods. Over the three years, a total of 18 NPS were found in at least one site. Synthetic cathinones were the most found class followed by phenethylamines and designer benzodiazepines. Furthermore, two ketamine analogues, one plant based NPS (mitragynine) and methiopropamine were also quantified across the three years. This work demonstrates that NPS are used across different continents and countries with the use of some more evident in particular regions. For example, mitragynine has highest mass loads in sites in the United States, while eutylone and 3-methylmethcathinone increased considerably in New Zealand and in several European countries, respectively. Moreover, 2F-deschloroketamine, an analogue of ketamine, has emerged more recently and could be quantified in several sites, including one in China, where it is considered as one of the drugs of most concern. Finally, some NPS were detected in specific regions during the initial sampling campaigns and spread to additional sites by the third campaign. Hence, wastewater surveillance can provide an insight into temporal and spatial trends of NPS use.

Localized recharge processes in the NE Mekong Delta and implications for groundwater quality

Understanding recharge in the Mekong Delta is critical for the delta's groundwater resources, and requires the investigation of recharge processes at the local scale. In this study of the north eastern area of the Mekong Delta, time-series of environmental tracer data (δ¹⁸O, δ²H, major ions and ³H) and markers of rural pollution (NH₄ and NO₃) were used to highlight localized recharge and impacts on groundwater quality. Results highlighted new hydrological insights into recharge processes, including that the Pleistocene aquifer receives recent recharge (< 60 years), predominantly during high rainfall months (> 100 mm/month). However, due to shallow clay layers there are significant spatial variations in these recharge processes, which were observed in the seasonal fluctuation of groundwater δ¹⁸O values in groundwater. Wet season δ¹⁸O changes ranged from below analytical uncertainty (≤ 0.10 ‰) to up to 0.56 ‰, and the calculated fraction of rainfall contribution to the aquifer is ≤5 % to 16 %. Rainfall recharge via the acrisol soils results in low groundwater EC (20-55 μS/cm), acidic groundwater (pH 3.6-5.6), and may also have resulted in the low groundwater NO₃ concentrations (≤ 5.3 mg NO₃/L) at many sites due to adsorption, therefore delaying not reducing NO₃ contamination. Site specific variations in nitrogen processes includes increased NO₃ (to 29.7 mg/L) from fertiliser transfers or nitrification, and increased NH₄ (to 1.4 mg/L) likely due to the recharge of irrigation waters. Unlike other recharge areas across the northern Mekong Delta, this north-eastern region provides a groundwater resource unaffected by arsenic contamination. Therefore, these results should inform on priority areas for protection from further contamination by rural anthropogenic activities.

Does eutrophication enhance greenhouse gas emissions in urbanized tropical estuaries?

Estuaries are considered as important sources of the global emission of greenhouse gases (GHGs). Urbanized estuaries often experience eutrophication under strong anthropogenic activities. Eutrophication can enhance phytoplankton abundance, leading to carbon dioxide (CO₂) consumption in the water column. Only a few studies have evaluated the relationship between GHGs and eutrophication in estuaries. In this study, we assessed the concentrations and fluxes of CO₂, methane (CH₄) and nitrous oxide (N₂O) in combination with a suite of biogeochemical variables in four sampling campaigns over two years in a highly urbanized tropical estuary in Southeast Asia (the Saigon River Estuary, Vietnam). The impact of eutrophication on GHGs was evaluated through several statistical methods and interpreted by biological processes. The average concentrations of CO₂, CH₄ and N₂O at the Saigon River in 2019-2020 were 3174 ± 1725 μgC-CO₂ L^-1, 5.9 ± 16.8 μgC-CH₄ L^-1 and 3.0 ± 4.8 μgN-N₂O L^-1, respectively. Their concentrations were 13-18 times, 52-332 times, and 9-37 times higher than the global mean concentrations of GHGs, respectively. While CO₂ concentration had no clear seasonal pattern, N₂O and CH₄ concentrations significantly differed between the dry and the rainy seasons. The increase in eutrophication status along the dense urban area was linearly correlated with the increase in GHGs concentrations. The presence of both nitrification and denitrification resulted in elevated N₂O concentrations in this urban area of the estuary. The high concentration of CO₂ was contributed by the high concentration of organic carbon and mineralization process. GHGs fluxes at the Saigon River Estuary were comparable to other urbanized estuaries regardless of climatic condition. Control of eutrophication in urbanized estuaries through the implantation of efficient wastewater treatment facilities will be an effective solution in mitigating the global warming potential caused by estuarine emissions.

Toxicity of di-2-ethylhexyl phthalate and tris (2-butoxyethyl) phosphate to a tropical micro-crustacean (Ceriodaphnia cornuta) is higher in Mekong River water than in standard laboratory medium

Plasticizers such as di(2-ethylhexyl) phthalate (DEHP) and tris (2-butoxyethyl) phosphate (TBOEP) are manufactured chemicals produced in high volumes. These chemicals are frequently detected in the aquatic environment and cause toxic effects on organisms. In this study, we assessed the chronic impacts of DEHP and TBOEP, respectively, at the concentration of 100 µg L^-1 dissolved in the artificial medium (M4/4) and Mekong River water on life history traits of a tropical micro-crustacean, Ceriodaphnia cornuta, for 14 days. DEHP and TBOEP substantially reduced the survival of C. cornuta. In M4/4 medium, both plasticizers strongly enhanced reproduction but did not influence the growth of C. cornuta. Mekong River water, plasticizers-exposed C. cornuta produced less neonates than those in the control. The detrimental impacts of DEHP and TBOEP on the fitness of C. cornuta were much stronger in natural river water than in M4/4. Our results suggest that plasticizers can cause adverse effects on tropical freshwater cladocerans, particularly in natural water. These results are of a deep concern, as national and international regulatory guidelines which are based on ecotoxicological tests using standard media may not fully capture these effects.

Mining chemical information in Swedish wastewaters for simultaneous assessment of population consumption, treatment efficiency and environmental discharge of illicit drugs

Consumption of illicit drugs poses health risks to the public and environment. Knowledge on their usage helps better implementations of intervention strategies to reduce drug-related harms in the society and also policies to limit their releases as emerging contaminants to recipient environments. This study aimed to investigate from the daily consumption to treatment efficiency and subsequent discharge of illicit drugs by the Swedish urban populations based on simultaneous collection and analysis of influent and effluent wastewater. Two different weekly monitoring campaigns showed similar drug prevalence in Stockholm and Uppsala, with amphetamine as the most popular drug. Almost all target drug residues were still measurable in effluent wastewater. High removal efficiencies (> 94%) were observed for amphetamine, cocaine and benzoylecgonine, whereas ketamine, 3,4-methylenedioxymethamphetamine (MDMA), mephedrone and methamphetamine were the least removed substances (< 64%), with the highest discharge observed for MDMA in both catchments (~ 3.0 g/day in Uppsala; ~ 18 g/day in Stockholm). Our study provides new insights into short-term changes in the use and related discharge of illicit drugs by urban populations. Such wastewater monitoring can provide useful information to public health, forensic and environmental authorities in planning future intervention and regulation policies.

What's in the water? - Target and suspect screening of contaminants of emerging concern in raw water and drinking water from Europe and Asia

There is growing worry that drinking water can be affected by contaminants of emerging concern (CECs), potentially threatening human health. In this study, a wide range of CECs (n = 177), including pharmaceuticals, pesticides, perfluoroalkyl substances (PFASs) and other compounds, were analysed in raw water and in drinking water collected from drinking water treatment plants (DWTPs) in Europe and Asia (n = 13). The impact of human activities was reflected in large numbers of compounds detected (n = 115) and high variation in concentrations in the raw water (range 15-7995 ng L^-1 for ∑₁₇₇CECs). The variation was less pronounced in drinking water, with total concentration ranging from 35 to 919 ng L^-1. Treatment efficiency was on average 65 ± 28%, with wide variation between different DWTPs. The DWTP with the highest ∑CEC concentrations in raw water had the most efficient treatment procedure (average treatment efficiency 89%), whereas the DWTP with the lowest ∑₁₇₇CEC concentration in the raw water had the lowest average treatment efficiency (2.3%). Suspect screening was performed for 500 compounds ranked high as chemicals of concern for drinking water, using a prioritisation tool (SusTool). Overall, 208 features of interest were discovered and three were confirmed with reference standards. There was co-variation between removal efficiency in DWTPs for the target compounds and the suspected features detected using suspect screening, implying that removal of known contaminants can be used to predict overall removal of potential CECs for drinking water production. Our results can be of high value for DWTPs around the globe in their planning for future treatment strategies to meet the increasing concern about human exposure to unknown CECs present in their drinking water.

Sorbent assisted immobilisation of perfluoroalkyl acids in soils - effect on leaching and bioavailability

Contamination of soils and groundwater with perfluoroalkyl acids (PFAAs) is widespread due to their use in aqueous film-forming foams (AFFF). In this study the effectiveness of RemBind®, a sorbent containing activated carbon and aluminium oxyhydroxides was tested, as a tool to reduce the leaching and bioavailability of 12 PFAAs in soils, by amending contaminated soils with 5-30% (by weight) of the sorbents. Batch tests were used to determine the leaching of PFAAs. Their bioavailability to earthworms and wheat grass was assessed in greenhouse microcosms. Leaching and bioavailability of PFOS was reduced by up to 99.9%, at most sorbent application rates. Lowest reduction of leaching was found for shorter perfluoroalkyl chain length chemicals. The specific formulation of RemBind®, which is available in a basic and superior formulation, as well as the application rate were parameters for increasing effectiveness of the treatment. Furthermore, differences in leaching as well as bioavailability were seen depending on the perfluoroalkyl chain length. A preliminary assessment of the long-term stability of the treatment, assessed after a three-year curing period, suggested that the sorbent continued to be effective in reducing PFAAs in leachates, thus showing the potential of this sorbent to hinder further environmental contamination.

Suspect and Nontargeted Strategies to Investigate in Vitro Human Biotransformation Products of Emerging Environmental Contaminants: The Benzotriazoles

Benzotriazole derivatives (BTRs) are high production volume chemicals involved in a wide range of applications and consumer products resulting in their ubiquitous presence in environmental matrices. Yet, the human exposure assessment to these chemicals is limited since it is based only on the analysis of parent compounds in biological matrices. The objective of this study was to investigate the in vitro human biotransformation for three widely used BTRs and to stepwise examine the role of Phase I and II enzymes (cytochrome P450 (CYP), uridine glucuronic acid transferase (UGT), and sulfotransferase (SULT)) in their biotransformation. Extracts with generated biotransformation products (bioTPs) were analyzed using liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS), followed by their identification based on a workflow combining suspect and nontargeted strategies. Ten bioTPs were identified for 1H-benzotriazole, 14 for tolyltriazole, and 14 for 5-chloro-1H-benzotriazole. Most of the proposed bioTPs were identified and structurally elucidated for the first time. Based on these findings, possible bioTPs and metabolic transformation pathways were subsequently predicted for other structurally close BTR derivatives. Our findings provide new identified in vitro biotransformation products for future biomonitoring studies and emphasize that it is important to investigate the biotransformation pathway to assess overall exposure to xenobiotics.

Multi-residue screening of non-polar hazardous chemicals in green turtle blood from different foraging regions of the Great Barrier Reef

Green turtles spend a large part of their lifecycle foraging in nearshore seagrass habitats, which are often in close proximity to sources of anthropogenic contaminants. As most biomonitoring studies focus on a limited number of targeted chemical groups, this study was designed to screen for a wider range of hazardous chemicals that may not have been considered in prior studies. Whole blood of sub-adult green turtles (Chelonia mydas) were sampled from three different locations, a remote, offshore 'control' site; and two coastal 'case' sites influenced by urban and agricultural activities on the Great Barrier Reef in North Queensland, Australia. In order to screen blood samples for chemicals across a wide range of K_OW's, a modified QuEChER's extraction method was used. The samples were analysed using a multi-residue gas chromatography with tandem mass spectrometry system (GC-MS/MS method that allowed simultaneous quantification of polychlorinated biphenyls (PCBs), polychlorinated diphenyl ethers (PBDES), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs). While PBDEs, PCBs and OCPS were below the limits of quantification, PAHs were detected in all turtle blood samples. However, PAH levels were relatively low (maximum ΣPAH = 13 ng/mL ww) and comparable to or less than those reported from other green turtles globally. The present study provides the first baseline PAH levels in blood samples from green turtles from nearshore and offshore locations in the Southern Hemisphere.

Leaching and bioavailability of selected perfluoroalkyl acids (PFAAs) from soil contaminated by firefighting activities

Historical usage of aqueous film-forming foam (AFFF) at firefighting training grounds (FTGs) is a potential source of perfluoroalkyl acids (PFAAs) to the surrounding environment. In this study the leaching of PFAAs from field contaminated soil and their uptake into biota was investigated. Soil was sampled from FTGs at two airports and the total as well as the leachable concentration of 12 PFAAs was determined. A greenhouse study was carried out to investigate the uptake of PFAAs from soils into earthworms (Eisenia fetida) and wheat grass (Elymus scaber). Perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) were the most dominant PFAAs in all soils samples, with concentrations of PFOS reaching 13,400 ng/g. Leachable concentrations of PFOS and PFHxS reached up to 550 μg/L and 22 μg/L, respectively. In earthworms concentrations of PFOS reached 65,100 ng/g after a 28-day exposure period, while in wheat grass the highest concentration was measured for uptake of PFHxS (2,800 ng/g) after a 10-week growth-period. Bioaccumulation factors (BAFs) for earthworms ranged from 0.1 for perfluorohexanoic acid (PFHxA) to 23 for perfluorododecanoic acid (PFDoA) and initially showed a decreasing trend with increasing perfluoroalkyl chain length, followed by an increase with increasing perfluoroalkyl chain length for perfluoroalkyl carboxylic acids (PFCAs). In wheat grass the highest BAF was found for perfluorobutanoic acid (BAF = 70), while the lowest was observed for perfluorononanoic acid (BAF = 0.06). BAFs in wheat grass decreased with increasing perfluoroalkyl chain length for both PFCAs and perfluoroalkyl sulfonic acids (PFSAs). The results show that PFAAs readily leach from impacted soils and are bioaccumulated into earthworms and plants in an analyte dependent way. This shows considerable potential for PFAAs to move away from the original source either by leaching or uptake into ecological receptors, which may be a potential entry route into the terrestrial foodweb.

Concentrations of Organophosphate Esters and Their Specific Metabolites in Food in Southeast Queensland, Australia: Is Dietary Exposure an Important Pathway of Organophosphate Esters and Their Metabolites?

There were several studies that measured organophosphate esters (OPEs) in foods to assess the dietary intake of OPEs but none has measured OPE metabolites (mOPEs) in the same samples. In this study, we measured the concentrations of OPEs and mOPEs in 87 food samples and in five tap water samples collected in Queensland, Australia belonging to eight food groups. Tris(2-chloroisopropyl) phosphate (TCIPP) (detection frequency (DF), 77%) and tributyl phosphate (TBP) (DF, 71%), were the most frequently detected OPEs, while dibutyl phosphate (DBP) (DF, 84%) and diphenyl phosphate (DPhP) (DF, 86%) were the most frequently detected mOPEs. Vegetables had the highest concentrations of both ∑₉OPEs and ∑₁₁mOPEs, with the mean concentrations of 2.6 and 17 ng/g wet weight. Compared with dust ingestion and inhalation, dietary intake was the most important exposure pathway for tris(2-chloroethyl) phosphate (TCEP) (4.1 ng/kg bw/day), TCIPP (25 ng/kg bw/day), and TBP (6.7 ng/kg bw/day), accounting for >75% of total intake. Furthermore, we found that the intakes of some mOPEs, that is, bis(1,3-dichloroisopropyl) phosphate (BDCIPP) and DPhP from diet were typically higher than that of their parent OPEs. Such high levels of mOPE intakes could interfere with the utilization of mOPEs as biomarkers for assessing OPE exposure and warrant further investigation.

Concentrations of organophosphate flame retardants and plasticizers in urine from young children in Queensland, Australia and associations with environmental and behavioural factors

In recent years, the production and usage volumes of organophosphate flame retardants (OPFRs) has increased substantially. Certain OPFRs are suspected reproductive toxins, carcinogenic, and neurotoxic. Insufficient information is available on human exposure pathways to these chemicals, particularly in Australia. We aim to assess the association between OPFR concentrations in the urine of children to environmental and behavioural risk factors. Concentrations of eight OPFRs and eleven metabolites were measured in the urine of 51 children, aged 3-29 months, in Southeast Queensland, Australia and compared to their behavioural and environmental risk factor data obtained by an online questionnaire. Of the 11 OPFR metabolites analysed, 55% were frequently detected in the majority (> 80%) of samples. The most frequently detected metabolite was bis(1,3-dichloroisopropyl) phosphate (BDCIPP) (detected in 100% of samples), followed by 1-hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP) (96%), diphenyl phosphate (DPHP) (94%) and bis(1-chloroisopropyl) phosphate (BCIPP) (86%). In multivariable modelling, age was positively associated with concentrations of bis(2-butoxyethyl) phosphate (BBOEP) and negatively associated with concentrations of BCIPP and BCIPHIPP. Other non-age related factors, including vacuuming frequency, hand-washing frequency and presence and number of some electrical appliances in the home were also associated with concentrations of OPFR metabolites.

Organophosphate and brominated flame retardants in Australian indoor environments: Levels, sources, and preliminary assessment of human exposure

Concentrations of nine organophosphate flame retardants (OPFRs) and eight polybrominated diphenyl ethers (PBDEs) were measured in samples of indoor dust (n = 85) and air (n = 45) from Australian houses, offices, hotels, and transportation (buses, trains, and aircraft). All target compounds were detected in indoor dust and air samples. Median ∑₉OPFRs concentrations were 40 μg/g in dust and 44 ng/m³ in indoor air, while median ∑₈PBDEs concentrations were 2.1 μg/g and 0.049 ng/m³. Concentrations of FRs were higher in rooms that contained carpet, air conditioners, and various electronic items. Estimated daily intakes in adults are 14000 pg/kg body weight/day and 330 pg/kg body weight/day for ∑₉OPFRs and ∑₈PBDEs, respectively. Our results suggest that for the volatile FRs such as tris(2-chloroethyl) phosphate (TCEP) and TCIPP, inhalation is expected to be the more important intake pathway compared to dust ingestion and dermal contact.

Urinary metabolites of organophosphate esters: Concentrations and age trends in Australian children

There is growing concern around the use of organophosphate esters (OPEs) due to their suspected reproductive toxicity, carcinogenicity, and neurotoxicity. OPEs are used as flame retardants and plasticizers, and due to their extensive application in consumer products, are found globally in the indoor environment. Early life exposure to OPEs is an important risk factor for children's health, but poorly understood. To study age and sex trends of OPE exposures in infants and young children, we collected, pooled, and analysed urine samples from children aged 0-5years from Queensland, Australia for 9 parent OPEs and 11 metabolites. Individual urine samples (n=400) were stratified by age and sex, and combined into 20 pools. Three individual breast milk samples were also analysed to provide a preliminary estimate on the contribution of breast milk to the intake of OPEs. Bis(1-chloroisopropyl) phosphate (BCIPP), 1-hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP), bis(1,3-dichloroisopropyl) phosphate (BDCIPP), dibutyl phosphate (DBP), diphenyl phosphate (DPHP), bis(2-butoxyethyl) phosphate (BBOEP), bis(2-butoxyethyl) 3-hydroxyl-2-butoxyethyl phosphate (3OH-TBOEP), and bis(2-butoxyethyl) hydroxyethyl phosphate (BBOEHEP) were detected in all urine samples, followed by bis(methylphenyl) phosphate (80%), and bis(2-ethylhexyl) phosphate (BEHP, 20%), and bis(2-chloroethyl) phosphate (BCEP, 15%). Concentrations of tris(2-chloroethyl) phosphate (TCEP), BCEP, tris(2-ethylhexyl) phosphate (TEHP), and DBP decreased with age, while bis(methylphenyl) phosphate (BMPP) increased with age. Significantly higher concentrations of DPHP (p=0.039), and significantly lower concentrations of TEHP (p=0.006) were found in female samples compared to males. The estimated daily intakes (EDIs) via breastfeeding, were 4.6, 26 and 76ng/kg/day for TCEP, TBP and TEHP, respectively, and were higher than that via air and dust, suggesting higher exposure through consumption of breast milk.

Fate and redistribution of perfluoroalkyl acids through AFFF-impacted groundwater

Leaching of perfluoroalkyl acids (PFAAs) from a local point source, a fire-fighting training area, has led to extensive contamination of a groundwater aquifer which has spread underneath part of a nearby town, Oakey, situated in the State of Queensland, Australia. Groundwater is extracted by residents from privately owned wells for daily activities such as watering livestock and garden beds. The concentration of 10 PFAAs in environmental and biological samples (water, soil, grass, chicken egg yolk, serum of horses, cattle and sheep), as well as human serum was investigated to determine the extent of contamination in the town and discuss fate and redistribution of PFAAs. Perfluorooctane sulfonate (PFOS) was the dominant PFAA in all matrices investigated, followed by perfluorohexane sulfonate (PFHxS). PFOS concentrations measured in water ranged between <0.17-14μg/L, concentrations of PFHxS measured between <0.07-6μg/L. PFAAs were detected in backyards (soil, grass), livestock and chicken egg yolk. Significant differences (p<0.01) in PFOS and PFHxS concentrations in two groups of cattle were found, one held within the contamination plume, the other in the vicinity but outside of the contamination plume. In human serum PFOS concentrations ranged from 38 to 381μg/L, while PFHxS ranged from 39 to 214μg/L. Highest PFOS concentrations measured in human serum were >30-fold higher compared to the general Australian population. Through use of contaminated groundwater secondary sources of PFAA contamination are created on private property, leading to further redistribution of contamination and creation of additional human exposure pathways.

Discovery of novel per- and polyfluoroalkyl substances (PFASs) at a fire fighting training ground and preliminary investigation of their fate and mobility

Aqueous film forming foams (AFFFs) have been released at fire training facilities for several decades resulting in the contamination of soil and groundwater by per- and polyfluoroalkyl substances (PFASs). AFFF compositions are proprietary and may contain a broad range of PFASs for which the chemical structures and degradation products are not known. In this study, high resolution quadrupole-time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS) in combination with data processing using filtering strategies was applied to characterize and elucidate the PFASs present in concrete extracts collected at a fire training ground after the historical use of various AFFF formulations. Twelve different fluorochemical classes, representing more than 60 chemicals, were detected and identified in the concrete extracts. Novel PFASs homologues, unmonitored before in environmental samples such as chlorinated PFSAs, ketone PFSAs, dichlorinated PFSAs and perfluoroalkane sulphonamides (FASAs) were detected in soil samples collected in the vicinity of the fire training ground. Their detection in the soil cores (from 0 to 2 m) give an insight on the potential mobility of these newly identified PFASs.

Extraction and Characterization of Surfactants from Atmospheric Aerosols

Surface-active compounds, or surfactants, present in atmospheric aerosols are expected to play important roles in the formation of liquid water clouds in the Earth's atmosphere, a central process in meteorology, hydrology, and for the climate system. But because specific extraction and characterization of these compounds have been lacking for decades, very little is known on their identity, properties, mode of action and origins, thus preventing the full understanding of cloud formation and its potential links with the Earth's ecosystems.

In this paper we present recently developed methods for 1) the targeted extraction of all the surfactants from atmospheric aerosol samples and for the determination of 2) their absolute concentrations in the aerosol phase and 3) their static surface tension curves in water, including their Critical Micelle Concentration (CMC). These methods have been validated with 9 references surfactants, including anionic, cationic and non-ionic ones. Examples of results are presented for surfactants found in fine aerosol particles (diameter <1 μm) collected at a coastal site in Croatia and suggestions for future improvements and other characterizations than those presented are discussed.

Occurrence and distribution of brominated flame retardants and perfluoroalkyl substances in Australian landfill leachate and biosolids

The levels of perfluroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDDs) were studied in Australian landfill leachate and biosolids. Leachate was collected from 13 landfill sites and biosolids were collected from 16 wastewater treatment plants (WWTPs), across Australia. Perfluorohexanoate (PFHxA) (12-5700ng/L) was the most abundant investigated persistent, bioaccumulative and toxic (PBT) chemical in leachate. With one exception, mean concentrations of PFASs were higher in leachate of operating landfills compared to closed landfills. Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane isomers (HBCDDs) were detected typically at operating landfills in comparatively lower concentrations than the PFASs. Decabromodiphenyl ether (BDE-209) (<0.4-2300ng/g) and perfluoroctanesulfonate (PFOS) (<LOD-380ng/g) were the predominant PBTs detected in biosolids. Using data provided by sites, the volume of leachate discharged to WWTPs for treatment was small (<1% total inflow), and masses of PBTs transferred reached a maximum of 16g/yr (PFHxA). A national estimate of masses of PBTs accumulated in Australian biosolids reached 167kg/yr (BDE-209), a per capita contribution of 7.2±7.2mg/yr. Nationally, approximately 59% of biosolids are repurposed and applied to agricultural land. To our knowledge this study presents the first published data of PFASs and HBCDDs in Australian leachate and biosolids.

Anionic, Cationic, and Nonionic Surfactants in Atmospheric Aerosols from the Baltic Coast at Askö, Sweden: Implications for Cloud Droplet Activation

Recent analyses of atmospheric aerosols from different regions have demonstrated the ubiquitous presence of strong surfactants and evidenced surface tension values, σ, below 40 mN m(-1), suspected to enhance the cloud-forming potential of these aerosols. In this work, this approach was further improved and combined with absolute concentration measurements of aerosol surfactants by colorimetric titration. This analysis was applied to PM2.5 aerosols collected at the Baltic station of Askö, Sweden, from July to October 2010. Strong surfactants were found in all the sampled aerosols, with σ = (32-40) ± 1 mN m(-1) and concentrations of at least 27 ± 6 mM or 104 ± 21 pmol m(-3). The absolute surface tension curves and critical micelle concentrations (CMC) determined for these aerosol surfactants show that (1) surfactants are concentrated enough in atmospheric particles to strongly depress the surface tension until activation, and (2) the surface tension does not follow the Szyszkowski equation during activation but is nearly constant and minimal, which provides new insights on cloud droplet activation. In addition, both the CMCs determined and the correlation (R(2) ∼ 0.7) between aerosol surfactant concentrations and chlorophyll-a seawater concentrations suggest a marine and biological origin for these compounds.

Bioaccumulation of PCBs in liver tissue of dusky Carcharhinus obscurus, sandbar C. plumbeus and white Carcharodon carcharias sharks from south-eastern Australian waters

Polychlorinated biphenyls (PCBs) are ubiquitous pollutants in the marine environment that are known to accumulate in apex predators such as sharks. Liver samples from dusky Carcharhinus obscurus, sandbar Carcharhinus plumbeus, and white Carcharodon carcharias sharks from south-eastern Australian waters were analysed for the seven indicator PCBs 28, 52, 101, 118, 138, 153 and 180. Median ∑PCBs were significantly higher in white than sandbar sharks (3.35 and 0.36 μg g(-1) lipid, respectively, p=0.05) but there were no significant differences between dusky sharks (1.31 μg g(-1) lipid) and the other two species. Congener concentrations were also significantly higher in white sharks. Significant differences in PCB concentrations between mature and immature dusky (3.78 and 0.76 μg g(-1) lipid, respectively) and sandbar (1.94 and 0.18 μg g(-1) lipid, respectively) sharks indicated that PCB concentrations in these species increased with age/growth. Higher-chlorinated congeners (hexa and heptachlorobiphenyls) dominated results, accounting for ~90% of ∑PCBs.

Use of pooled samples to assess human exposure to parabens, benzophenone-3 and triclosan in Queensland, Australia

Parabens, benzophenone-3 and triclosan are common ingredients used as preservatives, ultraviolet radiation filters and antimicrobial agents, respectively. Human exposure occurs through consumption of processed food and use of cosmetics and consumer products. The aim of this study was to provide a preliminary characterisation of exposure to selected personal care product chemicals in the general Australian population. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n=24 pools of 100). Concentrations of free and total (sum of free plus conjugated) species of methyl, ethyl, propyl and butyl paraben, benzophenone-3 and triclosan were quantified using isotope dilution tandem mass spectrometry; with geometric means 232, 33.5, 60.6, 4.32, 61.5 and 87.7ng/mL, respectively. Age was inversely associated with paraben concentration, and females had concentrations approximately two times higher than males. Total paraben and benzophenone-3 concentrations are significantly higher than reported worldwide, and the average triclosan concentration was more than one order of magnitude higher than in many other populations. This study provides the first data on exposure of the general Australian population to a range of common personal care product chemical ingredients, which appears to be prevalent and warrants further investigation.

Perfluoroalkyl substances in a firefighting training ground (FTG), distribution and potential future release

The present study investigates the occurrence and fate of 15 perfluoroalkyl substances (PFASs) and one fluorotelomer sulfonate from a firefighting training ground (FTG) that was contaminated by intensive use of aqueous film forming foams (AFFF). The contamination levels and their spatial and vertical distribution are assessed in the structure. At the surface of the pad, perfluorooctane sulphonate (PFOS) is the dominant PFASs measured, with concentration varying from 10 to 200 μg g(-1). PFASs were also detected in a concrete core at up to 12 cm depth, suggesting the vertical movement and higher transport potential of shorter chain compounds. The estimated mass load of linear PFOS in this specific pad was >300 g with a total of 1.7 kg for the sum of all PFASs analyzed. The kinetics of desorption of PFOS, PFOA and 6:2FTS from the concrete into an overlaying static water volume has been measured under field conditions at two constant temperatures. Fitting the desorption data and estimated rainfall/runoff to a kinetic model suggests that this and similar firefighting training pads will likely remain a source of PFASs for many decades (t0.5=25 years for PFOS).

Size and age-concentration relationships for perfluoroalkyl substances in stingray livers from eastern Australia

While the literature has reported a widespread occurrence of perfluoroalkyl substances (PFASs) in marine biota, very limited studies have been dedicated to the southern hemisphere. Hepatic concentrations of nine PFAAs were analysed in 49 stranded stingrays from eastern Australia using liquid chromatograph coupled with tandem mass spectrometry and relationships with biological parameters (i.e. body size, age and sex) were investigated. Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) were the predominant compounds quantified, with hepatic concentrations varying from 2 to 117 and from 0.2 to 19 ng·g(-1) w.w., respectively. A negative correlation between the concentration of PFASs in the livers of 32 blue-spotted stingrays and the body size/age was found. This relationship was independent of the animal's sex. We postulate that the dependence on body size is related to differing uptake kinetics of the chemicals, after the sting rays were exposed to an increased level of the contaminants in their environment. Such a pollution event could be related to a severe flood event that occurred at this location a few months before the samples' collection. Our results indicate that the influence of the body size/age should be taken into account when estimating bioaccumulation parameters from environmental measurements or exposure levels of biota to PFASs.

Towards development of a rapid and effective non-destructive testing strategy to identify brominated flame retardants in the plastics of consumer products

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants (BFRs) once extensively used in the plastics of a wide range of consumer products. The listing of certain congeners that are constituents of commercial PBDE mixtures (including c-octaBDE) in the Stockholm Convention and tightening regulation of many other BFRs in recent years have created the need for a rapid and effective method of identifying BFR-containing plastics. A three-tiered testing strategy comparing results from non-destructive testing (X-ray fluorescence (XRF)) (n=1714), a surface wipe test (n=137) and destructive chemical analysis (n=48) was undertaken to systematically identify BFRs in a wide range of consumer products. XRF rapidly identified bromine in 92% of products later confirmed to contain BFRs. Surface wipes of products identified tetrabromobisphenol A (TBBPA), c-octaBDE congeners and BDE-209 with relatively high accuracy (>75%) when confirmed by destructive chemical analysis. A relationship between the amounts of BFRs detected in surface wipes and subsequent destructive testing shows promise in predicting not only the types of BFRs present but also estimating the concentrations present. Information about the types of products that may contain persistent BFRs will assist regulators in implementing policies to further reduce the occurrence of these chemicals in consumer products.

Spatio-temporal assessment of perfluorinated compounds in the Brisbane River system, Australia: impact of a major flood event

Perfluorinated chemicals including PFOA and PFOS have been widely used in consumer products and have become ubiquitous pollutants widely distributed in the aqueous environment. Following a major flood event in 2011, water samples were collected along a spatial gradient of the Brisbane River system to provide an initial estimate of the release of PFASs from flooded urban areas. PFOA (mean concentrations 0.13-6.1 ng L(-1)) and PFOS (mean concentrations 0.18-15 ng L(-1)) were the most frequently detected and abundant PFASs. Mean total PFASs concentrations increased from 0.83 ng L(-1) at the upstream Wivenhoe Dam to 40 ng L(-1) at Oxley Creek, representing an urban catchment. Total masses of PFOA and PFOS delivered into Moreton Bay from January to March were estimated to be 5.6 kg and 12 kg respectively. From this study, urban floodwaters appear to be a previously overlooked source of PFASs into the surrounding environment.

Oxidation of atmospheric humic like substances by ozone: a kinetic and structural analysis approach

This work explores the heterogeneous reaction between HUmic-LIke Substances (so-called HULIS) and ozone. Genuine atmospheric HULIS were extracted from aerosol samples collected in Chamonix (France) in winter and used in coated flow tube experiments to evaluate heterogeneous uptake of O₃ on such mixtures. The uptake coefficient (γ) was investigated as a function of pH (from 2.5 to 10), O₃ concentration (from 8 to 33 × 10¹¹ molecules cm⁻³), relative humidity (20 to 65%) and photon flux (from 0 to 1.66 × 10¹⁵ photons cm⁻² s⁻¹). Reactive uptake was found to increase in the irradiated experiment with pH, humidity and photon flux. The extract was characterized before and after exposure to O₃ and/or UV light in the attempt to elucidate the effect of the photochemical aging. Carbon content measurements, UV-vis spectroscopy and functional groups analysis revealed a decrease of the UV absorbance as well as of the carbon mass content, while the functionalization rate (COOH and C═O) and therefore the polarity increased during the simulated photochemical exposure.