Running the gauntlet; flyway-wide patterns of pollutant exposure in blood of migratory shorebirds.

Shorebirds (order Charadriiformes) are among the world's most threatened avian taxa. Within the East Asian-Australasian Flyway (EAAF), a major threat to shorebirds' survival may be the gauntlet of pollution along the flyway. Metals, persistent organic pollutants (POPs), and per-/polyfluoroalkyl substances (PFASs) persist in the environment to the detriment of wildlife. In this study, we analysed element and PFAS concentrations in blood from 142 individuals across six species of Arctic-breeding migratory shorebirds with contrasting population trends, to discern species- and site-specific pollution differences, and determine how pollution correlated with population trends of EAAF shorebirds. Potential within-year pollution variations were investigated by blood-sampling birds at two sites, representing different points in the birds' annual migrations: staging in Taiwan on southward migrations and at non-breeding grounds in Western Australia (WA). Species' pollutant concentrations were compared to established population trends. Concentrations of potentially toxic elements were low in most individuals regardless of species. PFASs (range: <0.001-141 ng/g), Hg (<0.001-9910 ng/g) and Pb (<0.01-1210 ng/g) were higher in Taiwan than in WA (PFAS Taiwan median: 14.5 ng/g, WA median: 3.45 ng/g; Hg Taiwan: 338 ng/g, WA: 23.4 ng/g; Pb Taiwan: 36.8 ng/g, WA: 2.26 ng/g). Meanwhile As (range <0.001-8840 ng/g) and Se (290-47600 ng/g) were higher in WA than Taiwan (As Taiwan median: 500 ng/g, WA median: 1660 ng/g; Se Taiwan: 5490 ng/g, Se WA: 23700 ng/g). Nevertheless, pollutant concentrations in a subset of individuals may exceed sublethal effect thresholds (As, Se and PFASs). Finally, we found no consistent differences in pollution among species and demonstrated no correlation between pollution and population trends, suggesting pollution is likely not a major driver for population declines of EAAF shorebirds. However, ongoing and locally heavy environmental degradation and exposure to other contaminants not investigated here, such as POPs, warrants continued consideration when managing EAAF shorebird populations.

Identification of Poly(ethylene terephthalate) Nanoplastics in Commercially Bottled Drinking Water Using Surface-Enhanced Raman Spectroscopy.

Micro/nanoplastics have emerged as global contaminants of serious concern to human and ecosystem health. However, identification and visualization of microplastics and particularly nanoplastics have remained elusive due to the lack of feasible and reliable analytical approaches, particularly for trace nanoplastics. Here, an efficient surface-enhanced Raman spectroscopy (SERS)-active substrate with triangular cavity arrays is reported. The fabricated substrate exhibited high SERS performance for standard polystyrene (PS) nanoplastic detection with size down to 50 nm and a detection limit of 0.001% (1.5 × 1011 particles/mL). Poly(ethylene terephthalate) (PET) nanoplastics collected from commercially bottled drinking water were detected with an average mean size of ∼88.2 nm. Furthermore, the concentration of the collected sample was estimated to be about 108 particles/mL by nanoparticle tracking analysis (NTA), and the annual nanoplastic consumption of human beings through bottled drinking water was also estimated to be about 1014 particles, assuming water consumption of 2 L/day for adults. The facile and highly sensitive SERS substrate provides more possibilities for detecting trace nanoplastics in an aquatic environment with high sensitivity and reliability.

Maternal bisphenol urine concentrations, fetal growth and adverse birth outcomes: A population-based prospective cohort.

BACKGROUND: Exposure to bisphenols may affect fetal growth and development. The trimester-specific effects of bisphenols on repeated measures of fetal growth remain unknown. Our objective was to assess the associations of maternal bisphenol urine concentrations with fetal growth measures and birth outcomes and identify potential critical exposure periods. METHODS: In a population-based prospective cohort study among 1379 pregnant women, we measured maternal bisphenol A, S and F urine concentrations in the first, second and third trimester. Fetal head circumference, length and weight were measured in the second and third trimester by ultrasound and at birth. RESULTS: An interquartile range increase in maternal pregnancy-averaged bisphenol S concentrations was associated with larger fetal head circumference (difference 0.18 (95% confidence interval (CI) 0.01 to 0.34) standard deviation scores (SDS), p-value< 0.05) across pregnancy. When focusing on specific critical exposure periods, any detection of first trimester bisphenol S was associated with larger second and third trimester fetal head circumference (difference 0.15 (95% CI 0.05 to 0.26) and 0.12 (95% CI 0.02 to 0.23) SDS, respectively) and fetal weight (difference 0.12 (95% CI 0.02 to 0.22) and 0.16 (95% CI 0.06 to 0.26) SDS, respectively). The other bisphenols were not consistently associated with fetal growth outcomes. Any detection of bisphenol S and bisphenol F in first trimester was also associated with a lower risk of being born small size for gestational age (Odds Ratio 0.56 (95% CI 0.38 to 0.74) and 0.55 (95% CI 0.36 to 0.85), respectively). Bisphenols were not associated with risk of preterm birth. CONCLUSIONS: Higher maternal bisphenol S urine concentrations, especially in the first trimester, seem to be related with larger fetal head circumference, higher weight and a lower risk of being small size for gestational age at birth.

Dopamine mediates life-history responses to food abundance in Daphnia.

Expression of adaptive reaction norms of life-history traits to spatio-temporal variation in food availability is crucial for individual fitness. Yet little is known about the neural signalling mechanisms underlying these reaction norms. Previous studies suggest a role for the dopamine system in regulating behavioural and morphological responses to food across a wide range of taxa. We tested whether this neural signalling system also regulates life-history reaction norms by exposing the zooplankton Daphnia magna to both dopamine and the dopamine reuptake inhibitor bupropion, an antidepressant that enters aquatic environments via various pathways. We recorded a range of life-history traits across two food levels. Both treatments induced changes to the life-history reaction norm slopes. These were due to the effects of the treatments being more pronounced at restricted food ration, where controls had lower somatic growth rates, higher age and larger size at maturation. This translated into a higher population growth rate (r) of dopamine and bupropion treatments when food was restricted. Our findings show that the dopamine system is an important regulatory mechanism underlying life-history trait responses to food abundance and that bupropion can strongly influence the life history of aquatic species such as D. magna. We discuss why D. magna do not evolve towards higher endogenous dopamine levels despite the apparent fitness benefits.

Fetal exposure to phthalates and bisphenols and childhood general and organ fat. A population-based prospective cohort study.

OBJECTIVES: Fetal exposure to phthalates and bisphenols might have long-lasting effects on growth and fat development. Not much is known about the effects on general and organ fat development in childhood. We assessed the associations of fetal exposure to phthalates and bisphenols with general and organ fat measures in school-aged children. METHODS: In a population-based, prospective cohort study among 1128 mother-child pairs, we measured maternal urinary phthalate metabolites and bisphenol concentrations in first, second, and third trimester. Offspring body mass index, fat mass index by dual-energy X-ray absorptiometry, and visceral and pericardial fat indices and liver fat fraction were measured by magnetic resonance imaging at 10 years. RESULTS: After adjustment for confounders and correction for multiple testing, an interquartile range increase in first trimester phthalic acid concentrations remained associated with a 0.14 (95% confidence interval: 0.05, 0.22) standard deviation score increase in pericardial fat index. We also observed tendencies for associations of higher maternal low molecular weight phthalate urinary concentrations in second trimester with childhood pericardial fat index, but these were not significant after adjustment for multiple testing. High molecular weight phthalate, di-2-ethylhexyl phthalate, and di-n-octyl phthalate concentrations were not associated with childhood outcomes. Maternal urinary bisphenol concentrations were not associated with childhood adiposity. CONCLUSIONS: Maternal first trimester phthalic acid concentrations are associated with increased childhood pericardial fat index at 10 years of age, whereas maternal bisphenol concentrations are not associated with childhood adiposity. We did not find significant sex-specific effects. These findings should be considered as hypothesis generating and need further replication and identification of underlying mechanisms.

Fetal exposure to bisphenols and phthalates and childhood bone mass: a population-based prospective cohort study.

BACKGROUND: Exposure to bisphenols and phthalates might influence bone health. We hypothesized that exposure to bisphenols and phthalates during fetal life has persistent effects on bone development. OBJECTIVES: To analyze the associations of fetal exposure to bisphenols and phthalates with bone health in school-aged children. METHODS: Among 1,362 mother-child pairs participating in a population-based cohort study, we measured maternal urinary concentrations of bisphenols and phthalates at first, second and third trimester with high performance liquid chromatography electrospray ionization-tandem mass spectrometry. Total body bone mineral density (BMD) and bone area (BA) were measured using dual-energy X-ray absorptiometry (DXA) at 6 and 10 years, and were both used to calculate bone mineral content (BMC) and area-adjusted BMC (aBMC, a measure of volumetric BMD). RESULTS: Maternal bisphenol concentrations were not associated with childhood bone measures at 6 years. After adjustment for covariates and multiple testing correction, an interquartile range increase in maternal first trimester bisphenol S (BPS) concentrations was associated with lower BMD and aBMC at 10 years (-6.08 (95% confidence interval (CI), -9.97 to -2.19) mg/cm2 and -0.12 (95% CI, -0.20 to -0.04) g). Maternal third trimester low molecular weight (LMW) phthalate concentrations were associated with higher aBMC at 6 years whereas, maternal third trimester di-n-octylphthalate (DNOP) concentrations were associated with lower aBMC at 10 years. However, these associations did not remain statistically significant after multiple testing correction. DISCUSSION: Maternal first trimester BPS concentrations are associated with lower BMD and aBMC in school-aged children. These findings should be considered as hypothesis generating and need further replication and exploration of potential underlying mechanisms.

Bisphenol and phthalate concentrations and its determinants among pregnant women in a population-based cohort in the Netherlands, 2004-5.

BACKGROUND: Exposure to bisphenols and phthalates in pregnancy may lead to adverse health effects in women themselves and their offspring. OBJECTIVE: To describe first trimester bisphenol and phthalate urine concentrations, including bisphenol and phthalate replacements, and determine nutritional, socio-demographic and lifestyle related determinants. METHODS: In a population-based prospective cohort of 1396 mothers, we measured first trimester bisphenol, phthalate and creatinine urine concentrations (samples collected in 2004-2005, median gestational age 12.9 weeks [inter-quartile range (IQR) 12.1-14.4]). We examined associations of potential determinants with log-transformed bisphenol and phthalate concentrations. Outcomes were back-transformed. Nutritional analyses were performed in a subgroup of 642 Dutch participants only, as the Food Frequency Questionnaire was aimed at Dutch food patterns. RESULTS: Bisphenol A, bisphenol S, and bisphenol F were detected in 79.2%, 67.8% and 40.2% of the population, respectively. Mono-n-butylphthalate, mono-(2-ethyl-5-hydroxyhexyl)phthalate and monobenzylphthalate were detected in > 90% of the population. Nutritional intake was not associated with bisphenol and phthalate concentrations after correction for multiple testing was applied. Obesity was associated with higher high-molecular-weight phthalate concentrations and the lack of folic acid supplement use with higher di-n-octylphthalate concentrations (respective mean differences were 46.73nmol/l [95% CI 14.56-93.72] and 1.03nmol/l [0.31-2.06]). CONCLUSION: Bisphenol S and F exposure was highly prevalent in pregnant women in the Netherlands as early as 2004-5. Although associations of dietary and other key factors with bisphenol and phthalate concentrations were limited, adverse lifestyle factors including obesity and the lack of folic acid supplement use seem to be associated with higher phthalate concentrations in pregnant women. The major limitation was the availability of only one urine sample per participant. However, since phthalates are reported to be quite stable over time, results concerning determinants of phthalate concentrations are expected to be robust.

Determination of 89 drugs and other micropollutants in unfiltered wastewater and freshwater by LC-MS/MS: an alternative sample preparation approach.

A liquid chromatography-triple quadrupole-tandem mass spectrometry (LC-qQq-MS/MS) method was developed for simultaneous determination of 89 legal neuropsychiatric pharmaceuticals and illicit drugs (both parent compounds and metabolites) and other micropollutants in unfiltered wastewater and freshwater. The target chemicals fall under the classes of amphetamine-type stimulants, cocaine compounds, opiates and opioids, benzodiazepines, lysergic compounds, antipsychotics, anesthetics, antiepileptics, antidepressants, sympathomimetics, cannabinoids, blood thinners, antihistamines, ß-blockers, caffeine derivatives, nicotine derivatives, z-drugs, new designer drugs, and Alzheimer medications. The sample preparation procedure was designed for unfiltered wastewater and freshwater without the need to separate the particulate matter (if any) from the aqueous phase prior to extraction. Samples were pre-concentrated by rotary evaporation in the presence of a solvent. Method precision (absolute values; N = 6 replicate analyses at the fortification level of 50 ng, k = 6 days) for 87 out of 89 target analytes ranged from 2.8 to 34% (RSD %). The limits of detection ranged from 0.11 to 202 ng L-1, and the matrix effects ranged from +16 to -84%. A total of 10 samples, 8 wastewater, 1 drinking water, and 1 lake water, were collected from New York State, USA, and were analyzed for the target compounds to demonstrate the applicability of the developed method. This is the first study to report the analysis of multiple classes of pharmaceuticals, illicit drugs, and other micropollutants in unfiltered wastewater. Graphical abstract Analysis of 89 micropollutants in unfiltered wastewater by LC-MS/MS.

Migration of Parabens, Bisphenols, Benzophenone-Type UV Filters, Triclosan, and Triclocarban from Teethers and Its Implications for Infant Exposure.

Parabens (p-hydroxybenzoic acid esters), bisphenols, benzophenone-type UV filters, triclosan, and triclocarban are used in a variety of consumer products, including baby teethers. Nevertheless, the exposure of infants to these chemicals through the use of teethers is still unknown. In this study, 59 teethers, encompassing three types, namely solid plastic, gel-filled, and water-filled (most labeled "bisphenol A-free"), were collected from the U.S. market and analyzed for 26 potential endocrine-disrupting chemicals (EDCs) from intact surfaces through migration/leaching tests performed with Milli-Q water and methanol. The total amount of the sum of six parent parabens (Σ6 Parabens) leached from teethers ranged from 2.0 to 1990 ng, whereas that of their four transformation products (Σ4 Parabens) ranged from 0.47 to 839 ng. The total amount of the sum of nine bisphenols (Σ9 bisphenols) and 5 benzophenones (Σ5 benzophenones) leached from teethers ranged from 1.93 to 213 ng and 0.59 to 297 ng, respectively. Triclosan and triclocarban were found in the extracts of teethers at approximately 10-fold less amounts than were bisphenols and benzophenones. Based on the amount leached into Milli-Q water, daily intake of these chemicals was estimated from the use of teethers by infants at 12 months of age. This is the first study to document the occurrence and migration of a wide range EDCs from intact surfaces of baby teethers.

Synthetic Phenolic Antioxidants and Their Metabolites in Indoor Dust from Homes and Microenvironments.

Synthetic phenolic antioxidants (SPAs), including 2,6-di-tert-butyl-4-hydroxytoluene (BHT), are extensively used in food, cosmetic and plastic industries. Nevertheless, limited information is available on human exposures, other than the dietary sources, to SPAs. In this study, occurrence of 9 SPAs and their metabolites/degradation products was determined in 339 indoor dust collected from 12 countries. BHT was found in 99.5% of indoor dust samples from homes and microenvironments at concentrations that ranged from < LOQ to 118 µg/g and 0.10 to 3460 µg/g, respectively. This is the first study to measure BHT metabolites in house dust (0.01-35.1 µg/g) and their concentrations accounted for 9.2-58% of the sum concentrations (∑SPAs). 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHT-CHO), 2,6-di-tert-butyl-4-(hydroxymethyl)phenol (BHT-OH), 2,6-di-tert-butyl-1,4-benzoquinone (BHT-Q) were the major derivatives of BHT found in dust samples. The concentrations of gallic acid esters (gallates) in dust from homes and microenvironments ranged from < LOQ to 18.2 and < LOQ to 684 µg/g, respectively. The concentrations and profiles of SPAs varied among countries and microenvironments. Significantly elevated concentrations of SPAs were found in dust from an e-waste workshop (1530 µg/g). The estimated daily intake (EDI) of BHT via house dust ingestion ranged from 0.40 to 222 ng/kg/d (95th percentile).

Urinary biomarkers of exposure to 57 xenobiotics and its association with oxidative stress in a population in Jeddah, Saudi Arabia.

Oxidative stress arises from excessive free radicals in the body and is a trigger for numerous diseases, such as cancer and atherosclerosis. Elevated exposure to environmental chemicals can contribute to oxidative stress. The association between exposure to xenobiotics and oxidative stress, however, has rarely been studied. In this study, urinary concentrations of 57 xenobiotics (antimicrobials, parabens, bisphenols, benzophenones, and phthalates metabolites) were determined in a population from Jeddah, Saudi Arabia, to delineate association with the oxidative stress biomarker, 8-hydroxy-2'-deoxyguanosine (8OHDG). We collected 130 urine samples and analyzed for 57 xenobiotics using liquid chromatography-tandem mass spectrometry (LC/MS/MS) methods. The association between unadjusted and creatinine- or specific gravity-adjusted concentrations of xenobiotics and 8OHDG was examined by Pearson correlations and multiple regression analysis. High concentrations of mCPP (a metabolite of di-n-octyl phthalate; DnOP) and mCMHP (a metabolite of diethylhexyl phthalate; DEHP) were found in urine. In addition, the concentrations of bisphenol S (BPS) were higher than those of bisphenol A (BPA). The concentrations of metabolites of DEHP, phthalic acid, BPA, BPS, and methyl-protocatechuic acid were significantly associated with 8OHDG. This is the first biomonitoring study to report exposure of the Saudi population to a wide range of environmental chemicals and provides evidence that environmental chemical exposures contribute to oxidative stress.

Occurrence of traffic related trace elements and organic micropollutants in tunnel wash water.

Substantially polluted tunnel wash water (TWW) is produced during road tunnel maintenance. Previous literature has reported the presence of trace elements and polycyclic aromatic hydrocarbons (PAHs). However, it was hypothesized that other organic pollutants are present, and more knowledge is needed to prevent environmental harm. This study reveals for the first time the presence of four short- and 17 long-chained per- and polyfluoroalkyl substances (PFASs), three benzothiazoles (BTHs), six benzotriazoles (BTRs), four bisphenols, and four benzophenones in TWW from a Norwegian road tunnel over a period of three years. Concentrations of PAHs, PFASs, BTHs, and BTRs were higher than previously reported in e.g., road runoff and municipal wastewater. Trace elements and PAHs were largely particulate matter associated, while PFASs, BTHs, BTRs, bisphenols, and benzophenones were predominantly dissolved. 26 of the determined contaminants were classified as persistent, mobile, and toxic (PMT) and are of special concern. It was recommended that regulations for TWW quality should be expanded to include PMT contaminants (such as PFPeA, PFBS, BTR, and 4-OH-BzP) and markers of pollution (like 2-M-BTH, 2-OH-BTH, and 2-S-BTH from tire wear particles). These findings highlight the need to treat TWW before discharge into the environment, addressing both, particulate matter associated and dissolved contaminants.

Molecular formula assignment of dissolved organic matter by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry using two non-targeted data processing approaches: A case study from recirculating aquaculture systems.

BACKGROUND: The accumulation of dissolved organic matter (DOM) poses an issue in the management of the water quality from recirculating aquaculture systems (RAS), but its characterization is often not detailed enough to understand the DOM transformations in RAS. In this study, we investigated the application of two distinct non-targeted data processing approaches using ultra-performance liquid chromatography (UPLC) with quadrupole time-of-flight mass spectrometry (QTOF-MS) and two software with different algorithmic designs: PetroOrg and Progenesis QI to accurately characterize the molecular composition of DOM in RAS by UPLC-QTOF-MS. RESULTS: The UPLC-QTOF-MS resolution in combination with PetroOrg and Progenesis QI software successfully assigned 912 and 106 unique elemental compositions, respectively, including compounds containing carbon, hydrogen, and oxygen (CHO) and nitrogen-containing CHO compounds (CHON), in the DOM samples from RAS. The results of these two distinct data processing approaches were consistent with the list of DOM formulas from RAS identified by higher resolution mass spectrometry techniques confirming their reliability. PetroOrg approach revealed only compositional information in the DOM samples from RAS, while Progenesis QI in addition to identifying new elemental compositions, increased their chemical space by giving information about their polarity and their possible key structures. DOM samples from RAS were found to be rich in unsaturated CHO compounds, with tentatively key structures of terpenoids with medium polarity indicating natural origins in their composition. The analysis also revealed probable structures of sucrose fatty acid esters and polyethylene glycol, indicating anthropogenic sources. SIGNIFICANCE AND NOVELTY: The combination of these two non-targeted data processing approaches significantly improves the characterization of the complex mixture of DOM from RAS by UPLC-QTOF-MS reporting for the first time accurate DOM results in terms of its composition, while proposing its key structures. The presented methods can also be used to analyze different DOM samples with other HRMS techniques and software.

Role of niche and micro-habitat preferences in per- and polyfluoroalkyl substances occurrence in the gills of tropical lake fish species.

The present study has investigated per- and poly-fluoroalkyl substances (PFAS) in the gill tissues of various fish species inhabiting different trophic levels within Eleyele Lake, a tropical freshwater lake in Nigeria. The mean concentrations of PFAS congeners were determined, and their trends and patterns were analyzed across different trophic species. The results revealed variations in congener abundance and species-specific patterns that was influenced by habitat and niche preferences. Multivariate associations using canonical-correlation analysis (CCA) revealed distinct trends in the relationships between gill concentrations of specific PFAS congeners and different trophic groups. The strongest congener relationships were observed in the pelagic omnivore (Oreochromic niloticus: ON) with positive associations for 4:2 FTS, 9CL-PF3ONS, PFTDA, MeFOSA and PFHxS. The differences in congener profiles for the two herbivorous fish (Sarotherodon melanotheron (SM) and Coptodon galilaeus (CG)) reflect possible divergence in microhabitat and niche preferences. Furthermore, the congener overlaps between the herbivore (CG), and benthic omnivore (Clarias gariepinus: ClG) indicate a possible niche and microhabitat overlap. Our study provides valuable insights into the congener dynamics of PFAS at Eleyele Lake. However, the dissimilarity and overlapping PFAS congener profile in fish gills reflects the interplay of species niche preference and microhabitat associations. The present study highlights the need for further research to assess ecological risks and develop effective PFAS management strategies.

Eco-toxicological and climate change effects of sludge thermal treatments: Pathways towards zero pollution and negative emissions.

The high moisture content and the potential presence of hazardous organic compounds (HOCs) and metals (HMs) in sewage sludge (SS) pose technical and regulatory challenges for its circular economy valorisation. Thermal treatments are expected to reduce the volume of SS while producing energy and eliminating HOCs. In this study, we integrate quantitative analysis of SS concentration of 12 HMs and 61 HOCs, including organophosphate flame retardants (OPFRs) and per- and poly-fluoroalkyl substances (PFAS), with life-cycle assessment to estimate removal efficiency of pollutants, climate change mitigation benefits and toxicological effects of existing and alternative SS treatments (involving pyrolysis, incineration, and/or anaerobic digestion). Conventional SS treatment leaves between 24 % and 40 % of OPFRs unabated, while almost no degradation occurs for PFAS. Thermal treatments can degrade more than 93% of target OPFRs and 95 % of target PFAS (with the rest released to effluents). The different treatments affect how HMs are emitted across environmental compartments. Conventional treatments also show higher climate change impacts than thermal treatments. Overall, thermal treatments can effectively reduce the HOCs emitted to the environment while delivering negative emissions (from about -56 to -111 kg CO2-eq per tonne of sludge, when pyrolysis is involved) and producing renewable energy from heat integration and valorization.

Edible Sea urchins Echinus esculentus from Norwegian waters- Effect of season on nutritional quality and chemical contaminants.

This study aimed to characterize Echinus esculentus gonads in terms of biometric parameters and nutritional quality at two sites in Mid-Norway at four different seasons. The chemical contamination of the gonads was also investigated for the first time through the evaluation of 28 macro- and trace elements and 32 components from the emerging and persistent group per- and polyfluoroalkyl substances (PFAS). The spawning period was determined in summer, given that the gonad index was the lowest in this season for both sites. Protein concentrations were constant (8%-10%). However, lipid contents (1%-3%) were noticed to be higher in gonads during autumn and winter. The gonads had high contents of PUFA mainly EPA and DHA, followed by SFA, and MUFA year around for both locations. E. esculentus gonads constitute a good source of fatty acids, macro, and trace elements. This species could also be a bioindicator for the monitoring of marine environments.

Occurrence, bioaccumulation and trophic dynamics of per- and polyfluoroalkyl substances in two tropical freshwater lakes.

We have investigated the occurrence, distribution, and biomagnification of per- and polyfluoroalkyl substances (PFAS) in two tropical lakes (Asejire and Eleyele) of Southwestern Nigeria, with contrasting urban intensities. Over an 8-month period, we sampled sediment and fish species (Clarias gariepinus: CIG; Oreochromis niloticus: ON; Coptodon guineensis: CG; Sarotherodon melanotheron: SM) across trophic levels, and analyzed various PFAS congeners, in addition to a select group of toxicological responses. While herbivores (SM) and benthic omnivores (CIG) at Asejire exhibited elevated levels of PFBS and PFOS, the pelagic omnivores (ON) showed a dominance of PFOS, PFDA, PFHxDA and EtFOSE in the muscle. At the Eleyele urban lake, PFAS patterns was dominated by PFBS, EtFOSE, PFPeS, PFOcDA and PFOS in the herbivores (SM, CG), EtFOSE, PFOS and PFBS in the pelagic omnivore (ON) and benthic omnivore (ClG). The estimated biomagnification factor (BMF) analysis for both lakes indicated trophic level increase of PFOS, PFUnA and PFDA at the suburban lake, while PFOS and EtFOSE biomagnified at the urban lake. We detected the occurrence of diSAMPAP and 9CL-PF3ONS, novel compounds not commonly reported, in PFAS studies at both lakes. The studied toxicological responses varied across trophic groups in both lakes with probable modulations by environmental conditions, trophic structure, and relative PFAS exposures in the lakes. The present study documents, for the first time in Nigeria, or any other African country, the role of urbanization on contaminant load into the environment and their implications for contaminant dynamics within the ecosystem and for aquatic food safety.

Stabilization of PFAS-contaminated soil with sewage sludge- and wood-based biochar sorbents.

Sustainable and effective remediation technologies for the treatment of soil contaminated with per- and polyfluoroalkyl substances (PFAS) are greatly needed. This study investigated the effects of waste-based biochars on the leaching of PFAS from a sandy soil with a low total organic carbon content (TOC) of 0.57 ± 0.04 % impacted by PFAS from aqueous film forming foam (AFFF) dispersed at a former fire-fighting facility. Six different biochars (pyrolyzed at 700-900 °C) were tested, made from clean wood chips (CWC), waste timber (WT), activated waste timber (aWT), two digested sewage sludges (DSS-1 and DSS-2) and de-watered raw sewage sludge (DWSS). Up-flow column percolation tests (15 days and 16 pore volume replacements) with 1 % biochar indicated that the dominant congener in the soil, perfluorooctane sulphonic acid (PFOS) was retained best by the aWT biochar with a 99.9 % reduction in the leachate concentration, followed by sludge-based DWSS (98.9 %) and DSS-2 and DSS-1 (97.8 % and 91.6 %, respectively). The non-activated wood-based biochars (CWC and WT) on the other hand, reduced leaching by <42.4 %. Extrapolating this to field conditions, 90 % leaching of PFOS would occur after 15 y for unamended soil, and after 1200 y and 12,000 y, respectively, for soil amended with 1 % DWSS-amended and aWT biochar. The high effectiveness of aWT and the three sludge-based biochars in reducing PFAS leaching from the soil was attributed largely to high porosity in a pore size range (>1.5 nm) that can accommodate the large PFAS molecules (>1.02-2.20 nm) combined with a high affinity to the biochar matrix. Other factors like anionic exchange capacity could play a contributing role. Sorbent effectiveness was better for long-chain than for short-chain PFAS, due to weaker, apolar interactions between the biochar and the latter's shorter hydrophobic CF2-tails. The findings were the first to demonstrate that locally sourced activated wood-waste biochars and non-activated sewage sludge biochars could be suitable sorbents for the ex situ stabilization and in situ remediation of PFAS-contaminated soil, bringing this technology one step closer to full-scale field testing.

Effects of prolonged application of peracetic acid-based disinfectant on recirculating aquaculture systems stocked with Atlantic salmon parr.

The use of recirculating aquaculture systems (RAS) for Atlantic salmon (Salmo salar) production has become increasingly common. RAS water disinfection plays a crucial role on its biosecurity. Peracetic acid (PAA) is a promising disinfectant due to its powerful oxidative properties, broad antimicrobial spectrum, and rapid degradation into no harmful compounds. This study focused on assessing the consequences of prolonged application of a PAA-based disinfectant in a RAS stocked with salmon parr. The experiment included three treatment groups in triplicate: 0 mg/L PAA (control), 0.1 mg/L PAA, and 1 mg/L PAA, using nine-replicated RAS with a total of 360 fish (14.8 ± 2.3 g; N = 40/RAS). The study spanned 28 days, with samples collected on days 0, 14, and 28. The analyzed parameters were water quality, and fish parameters, including external welfare indicators, gill histology, total antioxidant capacity (TAC), reactive oxygen species/reactive nitrogen species (ROC/RNC), oxidative stress biomarkers related to DNA and protein, cellular DNA damage, and global gene expression. While water quality remained relatively stable, there was an increase in bacterial populations in the groups exposed to PAA, particularly 1 mg/L PAA. Fish weight did not differ between the control and PAA-exposed groups. TAC, ROC/RNC, and oxidative stress biomarkers exhibited similar trends. The study identified >400 differentially expressed genes (DEGs) in the skin, gill, and olfactory organ, with many of these DEGs associated with immune responses. Comparing the transcriptomic profiles of the three tissue organs revealed that the olfactory organ was the most reactive to PAA treatment. This study shows that calculated PAA concentrations of 0.1 mg/L and 1 mg/L in the pump-sump, contributed to an increase of bacteria whereas no detectable differences in health and welfare of salmon parr were found. These findings are promising for the implementation of PAA-based disinfectants in RAS stoked with Atlantic salmon parr.