Toxicity Thresholds Research Articles

Residual Assessment of Emerging Pesticides in Aquatic Sinks of Lahore, Pakistan

In recent decades, the use of pesticides has become fundamental to agricultural growth. However, the persistent and toxic nature of pesticides has led to significant concerns regarding their ecological and human health consequences. Therefore, for a better understanding of pesticide contamination and its potential risks, here we assessed the levels of five emerging pesticides—acetochlor, imidacloprid, MCPA, atrazine, and allethrin—in soil samples from ponds used for irrigation and in drinking water samples from nearby areas in Lahore, Pakistan. Our findings revealed that 100% of the samples were contaminated, posing substantial ecological and human health risks. Based on the toxic units (TUsum), all the soil samples showed higher toxic pressure, exceeding acute and chronic toxicity thresholds for earthworms, while 100% of water samples posed chronic toxicity risks to crustaceans and 10% to algae. Pollution index (PI) analysis further classified 100% of the soil samples and 10% of the water samples as highly polluted. These findings show high-pesticide residues in both soil and water and highlight immediate risk assessment and mitigation measures to protect non-target organisms. This preliminary information can be used to adopt risk assessment monitoring programmes and help higher authorities in making policies and guidelines to mitigate the escalating risk for ecology and humans.

The Assessment of Anthropometric Measures and Changes in Selected Biochemical Parameters in Obese Children in Relation to Blood Lead Level.

Our paper draws attention to the impact of lead (Pb) on the specificity of obesity development in children exposed to environmental pollution. An advantage of this paper is the homogeneous study group comprising children of identical age from a single geographic region. Moreover, while the influence of environmental toxins on adults has been extensively explored, this study delves into pediatric populations, which have yet to receive comprehensive scrutiny within the scientific literature. Initially, a group of 136 obese children (the research program lasted three consecutive years: 2016, 2017, and 2018) living in the north-western region of Poland, from whom biochemical tests and auxological data were obtained, were enrolled for analysis. Blood lead levels (BLLs) were determined in 115 children. The age of the children ranged from 7.1 to 10.4 years. The body mass index (BMI) of children averaged 21.5 ± 2.2. The results showed that a large proportion of the participants had BLLs above the threshold for Pb. BLLs ≤ 5 µg/dL (considered safe for children and pregnant women) were found in over 70% of the participants, with BLLs in the range of 5.01-10.00 µg/dL in over 26% of the children, and concentrations > 10 µg/dL (considered toxic threshold for adults) in nearly 2% of the children. The results of our research revealed a positive association between BLLs and average systolic and diastolic blood pressure in the studied children. Moreover, we found a negative correlation between BLLs and absolute fat tissue content and triglyceride concentration. Among the included biochemical factors, only insulin demonstrated a statistically significant relationship with fat mass. This result suggests that early carbohydrate metabolism disorders in overweight children involve decreased peripheral tissue insulin sensitivity. Lead exposure may significantly contribute to the development of hypertension, insulin resistance, and glucose metabolism disorders in overweight and obese children. It is essential to implement multidirectional actions to increase awareness of the harmful effects of xenobiotic exposure, including lead, in order to prevent early-life exposure.

Evaluation of the in vitro toxicity and anti-inflammatory activity of the methanolic extract of the leaves of Pistacia lentiscus L. harvested from northwestern Algeria.

Medicinal and aromatic plants have been used for thousands of years for their therapeutic properties, to treat various ailments and maintain health. This study was carried out to test the in vitro toxicity and anti-inflammatory activity of the methanolic extract of the leaves of Pistacia lentiscus L., native to the north-western region of Algeria. Toxicity was studied in vitro by the hemolysis test and anti-hemolytic activity on human red blood cells, while anti-inflammatory activity was assessed in vitro by the protein denaturation method. The study of toxicity by hemolysis of red blood cells showed a high rate of hemolysis at a dose of 200 mg/mL, with a hemolytic percentage of around 88.64%, while a high rate of anti-hemolysis was observed at a dose of 25 mg/mL, with an inhibition percentage of around 83.17%. Evaluation of anti-inflammatory activity revealed a high percentage of inhibition of ovalbumin denaturation, reaching 63.53% at the 2000 ug/mL dose, while the lowest percentage was obtained at the 3500 ug\mL concentration with 10.16%. This extract has a toxic substance but does not exceed the toxicity threshold which achieves significant anti-inflammatory activity with depandant doses.

Site-Blocking Antisense Oligonucleotides as a Mechanism to Fine-Tune MECP2 Expression.

Rett syndrome (RTT) is a neurodevelopmental disorder caused by loss-of-function mutations in the methyl CpG binding protein 2 (MECP2) gene. Despite its severe phenotype, studies in mouse models suggest that restoring MeCP2 levels can reverse RTT symptomology. Nevertheless, traditional gene therapy approaches are hindered by MECP2's narrow therapeutic window, complicating the safe delivery of viral constructs without overshooting the threshold for toxicity. The 3' untranslated region (3'UTR) plays a key role in gene regulation, where factors like miRNAs bind to pre-mRNA and fine-tune expression. Given that each miRNA's contribution is modest, blocking miRNA binding may represent a potential therapeutic strategy for diseases with high dosage sensitivity, like RTT. Here, we present a series of site-blocking antisense oligonucleotides (sbASOs) designed to outcompete repressive miRNA binding at the MECP2 3'UTR. This strategy aims to increase MECP2 levels in patients with missense or late-truncating mutations, where the hypomorphic nature of the protein can be offset by increased abundance. Our results demonstrate that sbASOs can elevate MECP2 levels in a dose-dependent manner in SH-SY5Y and patient fibroblast cell lines, plateauing at levels projected to be safe. Confirming in vivo functionality, sbASO administration in wild-type mice led to significant MeCP2 upregulation and the emergence of phenotypes associated with MeCP2 overexpression. In a T158M neural stem cell model of RTT, sbASO treatment significantly increased MECP2 expression and levels of the downstream effector protein, brain-derived neurotrophic factor (BDNF). These findings highlight the potential of sbASO-based therapies for MECP2-related disorders and advocate for their continued development.

Second-Generation Anticoagulant Rodenticide Toxicosis in a Wild Carnaby's Cockatoo (Zanda latirostris).

A wild male Carnaby's cockatoo (Zanda latirostris) was presented to a veterinary hospital after falling from a tree. The bird showed few clinical signs during the first days of hospitalization. On Day 4, the cockatoo showed excessive hemorrhage at a venipuncture site, epistaxis, and significant anemia (packed cell volume, 15%). The cockatoo was euthanized due to ongoing blood loss, weakness, and inappetence. Liver concentrations of brodifacoum (0.439 mg/kg wet weight) and difenacoum (0.033 mg/kg wet weight) had a total anticoagulant rodenticide concentration of 0.472 mg/kg wet weight and were above the threshold for toxicity for many avian species. To the authors' knowledge, this is the first time that anticoagulant rodenticide intoxication has been identified in a wild Australian psittacine species.

Dried Blood Spots Sampling and Population Pharmacokinetic Modeling for Dosing Optimization of Piperacillin in Chinese Neonates.

Piperacillin is commonly used off-label in neonates for the treatment of bacterial infections. This study aimed to assess a dried blood spots (DBS)-based microsampling strategy for supporting population pharmacokinetics and treatment optimization of piperacillin in Chinese neonates. DBS samples from neonatal patients were collected at predefined intervals. Drug blood concentrations were quantified using a validated ultra-high-performance liquid chromatography-tandem mass spectrometry method. A population pharmacokinetic model was developed using a nonlinear mixed-effects modeling approach. The pharmacokinetic/pharmacodynamics (PK/PD) target was 75% of the time with the unbound drug plasma concentration above the minimum inhibitory concentration (fT>MIC), with a toxicity threshold of unbound drug plasma trough concentration above 64 mg/L. A total of 45 piperacillin samples from 24 neonates were collected. The pharmacokinetics of piperacillin was described using a one-compartment model with postmenstrual age (PMA) as the most significant covariate on clearance. Simulations showed that dosing regimens achieving >90% PK/PD target attainment with <10% risk of possible toxicity were: PMA 33-35 weeks (50 mg/kg q12h), 35-37 weeks (50 mg/kg q8h), and 37-41 weeks (50 mg/kg q6h). In conclusion, Using DBS sampling, we developed a population pharmacokinetic model of piperacillin in Chinese neonates, incorporating PMA to determine optimal dosing regimens.

Legacy persistent organic pollutants among multiple cetacean species in the Northwest Atlantic

The historical contamination of eastern Canadian shelf waters remains an ongoing concern, predominantly stemming from anthropogenic discharges in the Great Lakes region. Although legacy persistent organic pollutants (POPs) were banned decades ago, it remains unclear whether their concentrations have sufficiently decreased to safer levels in cetaceans that feed in the continental shelf waters of the northwestern Atlantic. This study compares polychlorinated biphenyl (PCB) and organochlorine pesticide (OC) accumulation in six cetacean species sampled in the Northwest Atlantic from 2015 to 2022. We assessed the influence of relative trophic level and foraging habitat preferences on POP accumulations among species using stable isotopes and fatty acids as dietary tracers. We further identified the species most susceptible to the effects of these contaminants. Killer whales (Orcinus orca) exhibited the highest PCB (∼100 mg/kg lw) and OC concentrations, followed by other odontocetes, with lowest concentrations in mysticetes. Stable isotope analysis revealed an unexpected lack of correlation between δ15N values and contaminant levels. However, there was a positive correlation between δ13C values and POP concentrations. Cetaceans foraging on pelagic prey species, as indicated by elevated proportions of the FA markers 22:1n11 and 20:1n9, had lower contaminant loads compared to cetaceans with benthic/coastal FA signatures. PCB and DDT (dichlorodiphenyltrichloroethane) concentrations are lower now in most cetacean species than in the 1980s and 1990s, likely due to regulatory measures restricting their production and use. Although current PCB concentrations for most species are under the thresholds for high risks of immune and reproductive failure, concentrations in killer whales exceed all established toxicity thresholds, underscoring the need for further action to reduce sources of these contaminants to the continental shelf waters of the northwestern Atlantic.

Design, synthesis and biological evaluation of arylpropylamine derivatives as potential multi-target antidepressants

In this study, a series of novel arylpropylamine derivatives were designed, synthesized and evaluated as potential multi-target antidepressants. Among them, compound (R)-13j displayed unique pharmacological features, exhibiting excellent inhibitory potency against serotonin and noradrenaline transporters (SERT/NET) and high affinity for 5-HT2A/2C receptor, and showing low affinity for histamine H1, adrenergic α1 receptors and hERG channels (to reduce QT interval prolongation). Molecular docking studies provided a rational binding model of (R)-13j in complex with SERT and 5-HT2A/2C receptor. In animal models, compound (R)-13j dose-dependently reduced the immobility time in the tail suspension test (TST) and the forced swimming test (FST) in mice, with higher efficacy when compared to duloxetine, and showed no stimulatory effect on the locomotor activity. Moreover, compound (R)-13j significantly shortened the immobility time in the ACTH-induced rat model of treatment-resistant depression (TRD). Furthermore, compound (R)-13j also exhibited a higher threshold for acute toxicity than duloxetine. In addition, compound (R)-13j possessed a favorable pharmacokinetic profile in mice. Taken together, compound (R)-13j may constitute a novel class of drugs for the treatment of depression.

Discovery of a novel KV7.2/7.3 channels agonist for the treatment of neuropathic pain

Here, we designed, synthesized and evaluated a series of compounds as KV7.2/7.3 channels (or KCNQ2/3) agonists. The new compounds were assayed in vitro for KCNQ2/3 and other receptors binding affinity. The desired compound 16 showed high activity for KCNQ2/3 (EC50 = 1.03 ± 0.07 μM) without acute liver injury compared to flupirtine. It demonstrated powerful dose-dependent effects in multiple analgesic models, such as chronic constriction injury (CCI, ED50 = 12.02 mg/kg) and streptozotocin-induced diabetic peripheral neuropathic pain (DPNP, ED50 = 9.63 mg/kg) models. Additionally, compound 16 showed low affinity for human ether-a-go-go-related gene (hERG), high thresholds for acute toxicity, good motor performance in the rotarod test and acceptable pharmacokinetic properties. These results suggest the potentiality of compound 16 for the treatment of neuropathic pain.

Detection and Prediction of Toxic Aluminum Concentrations in High-Priority Salmon Rivers in Nova Scotia.

Elevated concentrations of toxic cationic aluminum (Ali) are symptomatic of terrestrial and freshwater acidification and are particularly toxic to salmonid fish species such as Atlantic salmon (Salmo salar). Speciated metal samples are rarely included in standard water monitoring protocols, and therefore the processes affecting Ali dynamics in freshwater remain poorly understood. Previous analysis of Ali concentrations in Nova Scotia (Canada) rivers found that the majority of study rivers had concentrations exceeding the threshold for aquatic health, but a wide-scale survey of Ali in Nova Scotia has not taken place since 2006 (Dennis, I. F., & Clair, T. A., 2012, Canadian Journal of Fisheries and Aquatic Sciences, 69(7), 1174-1183). The observed levels of dissolved aluminum in Atlantic salmon (Salmo salar) rivers of Atlantic Canada have potential serious and harmful effects for aquatic populations. We present the findings of the first large-scale assessment of the Ali status of Nova Scotia rivers in 17 years; we measured Ali concentrations and other water chemistry parameters at 150 sites throughout the Southern Uplands region of Nova Scotia from 2015 to 2022. We found that Ali concentrations exceeded toxic thresholds at least once during the study period at 80% of the study sites and that Ali concentrations increased during the study period at all four large-sample study sites. Modeling of relationships between Ali concentrations and other water chemistry parameters showed that the most important predictors of Ali are concentrations of the dissolved fractions of Al, iron, titanium, and calcium, as well as dissolved organic carbon and fluoride. We developed a fully Bayesian linear mixed model to predict Ali concentrations from a test data set within 15 μg/L. This model may be a valuable tool to predict Ali concentrations in rivers and to prioritize areas where Ali should be monitored. Environ Toxicol Chem 2024;00:1-12. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A comprehensive physicochemical characterization and proposed portfolios of applications for the fruits and seeds of 11 accessions of Jatropha curcas L.

The seed oil and extraction cake from 11 accessions of Jatropha curcas from Mexico, El Salvador, and India were comprehensively characterized with the objective of selecting parentals based on desirable traits for a hybridization program. Kernels contained up to 65 % oil and up to 30 % protein. The most abundant protein types were glutelins (48 %) and globulins (24 %), with arginine (0.096 mg/g) and leucine (0.070 mg/g) being the major amino acids. Glucose (0.09 g/g) and arabinose (0.03 g/g) were the most abundant carbohydrates. The oil was primarily composed of oleic (41 %) and linoleic (37 %) acids. The physicochemical properties of the oil included an acid value of 0.28–1.15 %, saponification value of 155–208 mg KOH/g, iodine value of 0.97–1.08 g I2/g, and viscosity of 21.9–40.9 cSt at 40 °C. Six accessions were selected as parental candidates based on their potential as feedstock for a diverse portfolio of products. The most common applicability of oils were lubricants, biopolymers, biofertilizer, and liquid biofuels production. One Mexican accession had a phorbol-ester concentration much lower than the toxicity threshold (0.06 mg/g) and a high protein content, making it attractive for the animal feed industry and for protein extraction. The selected accessions are preserved in a local germplasm bank and will be used for continued genetic improvement through hybridization, aiming to preserve the identified traits while increasing fruit productivity.

Contaminant Exposure and Liver and Kidney Lesions in North American River Otters in the Indian River Lagoon, Florida.

The harmful algal bloom (HAB) liver toxin microcystin (MC) and trace element biomagnification were previously detected in organisms in the Indian River Lagoon (IRL), Florida. Since there are no routine screening programs for these contaminants, liver tissue from North American river otters (Lontra canadensis), an important sentinel species in the IRL, was screened for MC via enzyme-linked immunoassay (ELISA), followed by confirmatory analyses via liquid-chromatography/mass spectrometry methods (LC-MS/MS). Liver and kidney samples were evaluated for trace element (As, Cd, Co, Cu, Fe, Hg, Mn, Mo, Pb, Se, Tl, and Zn) bioaccumulation via inductively coupled plasma mass spectrometry (ICP-MS). Histopathologic evaluation of the liver and kidney was conducted to assess possible correlation with toxic insults. Forty-three river otters were evaluated (2016-2022). Microcystin was not detected in any river otter sample (n = 37). Of those tested for trace element bioaccumulation (n = 22), no sample measured above provided reference ranges or estimated toxic thresholds for this species. There were no statistically significant patterns observed based on season, year, or age class, but sex had a small influence on trace element levels in the kidney. One individual had a kidney Cu level (52 μg/g dry weight) higher than any previously reported for this species. Trace elements were detected at presumed background levels providing baselines for future monitoring. For otters with available histopathologic evaluation (n = 28), anomalies indicative of contaminant exposure (non-specific inflammation, necrosis, and/or lipidosis) were present in the liver and kidney of 18% and 4% of individuals, respectively. However, since these lesions were not linked to abnormal trace element bioaccumulation or MC exposure, other causes (e.g., infectious disease) should be considered.

Differentiating Ischemic Hepatitis from Acetaminophen Overdose in Acute Liver Failure: Role of Acetaminophen Adducts-Ischemic Hepatitis vs Acetaminophen Overdose.

Acetaminophen (APAP) hepatotoxicity and ischemic hepatic injury (IH) demonstrate remarkably similar biochemical patterns. Deciding between these two etiologies in the setting of acute liver failure (ALF) can be challenging. We reviewed all cases in the Acute Liver Failure Study Group (ALFSG) registry where these diagnoses were considered, to determine reasons for, and frequency of, difficulties making these diagnoses. We hypothesized that the newly developed APAP-CYS adduct assay could help in discerning the correct diagnosis. Among 3364 patients with ALF or acute liver injury (ALI: INR ≥ 2.0 but without encephalopathy) between 1998 and 2019, 1952 (58%) received a final diagnosis of either APAP (1681) or IH (271). We utilized a review committee of senior hepatologists as well as the APAP-CYS assay (where sera were available), measuring the presence of toxic by-products of APAP injury to optimize adjudication. With these methods, a total of 575 adduct positive APAP cases included 488 recognized APAP, as well as an additional 87 patients previously diagnosed as other etiologies. Nine cases initially attributed to IH were deemed combination APAP-IH injuries. Conversely, 215 of the 280 IH subjects tested for adducts disclosed 173 confirmed as IH with adduct testing below the toxicity threshold, while 9 cases were revised from APAP to the IH-APAP combination phenotype, where both hypotension and APAP likely played a role. Discerning APAP from IH can be difficult-in rare cases, combined injury is observed (18/1952). APAP-CYS testing resulted in revising the diagnosis in 14.6% of cases.

Subcutaneous amikacin administration in red-eared sliders (Trachemys scripta elegans) produces prolonged detectable plasma concentrations without biochemistry evidence of impaired renal function.

To establish pilot data on the plasma concentrations of SC amikacin at 2 doses in red-eared sliders and evaluate concurrent plasma biochemistry parameters. 8 adult red-eared sliders (Trachemys scripta elegans). Amikacin was administered SC at target doses of 5 and 10 mg/kg with a 3-week washout period. Blood samples were collected at 0, 24, 48, 72, and 96 hours postadministration. Plasma amikacin concentrations were quantified using liquid chromatography tandem mass spectrometry. Plasma biochemistry analyses were performed before amikacin administration, 1 week post 5-mg/kg administration, and 1 week post 10-mg/kg administration. Mean maximum amikacin plasma concentrations were recorded 24 hours after 5-mg/kg and 10-mg/kg dosing and were 17.5 ± 2.32 µg/mL and 23.6 ± 2.92 µg/mL, respectively. Mean plasma concentrations after 5-mg/kg dosing steadily decreased to 9.1 ± 0.92 µg/mL by 96 hours postadministration. Amikacin remained detectable in all plasma samples 3 weeks post 5-mg/kg dosing with a mean plasma concentration of 1.04 ± 0.22 µg/mL. Mean plasma concentrations after 10-mg/kg dosing did not decrease over the 96-hour study period. There were no clinically relevant changes in biochemistry parameters. Amikacin persists at detectable plasma levels for at least 3 weeks after SC administration of a 5-mg/kg dose in red-eared sliders, which has not previously been reported in any species. No biochemistry changes consistent with renal toxicity occurred after either dose. Use caution with repeated amikacin dosing in this species until further studies can better characterize cumulative amikacin pharmacokinetics and toxic threshold.

Contamination of toxic elements in the sediments, water, and igneous rocks of the Sefid-rud River in Northern Iran using contamination indicators, with a specific focus on Ti-rich coastal sediments

The Sefid-rud River is a significant river on the southern coast of the Caspian Sea in Iran. In this study, we collected 28 samples of surface sediments and water to assess the level of metal contamination. Chemical analysis revealed that the average concentrations of heavy metals in both sediments and water increase from upstream to downstream. There is no clear significant relationship observed between changes in the values of investigated elements in sediments and water. The levels of these elements in the sediments, exceed toxic response thresholds. In the water samples, As, Ni and V concentrations exceed the WHO standard values. According to the Igeo, EF and PLI indices, the sediments at most stations are not contaminated by any of the elements. The CF and Dc indices suggest low contamination levels at all stations. The NIPI and ecological risk indices (Er and RI) indicate non-polluted conditions at all stations except SF22, SF20, SF11, and SF6. The MI and HEI indices indicate pollution in all water samples of the Sefid-rud, but critical values are only observed at SF5 and SF15. The other stations show no contamination. The Cf index indicates high pollution levels for all elements except Cu, Zn, and Pb. The upstream area poses a relatively high and considerable ecological risk according to the PERI index. In conclusion, the sediments of the Sefid-rud River have a higher potential for the exchange of toxic substances compared to the aquatic environment.

Health risk assessment for dietary exposure to 3-monochloropropane-1,2-diol, 2-monochloropropane-1,2-diol, and glycidol for Italian consumers

3-Monochloropropane-1,2-diol (3-MCPD), 2-monochloropropane-1,2-diol (2-MCPD) and 2,3-epoxy-1-propanol (glycidol), in their free form or esterified to fatty acids, are food contaminants formed during the refinement of oils and fats. We conducted a survey to quantify the levels of these compounds in 130 food items, in order to assess the exposure to them in food and the consequent health risk for consumers. Food samples, including infant formula, were analysed by gas-chromatography mass spectrometry with the indirect method, and we used the latest open access food consumption database for the Italian population for a probabilistic assessment of exposure. We adopted an in silico approach to fill the gap for the toxicity of 2-MCPD. The occurrence values for the three contaminants in food were in most cases lower than or comparable to those reported in previous surveys. Exposure assessment for the most exposed individuals (95thpercentiles of consumers only) of different age groups, gave values below the tolerable daily intake recommended by the European Food Safety Authority for 3-MCPD and below the simulated or predicted toxicity thresholds for 2-MCPD, indicating a negligible risk due to dietary exposure to these contaminants. For glycidol, however, estimated exposure indicated a non-negligible increase in cancer risk, and a margin of exposure <25,000 for younger population groups, indicating a potential health concern.

Utilization of formic acid by extremely thermoacidophilic archaea species.

The exploration of novel hosts with the ability to assimilate formic acid, a C1 substrate that can be produced from renewable electrons and CO2, is of great relevance for developing novel and sustainable biomanufacturing platforms. Formatotrophs can use formic acid or formate as a carbon and/or reducing power source. Formatotrophy has typically been studied in neutrophilic microorganisms because formic acid toxicity increases in acidic environments below the pKa of 3.75 (25°C). Because of this toxicity challenge, utilization of formic acid as either a carbon or energy source has been largely unexplored in thermoacidophiles, species that possess the ability to produce a variety of metabolites and enzymes of high biotechnological relevance. Here we investigate the capacity of several thermoacidophilic archaea species from the Sulfolobales order to tolerate and metabolize formic acid. Metallosphaera prunae, Sulfolobus metallicus and Sulfolobus acidocaldarium were found to metabolize and grow with 1-2 mM of formic acid in batch cultivations. Formic acid was co-utilized by this species alongside physiological electron donors, including ferrous iron. To enhance formic acid utilization while maintaining aqueous concentrations below the toxicity threshold, we developed a bioreactor culturing method based on a sequential formic acid feeding strategy. By dosing small amounts of formic acid sequentially and feeding H2 as co-substrate, M. prunae could utilize a total of 16.3 mM of formic acid and grow to higher cell densities than when H2 was supplied as a sole electron donor. These results demonstrate the viability of culturing thermoacidophilic species with formic acid as an auxiliary substrate in bioreactors to obtain higher cell densities than those yielded by conventional autotrophic conditions. Our work underscores the significance of formic acid metabolism in extreme habitats and holds promise for biotechnological applications in the realm of sustainable energy production and environmental remediation.

Mercury contamination and potential health risk to French seabirds: A multi-species and multi-site study

Mercury (Hg) is a naturally occurring highly toxic element which circulation in ecosystems has been intensified by human activities. Hg is widely distributed, and marine environments act as its main final sink. Seabirds are relevant bioindicators of marine pollution and chicks are particularly suitable for biomonitoring pollutants as they reflect contamination at short spatiotemporal scales. This study aims to quantify blood Hg contamination and identify its drivers (trophic ecology inferred from stable isotopes of carbon (δ13C) and nitrogen (δ15N), geographical location, chick age and species) in chicks of eight seabird species from 32 French sites representing four marine subregions: the English Channel and the North Sea, the Celtic Sea, the Bay of Biscay and the Western Mediterranean. Hg concentrations in blood ranged from 0.04 μg g−1 dry weight (dw) in herring gulls to 6.15 μg g−1 dw in great black-backed gulls. Trophic position (δ15N values) was the main driver of interspecific differences, with species at higher trophic positions showing higher Hg concentrations. Feeding habitat (δ13C values) also contributed to variation in Hg contamination, with higher concentrations in generalist species relying on pelagic habitats. Conversely, colony location was a weak contributor, suggesting a relatively uniform Hg contamination along the French coastline. Most seabirds exhibited low Hg concentrations, with 74% of individuals categorized as no risk, and < 0.5% at moderate risk, according to toxicity thresholds. However, recent work has shown physiological and fitness impairments in seabirds bearing Hg burdens considered to be safe, calling for precautional use of toxicity thresholds, and for studies that evaluate the impact of Hg on chick development.

Importance of glycoalkaloids analysis (α-solanine and α-chaconine) derived from potato consumption in pre-Hispanic inhabitants of the Americas

In the pre-Columbian societies of the Americas, a wide range of food practices was observed. However, several countries shared certain staple foods, such as the potato, which has held a significant place in the diet since ancient times. It is important to note that potatoes contain glycoalkaloids, a class of alkaloids with potential toxicity risks when consumed in high concentrations by both humans and animals. This study aims to offer guidance on the presence of glycoalkaloids in potatoes and proposes further research into these compounds in archaeological remains that were utilized as food across all American countries. This recommendation stems from the dearth of studies on this subject, particularly in cases where archaeological discoveries include potato starch granules. In this study, various databases were examined to discover historical insights into the potato and to elucidate the primary aspects of glycoalkaloid chemistry associated with this tuber. The findings underscore the crucial role played by the potato in pre-Columbian cultures of the Americas, particularly in the regions situated along the Andes mountain range. Furthermore, the analysis of its nutritional composition unveiled the prevalence of two key glycoalkaloids in the tuber: α-solanine and α-chaconine. In this research, a comprehensive review of the chemical properties, botanical functions, human metabolism, potential health effects, toxicity thresholds, and available analytical techniques for the detection and quantification of toxic compounds was conducted. The significance of identifying these molecules in archaeological contexts was highlighted, as their presence may prompt investigations into prevalent diseases among historical populations.

Unveiling mercury levels: Trophic habits influence on bioaccumulation in two Otariid species

Mercury, a toxic metal released by various human activities, exerts environmental stress through its bioaccumulation and biomagnification, particularly in marine habitats. South American fur seals (Arctocephalus australis) and sea lions (Otaria flavescens) reproduce on the Atlantic coast of Uruguay. As top predators, they can accumulate toxic levels of mercury and are often used as sentinel species for monitoring ecosystem health. Fur seals prey on pelagic species, such as fish and squid, while sea lions consume coastal-benthic prey. We analyzed the total mercury concentration (THg) in hair and the trophic habits (δ13C and δ15N) of females from both species. The average THg concentration in adult female sea lions (30.5 ± 9.3 μg/g dry weight) was significantly higher than in fur seals (6.3 ± 2.5 μg/g dry weight). Additionally, the mean δ15N and δ13C values were significantly higher in sea lion (δ15N: 19.2 ± 0.6‰, δ13C: −13.8 ± 0.2‰) compared to fur seals (δ15N: 16.5 ± 0.5‰, δ13C: −15.5 ± 0.6‰). Our results suggest that different trophic levels and feedings areas affect the THg concentration in Uruguayan Otariids. Notably, at the intraspecific level, the THg concentration in sea lions increased with δ13C values, suggesting a link to coastal feeding habits. This indicates that coastal feeding behaviors, compared to feeding in pelagic environments, enhance mercury bioaccumulation in Otariids along the Uruguayan coast, with the discharge of freshwater from the Río de la Plata (one of the largest estuaries in South America) basin identified as a potential mercury source. THg concentrations found in female sea lion hair are the highest reported in Otariids globally. Mercury levels exceeded toxic thresholds observed in other mammals and could pose significant health risks. Our findings may explain why sea lions were particularly affected by the avian influenza outbreak in Uruguay compared to fur seals. Monitoring the declining sea lion population is crucial, making our results significant for integrated conservation and management strategies.