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As is well known, implication is transitive but probabilistic support is not. Eells and Sober, followed by Shogenji, showed that screening off is a sufficient constraint for the transitivity of probabilistic support. Moreover, this screening off condition can be weakened without sacrificing transitivity, as was demonstrated by Suppes and later by Roche. In this paper we introduce an even weaker sufficient condition for the transitivity of probabilistic support, in fact one that can be made as weak as one wishes. We explain that this condition has an interesting property: it shows that transitivity is retained even though the Simpson paradox reigns. We further show that by adding a certain restriction the condition can be turned into one that is both sufficient and necessary for transitivity.

© 2022 American Chemical Society.Given that increasing temperature may aggravate the toxicity of pollutants, it is a daunting challenge to evaluate the realistic risks of rare earth elements (REEs) under global warming. Here, we studied how elevated temperatures (27 and 32 °C) impact the effect of yttrium (Y) on wheat plants (Triticum aestivum L.) at concentrations not causing effects (0, 0.5, and 1 μM) at the control temperature (22 °C) in a hydroponic system. After 14 days of exposure, significant inhibition (p < 0.05, 29.5%) of root elongation was observed only at 1 μM of Y at 32 °C. Exposure to Y at 27 °C showed no visible effects on root length, but induced significant (p < 0.05) metabolic disorders of a range of carbohydrates and amino acids related to galactose, phenylalanine, and glutamate metabolisms. Such cases were even shifted to substantial perturbation of the nucleotide pool reallocation involved in the disruption of purine and pyrimidine metabolism at 32 °C. These observations were regulated by sets of genes involved in these perturbed pathways. Using weighted gene co-expression network analysis, the disorder of nucleotide metabolism was shown to be responsible for the aggravated Y phytotoxicity at the extreme high temperature. Although the temperature fluctuation considered seems to be in an extreme range, unexpected implications driven by high temperature cannot be neglected. Our findings thus reduce the gaps of knowledge in REE toxicity to plants under future climate warming scenarios and highlight the importance of incorporating environmental temperature into the framework of the risk assessment of REEs.

Per- and polyfluoroalkyl substances (PFASs) are omnipresent and have been shown to induce a wide range of adverse effects, including hepatotoxicity, developmental toxicity and immunotoxicity. So far, little information is available about the mechanisms underlying the toxicity of PFASs, including those related to their immunotoxicity. Reported immunotoxic effects of PFASs include decreased antibody responses in experimental animals and humans, indicating that PFASs may, among others, affect B cell function. In the present study, we first assessed the effects of PFOA on the transcriptome of the human Namalwa B cell line using RNA seq analysis. Gene expression changes, analyzed using Ingenuity Pathway Analysis, pointed to various cellular processes affected by PFOA, including ‘B cell development’ and ‘Primary immunodeficiency signaling’. Interestingly, PFOA decreased the expression of RAG1 and RAG2, genes involved in immunoglobulin and T cell receptor V(D)J recombination. As a next step, time- and concentration-dependent changes in the expression of RAG1 and RAG2 upon exposure to PFOA, PFNA, PFHxS and PFOS were studied through RT-qPCR analysis. Analysis with the concentration–response modeling software PROAST resulted in the following potency ranking: PFNA > PFOA > PFOS > PFHxS. Altogether, the present in vitro study provides insights into the effects of selected PFASs on B cells, identifying RAG1 and RAG2 expression as possible relevant targets that may play a role in the immunotoxicity of PFASs.

Novel nanomaterial-based pesticide formulations are increasingly perceived as promising aids in the transition to more efficient agricultural production systems. The current understanding of potential unintended (eco)toxicological impacts of nano-formulated pesticides is scarce, in particular with regard to (non-target) aquatic organisms and ecosystems. The present study reports the results of a long-term freshwater mesocosm experiment which assessed responses of individual zooplankton taxa and communities to a novel TiO2-coated nano-formulation of the fungicide carbendazim. Population- and community trends were assessed and compared in response to the nano-formulation and its constituents applied individually (i.e. nano-sized TiO2, carbendazim) and in combination (i.e. nano-sized TiO2 & carbendazim). Minimal differences were observed between effects induced by the nano-formulation and its active ingredient (i.e. carbendazim) when applied at equivalent nominal test concentrations (4 μg L-1). Nano-sized TiO2 was found to affect zooplankton community trends when applied separately at environmentally realistic concentrations (20 μg L-1 nominal test concentration). However, when nano-sized TiO2 was applied in combination with carbendazim, nano-sized TiO2 was found not to alter effects on community trends induced by carbendazim. The findings of the current study provide an extensive and timely addition to the current body of work available on non-target impacts of nano-formulated pesticides.

Shelled pteropods and planktic foraminifers are calcifying zooplankton that contribute to the biological carbon pump via the sinking of their calcareous shells. However, their importance for regional and global plankton biomass and carbon fluxes is not well understood. Here, we modeled global annual patterns of pteropod and foraminifer total carbon (TC) biomass and total inorganic carbon (TIC) export fluxes over the top 200 m using five species distribution models (SDMs). An extended version of the MARine Ecosystem DATa (MAREDAT) of zooplankton abundance observations was used to estimate the biomass of both plankton groups. We found hotspots of mean annual pteropod biomass in the high Northern latitudes and the global upwelling systems, and in the high latitudes of both hemispheres and the tropics for foraminifers. This largely agrees with previously observed distributions. For both groups, temperature is the strongest environmental correlate, followed by chlorophyll-a. We found mean annual standing stocks of 52 Tg TC (48 to 57 Tg TC) and 0.9 Tg TC (0.6 to 1.1 Tg TC) for pteropods and foraminifers, respectively. This translates to mean annual TIC fluxes of 14 Tg TIC yr(-1) (9 to 22 Tg TIC yr(-1)) for pteropod shells and 11 Tg TIC yr(-1) (3 to 27 Tg TIC yr(-1)) for foraminifer tests. These results are similar to previous estimates for foraminifers, but approximately a factor of ten lower for pteropods. Pteropods contribute 0.2%-3.2% and foraminifers 0.1%-3.8% to global surface carbonate fluxes. Including global coccolithophore fluxes, this leaves 40%-60% of the global carbonate fluxes unaccounted for. Our figures are likely lower-bound estimates due to sampling data characteristics and uncertainty associated with organism growth rates., Global Biogeochemical Cycles, 37 (6), ISSN:0886-6236, ISSN:1944-9224

Not a territory escapes contamination. Microplastics have infiltrated agricultural soils and therefore potentially what we eat. Recently, in the Netherlands, researchers are studying the extent of the phenomenon. And for now, they have more questions than answers.

Over the last years there has been significant research on the presence and effects of plastics in terrestrial systems. Here we summarize current research findings on the effects of nano- and microplastics (NMPs) onterrestrial plants, with the aim to determine patterns of response and sensitive endpoints. We conducted a systematic review (based on 78 studies) on the effects of NMPs on germination, plant growth and biochemical biomarkers. This review highlights that the majority of studies to date have used pristinepolystyreneor polyethylene particles, either in ahydroponicor pot-plant setup. Based on these studies we found that effects on plants are widespread. We noted similar responses between and within monocots and dicots to NMPs, except for consistent lower germination seen in dicots exposed to NMPs. During early development, germination and root growth are more strongly affected compared to shoot growth. NMPs induced similar adverse growth effects on plant biomass and length in the most testedplant species(lettuce, wheat, corn, and rice) irrespective of the polymer type and size used. Moreover, biomarker responses were consistent across species; chlorophyll levels were commonly negatively affected, while stress indicators (e.g.,ROSor free radicals) and stress respondents (e.g., antioxidant enzymes) were consistently upregulated. In addition, effects were commonly observed at environmentally relevant levels. These findings provide clear evidence that NMPs have wide-ranging impacts on plant performance. However, as most studies have been conducted under highly controlled conditions and with pristine plastics, there is an urgent need to test under more environmentally realistic conditions to ensure the lab-based studies can be extrapolated to the field.

Emodin, a chemical isolated from Aspergillus terreus, was studied using chromatographic and spectroscopic methods and compound purity (96%) was assessed by TLC. Furthermore, high larvicidal activity against Aedes aegypti-AeA (LC50 5.08 and LC90 8.23 mg.L− 1), Culex quinquefasciatus-CuQ (7.13 and 12.01 mg.L− 1), and Anopheles stephensi-AnS larvae (6.40 and 15.24 mg.L− 1) was recorded. The first isolated fraction showed higher pupicidal activity against AeA (0.349 and 0.872 mg.L− 1). Most emodin-treated larvae (ETL) involutate variations in acetylcholine esterase, α and β-carboxylesterases, and phosphatase activities in the 4th instar, indicating intrinsic differences in their biochemical changes. ETL had numerous altered tissues, including muscle, gastric caeca, hindgut, midgut, nerve ganglia, and midgut epithelium. Acute toxicity of emodin against brine shrimp Artemia nauplii (154.0 and 184.5 mg.L− 1) and the zebrafish Danio rerio (less toxicity observed) was evaluated. In docking studies, Emodin interacted well with odorant-binding-proteins of AeA, AnS, and CuQ with docking scores of -8.89, -6.53, and − 8.09 kcal/mole, respectively. Therefore, A. terreus is likely to be effective against mosquito larvicides.

Elicitors are stressors that activate secondary pathways that lead to the increased production of bioactive molecules in plants. Different elicitors including the fungus Aspergillus niger (0.2 g/L), methyl jasmonate (MeJA, 100 µM/L), and silver nanoparticles (1 µg/L) were added, individually and in combination, in a hydroponic medium. The application of these elicitors in hydroponic culture significantly increased the concentration of photosynthetic pigments and total phenolic contents. The treatment with MeJA (methyl jasmonate) (100 µM/L) and the co-treatment of MeJA and AgNPs (silver nanoparticles) (100 µM/L + 1 µg/L) exhibited the highest chlorophyll a (29 µg g-1 FW) and chlorophyll b (33.6 µg g-1 FW) contents, respectively. The elicitor MeJA (100 µM/L) gave a substantial rise in chlorophyll a and b and total chlorophyll contents. Likewise, a significant rise in carotenoid contents (9 µg/g FW) was also observed when subjected to meJA (100 µM/L). For the phenolic content, the treatment with meJA (100 µM/L) proved to be very effective. Nevertheless, the highest production (431 µg/g FW) was observed when treated with AgNPs (1 µg/L). The treatments with various elicitors in this study had a significant effect on flavonoid and lignin content. The highest concentration of flavonoids and lignin was observed when MeJA (100 mM) was used as an elicitor, following a 72-h treatment period. Hence, for different plant metabolites, the treatment with meJA (100 µM/L) and a co-treatment of MeJA and AgNPs (100 µM/L + 1 µg/L) under prolonged exposure times of 120-144 h proved to be the most promising in the accretion of valuable bioactive molecules. The study opens new insights into the use of these elicitors, individually or in combination, by using different concentrations and compositions.

The leaves of plants are colonized by various microorganisms. In comparison to the rhizosphere, less is known about the characteristics and ecological functions of phyllosphere microorganisms. Phyllosphere microorganisms mainly originate from soil, air, and seeds. The composition of phyllosphere microorganisms is mainly affected by ecological and abiotic factors. Phyllosphere microorganisms execute multiple ecological functions by influencing leaf functions and longevity, seed mass, fruit development, and homeostasis of host growth. A plant can respond to phyllosphere microorganisms by secondary metabolite secretion and its immune system. Meanwhile, phyllosphere microorganisms play an important role in ecological stability and environmental safety assessment. However, as a result of the instability of the phyllosphere environment and the poor cultivability of phyllosphere microorganisms in the current research, there are still many limitations, such as the lack of insight into the mechanisms of plant–microorganism interactions, the roles of phyllosphere microorganisms in plant growth processes, the responses of phyllosphere microorganisms to plant metabolites, etc. This review summarizes the latest progress made in the research of the phyllosphere in recent years. This is beneficial for deepening our understanding of phyllosphere microorganisms and promoting the research of plant–atmosphere interactions, plant pathogens, and plant biological control.

Heisenberg’s uncertainty principle is a milestone of twentieth-century physics. We sketch the history that led to the formulation of the principle, and we recall the objections of Grete Hermann and Niels Bohr. Then we explain that there are in fact two uncertainty principles. One was published by Heisenberg in the Zeitschrift für Physik of March 1927 and subsequently targeted by Bohr and Hermann. The other one was introduced by Earle Kennard in the same journal a couple of months later. While Kennard’s principle remains untarnished, the principle of Heisenberg has recently been criticized in a way that is very different from the objections by Bohr and Hermann: there are reasons to believe that Heisenberg’s formula is not valid. Experimental results seem to support this claim.

It is an important topic in environmental sciences to understand the behavior and toxicology of chemical pollutants. Quantum chemical methodologies have served as useful tools for probing behavior and toxicology of chemical pollutants in recent decades. In recent years, machine learning (ML) techniques have brought revolutionary developments to the field of quantum chemistry, which may be beneficial for investigating environmental behavior and toxicology of chemical pollutants. However, the ML-based quantum chemical methods (ML-QCMs) have only scarcely been used in environmental chemical studies so far. To promote applications of the promising methods, this Perspective summarizes recent progress in the ML-QCMs and focuses on their potential applications in environmental chemical studies that could hardly be achieved by the conventional quantum chemical methods. Potential applications and challenges of the ML-QCMs in predicting degradation networks of chemical pollutants, searching global minima for atmospheric nanoclusters, discovering heterogeneous or photochemical transformation pathways of pollutants, as well as predicting environmentally relevant end points with wave functions as descriptors are introduced and discussed.

The uptake pathways of nanoplastics by edible plants have recently been qualitatively investigated. There is an urgent need to accurately quantify nanoplastics accumulation in plants. Polystyrene (PS) particles with a diameter of 200 nm were doped with the europium chelate Eu-β-diketonate (PS-Eu), which was used to quantify PS-Eu particles uptake by wheat (Triticum aestivum) and lettuce (Lactuca sativa), grown hydroponically and in sandy soil using inductively coupled plasma mass spectrometry. PS-Eu particles accumulated mainly in the roots, while transport to the shoots was limited (for example,3% for 5,000 μg PS particles per litre exposure). Visualization of PS-Eu particles in the roots and shoots was performed with time-gated luminescence through the time-resolved fluorescence of the Eu chelate. The presence of PS-Eu particles in the plant was further confirmed by scanning electron microscopy. Doping with lanthanide chelates provides a versatile strategy for elucidating the interactions between nanoplastics and plants.

There is a global research interest in metal nanoparticles (MNPs) due to their diverse applications, rapidly increasing use, and increased presence in the aquatic environment. Currently, most MNPs in the environment are at levels unlikely to cause overt toxicity. Sub-lethal effects that MNPs may induce, notable immunotoxicity, could however have significant health implications. Thus, deciphering the immunological interactions of MNPs with aquatic organisms constitutes a much-needed area of research. In this article, we critically assess the evidence for immunotoxic effects of MNPs in bivalves and fish, as key wildlife sentinels with widely differing ecological niches that are used as models in ecotoxicology. The first part of this review details the properties, fate, and fundamental physicochemical behavior of MNPs in the aquatic ecosystem. We then consider the toxicokinetics of MNP uptake, accumulation, and deposition in fish and bivalves. The main body of the review then focuses on immune reactions in response to MNPs exposure in bivalves and fish illustrating their immunotoxic potential. Finally, we identify major knowledge gaps in our current understanding of the implications of MNPs exposure for immunological functions and the associated health consequences for bivalves and fish, as well as the general lessons learned on the immunotoxic properties of the emerging class of nanoparticulate contaminants in fish and bivalves.

Contains fulltext : 247729.pdf (Publisher’s version ) (Open Access) 25 februari 2022

The concepts of Safe by Design (SbD) and Safe and Sustainable by Design (SSbD) are receiving increasing attention. The definitions of both concepts include the term ‘life cycle’ in combination with the terms ‘chemical’, ‘material’ and ‘product’, but their meanings are not further elaborated and defined in scholarly publications on SbD/SSbD. Here, we address two research questions: (1) How are the terms chemical, material and product used and defined in the scholarly literature on SbD and SSbD; (2) How are life cycles defined and which are considered in the scholarly literature on SbD/SSbD? We found largely consistent, though still confusing, uses of the terms product, material and chemical and we found four types of life cycles in the reviewed papers. Using consistent definitions of the terms product, material and chemical, we reduce the four types of life cycles found to three types of distinctive life cycles: (1) the life cycle of a product; (2) the life cycle of a chemical in a specific product; (3) the life cycle of a chemical in all its product applications. We discuss the different trade-offs that each of these life cycle approaches canidentify and argue that they are complementary and should preferably all be applied in SbD/SSbD studies.

As antimicrobials, graphene materials (GMs) may have advantages over traditional antibiotics due to their physical mechanisms of action which ensure less chance of development of microbial resistance. However, the fundamental question as to whether the antibacterial mechanism of GMs originates from parallel interaction or perpendicular interaction, or from a combination of these, remains poorly understood. Here, we show both experimentally and theoretically that GMs with high surface oxygen content (SOC) predominantly attach in parallel to the bacterial cell surface when in the suspension phase. The interaction mode shifts to perpendicular interaction when the SOC reaches a threshold of ∼0.3 (the atomic percent of O in the total atoms). Such distinct interaction modes are highly related to the rigidity of GMs. Graphene oxide (GO) with high SOC is very flexible and thus can wrap bacteria while reduced GO (rGO) with lower SOC has higher rigidity and tends to contact bacteria with their edges. Neither mode necessarily kills bacteria. Rather, bactericidal activity depends on the interaction of GMs with surrounding biomolecules. These findings suggest that variation of SOC of GMs is a key factor driving the interaction mode with bacteria, thus helping to understand the different possible physical mechanisms leading to their antibacterial activity.

The continuous release of nanoparticles and nanoplastics into the marine environment necessitates the examination of their combined effects in marine organisms. Natural Organic Matter (NOM) can significantly influence the behavior of nanomaterials in the marine environment. The present study explores the effects of algal Extracellular Polymeric Substances (EPS) in reducing the combined toxic effects of three different polystyrene nanoplastics (PSNPs)- aminated (NH2-PSNPs), carboxylated (COOH-PSNPs), and plain PSNPs - and P25 titanium dioxide nanoparticles (Nano-TiO2) towards the marine alga, Chlorella sp. Two doses (0.25 and 2.5 mg/L) of nano-TiO2 mixed with the PSNPs (1 mg/L) were employed. The COOH-PSNPs with 2.5 mg/L nano-TiO2 exhibited higher growth inhibition toward algal cells. Addition of algal EPS to the mixture of NMs decreased the negative effect significantly. The mean hydrodynamic diameter increased significantly from 666 to 797 nm and 1248 to 3589 nm at concentrations 0.25 and 2.5 mg/L, respectively when the mixtures of nano-TiO2 and COOH-PSNPs were incubated with the algal EPS. In comparison to the pristine NMs, the EPS-NMs were found to significantly reduce the superoxide and hydroxyl radical production. The results were further validated with the estimation of lipid peroxidation (LPO), esterase activity, photosynthetic efficiency, and membrane permeability in the cells. The major outcomes from this study highlight the role of algal EPS in significantly reducing the toxic impact of binary mixture of NMs in marine organisms.

Herein, we investigated to which extent metallic nanoparticles (MNPs) affect the trophic transfer of other coexisting MNPs from lettuce to terrestrial snails and the associated tissue-specific distribution using toxicokinetic (TK) modeling and single-particle inductively coupled plasma mass spectrometry. During a period of 22 days, snails were fed with lettuce leaves that were root exposed to AgNO3 (0.05 mg/L), AgNPs (0.75 mg/L), TiO2NPs (200 mg/L), and a mixture of AgNPs and TiO2NPs (equivalent doses as for single NPs). The uptake rate constants (ku) were 0.08 and 0.11 kg leaves/kg snail/d for Ag and 1.63 and 1.79 kg leaves/kg snail/d for Ti in snails fed with NPs single- and mixture-exposed lettuce, respectively. The elimination rate constants (ke) of Ag in snails exposed to single AgNPs and mixed AgNPs were comparable to the corresponding ku, while the ke for Ti were lower than the corresponding ku. As a result, single TiO2NP treatments as well as exposure to mixtures containing TiO2NPs induced significant biomagnification from lettuce to snails with kinetic trophic transfer factors (TTFk) of 7.99 and 6.46. The TTFk of Ag in the single AgNPs treatment (1.15 kg leaves/kg snail) was significantly greater than the TTFk in the mixture treatment (0.85 kg leaves/kg snail), while the fraction of Ag remaining in the body of snails after AgNPs exposure (36%) was lower than the Ag fraction remaining after mixture exposure (50%). These results indicated that the presence of TiO2NPs inhibited the trophic transfer of AgNPs from lettuce to snails but enhanced the retention of AgNPs in snails. Biomagnification of AgNPs from lettuce to snails was observed in an AgNPs single treatment using AgNPs number as the dose metric, which was reflected by the particle number-based TTFs of AgNPs in snails (1.67, i.e., higher than 1). The size distribution of AgNPs was shifted across the lettuce-snail food chain. By making use of particle-specific measurements and fitting TK processes, this research provides important implications for potential risks associated with the trophic transfer of MNP mixtures.

The wide production and use of metallic nanomaterials (MNMs) leads to increased emissions into the aquatic environments and induces high potential risks. Experimentally evaluating the (eco)toxicity of MNMs is time-consuming and expensive due to the multiple environmental factors, the complexity of material properties, and the species diversity. Machine learning (ML) models provide an option to deal with heterogeneous data sets and complex relationships. The present study established an in silico model based on a machine learning properties-environmental conditions-multi species-toxicity prediction model (ML-PEMST) that can be applied to predict the toxicity of different MNMs toward multiple aquatic species. Feature importance and interaction analysis based on the random forest method indicated that exposure duration, illumination, primary size, and hydrodynamic diameter were the main factors affecting the ecotoxicity of MNMs to a variety of aquatic organisms. Illumination was demonstrated to have the most interaction with the other features. Moreover, incorporating additional detailed information on the ecological traits of the test species will allow us to further optimize and improve the predictive performance of the model. This study provides a new approach for ecotoxicity predictions for organisms in the aquatic environment and will help us to further explore exposure pathways and the risk assessment of MNMs.

Sulfur cycling is known to control the speciation and bioavailability of copper in the environment via inorganic sulfur oxidation and reduction. However, it remains unclear how the mineralization of organic sulfur and associated microbial processes affect Cu transformations. This study discovered a neglected mechanism that mediates Cu mobility and speciation via cysteine mineralization in a paddy soil. We provide evidence for a pathway of sulfide production from cysteine via indigenous soil microorganisms. The produced sulfide promotes the formation of copper sulfide nanoparticles, constituting an alternative copper sulfide formation mechanism that bypasses sulfate reduction. A bacterium isolated from the soil, named Bacillus sp. TR1, played a role in forming cell-associated copper sulfide nanoparticles. A metagenomics approach was applied to detect genes related to cysteine mineralization (dcyD, CTH, CBS, and sseA) and the associated microbes in the soil. The sseA gene was most abundant, and the microorganisms involved in cysteine mineralization were taxonomically diverse, including members of phyla Proteobacteria, Firmicutes, and Thaumarchaeota. Geobacter, Sulfuriferula, Nitrososphaera, Noviherbaspirillum, and Clostridium were the dominant genera with potential to metabolize cysteine to form copper sulfide nanoparticles. Our study not only provides initial molecular-level insights into the abundance, diversity, and metabolism of cysteine-mineralizing microorganisms but also highlights their important ecological functions in metal and sulfur biogeochemical cycles.

Ideally, a Systems Toxicology (ST) approach is aimed at by (eco)toxicologists, i.e. a multidisciplinary area incorporating classical toxicological concepts with omics technologies, and the understanding of this through computational data sciences, chemistry, mathematics, and physics modelling. As outlined in sev-eral public reports (e.g. from ECHA-European Chemical Agency and EFSA-European Food Safety Authority), the way forward in the coming years in Europe is to integrate New Approach Methodologies (NAMs) (in-cluding omics technologies) into hazard and hence risk assessment (RA). Adverse Outcome Pathways (AOPs) describe a sequence of events in response to stress, from the molecular initiating event until an adverse outcome, which is relevant to RA or regulatory decision-making. AOPs are one of the facilitators to integrate mechanistic data into RA, but it is urgent to increase the inclusion of the vast mechanistic knowledge available, especially for the RA of novel smart and advanced materials (AdMa) with multi-functional characteristics. There are still many challenges to the routine usage of NAMs, e.g. omics-based information. Here, we summarise the current state of the art of ST, the benefits of human and environ-mental health cross knowledge and the available methods and output. The importance of this area has been highlighted for many years but is even more pressing in the context of AdMa. Furthermore, we outline the challenges and suggest recommendations for future implementation.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Direct discharge of chromium-containing waste water and improper disposal of waste residues in industrial sites may lead to the vertical migration of metals into aquifers, posing serious threat to soil-groundwater system. The heterogeneity in soil profile further aggravates the complexity and unpredictability of this transport process. However, topsoil was the main focus of most studies. Herein, the vertical transport and transformation of Cr in soils at different depths in three industrial sites (i.e., Shijiazhuang, Zhuzhou, and Guangzhou) were investigated to delineate Cr transport and retention characteristics under complex conditions. Regional and vertical differences in soil properties led to the specificity in Cr migration behaviors among these three sites. Correlation analysis showed that soil pH (r = −0.909, p < 0.05) and Fe content (r = 0.949, p < 0.01) were the major controlling factors of Cr(VI) migration and transformation in aquifers. Furthermore, the soil of Zhuzhou site showed the maximum adsorption capacity for Cr(VI) (0.225 mol/kg), and the strongest reduction ability of Cr(VI) was observed in the Guangzhou soil. Results of model-based long-term forecast indicated that the Cr(III) concentration in the liquid phase of Guangzhou subsoil could reach 0.08 mol/m3 within 20 years. Heavier rainfall condition exacerbated the contamination due to an increased pollutant flux and enhanced convection. Specially, Cr was fixed in the topsoil of Zhuzhou site with the formation of PbCrO4 and presented least vertical migration risk. The conclusions above can provide scientific theoretical guidance for heavy metal pollution prevention and control in industrial contaminated regions.

Shelled pteropods and planktic foraminifers are calcifying zooplankton that contribute to the biological carbon pump, but their importance for regional and global plankton biomass and carbon fluxes is not well understood. Here, we modelled global annual patterns of pteropod and foraminifer total carbon (TC) biomass and total inorganic carbon (TIC) export fluxes over the top 200m using an ensemble of five species distribution models (SDMs). An exhaustive newly assembled dataset of zooplankton abundance observations was used to estimate the biomass of both plankton groups. With the SDM ensemble we modeled global TC biomass depending on multiple environmental parameters. We found hotspots of mean annual pteropod biomass in the high Northern latitudes and the global upwelling systems, and in the high latitudes of both hemispheres and the tropics for foraminifers. This largely agrees with previously observed distributions. For the biomass of both groups, surface temperature is the strongest environmental correlate, followed by chlorophyll-a. We found mean annual standing stocks of 52 (48-57) Tg TC and 0.9 (0.6-1.1) Tg TC for pteropods and foraminifers, respectively. This translates to mean annual TIC fluxes of 14 (9-22) Tg TIC yr-1 for pteropod shells and 11 (3-27) Tg TIC yr-1 for foraminifer tests. These results are similar to previous estimates for foraminifers standing stocks and fluxes but approximately a factor of ten lower for pteropods. The two zooplankton calcifiers contribute approximately 1.5% each to global surface carbonate fluxes, leaving 40%-60% of the global carbonate fluxes unaccounted for. We make suggestions how to close this gap.

The study assessed the bactericidal effects of green rapid biogenic synthesis of Vitex trifolia leaves AgNPs on MDR bacteria. The synthesis of AgNPs is indicated by a color change from yellow to dark brown. The ultra-visible spectrophotometer displays AgNPs at 430 nm max. This demonstrates that ions (Ag+) were converted to silver (Ag), indicating the formation of silver nanoparticles. The synthesized nanoparticles were confirmed by their crystalline nature, shape, size, and functional groups via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X- ray spectroscopy (EDAX), and transmission electron microscopy (TEM). Biomolecules contain aqueous Vitex extract for capping and reducing the AgNPs. The nanoparticles have a face-centered cubic structure (FCC) crystallized. The antibacterial activity against Staphylococcus aureus, Vibrio cholerae, and Klebsiella pneumoniae exhibited a maximum zone of growth inhibition at 75 µg/mL. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs against the clinically isolated pathogen S. aureus were 3.12 µg/mL and 4.5 µg/mL. Furthermore, time-dependent killing kinetic experiments showed that a 6 h AgNPs treatment was sufficient to fully inhibit all bacterial growth. AgNPs at a concentration of 250 µg/mL demonstrated antioxidant activity as measured by the FRAP and DPPH tests (85% and 90%, respectively). AgNPs demonstrated efficient photocatalytic activity in the degradation of methylene blue (MB) and achieved their highest photocatalytic activity (95%) after 2.30 h. Besides, the synthesis of AgNPs was targeted towards C. vulgaris algae, and exhibited deleterious effects even at larger concentrations. The chosen AgNPs concentration reduced chlorophyll, impeded algal development, and damaged the whole membrane system, as evidenced by the increased electrolyte leakage and malondialdehyde (MDA) and glutathione s-transferase (GSH) content after AgNPs exposure. Our report demonstrates that AgNPs V. trifolia have promising antibacterial, antioxidant, and potential dye degradation activities and can be employed in biomedical applications.

The present volume collects papers on ten female thinkers who directly or indirectly contributed to the development of analytic philosophy but who did not always receive the attention they deserve. In this introduction, we briefly recall the standard account of analytic philosophy as we know it from the textbooks, provide an overview of the research that has been done on the role of women in analytic philosophy in the past few years, and offer a quantitative analysis of 3,274 publications in the major analytic journals between 1896 and 1960. We conclude our introduction with summaries of the ten chapters in this volume.

The continuous release of nanoparticles and nanoplastics into the marine environment necessitates the examination of their combined effects in marine organisms. Natural Organic Matter (NOM) can significantly influence the behavior of nanomaterials in the marine environment. The present study explores the effects of algal Extracellular Polymeric Substances (EPS) in reducing the combined toxic effects of three different polystyrene nanoplastics (PSNPs)— aminated (NH2-PSNPs), carboxylated (COOH-PSNPs), and plain PSNPs — and P25 titanium dioxide nanoparticles (Nano-TiO2) towards the marine alga, Chlorella sp. Two doses (0.25 and 2.5 mg/L) of nano-TiO2 mixed with the PSNPs (1 mg/L) were employed. The COOH-PSNPs with 2.5 mg/L nano-TiO2 exhibited higher growth inhibition toward algal cells. Addition of algal EPS to the mixture of NMs decreased the negative effect significantly. The mean hydrodynamic diameter increased significantly from 666 to 797 nm and 1248 to 3589 nm at concentrations 0.25 and 2.5 mg/L, respectively when the mixtures of nano-TiO2 and COOH-PSNPs were incubated with the algal EPS. In comparison to the pristine NMs, the EPS-NMs were found to significantly reduce the superoxide and hydroxyl radical production. The results were further validated with the estimation of lipid peroxidation (LPO), esterase activity, photosynthetic efficiency, and membrane permeability in the cells. The major outcomes from this study highlight the role of algal EPS in significantly reducing the toxic impact of binary mixture of NMs in marine organisms.

Ideally, a Systems Toxicology (ST) approach is aimed at by (eco)toxicologists, i.e. a multidisciplinary area incorporating classical toxicological concepts with omics technologies, and the understanding of this through computational data sciences, chemistry, mathematics, and physics modelling. As outlined in several public reports (e.g. from ECHA-European Chemical Agency and EFSA-European Food Safety Authority), the way forward in the coming years in Europe is to integrate New Approach Methodologies (NAMs) (including omics technologies) into hazard and hence risk assessment (RA). Adverse Outcome Pathways (AOPs) describe a sequence of events in response to stress, from the molecular initiating event until an adverse outcome, which is relevant to RA or regulatory decision-making. AOPs are one of the facilitators to integrate mechanistic data into RA, but it is urgent to increase the inclusion of the vast mechanistic knowledge available, especially for the RA of novel smart and advanced materials (AdMa) with multifunctional characteristics. There are still many challenges to the routine usage of NAMs, e.g. omics-based information. Here, we summarise the current state of the art of ST, the benefits of human and environmental health cross knowledge and the available methods and output. The importance of this area has been highlighted for many years but is even more pressing in the context of AdMa. Furthermore, we outline the challenges and suggest recommendations for future implementation.

The Safe by Design (SbD) concept aims to ensure the production, use and disposal of materials and products safely. While there is a growing interest in the potential of SbD to support policy commitments, such as the EU Green Deal and the Circular Economy Action Plan in Europe, methodological approaches and practical guidelines on SbD are, however, largely missing. The combined use of Life Cycle Assessment (LCA) and Risk Assessment (RA) is considered suitable to operationalize SbD over the whole life-cycle of a product. Here, we explore the potential of the combined use of LCA and RA at Technological Readiness Level (TRL) 1–6. We perform a review of the literature presenting and/or developing approaches that combine LCA and RA at early stages of product design. We identify that basic early-on-evaluations of safety (e.g., apply lifecycle thinking to assess risk hotspots, avoid use of hazardous chemicals, minimize other environmental impacts from chemicals) are more common, while more complex assessments (e.g., ex-ante LCA, control banding, predictive (eco)toxicology) require specialized expertise. The application of these simplified approaches and guidelines aims to avoid some obvious sources of risks and impacts at early stages. Critical gaps need to be addressed for wider application of SbD, including more studies in the product design context, developing tools and databases containing collated information on risk, greater collaboration between RA/LCA researchers and companies, and policy discussion on the expansion from SbD to Safe and Sustainable by Design (SSbD).

A general concept in risk assessment isthat a threshold of exposure exists abovewhich adverse effects are initiated. Toxicityis related to the target-site concentrationor the biologically active dose. Although itis often a huge challenge to measure thespecific dose metric of metal toxicity, sig-nificant progress has been obtained toapproach closer to the target-site concen-tration. Such developments are reviewedin the present study. In addition, a generalframework to simulate the subcellularmetal partitioning, which is supposed toaccount for the internal metal sequestra-tion, is developed and applied to variousmetals. The framework allows for delineat-ing mechanisms of internal metal sequestration. Moreover, the specificity in these mechanisms,which varies among metals, species, and exposure conditions, might explain the complicated rela-tionship between the internal concentration and metal toxicity. Attention should be paid to thedata requirements as the high number of unknown parameters might be accompanied by poten-tial uncertainties. In addition, future efforts should focus on linking the concentration of metals insensitive fractions and toxicological effects.

Due to special properties, nano-TiO2 will interact with heavy metals and other pollutants in water, thus affecting the environmental behavior and ecotoxicity of these pollutants. However, the exact manner in which nano-TiO2 affects the bioaccumulation mechanisms of heavy metals is still unclear now. In the present study, quantitative structure bioaccumulation relationship (QSBAR) models were established to explore the relationships between physicochemical parameters of heavy metals and their accumulation in Daphnia magna in the absence and presence of nano-TiO2 at low metal exposure concentrations. The results showed that different physicochemical parameters affected the bioaccumulation of metals in Daphnia magna. The metal accumulation could be described by means of a Comprehensive Parameter composed of seven parameters, i.e., atomic number (AN), relative atomic weight (AW), atomic radius (AR), atomic ionization potential (AN/ΔIP), covalent index (X2r), second ionization energy (I2) and electrochemical potential (E0), in the absence of nano-TiO2, whereas the metal accumulation increased with the increase in Van Der Waals radius (rw) of metals in the presence of nano-TiO2. It was demonstrated that the bioaccumulation mechanism of the metals to Daphnia magna changed in the presence of nano-TiO2. Moreover, the bioaccumulation of more than 85% of the metals increased in the presence of nano-TiO2, but it increased differently for different metals. The present study provides an alternative approach to understand the mechanism of heavy metal bioaccumulation at low metal exposure concentrations and the effect of nano-TiO2 on metal bioaccumulation.

Per- and polyfluoroalkyl substances (PFASs) are omnipresent and have been shown to induce a wide range of adverse health effects, including hepatotoxicity, developmental toxicity, and immunotoxicity. The aim of the present work was to assess whether human HepaRG liver cells can be used to obtain insight into differences in hepatotoxic potencies of a series of PFASs. Therefore, the effects of 18 PFASs on cellular triglyceride accumulation (AdipoRed assay) and gene expression (DNA microarray for PFOS and RT-qPCR for all 18 PFASs) were studied in HepaRG cells. BMDExpress analysis of the PFOS microarray data indicated that various cellular processes were affected at the gene expression level. From these data, ten genes were selected to assess the concentration–effect relationship of all 18 PFASs using RT-qPCR analysis. The AdipoRed data and the RT-qPCR data were used for the derivation of in vitro relative potencies using PROAST analysis. In vitro relative potency factors (RPFs) could be obtained for 8 PFASs (including index chemical PFOA) based on the AdipoRed data, whereas for the selected genes, in vitro RPFs could be obtained for 11–18 PFASs (including index chemical PFOA). For the readout OAT5 expression, in vitro RPFs were obtained for all PFASs. In vitro RPFs were found to correlate in general well with each other (Spearman correlation) except for the PPAR target genes ANGPTL4 and PDK4. Comparison of in vitro RPFs with RPFs obtained from in vivo studies in rats indicate that best correlations (Spearman correlation) were obtained for in vitro RPFs based on OAT5 and CXCL10 expression changes and external in vivo RPFs. HFPO-TA was found to be the most potent PFAS tested, being around tenfold more potent than PFOA. Altogether, it may be concluded that the HepaRG model may provide relevant data to provide insight into which PFASs are relevant regarding their hepatotoxic effects and that it can be applied as a screening tool to prioritize other PFASs for further hazard and risk assessment.

The aquatic system is a major sink for engineered nanomaterials released into the environment. Here, we assessed the toxicity of graphene oxide (GO) using the freshwater planarian Dugesia japonica, an invertebrate model that has been widely used for studying the effects of toxins on tissue regeneration and neuronal development. GO not only impaired the growth of normal (homeostatic) worms, but also inhibited the regeneration processes of regenerating (amputated) worms, with LC10 values of 9.86 mg/L and 9.32 mg/L for the 48-h acute toxicity test, respectively. High concentration (200 mg/L) of GO killed all the worms after 3 (regenerating) or 4 (homeostasis) days of exposure. Whole-mount in situ hybridization (WISH) and immunofluorescence analyses suggest GO impaired stem cell proliferation and differentiation, and subsequently caused cell apoptosis and oxidative DNA damage during planarian regeneration. Mechanistic analysis suggests that GO disturbed the antioxidative system (enzymatic and non-enzymatic) and energy metabolism in the planarian at both molecular and genetic levels, thus causing reactive oxygen species (ROS) over accumulation and oxidative damage, including oxidative DNA damage, loss of mitochondrial membrane integrity, lack of energy supply for cell differentiation and proliferation leading to retardance of neuron regeneration. The intrinsic oxidative potential of GO contributes to the GO-induced toxicity in planarians. These data suggest that GO in aquatic systems can cause oxidative stress and neurotoxicity in planarians. Overall, regenerated tissues are more sensitive to GO toxicity than homeostatic ones, suggesting that careful handling and appropriate decisions are needed in the application of GO to achieve healing and tissue regeneration.

Little is known about when and how planktonic species arise and persist in the open ocean without apparent dispersal barriers. Pteropods are planktonic snails with thin shells susceptible to dissolution that are used as bio-indicators of ocean acidification. However, distinct evolutionary units respond to acidification differently and defining species boundaries is therefore crucial for predicting the impact of changing ocean conditions. In this global population genomic study of the shelled pteropod Limacina bulimoides, we combined genetic (759,000 single nucleotide polymorphisms) and morphometric data from 161 individuals, revealing three major genetic lineages (FST = 0.29 to 0.41): an 'Atlantic lineage' sampled across the Atlantic, an 'Indo-Pacific lineage' sampled in the North Pacific and Indian Ocean, and a 'Pacific lineage' sampled in the North and South Pacific. A time-calibrated phylogeny suggests that the lineages diverged about one million years ago, with estimated effective population size remaining high (~10 million) throughout Pleistocene glacial cycles. We do not observe any signatures of recent hybridisation, even in areas of sympatry in the North Pacific. While the lineages are reproductively isolated, they are morphologically cryptic, with overlapping shell shape and shell colour distributions. Despite showing that the circumglobal L. bulimoides consists of multiple species with smaller ranges than initially thought, we found that these pteropods still possess high levels of genetic variability. Our study adds to the growing evidence that speciation is often overlooked in the open ocean, and suggests the presence of distinct biological species within many other currently defined circumglobal planktonic species.

A new report from the World Health Organization has evaluated the risks of dietary exposure to nanoplastic and microplastic particles (NMPs) to human health. Although challenges in the detection of NMPs in food and beverages remain, it is clear that humans are being exposed. Presently, no convincing evidence of adverse health effects are found, but major knowledge gaps remain.

Given that increasing temperature may aggravate the toxicity of pollutants, it is a daunting challenge to evaluate the realistic risks of rare earth elements (REEs) under global warming. Here, we studied how elevated temperatures (27 and 32 °C) impact the effect of yttrium (Y) on wheat plants (Triticum aestivum L.) at concentrations not causing effects (0, 0.5, and 1 μM) at the control temperature (22 °C) in a hydroponic system. After 14 days of exposure, significant inhibition (p < 0.05, 29.5%) of root elongation was observed only at 1 μM of Y at 32 °C. Exposure to Y at 27 °C showed no visible effects on root length, but induced significant (p < 0.05) metabolic disorders of a range of carbohydrates and amino acids related to galactose, phenylalanine, and glutamate metabolisms. Such cases were even shifted to substantial perturbation of the nucleotide pool reallocation involved in the disruption of purine and pyrimidine metabolism at 32 °C. These observations were regulated by sets of genes involved in these perturbed pathways. Using weighted gene co-expression network analysis, the disorder of nucleotide metabolism was shown to be responsible for the aggravated Y phytotoxicity at the extreme high temperature. Although the temperature fluctuation considered seems to be in an extreme range, unexpected implications driven by high temperature cannot be neglected. Our findings thus reduce the gaps of knowledge in REE toxicity to plants under future climate warming scenarios and highlight the importance of incorporating environmental temperature into the framework of the risk assessment of REEs.