A review on in vivo and in vitro nanotoxicological studies in plants: A headlight for future targets.

Owing to the unique properties and useful applications in numerous fields, nanomaterials (NMs) received a great attention. The mass production of NMs has raised major concern for the environment. Recently, some altered growth patterns in plants have been reported due to the plant-NMs interactions. However, for NMs safe applications in agriculture and medicine, a comprehensive understanding of bio-nano interactions is crucial. The main goal of this review article is to summarize the results of the toxicological studies that have shown the in vitro and in vivo interactions of NMs with plants. The toxicity mechanisms are briefly discussed in plants as the defense mechanism works to overcome the stress caused by NMs implications. Indeed, the impact of NMs on plants varies significantly with many factors including physicochemical properties of NMs, culture media, and plant species. To investigate the impacts, dose metrics is an important analysis for assaying toxicity and is discussed in the present article to broadly open up different aspects of nanotoxicological investigations. To access reliable quantification and measurement in laboratories, standardized methodologies are crucial for precise dose delivery of NMs to plants during exposure. Altogether, the information is significant to researchers to describe restrictions and future perspectives.

Global Perspective on Careers in Environmental Toxicologic Pathology: The 2019 Society of Toxicologic Pathology Annual Symposium Lunchtime Career Development Session.

A wide range of career options is available globally in the environmental toxicologic pathology (ETP) arena including academia, government, contract research organizations, and the agrichemical/chemical industry. This small and specialized subset of toxicologic pathologists addresses the effects of contaminants and pollutants on human, animal, and ecological health (One Health). Veterinary students and pathology trainees are primarily exposed to diagnostic pathology and often have limited exposure to toxicologic pathology and even less so to the issues and opportunities in environmental toxicology. The speakers provided a brief overview of global opportunities in their work sector and personal perspectives of their careers in ETP. The following panel discussion provided an opportunity to discuss issues related to careers in this specialty.

Corticosterone in American alligator (Alligator mississippiensis) tail scutes: Evaluating the feasibility of using unconventional samples for investigating environmental stressors.

Baseline plasma corticosterone (CORT) concentrations have been widely used to investigate the effects of stressors in wild and captive crocodilians. However, collecting baseline plasma CORT samples from wild crocodilians may be particularly difficult due to the capture and handling protocols used for large individuals. Thus, it may prove beneficial to use recently modified techniques for extracting CORT deposited in keratinized and non-keratinized tissues to better quantify the effects of long-term stress in crocodilians. In this study, we investigated the feasibility of using American alligator (Alligator mississippiensis) tail scute tissues to quantify CORT by collecting blood and tail scutes from 40 alligators before and after a short-term handling stressor. The objective of the current study was to better understand CORT deposition in crocodilian scutes and whether short-term increases in CORT could be detected. We found that CORT can be reliably extracted from alligator scute tissue and quantified using a commercially available enzyme immunoassay. However, there was a significant increase in scute CORT concentrations following an alligator being exposed to a short-term stressor (p = 0.017), although the magnitude of change was less than observed in plasma samples from the same individuals (p = 0.002). Furthermore, our results indicate that there was a significant effect of body condition on an alligator's post-stressor CORT concentration (p = 0.02). While our study is among the first to experimentally examine the usefulness of tissue CORT in crocodilians, a combination of field and laboratory experiments are needed to better understand deposition rates of CORT in scute tissues and to further validate the usefulness of tissue glucocorticoids for evaluating the effects of stress.

General introduction and outline of the special issue "Emerging advances and challenges in pesticide ecotoxicology".

The aim of this special issue was to bring together papers dealing with current challenges and trends in pesticide ecotoxicology. The special issue is composed of 25 papers into various topics, ranging from the development of more ecological ecotoxicological test approaches to an evaluation of citation bias in pesticide ecotoxicology literature. This paper provides a general introduction and an index of the various papers in the special issue. This special issue is trusted to provide a valuable contribution in addressing current challenges in pesticide ecotoxicology.

The challenge of the application of 'omics technologies in chemicals risk assessment: Background and outlook.

This survey by the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) highlights that 'omics technologies are generally not yet applied to meet standard information requirements during regulatory hazard assessment. While they are used within weight-of-evidence approaches to investigate substances' modes-of-action, consistent approaches for the generation, processing and interpretation of 'omics data are not applied. To date, no 'omics technology has been standardised or validated. Best practices for performing 'omics studies for regulatory purposes (e.g., microarrays for transcriptome profiling) remain to be established. Therefore, three frameworks for (i) establishing a Good-Laboratory Practice-like context for collecting, storing and curating 'omics data; (ii) 'omics data processing; and (iii) quantitative WoE approaches to interpret 'omics data have been developed, that are presented in this journal supplement. Application of the frameworks will enable between-study comparison of results, which will facilitate the regulatory applicability of 'omics data. The frameworks do not constitute prescriptive protocols precluding any other data analysis method, but provide a baseline for analysis that can be applied to all data allowing ready cross-comparison. Data analysis that does not follow the frameworks can be justified and the resulting data can be compared with the Framework-based common analysis output.

Applying 'omics technologies in chemicals risk assessment: Report of an ECETOC workshop.

Prevailing knowledge gaps in linking specific molecular changes to apical outcomes and methodological uncertainties in the generation, storage, processing, and interpretation of 'omics data limit the application of 'omics technologies in regulatory toxicology. Against this background, the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) convened a workshop Applying 'omics technologies in chemicals risk assessment that is reported herein. Ahead of the workshop, multi-expert teams drafted frameworks on best practices for (i) a Good-Laboratory Practice-like context for collecting, storing and curating 'omics data; (ii) the processing of 'omics data; and (iii) weight-of-evidence approaches for integrating 'omics data. The workshop participants confirmed the relevance of these Frameworks to facilitate the regulatory applicability and use of 'omics data, and the workshop discussions provided input for their further elaboration. Additionally, the key objective (iv) to establish approaches to connect 'omics perturbations to phenotypic alterations was addressed. Generally, it was considered promising to strive to link gene expression changes and pathway perturbations to the phenotype by mapping them to specific adverse outcome pathways. While further work is necessary before gene expression changes can be used to establish safe levels of substance exposure, the ECETOC workshop provided important incentives towards achieving this goal.

The evolution of environmental metalloproteomics over the last 15 years through bibliometric techniques.

Metalloproteomic studies in environmental scenarios are of significant value in elucidating metal uptake, trafficking, accumulation and metabolism linked to biomolecules in biological systems. The advent of this field occurred in the early 2000s, and it has since become an interesting and growing area of interdisciplinary research, although the number of publications in Environmental Metalloprotemics is still very low compared to other metallomic areas. In this context, the evolution of Environmental Metalloprotemics in the last decades was evaluated herein through the use of bibliometric techniques, identifying variables that may aid researchers in this area to form collaborative networks with established scientists in this regard, such as main authors, published articles, institutions, countries and established collaborations involved in academic research on this subject. Results indicate a growing trend of publications over time, reflecting the interest of the scientific community in Environmental Metalloprotemics, but also demonstrated that the research interactions in this field are still country- and organization-specific. Higher amounts of publications are observed from the late 2000's onwards, related to the increasing technological advances in the area, such as the development of techniques combining atomic spectroscopy and biochemical or proteomic techniques. The retrieved publications also indicate that the recent advances in genomic, proteomic and metallomic areas have allowed for extended applications of Environmental Metalloprotemics in non-model organisms. The results reported herein indicate that Environmental Metalloprotemics seems to now be reaching a more mature stage, in which analytical techniques are now well established and can be routinely applied in environmental scenarios, benefitting researchers and allowing for further insights into this fascinating field.

The comet assay: a heavenly method!

The contributions to this special issue of Mutagenesis have been selected to cover the main research areas served by the comet assay, namely genotoxicology, environmental toxicology, human biomonitoring and fundamental investigations into mechanisms of DNA damage and repair. Innovative methods are described, technical issues are explored, and guidelines are given for venturing into relatively new or unexploited areas of research. The popularity of the comet assay in a historical context is illustrated by a bibliometric survey.

International Conference on Contaminated Sediments - ContaSed 2015 8-13 March 2015, Monte Verità, Ascona, Switzerland.

About 80 participants from 22 countries from industry and academia gathered at the International Conference on Contaminated Sediments (ContaSed 2015) held at the Congressi Stefano Franscini (CSF), the conference center of ETH Zurich, located at Monte Verità, Ascona, Switzerland. ContaSed 2015 provided a platform for top experts as well as for junior researchers from different scientific disciplines to present recent results and novel approaches on the analysis, assessment and remediation of contaminated sediments. ContaSed 2015 served as a unique communication and discussion opportunity for environmental scientists with an emphasis on chemistry, sedimentology, ecotoxicology or remediation engineering.

Mass spectrometry in environmental toxicology.

In environmental toxicology, mass spectrometry can be applied to evaluate both exposure to chemicals as well as their effects in organisms. Various ultra-trace techniques are employed today to measure pollutants in different environmental compartments. Increasingly, effect-directed analysis is being applied to focus chemical monitoring on sites of ecotoxicological concern. Mass spectrometry is also very instrumental for studying the interactions of chemicals with organisms on the molecular and cellular level, providing new insights into mechanisms of toxicity. In the future, diverse mass spectrometry-based techniques are expected to become even more widely used in this field, contributing to the refinement of currently used environmental risk assessment strategies.

[Prospects of systemic radioecology in solving innovative tasks of nuclear power engineering].

A need of systemic radioecological studies in the strategy developed by the atomic industry in Russia in the XXI century has been justified. The priorities in the radioecology of nuclear power engineering of natural safety associated with the development of the radiation-migration equivalence concept, comparative evaluation of innovative nuclear technologies and forecasting methods of various emergencies have been identified. Also described is an algorithm for the integrated solution of these tasks that includes elaboration of methodological approaches, methods and software allowing dose burdens to humans and biota to be estimated. The rationale of using radioecological risks for the analysis of uncertainties in the environmental contamination impacts,at different stages of the existing and innovative nuclear fuel cycles is shown.

Recent advances in environmental risk assessment of transformation products.

When micropollutants degrade in the environment, they may form persistent and toxic transformation products, which should be accounted for in the environmental risk assessment of the parent compounds. Transformation products have become a topic of interest not only with regard to their formation in the environment, but also during advanced water treatment processes, where disinfection byproducts can form from benign precursors. In addition, environmental risk assessment of human and veterinary pharmaceuticals requires inclusion of human metabolites as most pharmaceuticals are not excreted into wastewater in their original form, but are extensively metabolized. All three areas have developed their independent approaches to assess the risk associated with transformation product formation including hazard identification, exposure assessment, hazard assessment including dose-response characterization, and risk characterization. This review provides an overview and defines a link among those areas, emphasizing commonalities and encouraging a common approach. We distinguish among approaches to assess transformation products of individual pollutants that are undergoing a particular transformation process, e.g., biotransformation or (photo)oxidation, and approaches with the goal of prioritizing transformation products in terms of their contribution to environmental risk. We classify existing approaches for transformation product assessment in degradation studies as exposure- or effect-driven. In the exposure-driven approach, transformation products are identified and quantified by chemical analysis followed by effect assessment. In the effect-driven approach, a reaction mixture undergoes toxicity testing. If the decrease in toxicity parallels the decrease of parent compound concentration, the transformation products are considered to be irrelevant, and only when toxicity increases or the decrease is not proportional to the parent compound concentration are the TPs identified. For prioritization of transformation products in terms of their contribution to overall environmental risk, we integrate existing research into a coherent model-based, risk-driven framework. In the proposed framework, read-across from data of the parent compound to the transformation products is emphasized, but limitations to this approach are also discussed. Most prominently, we demonstrate how effect data for parent compounds can be used in combination with analysis of toxicophore structures and bioconcentration potential to facilitate transformation product effect assessment.

Ultraviolet radiation and echinoderms: past, present and future perspectives.

There is general consensus that solar ultraviolet radiation (UVR) negatively impacts many marine species. Echinoderms are ubiquitous within the marine environment, with members of the phyla often long-lived and numerically dominant within the benthic macrofauna, consequently the impact of UVR on the population dynamics of these organisms will influence marine communities and ecosystems. Research to date has shown that exposure of echinoderms to solar UVR can, affect reproduction and development, change behaviour, cause numerous biochemical and physiological changes and potentially cause increased mutation rates, by causing DNA damage. There is also considerable evidence that echinoderms utilise several different mechanisms to protect themselves against excessive UVR and subsequent UVR-induced damage. However, these protective mechanisms may pose conflicting selection pressures on echinoderms, as UVR is an additional stressor in oceans subjected to anthropogenic-induced climate change. This review summarises our knowledge of the effects of UVR on the Echinodermata. We outline the research conducted to date, highlight key studies on UVR that have utilised echinoderms and look to the future of UVR research in a rapidly changing ocean.

Ecotoxicological effects of carbon nanomaterials on algae, fungi and plants.

The ecotoxicological effects of carbon nanomateriales (CNMs), namely fullerenes and carbon nanotubes, on algae, fungi and plants are analyzed. In different toxicity tests, both direct and indirect effects were found. The direct effects are determined by nanomaterial chemical composition and surface reactivity, which might catalyze redox reactions in contact with organic molecules and affect respiratory processes. Some indirect effects of carbon nanoparticles (CNPs) are physical restraints or release of toxic ions. Accumulation of CNPs in photosynthetic organs provokes obstruction in stomata, foliar heating and alteration in physiological processes. The phytotoxicity studies of CNMs should be focused on determining phytotoxicity mechanisms, size distribution of CNPs in solution, uptake and translocation of nanoparticles by plants, on characterization of their physical and chemical properties in rhizosphere and on root surfaces. More studies on plants and algae, as a part of food chain, are needed to understand profoundly the toxicity and health risks of CNMs as ecotoxicological stressors. Correct and detailed physical and chemical characterization of CNMs is very important to establish the exposure conditions matching the realistic ones. Ecotoxicity experiments should include examinations of both short and long-term effects. One must take into account that real carbon nanomaterials are complex mixtures of carbon forms and metal residues of variable chemistry and particle size, and the toxicity reported may reflect these byproducts/residues/impurities rather than the primary material structure. One more recommendation is not only to focus on the inherent toxicity of nanoparticles, but also consider their possible interactions with existing environmental contaminants.

Persistent organic pollutants in Antarctica: current and future research priorities.

As Antarctica's pivotal role in influencing global climate processes gains increasing attention so too does public and scientific interest in the general state of Antarctic ecosystem health as a function of multiple stressors, including contamination by anthropogenic chemicals. Persistent organic pollutant (POP) research internationally has sought to elucidate the impacts of an ever increasing diversity of POPs on the environment. The challenges of this research are compounded in the Antarctic context, by key gaps in historical data and our understanding of chemical behaviour in polar landscapes. In order to ensure maximum longevity and value of research outputs, efforts must be centred upon addressing these research gaps. Ultimately, Antarctic POP research will benefit from co-ordinated investment into spatially and temporally comprehensive research and monitoring efforts such as those responsible for the continued progress of this research field in the Arctic and other global regions.

Trends in the Application of "Omics" to Ecotoxicology and Stress Ecology.

Our ability to predict and assess how environmental changes such as pollution and climate change affect components of the Earth's biome is of paramount importance. This need positioned the fields of ecotoxicology and stress ecology at the center of environmental monitoring efforts. Advances in these interdisciplinary fields depend not only on conceptual leaps but also on technological advances and data integration. High-throughput "omics" technologies enabled the measurement of molecular changes at virtually all levels of an organism's biological organization and thus continue to influence how the impacts of stressors are understood. This bibliometric review describes literature trends (2000-2020) that indicate that more different stressors than species are studied each year but that only a few stressors have been studied in more than two phyla. At the same time, the molecular responses of a diverse set of non-model species have been investigated, but cross-species comparisons are still rare. While transcriptomics studies dominated until 2016, a shift towards proteomics and multiomics studies is apparent. There is now a wealth of data at functional omics levels from many phylogenetically diverse species. This review, therefore, addresses the question of how to integrate omics information across species.

Transcriptomics in ecotoxicology.

The emergence of analytical tools for high-throughput screening of biomolecules has revolutionized the way in which toxicologists explore the impact of chemicals or other stressors on organisms. One of the most developed and routinely applied high-throughput analysis approaches is transcriptomics, also often referred to as gene expression profiling. The transcriptome represents all RNA molecules, including the messenger RNA (mRNA), which constitutes the building blocks for translating DNA into amino acids to form proteins. The entirety of mRNA is a mirror of the genes that are actively expressed in a cell or an organism at a given time. This in turn allows one to deduce how organisms respond to changes in the external environment. In this article we explore how transcriptomics is currently applied in ecotoxicology and highlight challenges and trends.

Toxicity assessment and public policies: an urgent need for research.

The new European regulation on chemicals triggers a huge number of new testing. However, more than 2 years after the enforcement of this policy, toxicity assessment and risk assessment are still using single species tests that deliver little information. As it is often the case, the link between science and policy seems to be disrupted. However, policy makers need more than ever information on the fate and effects of chemicals on living systems. Without relevant knowledge for decision making, the application of the precautionary principle is the only reasonable way to manage risks. It is necessary to develop new risk assessment strategies using the last innovations from biology: the omics tools, ecology, ecosystem modeling, chemistry, and computing. This article highlights some of the recent trends in ecotoxicology and calls for a new research strategy. This strategy implies research to be funded by its users.

Micronucleus test in tadpole erythrocytes: Trends in studies and new paths.

The micronucleus test has been applied for more than three decades in tadpoles, generating an early warning of environmental quality. In this study, we reviewed 48 articles on the micronucleus test in tadpoles, published between 1987 and 2018. The findings reveal that pesticides have been the main topic discussed in the induction of micronucleus and other nuclear abnormalities in anuran larvae to the detriment of the widespread use of compounds used in agriculture. In addition to pesticides, a number of other xenobiotic agents have been targeted for genotoxic damage, such as heavy metals, radiation and wastewater. An appeal is reported to environmental contaminants, which when released naturally into the environment or because of human activities may contaminate aquatic habitats, threatening populations of tadpoles that depend on these environments for their survival. Larvae can bioaccumulate these contaminants that cause progressive impacts, ranging from DNA damage to metamorphosis delays, as well as malformations. We found that Argentina is the main driving force for the application of this test in anuran larvae along with Brazil. Different erythrocyte malformations have been reported for the erythrocyte nuclear abnormalities test, binucleated cells, nuclear buds, notched, lobed, reniform, nuclear bebbled, anucleated, picnotic and apoptotic cells are the most cited. In summary, the presence of chemical or physical agents, along with other disturbances of the habitat, can have a significant impact on the life history of the species, contributing to the decline of anuran populations.