Lethal, behavioral, growth and developmental toxicities of alkyl-PAHs and non-alkyl PAHs to early-life stage of brine shrimp, Artemia parthenogenetica

Is Fucus a suitable biomonitoring organism for polycyclic aromatic hydrocarbon contamination? A study from the Faroe Islands

To evaluate seaweed as a biomonitoring organism, Fucus was sampled in the Faroe Islands. Nineteen PAHs, including the EPA 16, and four groups of alkylated PAHs were quantified using GC-MS analysis of extracts obtained using a modified QuEchERS method with ultrasonication in acetonitrile, back-extraction into hexane, and Florisil® cleanup. Samples from the harbor of Tórshavn collected at high tide were the most polluted with PAH concentrations between 1.3 × 102 and 1.7 × 102 ng/g wet weight. All samples contained a factor 10 higher concentrations of alkylated PAHs compared to their parent compounds. These results suggest that Fucus might be suitable as a biomonitoring organism for PAH pollution. Differences between samples collected in close proximity and on different days were observed (same range of RSD 14-120% and 60-102%, respectively), suggesting that water exchange, tide levels, and direct exposure to surface diesel pollution have a strong influence on pollutant uptake in Fucus. The findings stress the need for further evaluation of the sampling strategy.

Ameliorative effects of Bifidobacterium longum peptide-1 on benzo(α)pyrene induced oxidative damages via daf-16 in Caenorhabditis elegans

Oxidative stress is implicated in numerous diseases, with benzo(α)pyrene (BaP) known for causing substantial oxidative damage. Bifidobacterium longum (B. longum) is recognized as an antioxidant bacterium for certain hosts, yet its influence on oxidative damages instigated by BaP remains undetermined. In our study, we introduced various strains of Caenorhabditis elegans (C. elegans) to BaP to trigger oxidative stress, subsequently treating them with different forms of B. longum to evaluate its protective effects. Additionally, we explored the role of daf-16 in this context. Our findings indicated that in wild-type N2 C. elegans, B. longum-even in the form of inactivated bacteria or bacterial ultrasonic lysates (BULs)-significantly extended lifespan. BaP exposure notably decreased lifespan, superoxide dismutase (SOD) activity, and motility, while simultaneously down-regulating the expression of reactive oxygen species (ROS)-associated genes (sod-3, sek-1, cat-1) and daf-16 downstream genes (sod-3, ctl-2). However, it significantly increased the ROS level, malondialdehyde (MDA) content, and lipofuscin accumulation and up-regulated another daf-16 downstream gene (clk-1) (P <0.05). Interestingly, when further treated with B. longum peptide-1 (BLP-1), opposite effects were observed, and all the aforementioned indices changed significantly. In the case of RNAi (daf-16) C. elegans, BaP exposure significantly shortened the lifespan (P <0.05), which was only slightly prolonged upon further treatment with BLP-1. Furthermore, the expression of daf-16 downstream genes showed minor alterations in RNAi C. elegans upon treatment with either BaP or BLP-1. In conclusion, our findings suggest that B. longum acts as a probiotic for C. elegans. BLP-1 was shown to safeguard C. elegans from numerous oxidative damages induced by BaP, but these protective effects were contingent upon the daf-16 gene.

Persistent organic pollutants (POPs) in marine crustaceans: Bioaccumulation, physiological and cellular responses

Persistent organic pollutants (POPs) are ubiquitous in marine ecosystems. These compounds can be accumulated in water, sediments and organisms, persist in time, and have toxic effects in human and wildlife. POPs can be uptaken and bioaccumulated by crustaceans, affecting different physiological processes, including energy metabolism, immunity, osmoregulation, excretion, growth, and reproduction. Nonetheless, animals have evolved sub-cellular mechanisms for detoxification and protection from chemical stress. POPs induce the activity of enzymes involved in xenobiotic metabolism and antioxidant systems, that in vertebrates are importantly regulated at gene expression (transcriptional) level. However, the activation and control of these enzyme systems upon the exposure to POPs have been scarcely studied in invertebrate species, including crustaceans. Herein, we summarize various aspects of the bioaccumulation of POPs in marine crustaceans and their physiological effects. We specially focus on the regulation of xenobiotics metabolism and antioxidant enzymes as key sub-cellular mechanisms for detoxification and protection from chemical stress.

Recent trends in polycyclic aromatic hydrocarbons pollution distribution and counteracting bio-remediation strategies

Polycyclic aromatic hydrocarbons (PAHs) are distributed worldwide due to long-term anthropogenic pollution sources. PAHs are recalcitrant and highly persistent in the environment due to their inherent properties, such as heterocyclic aromatic ring structures, thermostability, and hydrophobicity. They are highly toxic, carcinogenic, immunotoxic, teratogenic, and mutagenic to various life systems. This review focuses on the unique data of PAH sources, exposure routes, detection techniques, and harmful effects on the environment and human health. This review provides a comprehensive and systematic compilation of eco-friendly biological treatment solutions for PAH remediation, such as microbial remediation approaches utilizing microbial cultures. In situ and Ex situ bioremediation of PAH methods, including composting land farming, biopiles, bioreactors bioaugmentation, and phytoremediation processes, are discussed in detail, as is a summary of the factors affecting and limiting PAH bioremediation. This review provides an overview of emerging technologies that use multi-process combinatorial treatment approaches and answers to generating value-added by-products during PAH remediation.

Effects of diesel exhaust particles on the health and survival of the buff-tailed bumblebee Bombus terrestris after acute and chronic oral exposure

The diesel-powered transportation sector is a major producer of environmental pollution in the form of micro- and nanoscale diesel exhaust particles (DEP). Pollinators, such as wild bees, may inhale DEP or ingest it orally through plant nectar. However, if these insects are adversely affected by DEP is largely unknown. To investigate potential health threats of DEP to pollinators, we exposed individuals of Bombus terrestris to different concentrations of DEP. We analysed the polycyclic aromatic hydrocarbons (PAH) content of DEP since these are known to elicit adverse effects on invertebrates. We investigated the dose-dependent effects of those well-characterized DEP on survival and fat body content, as a proxy for the insects' health condition, in acute and chronic oral exposure experiments. Acute oral exposure to DEP showed no dose-dependent effects on survival or fat body content of B. terrestris. However, we could show dose-dependent effects after chronic oral exposure with high doses of DEP where significantly increased mortality was observed. Further, there was no dose-dependent effect of DEP on the fat body content after exposure. Our results give insights into how the accumulation of high concentrations of DEP e.g., near heavily trafficked sites, can influence insect pollinators' health and survival.

Benzo [a] pyrene-loaded aged polystyrene microplastics promote colonic barrier injury via oxidative stress-mediated notch signalling

The adsorption of toxic substances on polystyrene microplastics (PSMPs) can modify their biological toxicity and exacerbate the threat to human health. The effects of benzo [a] pyrene (B (a) P)-loaded aged PSMPs on colonic barrier integrity remains unclear. Here, we showed that binding environmentally relevant concentrations of B (a) P alteredl̥ the physicochemical features and markedly enhanced the toxicity of PSMPs. Compared to pristine PSMP, PSMP@B (a) P promoted colonic barrier degradation, body weight loss, colon length shortening, oxidative stress (OS), autophagy, inflammation, and bacterial translocation. Microplastic (MP) exposure induced injury to the colon barrier, including tight junction (TJ) and mucosal barriers, via overactivation of the Notch signalling pathway under increased OS in mice and intestinal organoids. Notably, PSMP@B (a) P exposure exacerbated damage to TJ and the mucosal barrier via the overproduction of reactive oxygen species (ROS), which could be related to the release of B (a) P from PSMP@B (a) P induced by the acidic environment of autophagosomes, which in turn exert synergistic toxic effects with PSMPs. Our study elucidates some of the potential molecular mechanisms by which B (a) P enhances PSMP-related intestinal toxicity, which provides a potential therapeutic approach for diseases caused by PSMP@B (a)P and PSMP pollution.

Emerging studies on oil pollution biomonitoring: A systematic review

In the last decade, several methods were applied to monitor the impact of oil pollution on marine organisms. Recent studies showed an eminent need to standardize these methods to produce comparable results. Here we present the first thorough systematic review of the literature on oil pollution monitoring methods in the last decade. The literature search resulted on 390 selected original articles, categorized according to the analytical method employed. Except for Ecosystem-level analyses, most methods are used on short-term studies. The combination of Biomarker and Bioaccumulation analysis is the most frequently adopted strategy for oil pollution biomonitoring, followed by Omic analyses. This systematic review describes the principles of the most frequently used monitoring tools, presents their advantages, limitations, and main findings and, as such, could be used as a guideline for future researches on the field.

Impacts of exhaust gas cleaning systems (EGCS) discharge waters on planktonic biological indicators

Exhaust Gas Cleaning Systems (EGCS), operating in open-loop mode, continuously release acidic effluents (scrubber waters) to marine waters. Furthermore, scrubber waters contain high concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and alkylated PAHs, potentially affecting the plankton in the receiving waters. Toxicity tests evidenced significant impairments in planktonic indicators after acute, early-life stage, and long-term exposures to scrubber water produced by a vessel operating with high sulphur fuel. Acute effects on bacterial bioluminescence (Aliivibrio fischeri), algal growth (Phaeodactylum tricornutum, Dunaliella tertiolecta), and copepod survival (Acartia tonsa) were evident at 10 % and 20 % scrubber water, while larval development in mussels (Mytilus galloprovincialis) showed a 50 % reduction at ∼5 % scrubber water. Conversely, larval development and reproductive success of A. tonsa were severely affected at scrubber water concentrations ≤1.1 %, indicating the risk of severe impacts on copepod populations which in turn may result in impairment of the whole food web.

Cumulative environmental risk assessment of metals and polycyclic aromatic hydrocarbons from ship activities in ports

Marine environmental risk assessments rarely consider the cumulative risk from multiple contaminants and sources. Ships give rise to a range of contaminants, originating from different onboard sources, resulting in contaminant loads to the marine environment. Here, the Ship Traffic Emission Assessment Model (STEAM), in combination with the hydrodynamic and chemical fate model MAMPEC, was used to calculate loads and predicted environmental concentrations (PECs) of metals and polycyclic aromatic hydrocarbons, in four ports. PECs were compared to the predicted no effect concentrations (PNEC) to assess environmental risk from the different onboard sources, both separately and cumulatively. The results show that three out of four ports were subject to unacceptable risk. This study highlights the importance of accounting for multiple contaminant sources when assessing the marine environmental risks of shipping and challenges the suitability of the proposed new international guidelines on how to assess risk of scrubber water discharge.

Molluscicidal Activity of Compounds From the Roots of Aralia armata Against the Golden Apple Snail (Pomacea canaliculata)

Background: Aralia armata (Araliaceae) is considered to exhibit effective molluscicidal activity, however, the relationship between the chemical components and molluscicidal activity has not been clearly elucidated. This research attempts to decipher these correlations among the 15 compounds isolated from Vietnam-grown A. armata roots against the freshwater snail, Pomacea canaliculata, a gastropod causing severe damage in agricultural production. Methods: Fifteen saponins were isolated from the methanol root extract of A. armata using chromatographic methods and were identified using spectroscopic techniques. The compounds were screened for molluscicidal activity against P. canaliculata, as well as toxicity against brine shrimp ( Artemia sp.) and phytotoxicity against rice germination and growth. Results: The saponin compounds exhibited extraordinary inhibition of P. canaliculata with LC50 values ranging from 7.90 to 17.50 µg/mL. Notably, the active compounds from A. armata exhibit safety for both nontarget aquatic animals, specifically Artemia sp. with LC50 values between 148.55 and 193.22 µg/mL, and the growth and development of Oryza sativa L. plants showed very little difference compared with the negative control . A molecular docking analysis indicated P. canaliculata acetylcholinesterase (PcAChE) and the actin-binding protein villin (PcVillin) to be potential biomolecular targets of the A. armata saponins. Conclusion: The present experimental and in silico data illustrate the potential of A. armata in agricultural applications.

Uptake of potentially toxic elements and polycyclic aromatic hydrocarbons from the hydromorphic soil and their cellular effects on the Phragmites australis

The current study provides an information on the combined effect of pollution with potentially toxic elements (PTEs) and polycyclic aromatic hydrocarbons (PAHs) in hydromorphic soils on the accumulation, growth, functional and morphological-anatomical changes of macrophyte plant, i.e., Phragmites australis Cav., as well as information about their bioindication status on the example of small rivers of the Azov basin. The territory of the lower reaches of the Kagalnik River is one of the small rivers of the Eastern Azov region was examined with different levels of PTEs contamination in soils, where the excess of the lithosphere clarkes and maximum permissible concentrations (MPC) for Mn, Cr, Zn, Pb, Cu, and Cd were found. The features of the 16 priority PAHs quantitative and qualitative composition in hydromorphic soils and P. australis were revealed. The influence of soil pollution on accumulation in P. australis, as well as changes in the morphological parameters were shown. It has been observed that morphometric changes in P. australis at sites experiencing the сontamination and salinity are reflected with the changes in the ultrastructure of plastids, mitochondria, and EPR elements of plant cells. PTEs accumulated in inactive organs and damaged cell structures. At the same time, PAHs penetrated through the biomembranes and violated their integrity, increased permeability, resulted cell disorganization, meristem, and conductive tissues of roots. The nature and extent of the structural alterations found are dependent on the type and extent of pollution in the examined regions and can be utilized as bioindicators for evaluating the degree of soil phytotoxicity characterized by the accumulation of PTE and PAHs.

Toxicity of nanoplastics to zooplankton is influenced by temperature, salinity, and natural particulate matter

Increases in temperature/salinity promote nanoplastics toxicity, while organic matter/natural colloids mitigate toxicity.

Metabolomic Studies for the Evaluation of Toxicity Induced by Environmental Toxicants on Model Organisms

Environmental pollution causes significant toxicity to ecosystems. Thus, acquiring a deeper understanding of the concentration of environmental pollutants in ecosystems and, clarifying their potential toxicities is of great significance. Environmental metabolomics is a powerful technique in investigating the effects of pollutants on living organisms in the environment. In this review, we cover the different aspects of the environmental metabolomics approach, which allows the acquisition of reliable data. A step-by-step procedure from sample preparation to data interpretation is also discussed. Additionally, other factors, including model organisms and various types of emerging environmental toxicants are discussed. Moreover, we cover the considerations for successful environmental metabolomics as well as the identification of toxic effects based on data interpretation in combination with phenotype assays. Finally, the effects induced by various types of environmental toxicants in model organisms based on the application of environmental metabolomics are also discussed.

Distinct metabolic alterations in different Caenorhabditis elegans mitochondrial mutants

Mitochondria play an essential role in various biochemical processes that maintain cellular homeostasis. Minor defects in the mitochondrial genome can lead to aversive behavioral responses in an organism. Nevertheless, little is known about the impact of mitochondrial mutations on the metabolome of Caenorhabditis elegans (C. elegans). In this study, an untargeted metabolomics approach was employed to elucidate the metabolic aberrant caused by mitochondrial DNA mutations in C. elegans. Specifically, three mutant strains of C. elegans, including clk-1, mev-1, and phb-2, were adopted to study corresponding metabolic signatures. Adult worms were collected, and metabolites were extracted and analyzed by gas chromatography-mass spectrometry. Uni- and multivariate analyses were performed to elucidate perturbed metabolism between wildtype worms and mutant strains, and metabolic differences among the mutants. The tricarboxylic acid cycle intermediates, amino acids, and sugars were significantly affected in the mitochondrial mutants. Overall, each mitochondrial DNA mutation exhibited a different pattern of metabolic alterations. The shift of metabolome appeared to be associated with the lifespan of C. elegans. In particular, clk-1 and mev-1 strains, which had the opposite phenotypes of lifespan, had apparently different metabolomes. Our findings set light on the metabolic consequences of mitochondrial genetic variants, which may help better understand mitochondrial disease mechanisms.