Despite intensive ecotoxicological research, we still know relatively little about the ecological impacts of many environmental contaminants. Filling these knowledge gaps is particularly important regarding amphibians, because they play significant roles in freshwater and terrestrial ecosystems, and their populations are declining worldwide. In this study, we investigated two pollutants that have been poorly studied in ecotoxicology despite their widespread occurrence in surface waters: the herbicide terbuthylazine and the pharmaceutical drug carbamazepine. We exposed two anuran species throughout their larval development to each of two environmentally relevant concentrations of each pollutant, and recorded mortality and 17 sub-lethal endpoints up to several months after exposure. Mortality was low and unrelated to treatment. In agile frogs (Rana dalmatina), we found that treatment with 0.3 μg/L terbuthylazine decreased tadpole activity and reduced fat bodies in juveniles, whereas treatment with 50 μg/L carbamazepine decreased spleen size and increased spleen pigmentation. In common toads (Bufo bufo), treatment with 0.003 μg/L terbuthylazine increased body mass at metamorphosis, treatment with 0.3 μg/L terbuthylazine increased the size of optic tecta, and treatment with 0.5 μg/L carbamazepine decreased hypothalamus size. Treatment with 50 μg/L carbamazepine reduced the feeding activity of toad tadpoles, decreased their production of anti-predatory bufadienolide toxins, and increased their body mass at metamorphosis; juvenile toads in this treatment group had reduced spleen pigmentation. Neither treatments affected the time to metamorphosis, post-metamorphic body mass, or sex ratios significantly. These results show that environmental levels of both terbuthylazine and carbamazepine can have several sub-lethal effects on anurans, which may be detrimental to individual fitness and population persistence in natural conditions. Our findings further highlight that toxic effects cannot be generalized between chemicals of similar structure, because the terbuthylazine effects we found do not conform with previously reported effects of atrazine, a related and extensively studied herbicide.

Underground coal fires start naturally or as a result of human activities. Besides burning away the important non-renewable energy resource and causing financial losses, burning coal seams emit carbon dioxide, carbon monoxide, sulfur oxide and methane, and is a leading cause of smog, acid rain, global warming, and air toxins. In the U.S. alone, the combined cost of coal-fire remediation projects that have been completed, budgeted, or projected by the U.S. Department of the Interior's Office of Surface Mining Remediation and Enforcement (OSM), exceeds $1 billion. It is estimated that these fires generate as much as 3% of the world's annual carbon dioxide emissions and consume as much as 5% of its minable coal. Considering the magnitude of environmental impact and economic loss caused by burning underground coal seams, we have developed a new, safe, reliable surface measurement of coal fire gases to assess the nature of underground coal fires. We use a drone mounted with gas sensors. Drone collected gas concentration data provides a safe alternative for evaluating the rank of a burning coal seam. In this study, a new method of determining coal rank by gas ratios is developed. Coal rank is valuable for defining parameters of a coal seam such as burn temperature, burn rate, and volume of burning seam.

The density-dependence of terrestrial plant–plant interactions in the presence of toxins has previously been explored using biodegradable compounds. We exposed barley and lettuce to four copper concentrations at four stand densities. We hypothesized that toxin effects would decrease and Cu uptake would increase at increasing plant densities. We analyzed toxin effects by (a) comparing plant biomasses and (b) using a recent regression model that has a separate parameter for the interaction of resource competition and toxin interference. Plant response to Cu was density-dependent in both experiments. Total Cu uptake by barley increased and the dose per plant decreased as plant density increased. This study is the first to demonstrate that plant density mediates plant response to metals in soil in a predictable way. This highlights the need to explore the mechanisms for and consequences of these effects, and to integrate the use of several plant densities into standard ecotoxicological testing.

Blubber samples of Indo-Pacific bottlenose (Tursiops aduncus) and spinner (Stenella longirostris) dolphins from Zanzibar, East Africa, were analyzed for a wide range of organohalogen compounds. Methoxylated polybrominated diphenyl ethers (MeO-BDEs), presumably biogenic, were found at higher concentrations than anthropogenic organochlorine pesticides (OCPs). Only traces of industrial pollutants, such as polychlorinated biphenyls, were detected. The OCP levels found off Zanzibar were lower than those reported from other regions while MeO-BDE levels were higher. The relative composition of the OCPs indicated recent use of lindane (γ-hexachlorocyclohexane) and aged residues of DDT and technical HCH. Placental transfer was estimated to 2.5% and 0.5% of the total burden of OCPs and MeO-BDEs, respectively. Overall transfer from mother to calf in Indo-Pacific bottlenose dolphins was estimated to 72% and 85% for the OCPs and MeO-BDEs burdens, respectively. Health effects of MeO-BDEs are not known, but structural similarities with well-known environmental toxins are cause for concern.

Gymnodimine A has been found in mollusks obtained along the whole northern coast of Spain from April 2017 to December 2019. This is the first time that this toxin is detected in mollusks from the Atlantic coast of Europe. The prevalence of the toxin was, in general, low, being detected on average in approximately 6% of the obtained samples (122 out of 1900). The concentrations recorded were also, in general, low, with a median of 1.3 μg kg⁻¹, and a maximum value of 23.93 μg kg⁻¹. The maxima of prevalence and concentration were not geographically coincident, taking place the first at the easternmost part of the sampled area and the second at the westernmost part. In most cases (>94%), gymnodimine A and 13-desmethyl spirolide C were concurrently detected, suggesting that Alexandrium ostenfeldii could be the responsible producer species. The existence of cases in which gymnodimine A was detected alone suggests also that a Karenia species could also be involved. The geographical heterogeneity of the distribution suggests that blooms of the producer species are mostly local. Not all bivalves are equally affected, clams being less affected than mussels, oysters, and razor clams. Due to their relatively low toxicity, and their low prevalence and concentration, it seems that these toxins do not pose an important risk for the mollusk consumers in the area.

Known as a cause of food poisoning, Bacillus cereus (B. cereus) is widespread in nature. Cereulide, the heat-stable and acid-resistant emetic toxin which is produced by some B. cereus strains, is often associated with foodborne outbreaks, and causes acute emetic toxicity at high dosage exposure. However, the toxicological effect and underlying mechanism caused by chronic low-dose cereulide exposure require to be further addressed. In the study, based on mouse model, cereulide exposure (50 μg/kg body weight) for 28 days induced intestinal inflammation, gut microbiota dysbiosis and food intake reduction. According to the cell models, low dose cereulide exposure disrupted the intestinal barrier function and caused intestinal inflammation, which were resulted from endoplasmic reticulum (ER) stress IRE1/XBP1/CHOP pathway activation to induce cell apoptosis and inflammatory cytokines production. For gut microbiota, cereulide decreased the abundances of Lactobacillus and Oscillospira. Furthermore, cereulide disordered the metabolisms of gut microbiota, which exhibited the inhibitions of butyrate and tryptophan. Interestingly, cereulide exposure also inhibited the tryptophan hydroxylase to produce the serotonin in the gut and brain, which might lead to depression-like food intake reduction. Butyrate supplementation (100 mg/kg body weight) significantly reduced intestinal inflammation and serotonin biosynthesis suppression caused by cereulide in mice. In conclusion, chronic cereulide exposure induced ER stress to cause intestinal inflammation, gut microbiota dysbiosis and serotonin biosynthesis suppression. IRE1 could be the therapeutic target and butyrate supplementation is the potential prevention strategy.

The townships of Puchuncaví and Quintero, on the coast of central Chile, have soils contaminated by atmospheric deposition of sulfur dioxide and trace elements from the nearby Ventanas Industrial Complex. The purpose of this study was to evaluate potential human health and ecological risks, by determining the spatial distribution of soil total concentrations arsenic (As), copper (Cu), lead (Pb), and zinc (Zn) in these townships. Total concentrations of these elements were determined in 245 topsoil samples, used to generate continuous distribution maps. The background concentrations of Cu, As, Pb, and Zn in the studied soils were 100, 16, 35, and 122 mg kg⁻¹, respectively. The concentrations of Cu, As, and Pb were positively correlated with each other, suggesting that their source is the Ventanas copper smelter. On the other hand, correlations for Zn were weaker than for other trace elements, suggesting low impact of the Ventanas copper smelter on spatial distribution of Zn. Indeed, only 6% of the study area exhibited Zn concentrations above the background level. In contrast, 77, 32 and 35% of the study area presented Cu, As, and Pb concentrations, respectively, above the background level. The carcinogenic risk due to exposure to As was above the threshold value of 10⁻⁰⁴ in the population of young children (1–5 years old) on 27% of the study area. These risk values are classified as unacceptable, which require specific intervention by the Chilean government. Based on the estimated concentrations of exchangeable Cu, 10, 15, and 75% of the study area exhibited high, medium, and low phytotoxicity risk, respectively.

Leachates from municipal landfills are formed as infiltration waters flowing through the landfill. They contain toxic, dissolved products of biochemical reactions taking place in the deposit. They cause soil and groundwater pollution. It is necessary to take them out of the landfill cover and utilize toxins contained therein, in particular heavy metals. Such processes are conducted with the use of microorganisms. Due to the content of toxic compounds, introducing leachates into the process of biological purification poses a threat to the microorganisms used in these processes.An alternative to microbial co-treatment of sludge and leachate as well as soil contaminated with communal leachate is to use red hybrid of California (Eisenia fetida Sav.), an earthworm resistant to environmental toxins, in particular heavy metals.The aim of the conducted research is to demonstrate the possibility of using red hybrid of California in leachate bioutilization as a complementary or alternative method to the process of leachate utilization with the use of microorganisms.The obtained results led to the conclusion that Eisenia fetida accumulates environmental toxins well. By collecting and processing them in the tissues, it remedies the substrate and retains long life and fertility, and the ability to reproduce. The research demonstrated high dynamics of population growth (from 25 individuals in the initial deposit to 298 individuals after six months of research). These properties are related to the presence of enzyme proteins from the metallothionein group in the gastrointestinal tract cells. Packing heavy metals found in leachates into the metallothionein coat limits their toxic effect on earthworm tissues, which confirms the possibility of using earthworms in the processes of detoxification of municipal leachate.

The present study introduces a mechanically robust, sealable SPME sampler for the on-site sampling and extraction of a wide range of untargeted pollutants in environmental waters. Spray-coating and dip coating methodologies were used to coat the surfaces of six stainless steel bolts with a layer of HLB/PAN particles, which served as the extractive substrate in the proposed device. In addition, this sampler was designed to withstand rough handling, long storage times, and various environmental conditions. In order to identify whether the sampler was able to stabilize extracted compounds for long periods of time, the effects of storage time and temperature were evaluated. The results of these tests showed no significant differences in the quantity and quality of the extracted chemicals following 12 days storage at room temperature, thus confirming the device's suitability for use at sampling sites that are far away from the laboratory facilities. The proposed device was also used to perform extraction and untargeted analyses of river waters in five different geographical locations. The constituent chemicals in the samplers were analyzed and determined using high-resolution HPLC-Orbitrap MS. Toxin and Toxin-Target Database was used as a reference database for toxins and environmental contaminants. Ultimately, over 80 tentative chemicals with widely varying hydrophobicities ranging within −2.43 < logP <11.9—including drugs, metabolites, wide ranges of toxins, pesticide, and insecticides—were identified in the samplers used in the different rivers. The log P values for the tentative analytes confirmed that the introduced device is suitable for the extraction and trace analysis of wide ranges of targeted and untargeted pollutants.