Ecotoxicology

Published by Springer Nature
Online ISSN: 1573-3017
Print ISSN: 0963-9292
Learn more about this page
Recent publications
Protein concentration [µg/mg of tissue ±SD] in the 4th and 5th larval stages and pupae (different big letters indicate significant differences between different groups with respect to the history of cadmium exposure; different small letters indicate significant differences between different groups with respect to the age of animals; *significant differences between different groups with respect to the starvation period; Kruskal–Wallis, p < 0.05, n = 6)
Carbohydrate concentration [µg/mg of tissue ±SD] in the 4th and 5th larval stages and pupae (description as in Fig. 1, Kruskal–Wallis test, p < 0.05)
Lipid concentration [µg/mg of tissue ±SD] in the 4th and 5th larval stages and pupae (description as in Fig. 1, Kruskal–Wallis test, p < 0.05)
Glycogen concentration [µg/mg of tissue ±SD] in the 4th and 5th larval stages and pupae (description as in Fig. 1, Kruskal–Wallis test, p < 0.05)
TAC [µmol/mg protein] and lipid peroxidation level [µM MDA/mg protein ±SD] in the 4th larval stage (description as in Fig. 1, Kruskal–Wallis test, p < 0.05, n = 5)
Different factors, such as starvation and metal exposure, may affect development and cause oxidative stress in insects. Some host plants may contain a high concentration of cadmium due to their hyperaccumulating property. The negative effects of metals and hunger may be manifested by low availability of energetic substrates. This study aimed to assess whether the insect population with a history of long metal exposure may better manage metal stress or/and starvation at different developmental stages, with the use of energetic substrates. Two strains of Spodoptera exigua model organism were tested: control strain and cadmium strain (treated continuously for over 200 generations with subtoxic amounts of cadmium). The effects of different factors, individually and in combination, on the tested strains were assessed, first by determining the body weight of larvae and pupae and then by estimating the concentration of biomolecules (proteins, carbohydrates, lipids, or glycogen) in the 4th and 5th larval stages and in pupae, and the total antioxidant capacity and lipid peroxidation level in the 4th larval stage. Compared to control strain, cadmium strain individuals exhibited changes in the concentration of soluble carbohydrates and protein. This was partly related to earlier 1-day starvation. In particular, changes in carbohydrate concentration seemed to be a sensitive biomarker of metal stress, independent of the age of individuals and period of starvation. However, the increase in the total antioxidant capacity and the concentration of lipid peroxidation products in the 4th larval stage under the effect of cadmium was dependent on strain origin.
 
Sunscreen use has increased in recent years, as sunscreen products minimize the damaging effects of solar radiation. Active ingredients called ultraviolet (UV) filters or UV agents, either organic or inorganic, responsible for defending skin tissue against harmful UV rays, are incorporated in sunscreen formulations. UV agents have a serious impact on many members of bio communities, and they are transferred to the environment either directly or indirectly. Many organic UV filters are found to be accumulated in marine environments because of high values of the octanol/water partition coefficient. However, due to the fact that UV agents are not stable in water, unwanted by-products may be formed. Experimental studies or field observations have shown that organic UV filters tend to bioaccumulate in various aquatic animals, such as corals, algae, arthropods, mollusks, echinoderms, marine vertebrates. This review was conducted in order to understand the effects of UV agents on both the environment and marine biota. In vivo and in vitro studies of UV filters show a wide range of adverse effects on the environment and exposed organisms. Coral bleaching receives considerable attention, but the scientific data identify potential toxicities of endocrine, neurologic, neoplastic and developmental pathways. However, more controlled environmental studies and long-term human use data are limited. Several jurisdictions have prohibited specific UV filters, but this does not adequately address the dichotomy of the benefits of photoprotection vs lack of eco-friendly, safe, and approved alternatives.
 
Sampling sites at Potter Peninsula, 25 de Mayo Island (King George Island), South Shetland Islands, Antarctica. A Carlini Station.and Peñón VII (pristine zone) are highlighted in red B Location of the Carlini´s buildings. Locations of sampling sites are highlighted in red. C Peñón VII area. D Supply area. E Electric power station area. F Fuel tanks area
The leaf of Deschampsia antarctica. General view: A Abaxial side. Section of the side with stomata. B Adaxial side. Face showing a lower number of stomata. C Detail of paracytic stoma. GC guard cells, LSC lateral subsidiary cell, N nucleus of the lateral subsidiary cell, FN filiform nucleus, SP stoma pore, TW thickened wall. Scale bar: A and B 20 µm, C 50 µm
Until not so long ago, Antarctica was considered to be a polar region practically pristine. The Antarctic Peninsula has the highest concentration of scientific stations from different countries. Anthropogenic activity has caused alterations in the Antarctic ecosystems directly affecting terrestrial vegetation. This fact requires the finding of biomarkers in native plants to estimate the effects of human impact. Deschampsia antarctica Desv. (Poaceae) is the unique native grass described so far for Antarctica and was used for multiple investigations. In this study, plants were collected on Carlini scientific station, 25 de Mayo (King George) Island, Potter Peninsula, South Shetland Islands. Thus, the main objective planned consists of the evaluation of leaf stomata-related parameters as pollution biomarkers. The results of the stomatic index (SI), density (SD), and area (SA) were shown at sites with different levels of human impact (close and far away from the scientific station). It was found that the correlation between SD and SI, on the adaxial side of the leaves, resulted in a good biomarker for estimating the degree of anthropogenic impact in each studied area. Graphical abstract
 
Typical LC–MS/MS multiple reaction monitoring chromatograms of sulfoxaflor A, X11719474 B, X11721061 C, X11519540 D, and carbendazim E in S. splendens nectar
The content of sulfoxaflor and its three metabolites and carbendazim in S. splendens samples: A Soil from soil application groups; B Leaf from soil application samples; C Nectar from sulfoxaflor soil applied S. splendens plant; D Nectar from sulfoxaflor foliar applied S. splendens plants
Sulfoxaflor is a new systemic insecticide developed as a replacement for older neonicotinoids which are known to be toxic to pollinators. However, its metabolism in nectar and effect on nectar biosynthesis have not been investigated. After soil and foliar application, sulfoxaflor and its main metabolites in soil, leaf and Salvia splendens nectar, were measured by liquid chromatography coupled with triple quadrupole mass spectrometer (LC-MS/MS). The chemical composition between the clean and sulfoxaflor spiked nectar were also compared. The activities of two possible sulfoxaflor detoxifying enzymes in S. splendens nectar, nitrile hydratase and glutathione-s-transferase, were measured by LC-MS and spectrophotometry. S. splendens nectar proteome was investigated by high-resolution orbitrap-based MS/MS to screen for sulfoxaflor detoxifying relevant proteins. S. splendens could absorb sulfoxaflor through root or leaf surface and secrete a proportion of sulfoxaflor along with its metabolites into the nectar. After soil application, sulfoxaflor’s low toxic metabolite X11719474 was dominant in the nectar and reached an average concentration of 8905 ppb. However, after foliar application, sulfoxaflor was dominant over its metabolites in the nectar. S. splendens nectar has no nitrile hydratase and glutathione-s-transferase activity and none of the 106 proteins identified in the nectar were predicted to function in detoxifying sulfoxaflor. Soil and foliar sulfoxaflor application can result in different profiles of sulfoxaflor and its metabolites presented in the nectar. However, sulfoxaflor had no effects on S. splendens nectar secretion and chemical composition and cannot be directly detoxified by components in the nectar.
 
Biomass variation of test organisms in the lethality assay
Average percentage of earthworm escape
Leachate toxicity using bioindicators such as microcrustaceans and earthworms has not been fully elucidated. These bioindicators are traditionally determined through physicochemical and microbiological analyses. The ecotoxicological assessment of leachate using indicator organisms from different environments is a technique to ensure the treatment and safe disposal of this effluent with minimum impact on human health and the environment. The current study aimed to evaluate the ecotoxicological responses of Daphnia magna and Eisenia andrei in landfill leachate, identifying which organism was more sensitive to this effluent. The leachate used in ecotoxicological tests was collected at the Campina Grande Sanitary Landfill (ASCG), Paraíba, Brazil. The leachate sample contained a high content of organic matter in the form of chemical oxygen demand (19496.86 mg.L⁻¹) and ammoniacal nitrogen (2198.00 mg.NL⁻¹), in addition to metals with carcinogenic potential, such as Cr (0.64 mg.L⁻¹) and Fe (1.16 mg.L⁻¹). The exposure of Daphnia magna to the leachate showed that the effluent is harmful to aquatic organisms, obtaining an EC 50, 48 h = 1.22%, FT of 128 and a TU of 81.96%. Among the contaminant concentrations tested in Eisenia andrei, 57% (59.28 mL.kg⁻¹) caused the highest lethality, causing the death of 21 earthworms within 72 hours of exposure. The avoidance test showed that exposure to leachate concentrations between 10.38 and 39.86 mL.kg⁻¹ led to the leakage of earthworms, and habitat loss was observed at a concentration of 55.80 mL.kg⁻¹, in which leak response (LR) ≥80% was obtained. This study demonstrates that the mentioned organisms are suitable for ecotoxicological tests in landfill leachate. Moreover, the microcrustacean Daphnia magna showed the most significant sensitivity, presenting a rapid ecotoxicological response to the leachate.
 
Radiation can cause the differential expression of biological miRNA molecules. This research was based on the development of the laboratory red crucian carp (LRCC) to explore the feasibility of its application in the detection of low-dose ionizing radiation-induced biological damage in aquatic environments and the development of related molecular markers. Adult LRCC were irradiated with caesium-137 at 0.3 Gy, while RNA-seq and bioinformatics techniques were used to identify miRNAs that were differentially expressed relative to their levels in the nonirradiation group. Analysis of liver sections showed that liver cells in the radiation group showed nuclear pyknosis. In this study, 34 miRNAs differentially expressed in the liver of LRCC after irradiation were identified, among which seven were new crucian carp miRNAs; a total of 632 target genes were predicted in the prediction analysis. The results of comprehensive GO enrichment and KEGG pathway analyses showed that these target genes were mainly involved in energy transfer and material catabolism, especially malonyl-CoA biosynthesis, acetyl-CoA carboxylase activity, fatty acid biosynthesis and metabolism, and pyruvate metabolism; in addition, the AMPK signalling pathway was the most active pathway. This study shows that the LRCC is sensitive to radiation, or can be used as a candidate experimental animal to study the biological effects of radiation, and the screened miRNA can be used as a pre-selected biomarker for radiation damage detection and radiation biological environmental monitoring. Clinical Trials Registration None.
 
Reference toxicant test results using artificial soil spiked with boric acid. Outliers, indicated by dots outside of the interquartile range of the boxplots, are included in the data. a Shoot lengths. b Root lengths. c Shoot dry weights. d Root dry weights. e Emergence rates
Results of shoot lengths when grown in the three different pairs of background: PHC-contaminated soils. Outliers, indicated by dots outside of the interquartile range of the boxplots, are included in the data. a GIBG and 018X—coarse-grained. b MEBG and BAT3—fine-grained. c BIBG and BIT5—fine-grained
Results of shoot dry weights when grown in the three different pairs of background and PHC-contaminated soils. Outliers, indicated by dots outside of the interquartile range of the boxplots, are included in the data. a GIBG and 018X—coarse-grained. b MEBG and BAT3—fine-grained. c BIBG and BIT5—fine-grained
Results of root length when grown in the three different pairs of background and PHC-contaminated soils. Outliers, indicated by dots outside of the interquartile range of the boxplots, are included in the data. a GIBG and 018X—coarse-grained. b MEBG and BAT3—fine-grained. c BIBG and BIT5—fine-grained
Results of root dry weights when grown in the three different pairs of background and PHC-contaminated soils. Outliers, indicated by dots outside of the interquartile range of the boxplots, are included in the data. a GIBG and 018X—coarse-grained. b MEBG and BAT3—fine-grained. c BIBG and BIT5—fine-grained
Remedial guidelines for petroleum hydrocarbons (PHCs) in soil aid in the mitigation of risks to human health and the environmental. However, some remediation guidelines may overestimate the potential for adverse effects to native plant species, contributing to unnecessary remedial efforts in attempts to meet the guidelines. At sites where PHC-contaminated soils undergo weathering, some PHCs may persist but with decreased bioavailability to organisms. In this study, the toxicity of both coarse and fine-grained subarctic soils, contaminated with weathered PHCs were assessed using five native plant species (Picea mariana, Achillea millefolium, Alnus viridis, Elymus trachycaulus and Salix bebbiana). Soil toxicity tests were conducted in a growth chamber with parameters set to simulate the site’s subarctic climate conditions. Reference toxicant tests using boric acid were conducted to provide confidence in the interpretation of the results for the PHC-contaminated soils, and also provide new information on the sensitivities of the four boreal species to boric acid. All plants exhibited reduced growth and germination rates as boric acid concentrations increased. Despite exceeding the Canada-wide standard guidelines for Fraction 3 PHCs, field-collected contaminated soils had no significant negative impacts on the growth (i.e., length, dry weight and emergence) of any of the plant species tested.
 
Graphic description of integrating rice microarray and co-expression network analysis in rice plants. a Identification of genes activated in DNA repair pathways, based on KEGG analysis, and analysis of expression profiles of genes activated in DNA repair pathways in rice seedlings under Cr(VI) stress with or without exogenous Pro by rice microarray analysis; (b) construction of co-expression network modules of genes activated in DNA repair pathways by the STRING program, and estimation of the effect of exogenous Pro on the key DNA repair pathways, based on gene expression variation factors (GEVFs)
Construction of co-expression network modules of genes activated in DNA repair pathways in rice plants by the STRING program
Expression profiles of genes activated in DNA repair pathways in rice under (a) Cr(VI) and (b) “Pro+Cr(VI)” treatments using heat-map representation. Red color refers to up-regulation, whereas blue color represents down-regulation. White color indicates the average expression level
The detailed information of GEVFs and similarity comparison of genes in the selected modules in responses to Cr exposure. Module 1 is (4a), Module 2 is (4b) and Module 3 is (4c). *The GEVFs of genes (LOC_Os03g10780.1, LOC_Os12g31370.1, LOC_Os02g53680.1, LOC_Os03g19190.1 and LOC_Os09g32450.1) in Module 1 of rice roots are expressed as ×10⁻¹. The GEVFs of genes (LOC_Os02g35450.1 and LOC_Os04g43300.1) in Module 1 of rice shoots are expressed as ×10⁻¹
Illustration of gene expression regulatory network involved in Pro-mediated modulation on DNA repair pathway in rice seedlings under chromium stress
Chromium (Cr) pollution can cause an oxidative burst in plants. The application of exogenous proline (Pro) is one of the most effective approaches to improve the tolerance of plants to Cr stress. In this study, we integrated the data of gene chip with co-expression network analysis to identify the key pathways involved in the DNA repair process in rice seedlings under Cr(VI) stress. Based on KEGG pathway analysis, 158 identified genes are activated in five different types of DNA repair pathways, namely base excision repair (BER, 20 genes), mismatch repair (MMR, 30 genes), nonhomologous end joining (NHEJ, 8 genes), nucleotide excision repair (NER, 56 genes) and homologous recombination (HR, 44 genes). Co-expression network analysis showed that genes activated in DNA repair pathways were categorized into six different modules, wherein Module 1 (45.36%), Module 2 (27.84%) and Module 3 (19.59%) carried the dominant weight than others. Gene chip and co-expression network analysis indicated that coordinated actions of HR and NER pathways are mainly associated with DNA repair processes in Cr(VI)-treated rice seedlings supplied with exogenous Pro. OsCSB, OsXPG, OsBRIP1, OsRAD51C, OsRAD51A2, OsRPA, OsTOPBP1C, OsTOP3, and OsXRCC3 activated in the HR pathway carried more weight in repairing DNA damage induced by Cr(VI) stress in rice seedlings supplied with exogenous Pro, while OsXPB1, OsTTDA2, OsTFIIH1, OsXPC, OsRAD23, OsDSS1, and OsRPA located at the NER pathway showed more contribution to repairing DNA damage than others.
 
Weekly average height of plant (A) and new plants (B) of Eleocharis palustris exposed to seven concentrations of crude oil during May 2020 to January 2021. *Treatment means with statistical significant differences (Duncan, p < 0.05, n = 4)
Weekly values of the Physiological Hormesis Index (PHI) due to exposure to seven concentrations of crude oil on the growth of Eleocharis palustris. Plant height (A) and new plants (B). *Treatment means with statistical significant differences (Duncan, p < 0.05, n = 4). PHI ≥ 1 indicates hormesis
Physiological hormesis index for number of primary roots (NPR), root dry matter (RDM), aerial dry matter (ADM), and total TPHI of Eleocharis palustris exposed to seven concentrations of crude oil during May 2020 to January 2021. *Treatment means with statistical significant differences (Duncan, p < 0.05, n = 4)
Microbiological hormesis index for populations of microalgae (Mi), fungi (TF), actinomycetes (ACT), Pseudomonas spp (PsB) (A), and hydrocarbonoclastic bacteria (HB) (B). Total microbiological hormetic index (TMHI) (B) for the rhizosphere of Eleocharis palustris exposed to seven concentrations of crude oil during May 2020 to January 2021. *Treatment means with statistical significant differences (Duncan, p < 0.05, n = 4)
Removal of total petroleum hydrocarbons from soil contaminated during May 2020 to January 2021. A Effect of crude oil concentration, and B Technology type effect. *Treatment means with statistical significant differences (Duncan, p < 0.05, n = 4)
Soil contamination with petroleum hydrocarbons affects plants and rhizospheric microorganisms. Microbial activity participates in important biochemical processes that stimulate, together with plants, the modification of toxic compounds for organisms. A nine-month experiment was set up to study the effect over time of oil on plant height (cm), formation of new plants, plant matter production (gravimetry), and population of rhizospheric microorganisms (serial dilution) in the sedge Eleocharis palustris. Removal of total petroleum hydrocarbons (soxhlet and gravimetry) from the soil was also evaluated. The means of the evaluated variables registered significant statistical differences (Duncan, p < 0.05) regarding the age of the plant and the amount of crude oil. There was a high correlation between oil and plant height (0.848) and with new plants (0.994). 60 mg oil dose promoted the greatest statistical difference in the amounts of roots and plant biomass (p < 0.05). E. palustris exposed to 60 and 75 mg of oil stimulated high densities of microalgae, actinomycetes, fungi, hydrocarbonoclastic bacteria and Pseudomonas spp; the overall ratio was 2:1 relative to natural attenuation. Plant and microorganism variables evaluated registered physiological and microbiological hormetic indices ≥1, showing a positive linear relationship. Natural attenuation was more efficient in removing crude oil. We conclude that E. palustris is tolerant to oil exposure. It is suggested to combine it with natural attenuation for the optimization of soils contaminated with crude oil.
 
The exposure of animals to toxicants may cause a depletion in the energy uptake, which compromises reproduction and growth. Although both parameters are ecologically relevant, they usually need long-term bioassays. This is a handicap for the availability of toxicological data for environmental risk assessment. Short-term bioassays conducted with environmental concentrations, and using relevant ecological parameters sensitive to short-term exposures, such as behavior, could be a good alternative. Therefore, to include this parameter in the risk assessment procedures, it is relevant the comparison of its sensitivity with that of growth and reproduction bioassays. The study aim was the assessment of differences between endpoints based on mortality, behaviour, reproduction, and growth for the toxicity of metals on aquatic animals. We used the ECOTOX database to gather data to construct chemical toxicity distribution (CTD) curves. The mean concentrations, the mean exposure time, and the ratio between the mean concentration and the exposure time were compared among endpoints. Our results showed that behavioral, growth, and reproduction bioassays presented similar sensitivity. The shortest exposure was found in behavioral and reproduction bioassays. In general, the amount of toxicant used per time was lower in growth and reproduction bioassays than in behavioral and mortality bioassays. We can conclude that, for metal toxicity, behavioral bioassays are less time-consuming than growth bioassays. As the sensitivity of behavior was similar to that of growth and reproduction, this endpoint could be a better alternative to longer bioassays.
 
The use of insecticides to control undesirable pest species in forestry has undergone a shift from broad spectrum to narrow spectrum insecticides to reduce the risk of effects on non-target species. However, there is still risk of direct effects on non-target species as some insecticides function as hormone mimics, or through indirect pathways as the insecticide is broken down in the environment. Tebufenozide, an ecdysone hormone mimic, is the active ingredient in insecticides used in a variety of large scale pest control programs. An oft cited reason for the safety of Tebufenozide is that it is rapidly broken down in the environment by microbes. We investigated the potential non-target effects of two Tebufenozide formulations used in Canada, Mimic 240LV and Limit 240, on aquatic communities using an outdoor mesocosm experiment. We focus on direct effects on amphibian larvae (wood frog, Rana sylvaticus ), zooplankton communities, and effects on biofilm and phytoplanktonic microbial communities that could arise from either direct toxicity, or from breaking down the insecticide as a nutrient and/or carbon source. There was limited evidence for direct effects on amphibian larvae or zooplankton communities. There were small but non-significant shifts in biofilm microbial communities responsible for nutrient cycling. Beta diversity in the plankton community was slightly higher among tanks treated with insecticide indicating a community dispersion/disbiosis effect. Overall, we found limited evidence of negative effects, however, subtle changes to microbial communities did occur and could indicate changes to ecosystem function.
 
Highly persistent perfluorooctane sulfonate (PFOS) is an industrial fluorinated organic chemical with significant bioaccumulation and biomagnification properties. The purpose of this study was to determine the toxic effects of sublethal PFOS on the aquatic invertebrate organism, narrow-clawed crayfish [Astacus leptodactylus Eschscholtz, 1823]. The 96 h LC50 value was determined as 48.81 mg/L (34.19–63.68 mg/L) with probit analysis. The sublethal experimental design was formed into four groups solvent control (DMSO, dimethyl sulphoxide), non-treated control group, and 1/10 (5 mg/L) and 1/100 (0.5 mg/L) of 96 h LC50 of PFOS, and crayfish were exposed for 48 h, 7 d, and 21 d under laboratory conditions. Total haemocyte counts (THCs) decreased, while the haemolymph total antioxidant status (TAS) values increased (p < 0.05) after exposure to 0.5 and 5 mg/L PFOS for 48 h, 7 d, and 21 d. Haemolymph total oxidative stress (TOS) levels significantly increased at 5 mg/L PFOS concentration (p < 0.05). Catalase (CAT) activities increased at both concentrations after 48 h and 7 d and then returned to control levels after 21 d; whereas superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities did not change in muscle tissue (p > 0.05). GPX and CAT activities decreased, but SOD activity increased in hepatopancreas tissue (p < 0.05). SOD activity at both concentrations and CAT activity at 5 mg/L PFOS exposure decreased in gill tissue, while GPX activity increased at both concentrations of 48 h and 7 d and returned to control values on day 21 of exposure. Histopathological alterations were detected in hepatopancreas and gill tissues. Lamellar deformations, epithelial hyperplasia, and haemocytic infiltrations were observed in the gill tissues, whereas tubular degeneration, tubule loss, necrosis, and lesions in the hepatopancreas tissues were the major recorded alterations. As a result, the sublethal concentrations of PFOS have toxic effects on crayfish and histologically cause tissue damage. Our findings also support a better understanding of the early toxicological effects of PFOS in freshwater ecosystems. Also, it could be concluded that A. leptodactylus is a reliable model for examining histopathological alterations and differences in enzyme activities together with the haemolymph findings in toxicology studies amid aquatic species.
 
Glyphosate herbicide is widely used in worldwide crop production. Consequently, its active ingredient, surfactants, and adjuvants commonly reach the aquatic ecosystem, thereby harming the biota. An investigation into how this herbicide affects aquatic species is important, especially in fish, as they have the ability to absorb and concentrate toxins. We aimed to evaluate the effects of glyphosate on the embryonic, larval and adult stages of zebrafish (Danio rerio), an appreciable organismal model. In this sense, we performed a meta-analysis using published articles from online databases (PubMed and ScienceDirect), which covered studies published until 2022. From a massive compilation of studies evaluating the effects of active substance glyphosate and Glyphosate-Based Herbicides (GBH) on zebrafish, we selected 36 studies used in downstream analyses. Overall, we report that glyphosate affects developmental stages and demonstrates toxicity and damage in zebrafish. We observed that embryos exposed to glyphosate exhibit increased mortality. There was also an increase in the number of morphological abnormalities related to yolk sac oedema, pericardial oedema, spinal curvature and body malformations, and a decrease in body size was observed. Furthermore, there was a decrease in the number of beats. The biochemical results demonstrated an increase in reactive oxygen species and antioxidant capacity against peroxyl radicals in the gills. The literature shows that glyphosate decreased the distance covered and the mean speed of the animals and increased the number of rotations. We concluded that glyphosate causes damage in the embryonic, larval and adult stages of this species. These results are valid for zebrafish and can be applied to other freshwater fish species. Graphical abstract
 
Scanning electron microscopy of gills of Astyanax lacustris exposed to different concentrations of metformin. a, b Control, c, d 50 µg/L, e, f 100 µg/L and g, h 1000 μg/L. PL primary lamellae, SL secondary lamellae, MD microridges, PLH primary lamella hypertrophy, SLH secondary lamella hypertrophy. Bars: 50 µm
Scanning electron microscopy of Astyanax lacustris gills exposed to the highest concentration of metformin. a–h PLH primary lamella hypertrophy, SLH secondary lamella hypertrophy, SLF secondary lamella fusion, PLF primary lamella fusion, MD microridges. Bars: a, b, d, e = 50 µm; c = 25 µm; f = 15 µm; h = 5 µm
Photomicrograph of Astyanax lacustris gills exposed to different concentrations of metformin and stained with hematoxylin and eosin. A Control, B, C, D, E, H 10,000 μg/L, F 100 μg/L, G 50 μg/L. PL primary lamellae, SL secondary lamellae, T Telangiectasia, B bleeding, E edema, PLF primary lamella fusion, SLF secondary lamella fusion, V vacuolization, HY hyperplasia. Bars: 50 µm
Graphs demonstrating the mean values of change (M.V.C.) of alterations in the gills of Astyanax lacustris gills in relation to metformin concentration. A hyperplasia, B lamellar fusion, C Telangiectasia, p < 0.05 when compared to the control group
The antidiabetic drug metformin is widely prescribed and found in different concentrations in the environment around the world, raising concern about potential impacts on aquatic life. Analyses of the effects of exposure of biological models to aquatic contaminants are important for assessing pollution effects on fish health. The gills of fishes represent primary targets of disturbance by pollutants, mainly because of the large surface of the respiratory epithelium and the high perfusion rate, which both help the entry of pollutants into this tissue. In this context, the aim of this work was to use gill histological analyses biomarkers to evaluate the toxicity of metformin on aquatic environmental systems, by means of chronic exposure for 90 days of Astyanax lacustris (lambari), an ecologically important neotropical species that can be used as an environmental bioindicator. Histopathological analyses were performed using Light and Scanning Electron Microscopy. The main changes were lamellar fusion, telangiectasia hyperplasia and disappearance of microridges. The morphological changes observed possibly interfere with the gill physiology, indicating an unfavorable situation to the presence of metformin in the water, pointing to a concern that metformin may pose a risk to Astyanax lacustris and likely to other fish species, compromising the dynamics of the aquatic ecosystem as a whole. Graphical abstract
 
This study investigated the changes in the sinking rates and physiochemical characteristics of the planktonic marine diatom, Thalassiosira pseudonana, caused by 72 h exposure to antifouling agent tributyltin (TBT) at 1.0 µg L⁻¹ (72-h 10% effective concentration for growth rate, EC10), and 1.7 µg L⁻¹ (EC50). After 72 h of exposure, the sinking rates of T. pseudonana cells were changed from 0.13–0.08 m day⁻¹ in the control, 0.08–0.05 m day⁻¹ in the EC10 treatment, and 0.04–0.006 m day⁻¹ in the EC50 treatment. The results revealed that the sinking rate of T. pseudonana decreased significantly compared with the control at 48 h in the EC10 treatment group and at 24, 48, and 72 h in the EC50 treatment group. The photosynthetic performance index on an absorption basis and the maximum quantum yields of photosystem II also decreased significantly (P < 0.05) in the TBT treatments compared with the control. There was a significant (P < 0.05) positive correlation between sinking rates and cellular protein contents (ng cell⁻¹). Changes in the biochemical and physiochemical composition of the cells suggest that interference with photosynthetic processes by TBT may have reduced their specific gravity and thereby caused a decrease in the sinking rates of T. pseudonana. The results of this investigation suggest the importance of considering the effects of pollutants on the sinking behaviors of diatoms when evaluating the adverse effects of pollutants on marine primary production.
 
Spearman's rank correlation coefficients, r s (−1 ≥ r s ≥ +1), between gene expressions (current study) and data published in Jantawongsri et al. (2021), i.e., biometrics, Pb concentrations in organs and blood, and histology (severity of lesion in organs, gill mucous
Old lead–zinc (Pb–Zn) mining sites in Greenland have increased the environmental concentration of Pb in local marine organisms, including the shorthorn sculpin. Organ metal concentrations and histopathology have been used in environmental monitoring programs to evaluate metal exposure and subsequent effects in shorthorn sculpins. So far, no study has reported the impact of heavy metals on gene expression involved in metal-related stress and immune responses in sculpins. The aim of this study was to investigate the effect of exposure to environmentally relevant waterborne Pb (0.73 ± 0.35 μg/L) on hepatic gene expression of metallothionein ( mt ), immunoglobulin M ( igm ), and microRNAs (miRNAs; mir132 and mir155 ) associated with immune responses in the shorthorn sculpin compared to a control group. The mt and igm expression were upregulated in the Pb-exposed group compared to the control group. The transcripts of mir132 and mir155 were not different in sculpins between the Pb-exposed and control group; however, miRNA levels were significantly correlated with Pb liver concentrations. Furthermore, there was a positive correlation between liver Pb concentrations and igm , and a positive relationship between igm and mir155 . The results indicate that exposure to Pb similar to those concentrations reported in in marine waters around Greenland Pb–Zn mine sites influences the mt and immune responses in shorthorn sculpins. This is the first study to identify candidate molecular markers in the shorthorn sculpins exposed to waterborne environmentally relevant Pb suggesting mt and igm as potential molecular markers of exposure to be applied in future assessments of the marine environment near Arctic mining sites.
 
A Concentration (mg/L) of Ytterbium (Yb³⁺) under abiotic and biotic conditions after the supplementation (T0) and after 96 h (T96h) of exposure in the media of ZF4 cells. B percentage of nominal concentration considering all tested conditions under abiotic and biotic conditions after the supplementation (T0) and after 96 h (T96h) of exposure in the media regardless of Lanthanides, Lanthanides concentration (alone or in mixtures) and cell lines. Data are expressed as the mean ± one standard deviation (n = 3) per condition
Dose-response curves for the viability of ZF4 cells exposed for 24–96 h to Neodymium (A), Gadolinium (B) and Ytterbium (C) at nominal concentrations ranging from 0.5 to 3000 µM. Data are expressed as the mean ± one standard deviation (n = 3) per condition
A Three-dimensional response surface plot (3D) showing the combined effect of the Neodymium (Nd³⁺) and Ytterbium (Yb³⁺) mixtures on the viability of ZF4 cells after 96 h of exposure; B Two-dimensional level contour plots (2D), i.e., isobologram showing the relationship between combinations of Neodymium (Nd³⁺) and Ytterbium (Yb³⁺) concentrations to attain predetermined values of ZF4 cell viability after 96 h of exposure (print in color)
The growing use of Lanthanides in new technologies has increased their anthropogenic releases into the aquatic environment over the last decades. However, knowledge on their ecotoxicological impacts is still incomplete, especially with regard to biological effects of Lanthanides mixtures and the possible regular variation in toxicity along the Lanthanides series. The present study evaluated the individual toxicity of all Lanthanides and the toxicity of mixtures of three of them, namely Neodymium (Nd3+), Gadolinium (Gd3+), and Ytterbium (Yb3+) on Danio rerio fibroblast-like cells (ZF4). Individual and mixtures toxicity of Neodymium (Nd3+) and Ytterbium (Yb3+) were also assessed on Danio rerio hepatic cells (ZFL) and Oncorhynchus mykiss epithelial cells (RTgill-W1). The measured Lanthanide concentrations were close to the nominal ones in the culture media of ZF4, ZFL, and RTgill-W1 cells (85–99%). A toxic impact was observed on the three fish cell lines exposed to all Lanthanides tested individually. RTgill-W1 appeared as the less sensitive cells, compared to the two others. Four Lanthanides, Erbium (Er3+), Thulium (Tm3+), Ytterbium (Yb3+) and Lutetium (Lu3+) showed a higher toxicity than the others on ZF4 cells but no correlation could be established between the toxicity of Lanthanides and the order of the elements within the Lanthanides series. Exposures to binary mixtures highlighted the presence of synergistic effects on cell viability for all cell lines.
 
Perfluoroalkyl substances (PFAS) are highly persistent organic pollutants that have been detected in a wide array of environmental matrices and, in turn, diverse biota including humans and wildlife wherein they have been associated with a multitude of toxic, and otherwise adverse effects, including ecosystem impacts. In the present study, we developed a toxicity assay for embryonic stages of mahi-mahi (Coryphaena hippurus), as an environmentally relevant pelagic fish species, and applied this assay to the evaluation of the toxicity of “legacy” and “next-generation” PFAS including, respectively, perfluorooctanoic acid (PFOA) and several perfluoroethercarboxylic acids (PFECA). Acute embryotoxicity, in the form of lethality, was measured for all five PFAS toward mahi-mahi embryos with median lethal concentrations (LC50) in the micromolar range. Consistent with studies in other similar model systems, and specifically the zebrafish, embryotoxicity in mahi-mahi generally (1) correlated with fluoroalkyl/fluoroether chain length and hydrophobicity, i.e., log P, of PFAS, and thus, aligned with a role of uptake in the relative toxicity; and (2) increased with continuous exposure, suggesting a possible role of development stage specifically including a contribution of hatching (and loss of protective chorion) and/or differentiation of target systems (e.g., liver). Compared to prior studies in the zebrafish embryo model, mahi-mahi was significantly more sensitive to PFAS which may be related to differences in either exposure conditions (e.g., salinity) and uptake, or possibly differential susceptibility of relevant targets, for the two species. Moreover, when considered in the context of the previously reported concentration of PFAS within upper sea surface layers, and co-localization of buoyant eggs (i.e., embryos) and other early development stages (i.e., larvae, juveniles) of pelagic fish species to the sea surface, the observed toxicity potentially aligns with environmentally relevant concentrations in these marine systems. Thus, impacts on ecosystems including, in particular, population recruitment are a possibility. The present study is the first to demonstrate embryotoxicity of PFAS in a pelagic marine fish species, and suggests that mahi-mahi represents a potentially informative, and moreover, environmentally relevant, ecotoxicological model for PFAS in marine systems.
 
Location of sampling sites, mercury deposition, and mercury blood concentrations. A Location of alligator sampling sites in North Carolina are indicated with an orange-colored circle, and the site of sampling on the St Johns River is indicated with a blue circle. Location of the Mercury Deposition Network sampling sites are indicated with yellow icons. B Shown is the average weekly mercury deposition in precipitation recorded from the Mercury Deposition Network site NC08 at Lake Waccamaw (orange), and Florida Everglades site FL11 (blue) and Chassahowitzka National Wildlife Refuge site FL05 (dark gray) C Mean total mercury blood concentrations (ng/g) from alligators sampled from the Cape Fear River (n = 13), Lake Waccamaw (n = 31), and the St Johns River (n = 24). Shown are the results from Kruskal-Wallis test and Dunn’s multiple comparison test of log10 transformed concentration data from each site
Mercury (Hg) is a widespread and harmful persistent pollutant of aquatic ecosystems. Except for the northern most populations of American alligators (Alligator Mississippiensis) found in North Carolina, the potential adverse health impacts of Hg on ecosystems and humans consuming alligator meat have been studied for over three decades. Now that alligators are being recreationally hunted and consumed across their range, it is especially important to monitor toxic contaminant levels to best understand possible adverse impacts of exposures on alligator populations and human health. In this study, we determined blood Hg concentrations in American alligators from an urbanized site in Wilmington, NC, a nearby site at Lake Waccamaw, NC, and a site on the St Johns River in Florida. Median blood total Hg (tHg) concentrations were particularly high at Lake Waccamaw (526 ng/g, range 152–946 ng/g), resulting in median muscle concentrations (0.48 mg/kg, range 0.13–0.88 mg/kg) well above US EPA screening values for fish consumption. Median concentrations at the Wilmington site (69 ng/g, range 22–336 ng/g) were generally low, and Hg concentrations from the St Johns River site (143 ng/g, range 54–244 ng/g) were comparable to those reported in previous studies. Analysis of relationships between tHg concentrations and a panel of blood chemistry biomarkers found only modest concentration-dependent impact on biomarkers of renal function. The results of this study reveal that local environmental factors greatly impact Hg bioaccumulation in alligators, findings that reaffirm local contaminant biomonitoring in alligator populations will be critical for affective management and determination of guidelines for safe consumption of harvested alligators.
 
Abundance of Brook trout TPM normalized transcripts for the genes comp52303 (A) which codes for bhmt which is a liver protein that aids in osmoregulation as well as adaptation to saline exposures. Upon exposure to increasing salinity, expression of this gene decreases to acclimate to the new conditions. Comp56617 (B) coding for the protein stt3b is not characterized but another isoform stt3a confers adaptation to saline environments in Arabidopsis. comp55102 and comp55667 (C) (Vitellogenin; vtg) as well as comp57790 and comp57791 (D) representing zona pellucida glycoprotein 3a (zp3a.2) across the three watershed conditions from sampled trout livers. Within this study, three watershed conditions were present including undeveloped (N = 4) with no wellpad (NWP) and no fracking (NFR), partially developed (N = 3) including a developed wellpad (WP) but no active fracking (NFR), and fully developed (N = 5) with a wellpad (WP) and active fracking (FR). Each gene was differentially expressed (DE) (BH adjusted p < 0.05) and upregulated in the fully developed (WP.FR) state when compared to both the undeveloped and partially developed states. Error bars represent standard error of the TPM abundance values across all streams in the watershed state
Unconventional natural gas development (fracking) has been a rapidly expanding technique used for the extraction of natural gas from the Marcellus Shale formation in Pennsylvania. There remains a knowledge gap regarding the ecological impacts of fracking, especially regarding the long-term health of native Brook trout (Salvelinus fontinalis) populations. During the summer of 2015, Brook trout were sampled from twelve streams located in forested, northwestern Pennsylvania in order to evaluate the impacts of fracking on Brook trout. Four stream sites were undisturbed (no fracking activity), three had a developed well pad without fracking activity, and five had active fracking with natural gas production. Liver tissue was isolated from two to five fish per stream and underwent RNA-Seq analysis to identify differentially expressed genes between ecosystems with differing fracking status. Data were analyzed individually and with samples pooled within-stream to account for hierarchical data structure and variation in sample coverage within streams. Differentially expressed and differentially alternatively spliced genes had functions related to lipid and steroid metabolism, mRNA processing, RNA polymerase and protein regulation. Unique to our study, genes related to xenobiotic and stress responses were found as well as potential markers for endocrine disruption and saline adaptation that were identified in watersheds with active fracking activity. These results support the utility of RNA-Seq to assess trout health and suggest detrimental impacts of fracking on sensitive trout populations.
 
Schematic diagram of the possible routes of NZVI uptake by roots (A and B), transportation via the xylem and phloem (C), and uptake by leaves (D). (The ultimate ownership of the figure is the author of this article)
Scanning electron micrographs (ZEISS EVO-MA 10; Carl Zeiss Pvt. Ltd., Oberkochen, Germany) of onion roots tips、onion epidermis and onion root hair exposed to different concentrations of nanoscale zero-valent iron particles (NZVI) for 24 hours
Scanning electron micrographs (ZEISS Ultra 55 SEM) of rice root tips. A, B Root tip morphology in the control. C, D Morphology of root tips exposed to 1,000 mg kg⁻¹ nanoscale zero-valent iron particles (NZVI)
Schematic diagram of antioxidant enzymes in that scavenge excessive reactive oxygen species (ROS) resulting from exposure to nanoscale zero-valent iron particles (NZVI). (The ultimate ownership of the figure is the author of this article)
Nanoscale zero-valent iron particles (NZVI) are widely used in a variety of industries owing to their advantageous mechanical, physical, and chemical properties. These particles can be released into environmental media, including water, soil, and air, through several pathways. NZVI in the ecosystem can be taken up, excreted and distributed within organisms, which is harmful to plants, animals and humans. Plants play a significant role as producers in the ecological circle and can both positively and negatively affect the ecological behavior of NZVI. Therefore, understanding the relationship between plants and NZVI is likely to be of great value for the assessment of NZVI-associated risks and future research directions. In this review, we summarize the current knowledge on the uptake, distribution, and accumulation of NZVI in plants; the phytotoxicity triggered by NZVI exposure at the physiological, biochemical, and molecular levels; and the defense mechanism used by plants to defend against NZVI-induced insults. We further discuss the toxic effects of NZVI on soil animals and microorganisms as well as the risk posed by the presence of NZVI in the food chain.
 
Characteristic of nano-TiO2 in the distilled water (1.0 g/L): (I), (II) and (III) are TEM image; (IV) is size distribution; (V) is the zeta potential
Growth inhibition of algae under different exposure concentration. x is the logarithm (base 10) of concentration; y is the probit of inhibition rate
Survival rates of rotifers exposure in different nanoparticles concentrations
Specific death and reproduction time for rotifers (mean ± SD). For each parameter, values in each column with * indicate significant different compared with control according to SNK at P < 0.05
Accumulation of nano-TiO2 in S. obliquus and rotifers at different exposure concentration and time (Mean ± SD, N = 3). I is the accumulation of nanoparticles in algae; II is the accumulation of nanoparticles in rotifers. For each nanoparticle concentration, values in each column with different capital letters indicate significant different among treatments according to SNK at P < 0.05; For each exposure time, values in each column with different lowercase letters indicate significant different among treatments according to SNK at P < 0.05
The increasing production of nano-TiO2 has attracted extensive concerns about the ecological consequence and health risk of these compounds in natural ecosystem. However, little is known about its toxicity on zooplankton, especially its possibility to access to the food chain via dietary exposure. To address this concern, the toxic and cumulative effects of nano-TiO2 on an aquatic food chain were explored through two trophic levels independently or jointly including producer and consumer. The results revealed that exposure to suspensions of nanomaterials had negative effects on both producers and consumers. Specifically, nanoparticles reduced the density of algal cells in a concentration-dependent way, and hatching life expectancy, average lifespan, net reproductive rate, and population intrinsic growth rate of rotifers decreased significantly with the concentration of nanomaterials increased (P < 0.05). Notably, nanoparticles accumulated in algal cells and were transferred to consumers through dietary exposure. Biomagnification of nano-TiO2 was observed in this simplified food chain, as many of the biomagnification factor (BMF) values in this study were >1. Exposure concentration, exposure time and their interactions play a strong part in the accumulation of nanoparticles in algae and rotifers. Overall, the present findings confirmed that nano-TiO2 was deleterious to plankton, posing a significant environmental threat to aquatic ecosystems. Graphical abstract
 
Chloroquine (CQ) has been widely used for many years against malaria and various viral diseases. Its important use and high potential to being persistent make it of particular concern for ecotoxicological studies. Here, we evaluated the toxicity of CQ alone and in combination with copper (Cu) to the euryhaline rotifer Proales similis. All experiments were carried out using chronic toxicity reproductive five‐day tests and an application factor (AF) of 0.05, 0.1, 0.3, and 0.5 by multiplying the 24-h LC50 values of CQ (4250 µg/L) and Cu (68 µg/L), which were administered in solution. The rate of population increase (r, d−1) ranged from 0.50 to 52 (controls); 0.20 to 0.40 (CQ); 0.09 to 0.43 (Cu); and −0.03 to 0.30 (CQ-Cu) and showed significant decrease as the concentration of both chemicals in the medium increased. Almost all tested mixtures induced synergistic effects, mainly as the AF increased. We found that the presence of Cu intensifies the vulnerability of organisms to CQ and vice versa. These results stress the potential hazard that these combined chemicals may have on the aquatic systems. This research suggests that P. similis is sensitive to CQ as other standardized zooplankton species and may serve as a potential test species in the risk assessment of emerging pollutants in marine environments.
 
Carmoisine belongs to a water-soluble synthetic dye and is often used as a food additive. Previous research has shown that carmoisine is toxic to rats and zebrafish, but there have been few reports on the effect of carmoisine on soil-dwelling social insects. The present study evaluated carmoisine toxicity in Polyrhachis vicina Roger. We found that the effects of different concentrations of carmoisine on the mortality of workers were dose-dependent. The 10% lethal dose (LD10), 50% lethal dose (LD50) and 90% lethal dose (LD90) of carmoisine to workers at 96 h was calculated to be 0.504, 5.491 and 10.478 g/L, respectivily. LD10 of workers were selected to treat the fourth instar larvae, pupae and adults for 10 days. The results showed that the survival rate of all ants, except for females, was significantly reduced, especially larvae and workers. The body weight of larvae, pupae and males decreased significantly, while weight gain was observed in the females and workers. The appearance of larvae, pupae and workers changed after carmoisine treatment, such as body darkening and epidermis shrinking of larvae and pupae, as well as body segment expansion of workers. Furthermore, carmoisine altered the expression of the estrogen-related receptor, tailless and homothorax of P. vicina (Pv-ERR, Pv-tll and Pv-hth) to varying degrees in larvae and adults. We believe that variations in body weight can lead to a decrease in survival rate and appearance changes in the ants, which may be related to abnormal gene expressions caused by carmoisine treatment. Therefore, we confirm that carmoisine has negative effects on the growth and development of P. vicina.
 
Toxicity of pyriproxyfen to Aedes aegypti second instar (L2) larvae and backswimmer Buenoa amnigenus adults
A Survival curves of mosquito larvae exposed to pyriproxyfen concentrations of 10 and 20 μg a.i./L. B Concentration-response curve of pyriproxyfen for backswimmer adults after 24 h of exposure. The lines denote the lethal concentration (LC) values based on concentration-mortality bioassays using probit analyses. Dotted lines represent 95% confidence intervals for the LC estimations. Symbols ( ± standard error) show the average mortality recorded for each insecticide concentration
Survival abilities of backswimmer Buenoa amnigenus adults exposed to pyriproxyfen concentrations of 100 and 150 μg a.i./L
A Survival curves of B. amnigenus exposed to pyriproxyfen for 10 consecutive days (without insecticide recovery). B Survival curves of backswimmer adults exposed to pyriproxyfen for 24 h and then transferred to insecticide-untreated water (with insecticide recovery). Treatments with the same letter do not differ according to Holm-Sidak’s test (P > 0.05)
Abilities of the backswimmer Buenoa amnigenus to prey upon Aedes aegypti second instar (L2) larvae
The predatory abilities of backswimmers that faced sublethal exposure to pyriproxyfen (either 100 or 150 μg a.i./L), or were unexposed, were recorded when these predators were subjected to larval densities of three (A), six (B), and nine (C) larvae/100 mL water. Symbols show the average number ( ± standard error, SE) of preyed larvae by each backswimmer
The total number of Aedes aegypti second instar (L2) larvae preyed upon by backswimmers Buenoa amnigenus at the end of the experiment (2 h)
The predators’ abilities were assessed at larval densities of three (A), six (B) and nine (C) larvae/100 mL of water. The results represent the average number ( ± standard error, SE) and dots denote the value of each replicate. Means grouped under the same horizontal line are not significantly different by Tukey’s HSD test (P < 0.05)
Pyriproxyfen is a juvenile hormone analogue that is commonly used to control the immature stages of mosquitoes in both artificial and natural water reservoirs. Recently, concerns have been raised regarding the community effectiveness of pyriproxyfen in preventing vector-transmitted diseases. Such concerns have been based on the unintended effects on non-target organisms and the selection of resistant mosquito populations. This investigation was, therefore, conducted to evaluate the toxicity of pyriproxyfen to Aedes aegypti (Diptera: Culicidae) larvae and the backswimmer Buenoa amnigenus (Hemiptera: Notonectidae), a naturally occurring mosquito larvae predator. We also assessed the abilities of backswimmers exposed to sublethal levels of pyriproxyfen to prey upon mosquito larvae (L2) under three larval densities (3, 6, or 9 larvae/100 mL of water) using artificial containers. Our results revealed that pyriproxyfen killed backswimmers only at concentrations higher than 100 μg active ingredient [a.i.]/L, which is 10 times higher than that recommended for larvicidal field application (i.e, 10 μg a.i./L). The abilities of backswimmers exposed to sublethal levels of pyriproxyfen (100 μg a.i./L) to prey upon mosquito larvae were not affected. Harmful effects on the backswimmer predatory abilities were detected only at concentrations of 150 μg a.i./L and when there was a higher prey availability (i.e., 9 larvae/100 mL of water). Together, our findings indicate that the reduced community effectiveness of this insecticide derives from factors other than its detrimental effects on non-target organisms such as backswimmers.
 
Schoeller Diagram showing the relative proportion of ions within coal bed waters in NSW and Qld. Each line in the graph represents the relative ionic proportions within one of the 15 mining sites. A clear distinction can be seen between waters that are chloride dominant and those that are bicarbonate dominate
Concentration response curves showing the 96 h toxicity of NaHCO3 (blue diamonds), WT1 (yellow circles) and WT2 (red squares) to P. australiensis in terms of measured, electrical conductivity (a) and measured bicarbonate concentration (b)
Concentration response curves showing the 96 h toxicity of NaHCO3 (blue diamonds), WT1 (yellow circles), and WT2 (red squares) to A. pusillus in terms of measured, electrical conductivity (a) and measured bicarbonate concentration (b)
Concentration response curves showing the 48 h toxicity of NaHCO3 (blue diamonds), WT1 (yellow circles), and WT2 (red squares) to C. dubia in terms of measured, electrical conductivity (a) and measured bicarbonate concentration (b)
Concentrations of major ions in coal mine discharge waters and unconventional hydrocarbon produced waters derived from coal bed methane (CBM) production, are potentially harmful to freshwater ecosystems. Bicarbonate is a major constituent of produced waters from CBM and coal mining. However, little is known about the relative toxicity of differing ionic proportions, especially bicarbonate, found in these CBM waters. As all freshwater invertebrates tested are more acutely sensitive to sodium bicarbonate (NaHCO3) than sodium chloride (NaCl) or synthetic sea water, we tested the hypotheses that toxicity of CBM waters are driven by bicarbonate concentration, and waters containing a higher proportion of bicarbonate are more toxic to freshwater invertebrates than those with less bicarbonate. We compared the acute (96 h) lethal toxicity to six freshwater invertebrate species of NaHCO3 and two synthetic CBM waters, with ionic proportions representative of water from CBM wells across New South Wales (NSW) and Queensland (Qld), in Australia. The ranking of LC50 values expressed as total salinity was consistent with the hypotheses. However, when toxicity was expressed as bicarbonate concentration, the hypothesis that the toxicity of coal bed waters would be explained by bicarbonate concentration was not well supported, and other ionic components were either ameliorating or exacerbating the NaHCO3 toxicity. Our findings showed NaHCO3 was more toxic than NaCl and that the NaHCO3 proportion of synthetic CBM waters drives toxicity, however other ions are altering the toxicity of bicarbonate.
 
Wildlife species at risk to primary AR exposure (domestic livestock, yellow-vented bulbul, plantain squirrel, wild pig, long-tailed macaque) and wildlife species at risk to secondary AR exposure (barn owl, black-winged kite, common palm civet, Asian water monitor, leopard cat).
Anticoagulant rodenticides (ARs) are used worldwide for the control of rodent pests and are the main method of control of rat pest populations in agricultural areas. The main aim of this review is to discuss the risk of ARs to non-target wildlife in oil palm areas in Southeast Asia, mainly Indonesia and Malaysia. We discussed AR use in oil palm areas and toxicities of ARs on target and non-target animals. We also reviewed published literature on wildlife species reported in oil palm areas in Southeast Asia and utilizing this information, we assessed the hazard risk of ARs to non-target wildlife in oil palm plantations. ARs are a secondary exposure hazard to rodent-consuming mammalian carnivores, such as leopard cats and civets, and rodent-consuming raptors, such as barn owls. Consumption of dead poisoned prey puts scavengers, such as water monitors, at high risk for AR exposure. Domestic livestock and granivorous birds are at high risk for AR exposure via primary exposure to toxic bait, while omnivores such as macaques and wild pigs are at moderate risk for both primary and secondary exposure to ARs. The effects of ARs on barn owls have been well studied in the field and in laboratory secondary toxicity studies. Thus, the nest-box occupancy and reproductive parameters of local barn owl populations can be monitored as an indicator of the AR exposure level in the area. Clinical Trials Registration No clinical trials were involved in this study.
 
Methodology’s scheme used in the study
Grain Size Distribution curve of the soil used in the experiments at 23 and 33 °C
Mean ± standard deviation percent of Ceriodaphnia silvestrii immobility at different assessed times (1, 8, and 15 days) exposed to elutriate for treatments (Clab – laboratory control; C - control, K - Kraft, S - Score, K + S - Kraft and Score mixture) at 23 and 33 °C
Mean ± standard deviation percent of Daphnia similis immobility at different assessed times (1, 8, and 15 days) exposed to elutriate for treatments (Clab – laboratory control; C - control, K - Kraft, S - Score, K + S – Kraft and Score mixture) at 23 and 33 °C
Brazil has become one of the largest consumers of pesticides in the world. However, there are still few studies evaluating pesticide toxicity integrating local aquatic and terrestrial environments. In addition, there is growing concern about the influence of temperature conditions related with climate change on contaminants toxicity. The aim of the present study was to evaluate the elutriate toxicity of the insecticide Kraft® 36 EC (a.i. abamectin), the fungicide Score® 250 EC (a.i. difenoconazole) and their mixture to the cladocerans Ceriodaphnia silvestrii and Daphnia similis, using model ecosystems (mesocosms). To this end, mesocosms were filled with natural soil and subjected to the following treatments: Control (Milli-Q water), Kraft (10.8 g abamectin ha⁻¹), Score (20 g difenoconazole ha⁻¹), and Kraft + Score (10.8 g abamectin ha⁻¹ + 20 g difenoconazole ha⁻¹). The experiment lasted 18 days, and the applications were made on days 1, 8, and 15; the occurrence of rainfall was simulated on days 1, 8, and 15 after applications and only rainfall simulation on days 4, 11, and 18. The experiment was conducted under two different temperatures: 23 °C and 33 °C. At 23 °C, single Kraft treatment and in combination with Score showed high toxicity to both cladocerans. At 33 °C, elutriate of the Kraft® and mixture treatments were highly toxic to D. similis but not to C. silvestrii. The results indicate that while Kraft had higher toxicity than Score to both cladocerans, this toxicity was counteracted at 33 °C only for the exotic species, D. similis. The results portray the complexity of pesticide toxicity when considering realistic experimental settings including different organisms and temperature treatments.
 
A-I, II XRD pattern and UV-visible spectrum of CuNPs. B Effect of Cu and CuNPs on the growth of Nostoc muscorum and Anabaena sp. exposed to different concentrations of Cu: 0.2 and 1.0 µM, and CuNPs: 0.2 and 1.0 mM after 72 h of treatment. Data are means ± standard error of three replicates (n = 3). Bars followed by different letters show significant difference at P < 0.05 significance level according to Duncan multiple range test (DMRT)
A Effect of Cu and CuNPs on photosynthesis and respiration of Nostoc muscorum and Anabaena sp. exposed to different concentrations of Cu: 0.2 and 1.0 µM, and CuNPs: 0.2 and 1.0 mM after 72 h of treatment. Data are means ± standard error of three replicates (n = 3). Bars followed by different letters show significant difference at P < 0.05 significance level according to Duncan multiple range test (DMRT). B Effect of Cu and CuNPs on chlorophyll a fluorescence transient-JIP parameters of Nostoc muscorum and Anabaena sp. exposed to different concentrations of Cu: 0.2 and 1.0 µM, and CuNPs: 0.2and 1.0 mM
A Effect of Cu and CuNPs on in-vitro SOR, H2O2 and MDA equivalent contents of Nostoc muscorum and Anabaena sp. exposed to different concentrations of Cu: 0.2 and 1.0 µM, and CuNPs: 0.2 and 1.0 mM after 72 h of treatment. Data are means ± standard error of three replicates (n = 3). Bars followed by different letters show significant difference at P < 0.05 significance level according to Duncan multiple range test (DMRT). B Showing the in-vivo visualization of SOR, H2O2 and MDA of Nostoc muscorum and Anabaena sp. exposed to different concentrations of Cu: 0.2 and 1.0 µM, and CuNPs: 0.2 and 1.0 mM after 72 h of treatment
A Effect of Cu and CuNPs on superoxide dismutase (SOD) and peroxidase (POD) activities of Nostoc muscorum and Anabaena sp. exposed to different concentrations of Cu: 0.2 and 1.0 µM, and CuNPs: 0.2 and 1.0 mM after 72 h of treatment. Data are means ± standard error of three replicates (n = 3). Bars followed by different letters show significant difference at P < 0.05 significance level according to Duncan multiple range test (DMRT). B Effect of Cu and CuNPs on catalase (CAT) and glutathione-S-transferase (GST) activities of Nostoc muscorum and Anabaena sp. exposed to different concentrations of Cu: 0.2 and 1.0 µM, and CuNPs: 0.2 and 1.0 mM after 72 h of treatment. Data are means ± standard error of three replicates (n = 3). Bars followed by different letters show significant difference at P < 0.05 significance level according to Duncan multiple range test (DMRT)
A Effect of Cu and CuNPs on SOD, POD and GST isoenzymes pattern in Nostoc muscorum and Anabaena sp. For determination of isoenzyme activity, 300 µg proteins from cell extracts were loaded onto each well of the native PAGE. Where lane 1: Control, lane 2: Cu-0.2 µM, lane 3 Cu-1.0 µM, lane 4:CuNPs- 0.2 mM, lane 5: CuNPs-1.0 mM. B Schematic representation of stimulatory and inhibitory responses to Cu and CuNPs exposure in cyanobacteria
The current study explored the role of ionic copper (CuCl2; 0.2 µM and 1 µM) and synthesized copper nanoparticles (CuNPs; 0.2 mM and 1 mM) in the two paddy field cyanobacteria (Nostoc muscorum ATCC 27893 and Anabaena sp. PCC 7120) with respect to growth, photosynthetic pigments, photosynthetic efficiency (O2 evolution and photochemistry of photosystem II; PS II), oxidative stress biomarkers, and antioxidant system. The low doses of ionic Cu (0.2 µM) and CuNPs (0.2 mM) showed stimulating effects on growth, pigment content (chlorophyll a, phycobiliproteins, and carotenoids), oxygen evolution, and PS II photochemistry. High doses of Cu/CuNPs (1 µM Cu and 1 mM CuNPs) caused a decline in the above-mentioned parameters. The values of fluorescence kinetics parameters: ϕP0, FV/F0, ϕE0, Ψ0, and PIABS, except for F0/FV, associated with PS II photochemistry in tested cyanobacteria and subjected to the high doses of ionic Cu and CuNPs, were decreased, while energy fluxes, ABS/RC, TR0/RC, ET0/RC, and DI0/RC, were increased. Conversely, treatment with low doses of Cu and CuNPs caused a reverse trend, indicating normalization of PS II performance. Although the activity of enzymatic antioxidants (superoxide dismutase SOD; peroxidase POD; catalase CAT and glutathione-S-transferase GST) in both cyanobacteria exposed to high doses of ionic Cu and CuNPs was accelerated considerably, the oxidative stress remained high. Conversely, at low doses of ionic Cu and CuNPs, a significant enhancement in the activities of enzymatic antioxidants decreased the levels of oxidative stress biomarkers. Nevertheless, in Anabaena sp., the levels of biomarkers were greater than those of the control. The current study concluded that compared to synthesized CuNPs, ionic Cu at elevated concentration had a damaging effect on growth, photosynthetic pigments, and PS II photochemistry via increased oxidative stress, and this effect was enhanced in Anabaena sp. than N. muscorum.
 
Effects of (A) avobenzone and (B) octinoxate on embryo coagulation, time to hatch, hatchability, larvae survival, malformation rate, larvae length, and larvae weight in wild-type (black circle) and thrαa−/− (white circle) zebrafish embryo/larvae. The results are shown as mean ± standard deviation of three replicates. Asterisk (*) indicates significant difference between solvent control and treatment groups, and # indicates significant difference between wild-type and thrαa−/− groups (p < 0.05)
Effects of (A) avobenzone and (B) octinoxate on triiodothyronine (T3), thyroxine (T4), and normalized T3/T4 ratio in zebrafish larvae. The results are shown as mean ± standard deviation of three replicates. Asterisk indicates significant difference from solvent control
Transcriptional response of genes related to the hypothalamus-pituitary-thyroid (HPT) axis after exposure to A avobenzone and B octinoxate
Avobenzone and octinoxate are frequently used as organic ultraviolet filters, and these chemicals are widely detected in water. This study evaluated the potential of avobenzone and octinoxate to disrupt thyroid endocrine system in wild-type and thyroid hormone receptor alpha a knockout (thrαa−/−) zebrafish embryo/larvae. Following a 120 h exposure to various concentrations of avobenzone and octinoxate, larvae mortality and developmental toxicity in wild-type and thrαa−/− fish were assessed. Triiodothyronine (T3) and thyroxine (T4) levels as well as transcriptional levels of ten genes associated with the hypothalamus-pituitary-thyroid (HPT) axis were measured in wild-type fish. Significantly lower larvae survival rate in thrαa−/− fish exposed to ≥3 μM avobenzone and octinoxate suggests that the thyroid hormone receptor plays a crucial role in the toxic effects of avobenzone and octinoxate. A significant increase in the deio2 gene level in avobenzone-exposed zebrafish supports the result of an increased ratio of T3 to T4. Significant decrease of T4 level with upregulation of trh, tshβ, and tshr genes indicates feedback in the hypothalamus and pituitary gland to maintain hormonal homeostasis. Our observation indicates that exposure to avobenzone and octinoxate affects the thyroid hormone receptor and the feedback mechanisms of the HPT axis. Clinical trials registration Not applicable.
 
a Description of anticoagulant rodenticide (AR) residue analyses for control and free ranging red-tailed hawks (RTHs). b Description of coagulation parameter analyses for control and free ranging red tailed hawks (RTHs) including prothrombin time (PT), Russell’s viper venom time (RVVT), and fibrinogen. c Description of hematology and biochemistry results available for control and free ranging red-tailed hawks (RTHs)
RVVT, PT and fibrinogen in control, free-ranging AR exposed, free-ranging AR not exposed, and free-ranging unknown exposure RTHs using the Tukey method for plotting whiskers and outliers (Tukey, 1977)
Deming regression analysis of log-transformed coagulation times obtained by RVVT and PT assays
Regression of coagulation time (s) on liver brodifacoum concentration (ppm) for PT and RVVT methods
Anticoagulant rodenticides (ARs) continue to be used across the United States as a method for controlling pest rodent species. As a consequence, wild birds of prey are exposed to these toxicants by eating poisoned prey items. ARs prevent the hepatic recycling of vitamin K and thereby impede the post-translational processing of coagulation factors II, VII, IX, and X that are required for procoagulant complex assembly. Through this mechanism of action, ARs cause hemorrhage and death in their target species. Various studies have documented the persistence of these contaminants in birds of prey but few have attempted to use affordable and accessible diagnostic tests to diagnose coagulopathy in free-ranging birds of prey. In our study free-ranging red-tailed hawks were found to be exposed to difethialone and brodifacoum. Eleven of sixteen (68%) livers tested for AR exposure had detectable residues. Difethialone was found in 1/16 (6%), and brodifacoum was detected in 10/16 (62%) liver samples that were tested for rodenticide residues. Difethialone was found at a concentration of 0.18 ug/g wet weight and brodifacoum concentrations ranged from 0.003–0.234 ug/g wet weight. Two out of 34 (6%) RTHA assessed for blood rodenticide had brodifacoum in serum with measured concentrations of 0.003 and 0.006 ug/g. The range of clotting times in the prothrombin time (PT) and Russell’s viper venom time assays for control RTHA were 16.7 to 39.7 s and 11.5 to 91.8 s, respectively. One study bird was diagnosed with clinical AR intoxication with a brodifacoum levels in blood of 0.006 and 0.234 ug/g wet weight in blood and liver respectively, a packed cell volume (PCV) of 19%, and PT and RVVT times of >180 s. No correlation was found between PT and RVVT in the control or free-range RTHA, and there was no relationship found between the presence of liver anticoagulant residues and clotting times in the PT and RVVT.
 
Mean (±SE) of longevity(A) and fecundity(B) of initial (F0) adult Aphis craccivora exposed to LC10 and LC25 of flupyradifurone compared with untreated control. The different letters indicate significant differences based on one-way ANOVA test and Tukey’s post-hoc test (P < 0.05)
Age-stage-specific survival rates (sxj) of Aphis craccivora F1 generations whose parents (F0) were exposed to LC10 and LC25 of flupyradifurone
Age-stage reproductive value (vxj) of Aphis craccivora F1 generations whose parents (F0) were exposed to LC10 and LC25 of flupyradifurone
Age-specific survival rate (lx), age-specific fecundity of total population (mx), and age-specific maternity (lxmx) of Aphis craccivora F1 generations whose parents (F0) were exposed to LC10 and LC25 of flupyradifurone
Age-stage-specific life expectancy (exj) Aphis craccivora F1 generations whose parents (F0) were exposed to LC10 and LC25 of flupyradifurone compared with untreated control
With low-dose stimulation and high-dose inhibition, insecticide-induced hormesis, a biphasic phenomenon, can contribute to pest resurgence. The cowpea aphid, Aphis craccivora (Koch) (Homoptera: Aphididae), is a vital insect that infests legume crops. Its hormesis of flupyradifurone has not been previously established. Age-stage two-sex life analysis is used to investigate the sublethal and transgenerational effects of flupyradifurone on two successive generations of A. craccivora. A leaf-dip bioassay method revealed high toxicity of flupyradifurone against A. craccivora, with lethal concentration 50% value (LC50) of 1.82 mg L⁻¹ after 48 h exposure. Treatment of parent generation (F0) with LC10 and LC25 of flupyradifurone significantly increased the longevity and fecundity of the directly exposed adults. The results of transgenerational effects showed that the treatment of (F0) with LC25 induced significant hormetic effects in progeny generation (F1). Furthermore, flupyradifurone at LC25 significantly enhanced the biological traits, such as intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0) compared with the control. Similarly, both LC10 and LC25 induced a significant increase in the mean generation time T (d). Conversely, both treatments caused a significant decrease in the doubling time (DT). Data in the present study demonstrate that the exposure of (F0) to flupyradifurone at LC10 and LC25 enhanced longevity and fecundity in the directly exposed adults of A. craccivora, and induced transgenerational hormesis across the subsequent (F1) generation. These results should be taken into consideration when using flupyradifurone for controlling cowpea aphid.
 
Species sensitivity distributions of lanthanum acute toxicity based on measured toxicity data (orange), toxicity data predicted by interspecies correlation estimation (ICE, green), and all toxicity data (blue). The acute toxicity data were log-transformed
Species sensitivity distributions of lanthanum chronic toxicity. The chronic toxicity data were log-transformed
The increasing exploitation and application of rare earth elements (REEs) may induce hazardous risks to freshwater aquatic organisms. Due to the lack of water quality criteria (WQC) and sufficient reliable toxicity data, little information is available on the ecological risk of REEs in surface water. In this study, lanthanum (La) toxicity data were collected from published toxicological studies, and the data quality was assessed using a toxicological data reliability assessment tool. To obtain more toxicity data, Daphnia magna, Cyprinus carpio, and Dania rerio embryos were selected as surrogate species, and an interspecies correlation estimation (ICE) model was used to predict the toxicity of La for untested species. The species sensitivity distributions (SSDs) of La toxicity and WQC were investigated. Differences were observed in the hazardous concentrations for 5% of species (HC5), but no statistically significant differences were noted in the SSD curves between the measured acute toxicity data and the predicted data. For the SSDs constructed from the measured toxicity data, the ICE-predicted toxicity data and all acute data supplemented with the ICE-predicted data, the acute WQC values of La were 88, 1022 and 256 μg/L, respectively. According to the SSD and corresponding HC5 of chronic toxicity data, the chronic WQC was 14 μg/L. The results provide a scientific reference for establishing WQC for freshwater aquatic organisms and ecological risk assessments of REEs.
 
The herbicides atrazine and glyphosate are used worldwide and their excessive usage results in the frequent presence of these pesticides in environmental compartments. We evaluated the effects of environmentally relevant concentrations of analytical standards and commercial formulations of atrazine (2 µg L⁻¹) and glyphosate (65 µg L⁻¹), isolated and in mixture (2 + 65 µg L⁻¹) on the microcrustacean Daphnia magna. Through chronic exposure (21 days) of two generations, we observed effects on survival, reproductive capacity and responses of the antioxidant defense system (catalase) and biotransformation system (glutathione S-transferase). The survival of organisms was affected in the second generation (F1) with a mortality of 17% in the mixture of commercial formulations treatments. In the evaluation of the first generation (F0) we observed only effects on sexual maturation of organisms, while in the F1, changes were observed in all parameters evaluated. A statistical difference (p < 0.05) was also observed between the analytical standards and the commercial formulations for all parameters evaluated, indicating that other components present in the formulations can change the toxicity of products. We suggest that atrazine can modulate toxicity when mixed with glyphosate, as the standard analytical atrazine and mixture of analytical standards results were similar in most parameters. Given the difficulty in estimating effects of mixtures and considering that various stressors are found in the environment, our results support the need to carry out long-term studies and, above all, to verify what are the impacts across generations, so that the toxicity of products is not underestimated. Graphical abstract
 
Site locations in Bhitarkanika and Mahanadi mangrove ecosystems
Seasonal variation in water quality parameters of mangrove ecosystem, viz water temperature, pH and salinity. a Bhitarkanika and b Mahanadi
Seasonal variation in soil quality parameters of mangrove ecosystem, viz soil pH, EC, SOC, bulk density and soil texture. a Bhitarkanika and b Mahanadi
The present study investigated the effects of rising carbon dioxide levels in nature and the carbon sequestration potential of dominant mangrove species for reducing the toxic effects of ocean acidification. The study was conducted on the east coast of Odisha, in the western Bay of Bengal. To determine the effect of these ambient parameters on the absorption of carbon dioxide by the mangroves, water temperature, salinity, pH levels of seawater along with soil texture and pH, salinity expressed in electrical conductivity, compactness expressed in bulk density, and soil organic carbon were simultaneously monitored. The aboveground biomass and carbon of the selected species were studied for 2 consecutive years at 10 designated stations. The total carbon calculated for the study area varied from 242.50 ± 49.00 to 1321.29 ± 445.52 tons with a mean of 626.68 ± 174.81 tons for Bhitarkanika and Mahanadi mangrove chunks. This is equivalent to 2299.92 ± 641.55 tons of CO2 absorbed from the atmosphere. A total of 27 equations were selected as the best fit models for the study area. The equations between mangrove biomass and carbon along with aquatic and edaphic factors governing the pH of water and soil strongly support the positive influence of mangrove photosynthetic activity in shifting the equilibrium toward alkalinity. This calls for conservation of mangrove ecosystem to minimize the pace of acidification of estuarine water. The results indicate that Excoecariaagallocha and Avicennia marina as are the most capable species for combatting maximum carbon dioxide toxicity from the atmosphere; which will be helpful in REDD + programs and carbon-based payments for ecosystem services (PES).
 
The dense vegetation in the wetland could effectively retain microplastic particles, and the distribution of microplastics varied significantly under different planting densities. In addition, microplastics in the soil environment can affect soil properties to a certain extent, which in turn can affect soil functions and biodiversity. In this study, we investigated the distribution of soil microplastics in a mangrove restoration wetland under different planting densities and their effects on wetland soil properties. The results indicated that the average abundance of soil microplastics was 2177.5 n/500 g, of which 70.9% exhibited a diameter ranging from 0.038–0.05 mm, while the remaining soil microplastics accounted for less than 20% of all microplastics, indicating that smaller-diameter microplastics were more likely to accumulate in wetland soil. The microplastic abundance could be ranked based on the planting density as follows: 0.5 × 0.5 m > 1.0 × 0.5 m > 1.0 × 1.0 m > control area. Raman spectroscopy revealed that the predominant microplastic categories in this region included polyethylene terephthalate (PET, 52%), polyethylene (PE, 24%) and polypropylene (PP, 15%). Scanning electron microscopy (SEM) images revealed fractures and tears on the surface of microplastics. EDS energy spectra indicated a large amount of metal elements on the surface of microplastics. Due to the adsorptive features of PET, this substance could influence the soil particle size distribution and thus the soil structure. All physicochemical factors, except for the soil pH, were significantly affected by PET. In addition, the CV analysis results indicated that soils in vegetated areas are more susceptible to PET than are soils in bare ground areas, leading to greater variation in their properties.
 
The concentrations, distribution, and ecological risks of 24 typical antibiotics in Hong Kong rivers and seawater were investigated using high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UHPLC-EI-MS/MS). The results showed that the select antibiotics were widely distributed in the study area. Among the target antibiotics, the detection rate of tetracyclines (TCs) was 100%, which indicated the widespread use of TCs in Hong Kong. The detection rates of sulfonamides (SAs) (57.1-100%), fluoroquinolones (FQs) (78.6-100%), roxithromycin (RTM) (50%) and novobiocin (NOV) (50%) were all above 50%. Compared with river water (7.9-114.26 ng/L, medium: 27.7 ng/L), concentrations of the most antibiotics in seawater (9.5-32.0 ng/L, medium: 13.3 ng/L) were lower; seawater concentrations were similar to those reported from other coastal cities, such as Guangzhou and Zhuhai in China, which implied that the source of marine antibiotic pollution may be the nearby rivers, and the vastness of the ocean causes environmental dilution of antibiotics. According to the ratio of the measured environmental concentration (MEC) to the predicted no-effect concentration (PNEC), ofloxacin (OFX) (average risk quotient: 1.94E-01) and ciprofloxacin (CFX) (average risk quotient: 3.53E-01) posed medium to high ecological risk in most places, whereas other antibiotics posed lower risk. In Yuen Long, where there were many livestock farms nearby, the detected concentration of antibiotics was higher, indicating that livestock wastewater may be the major reason for the increase in antibiotic levels in this area. In general, the detected concentration of antibiotics in Hong Kong was lower than that in the United States, Japan, the United Kingdom, and coastal areas of China, but the long-term existence of low concentrations of antibiotics also poses great risks. According to the risk assessment, Hong Kong should pay more attention to the use of FQs (e.g., OFX and CFX) in the future.
 
Embryonic malformations N: Normal pluteus, P1: pluteus with skeletal malformations, P2: blockage at pre-pluteus stages. D: early embryonic death
Mitotic aberrations A chromosome bridge, B lagging chromosome, C scattered, D fractured, E multipolar spindle. F normal mitosis
Average affected embryo percentages in embryotoxicity tests after BP-A or BP-S treatment (*p < 0.05, **p < 0.01 vs control, Tamhane’s, Tukey’s)
Cytogenetic toxicity after BP-A or BP-S exposure in A. lixula sea urchin embryos. a Mean of no.mitoses per embryo (*p < 0.05; **p < 0.01; ***p < 0.001 vs control, Tukey’s). b Percentages of interphase embryos (*p < 0.05; **p < 0.01; ***p < 0.001 vs control, Student’s t and Mann-Whitney U tests). c Metaphase/Anaphase ratio (*p < 0.05; **p < 0.01; ***p < 0.001 vs control, Student’s t). d Percentage of affected embryos (percent embryos having ≥1 mitotic aberrations) (*p < 0.05; **p < 0.01; ***p < 0.001 vs control, Tukey’s)
Bisphenol S (BP-S) is one of the most important substitutes of bisphenol A (BP-A), and its environmental occurrence is predicted to intensify in the future. Both BP-A and BP-S were tested for adverse effects on early life stages of Arbacia lixula sea urchins at 0.1 up to 100 µM test concentrations, by evaluating cytogenetic and developmental toxicity endpoints. Embryonic malformations and/or mortality were scored to determine embryotoxicity (72 h post-fertilization). It has been reported in academic dataset that bisphenols concentration reached μg/L in aquatic environment of heavily polluted areas. We have chosen concentrations ranging from 0.1-100 μM in order to highlight, in particular, BP-S effects. Attention should be paid to this range of concentrations in the context of the evaluation of the toxicity and the ecological risk of BP-S as emerging pollutant. Cytogenetic toxicity was measured, using mitotic activity and chromosome aberrations score in embryos (6 h post-fertilization). Both BP-A and BP-S exposures induced embryotoxic effects from 2.5 to 100 µM test concentrations as compared to controls. Malformed embryo percentages following BP-A exposure were significantly higher than in BP-S-exposed embryos from 0.25 to 100 µM (with a ~5-fold difference). BP-A, not BP-S exhibited cytogenetic toxicity at 25 and 100 µM. Our results indicate an embryotoxic potential of bisphenols during critical periods of development with a potent rank order to BP-A vs. BP-S. Thus, we show that BP-A alternative induce similar toxic effects to BP-A with lower severity.
 
Mortality and immobilization percentages and Swimming Speed (mm/s) recorded after 2, 4 and 24 h of incubation in 0.22 µm clean FNSW at 20 °C (dark) for A. amphitrite nauplii stored at 4 ± 1 °C for 0, 24, 72 and 120 h (T0, T1, T2, T3) before assay set up (M ± ES; n = 6). Asterisk indicates = significant difference (*p < 0.05) from T0 (no cold storage)
Mortality (A), Immobilization (B) and Swimming Speed Alteration (SSA) (C) percentages recorded after 24 h from bioassay set up with a Cadmium Nitrate solution (0; 0.2; 0.4; 0.8; 1.6; 3.2 mg/L) for A. amphitrite nauplii stored at 4 ± 1 °C for 0, 24, 72 and 120 h (T0, T1, T2, T3) before assay set up (M ± ES; n = 3). * = lowest cadmium concentration showing a significant (p < 0.05) difference from controls (0 mg/L)
Mortality and immobilization percentages after 24 h of contact with the environmental matrix (sediment elutriate) for A. amphitrite nauplii stored at 4 ± 1 °C for 0, 24, 72 and 120 h (T0, T1, T2, T3) before assay set up (M ± ES; n = 3). Control water (clean 0.22 µm FNSW): white bars; Sediment elutriate: black bars
Bioassays are extensively used in ecotoxicology and there is a constant need for even more sensitive, reliable and easy to rear and obtain model organisms. Larvae of the crustacean Amphibalanus amphitrite are a good ecotoxicological model, for their high sensitivity to a wide range of toxicants and emerging contaminants. A standardized protocol for this toxicity bioassay has been recently proposed. Nevertheless, a limit of this model organism is the lack of resting stages and the need to use larvae immediately after their release from adults, thus increasing laboratory efforts related to the maintenance of adults. The aim of this work is to verify if short-term cold storage of A. amphitrite larvae prior to use in ecotoxicological tests may affect the ecotoxicological responses of these organisms. Three end-points (mortality, immobilization and swimming speed alteration) were measured on nauplii after storing them at 4 ± 1 °C for different times (24, 72 and 120 h) before bioassay set-up. Bioassays were set up using: (i) clean filtered natural sea water (0.22 µm FNSW), (ii) a reference toxicant (Cadmium Nitrate) and (iii) an environmental matrix (sediment elutriate). Results show that mortality, differently from the other two endpoints, was not affected by cold-storage. Even after 5 days of larvae storage at 4 ± 1 °C before bioassay set up, mortality data were comparable to those obtained for non-cold-stored organisms. Moreover, larval sensitivity to the reference toxicant and sediment elutriate did not change. Regarding the other two end points, low cadmium concentrations significantly changed immobility and swimming activity in cold-stored nauplii compared to larvae used immediately after larval release. In conclusion, short-term cold storage of A. amphitrite nauplii before bioassay set up is an appropriate procedure in ecotoxicological testing if mortality is the endpoint to be considered for final evaluation.
 
The goal of this study was to assess the harmful effects of heavy metal accumulation on Clarias gariepinus (catfish) in two different polluted areas in the Al Sharkia governorate and assess the impact on oxidative stress and histological changes. The results revealed a highly significant difference in heavy metal levels in the water and inside fish tissues (liver and gonads) between the two sites. The total prevalence of parasitic infection was at the highest percentage in area B, in addition to severe histopathological damage to the liver and the gonads. Findings show that the total prevalence of parasitic infection is associated with uptake of metals, depleted antioxidant activity, and incidence of lipid peroxidation in tissue.
 
Unconventional natural gas development (fracking) has been a rapidly expanding technique used for the extraction of natural gas from the Marcellus Shale formation in Pennsylvania. There remains a knowledge gap regarding the ecological impacts of fracking, especially regarding the long-term health of native Brook trout (Salvelinus fontinalis) populations. During the summer of 2015, Brook trout were sampled from twelve streams located in forested, northwestern Pennsylvania in order to evaluate the impacts of fracking on Brook trout. Four stream sites were undisturbed (no fracking activity), three had a developed well pad without fracking activity, and five had active fracking with natural gas production. Liver tissue was isolated from two to five fish per stream and underwent RNA-Seq analysis to identify differentially expressed genes between ecosystems with differing fracking status. Data were analyzed individually and with samples pooled within-stream to account for hierarchical data structure and variation in sample coverage within streams. Differentially expressed and differentially alternatively spliced genes had functions related to lipid and steroid metabolism, mRNA processing, RNA polymerase and protein regulation. Unique to our study, genes related to xenobiotic and stress responses were found as well as potential markers for endocrine disruption and saline adaptation that were identified in watersheds with active fracking activity. These results support the utility of RNA-Seq to assess trout health and suggest detrimental impacts of fracking on sensitive trout populations.
 
Carmofur is an antineoplastic agent that inhibits ceramidase, a key enzyme in the sphingolipid pathway. Previous research suggests carmofur represses reproductive maturity in Daphnia magna. The purpose of this experiment was to confirm carmofur’s effects on fecundity and reproductive maturity over two generations. A chronic toxicity test found reproductive maturity was delayed from 9 to 19 days by 0.80 μM carmofur with a 99.7% drop in reproduction, probably caused by delayed ovarian development. Second generation effects were even greater with 0% reproductive success at 0.40 μM. To our surprise, carmofur was not measured in the media by HPLC 24 h after exposure. Previous research indicated that carmofur is unstable in water and hydrolyzed into 5-fluorouracil (5-FU). Therefore, the chronic toxicity study was repeated with 5-FU and similar effects on reproductive maturity were observed at similar concentrations despite very different acute toxicities (48 h carmofur LC50 = 1.93 μM; 5-FU LC50 = 207 μM). 5-FU delayed reproductive maturity from 9 to 21 days with a 71.12% drop in reproduction at 0.80 μM and greater effects in the 2nd generation similar to carmofur. 5-FU was found stable in aquatic media and HPLC confirmed 5-FU was hydrolyzed from carmofur within 24 h. In conclusion, carmofur and 5-FU reduce fecundity because they delay reproductive maturity and ovarian development in Daphnia magna. We conclude that the reproductive effects observed after carmofur treatment are primarily mediated by its breakdown product, 5-FU. This further underscores the importance of measuring chemical concentrations and evaluating chemical metabolism and decomposition when determining toxicity, especially of chemotherapeutic agents. Clinical trials registration Not applicable
 
The contents of H2O2 and MDA in wheat seedlings under different treatment conditions. Bars with different letters indicate significant differences (P < 0.05)
The activities of SOD, CAT and POD in wheat seedlings under different treatment conditions. Bars with different letters indicate significant differences (P < 0.05)
The expression of CCaMK, CPK10, CIPK2 and CIPK15 in wheat seedlings under different treatment conditions. Bars with different letters indicate significant differences (P < 0.05)
The expression of ERF1 and MYB30 in wheat seedlings under different treatment conditions. Bars with different letters indicate significant differences (P < 0.05)
Schematic of Ca²⁺-mediated improvement of stress tolerance in wheat seedlings
Sulfur dioxide (SO2) and drought are two important co-occurring abiotic stresses affecting the growth and productivity of plants. Here, we will investigate the role of Ca²⁺ in regulating antioxidant defense during drought or SO2/drought stress, and the effect of SO2 pretreatment on the physiological response of wheat seedlings to drought stress. The results showed that exogenous Ca²⁺ increased the activities of SOD, CAT and POD, and reduced the contents of H2O2 and MDA in drought-treated wheat seedlings, suggesting Ca²⁺ could improve drought tolerance by promoting antioxidant defense in plants. Moreover, exogenous Ca²⁺ up-regulated the expression of two stress-responsive transcription factor (TF) genes, ERF1 and MYB30, to cope with drought stress. Exposure of wheat seedlings to 10 mg m⁻³ SO2 significantly enhanced the activities of SOD, CAT and POD. The contents of H2O2 and MDA remained at control levels, showing that SO2 at this concentration led to an activation of the antioxidant defense system and did not cause oxidative damage to the seedlings. Furthermore, 10 mg m⁻³ SO2 pretreatment increased the expression of CCaMK and CPK10, enhanced the activities of SOD and POD, and reduced the accumulation of H2O2 and MDA in drought-treated wheat seedlings, showing a role of SO2 in protection of plants against drought stress. However, with removal of Ca²⁺ by spraying EGTA on the SO2-pretreated wheat seedlings, the expression of transcription factor genes and activities of antioxidant enzymes were decreased, and the contents of H2O2 and MDA enhanced to the level of drought treatment alone, suggesting a role of Ca²⁺ in the SO2-induced alleviation of drought stress. Together, these results indicated that exogenous Ca²⁺ increased defense-related gene expression and enzyme activity in response to drought stress, and that pre-exposure to appropriate levels of SO2 could improve drought tolerance through activation of Ca²⁺ signaling pathways in plants. This study would provide new strategy for enhancing plant resistance to environmental stress.
 
Levels of nuclear pathologies in the erythrocytes of the hens living in Binagady and Ramana. ***p < 0.001
Levels of SMAP in the tissues of the hens living in Binagady and Ramana. ***p < 0.001
Levels of cytochrome P-450 in the tissues of the hens living in Binagady and Ramana. *p < 0.05, **p < 0.01
Western blotting of the protein extract of the rat bone marrow sampled 1.5, 3 and 5 h after intra-peritoneal administration of SMAP
Levels of nuclear pathologies in the immature erythrocytes of the rats administered with SMAP 3 h prior to their exposure to γ-irradiation at a dose 8 Gy
High levels of background γ-radiation exist in the suburbs of Baku, Azerbaijan. We examined the impact of radiation on erythrocyte nuclear pathologies, levels of cytochrome P-450, and serotonin-modulating anticonsolidation protein (SMAP) in the tissues of the hens from three settlements with different levels of background radiation. Higher levels of radiation resulted in increased nuclear pathologies, upregulation of tissue SMAP levels, and downregulation of cytochrome P-450. We also carried out controlled dosage studies on Wistar male rats, which showed significant upregulation of heat shock proteins with molecular mass 70 kDa (HSP70) in the bone marrow 3 and 5 h after SMAP intraperitoneal administration. Administration of SMAP to rats 3 h prior to γ-radiation exposure (8 Gy) provided significant protection to somatic cell nuclei. We conclude that SMAP can provide protection from the genotoxic effects of γ-radiation through upregulation of HSP70 or the transformation of chromatin into a condensed, more protective conformational state.
 
Location of sites within the Bear River Migratory Bird Refuge and The Nature Conservancy’s Shorelands preserve. The map of the conterminous 48 US states shows the location of the field site at a broad scale. The blue polygon represents the outline and location of the Great Salt Lake
Concentrations of metals in the soils of the four wetland habitats. For each metal, color-coded letters above bars indicate differences in soil concentrations. The same color letters indicate soil concentrations that are not different from each other for that particular metal
Concentrations of (a) As, (b) Pb and (c) Cu in tissues collected from the four habitat types. Bars indicate mean values, error bars represent standard errors
Concentrations of (a) Cd, (b) Hg, and (c) Se collected from the four different habitat types. Bars indicate mean values, error bars represent standard errors
Wetland plants tolerate potentially hazardous metals through a variety of strategies, including exclusion or accumulation. Whether plants sequester metals and where they store them in their tissues is important for understanding the potential role of plants as remediators or vectors of metals to terrestrial food webs. Here we evaluate metal sequestration in Great Salt Lake wetlands for one invasive (Phragmites australis; phragmites) and three native plant species, i.e. threesquare bulrush (Schoenoplectus americanus), hardstem bulrush (Schoenoplectus acutus), alkali bulrush (Bolboschoenus maritimus), and their terrestrial invertebrates. We observed higher concentrations of arsenic and copper than other metals in plant tissues, although high lead concentrations were observed in phragmites. All plants acted as excluders of arsenic and selenium, retaining the bulk of the metal mass in belowground tissues. In contrast, lead, copper, and cadmium were transferred to above ground tissues of hardstem bulrush and phragmites. The aboveground translocation facilitated the movement of these metals into invertebrates, with the highest concentrations in most cases found in predators. Though our results highlight the potential for metal remediation via wetland plant growth and removal, care should be taken to ensure that remediation efforts do not lead to bioaccumulation.
 
A lack of toxicity data quantifying responses of Australian native mammals to agricultural pesticides prompted an investigation into the sensitivity of the stripe-faced dunnart, Sminthopsis macroura (Gould 1845) to the insecticide, fipronil (5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinyl pyrazole, CAS No. 120068-37-3). Using the Up-And-Down method for determining acute oral toxicity in mammals (OECD) median lethal dose estimates of 990 mg kg ⁻¹ (95% confidence interval (CI) = 580.7–4770.0 mg kg ⁻¹ ) and 270.4 mg kg ⁻¹ (95% CI = 0.0–>20,000.0 mg kg ⁻¹ ) were resolved for male and female S. macroura , respectively. The difference between median lethal dose estimates for males and females may have been influenced by the older ages of two female dunnarts. Consequently, further modelling of female responses to fipronil doses used the following assumptions: (a) death at 2000 mg kg ⁻¹ , (b) survival at 500 mg kg ⁻¹ and (c) a differential response (both survival and death) at 990 mg kg ⁻¹ . This modelling revealed median lethal dose estimates for female S. macroura of 669.1 mg kg ⁻¹ (95% CI = 550–990 mg kg ⁻¹ ; assuming death at 990 mg kg ⁻¹ ) and 990 mg kg ⁻¹ (95% CI = 544.7–1470 mg kg ⁻¹ ; assuming survival at 990 mg kg ⁻¹ ). These median lethal dose estimates are 3–10-fold higher than available LD 50 values of 94 mg kg ⁻¹ for a similarly sized eutherian mammal, Mus musculus (L. 1758) and 97 mg kg ⁻¹ for Rattus norvegicus (Birkenhout 1769). Implications for pesticide risk assessments in Australia are discussed.
 
Mercury has been studied extensively in lakes due to health risks associated with the consumption of contaminated fish, while stream ecosystems have received less attention. To better understand mercury bioavailability in the lower food web of streams, we collected macroinvertebrates (predators and detritivore) along with autochthonous (epilithic algae) and allochthonous (leaf litter) basal resources in eight streams entering Lake George. Samples were analyzed for methylmercury (MeHg), total mercury, and carbon and nitrogen isotopes (δ¹³C & δ¹⁵N) to determine how mercury concentrations in basal resources, biomagnification rates, and environmental factors (watershed characteristics and water chemistry) effected MeHg concentrations in predatory macroinvertebrates. While biomagnification rates, calculated as trophic magnification slope, explained between 68% and 98% of MeHg variability within a stream food web, the range was small (0.310–0.387) resulting in the biotic components following a consistent pattern of increasing MeHg among streams. The stream order was negatively related to basin slope for all biotic components and explained 70% of MeHg variability in predatory macroinvertebrates. Methylmercury concentrations were significantly and negatively related to δ¹³C in predators, epilithic algae, and leaf litter. We believe the biofilms on leaf litter utilized bacterial-respired carbon dioxide decreasing δ¹³C (<−28‰) and increasing MeHg while epilithic algal δ¹³C increased due to enhanced primary production resulting in biodilution of MeHg. Methylmercury in basal resources responded to δ¹³C similarly but through different processes. Our findings show shallow slopes elevate MeHg in basal resources and explain most of the predator MeHg variation among streams with little influence of biomagnification rates.
 
Geometric mean Hg concentrations across four species of songbirds from Southeast Michigan: American goldfinch (AMGO; n = 109), American robin (AMRO; n = 66), European starling (EUST; n = 18), and house sparrow (HOSP; n = 30). Mean values are significantly different (Tukey p < 0.001) between species with the exception of AMGO and HOSP (Tukey p = 0.17). Error bars represent one SE of the geometric mean
Geometric mean Hg concentrations among adults and juveniles in each species: American robin (AMRO), American goldfinch (AMGO), European starling (EUST), and house sparrow (HOSP). Error bars represent one SE of the geometric mean. Sample sizes are indicated above the error bars. An asterisk (*) above bars indicates statistically significant differences (Tukey p < 0.05) in means within each pair group
Log-transformed mean Hg concentrations of four species in each study site of southeast Michigan. American goldfinches (AMGO) are coded in gray triangle, American robins (AMRO) in black circle, European starlings (EUST) in open circle, and house sparrows (HOSP) in black triangle. Error bars represent one SE of the mean
Linear regression analysis for Hg concentrations and body condition in American robins (n = 57). Outliers for body condition (+/− 2σ) are displayed as open circles and these points were excluded from the regression analysis. Triangles represent potential influential points (Cook’s D = 4/n) that were included in the regression analysis
Parameter estimates including effect size and standard error of parameters from the generalized linear mixed model. Comparative groups are HOSP (species), Willson (site), Juvenile (age), and Unkonwn (sex)
Sublethal exposure to methylmercury (MeHg) can have consequences for the reproductive, neurological, and physiological health of birds. Songbirds, regardless of trophic position, are often exposed to mercury (Hg) and may be at risk for health effects – especially if they inhabit a place that is subject to high Hg atmospheric deposition and/or have local conditions that are prone to methylation. This study investigates Hg concentrations in terrestrial songbirds of Southeast Michigan, where historical and present-day anthropogenic emissions of heavy metals are elevated. We collected tail feather samples from 223 songbirds across four different species during summer and fall of 2018 and 2019. The mean (±SE) Hg concentration across all samples was 103 ± 3.43 ng/g of dry feather weight. Mercury concentration varied significantly among species, and by age and site in some species, but not by sex. Mean concentrations were nearly seven times higher in two omnivore species, American robin (Turdus migratorius) and European starling (Sturnus vulgaris), than in the two granivore species, American goldfinch (Spinus tristus) and house sparrow (Passer domesticus). Juveniles had higher feather Hg concentrations than adults in all species except American goldfinches - which feed their young primarily seeds, further supporting a role of diet in exposure. We also found a negative correlation between Hg concentration and body condition in American robins, but further research is needed to verify this relationship. While our sample concentrations do not exceed the threshold for sublethal effects, our findings provide insight into the patterns of Hg concentrations in terrestrial songbirds, which may help in understanding Hg exposure pathways, bioaccumulation and risks in terrestrial species.
 
Survivorship curve of Dendroctonus mexicanus exposed to three pyrethroid insecticides by the method of topical application. N = 10
Survivorship curve of Dendroctonus mexicanus exposed to three pyrethroid insecticides by the method of bark application. N = 10
The concentrations of bifenthrin found in samples. Middle figure (soil). Top figure (water). Bottom figure (sediment)
Effectiveness of pyrethroid insecticides against pests including bark beetles (Dendroctonus spp.) is well known, but little is known about their (a) residuality and persistence in forests after application to control an outbreak and (b) ability to bioaccumulate in insects, which could cause adverse effects on the trophic chains. The 24 h lethal toxicity, bioaccumulation factors, and lethal body burdens of the pyrethroid insecticides bifenthrin, deltamethrin, and cypermethrin were evaluated in the bark beetle Dendroctonus mexicanus. The residuality and persistence of the insecticide bifenthrin in the forest ecosystem (soil, water, and sediment) was also monitored after its application in a region infested by bark beetles. We determined whether contamination of soil, water, and sediments occurred near the sanitation site. For D. mexicanus, the most toxic insecticide for adults was bifenthrin for topical application (LC50 = 0.94 mg/L) and cypermethrin for bark application (LC50 = 5.04 mg/L). The insecticide that bioaccumulated the most in the insect body was deltamethrin (622.41 μg g⁻¹ dw) and the insecticide that bioaccumulated the least amount was cypermethrin (183.09 μg g⁻¹ dw). However, cypermethrin was the active substance that presented the lowest body burdens, and therefore required a lower dose to cause death of D. mexicanus adults. Our results demonstrate that prolonged presence of bifenthrin in the forest ecosystem could lead to bioaccumulation in soil, sediment, and insects.
 
Largemouth bass (LMB, 265–475 mm) were collected to document whether changes in fish condition and reproductive status influenced the concentration of total mercury (Hg) and selenium (Se) in axial muscle by season and sex. The fatty acid (FA) composition of fish was also examined to describe seasonal and sexual differences and identify whether arachidonic acid (ARA) could be used as a biomarker of Hg toxicity. There was a trend for females to have lower (p < 0.062) Se concentrations than males. The concentration of Se for females during spring (mean ± SD, 686 ± 51 ng/g dw) was 15% lower than males (806 ± 67 ng/g dw). Lower Se concentrations in females than males continued through summer and fall. Concentration of Hg for females during spring (152 ± 39 ng/g ww) was also 59% lower than males (373 ± 303 ng/g ww), but the difference was not significant (p > 0.2). The percent of lipids was greatest in fall and winter (3%) and comprised primarily of omega-3 fatty acids (35 g/100 g lipid). Fish condition as measured by percent lipids and relative weight was negatively (p < 0.02) related to Hg concentration for females and males. Lipid content for both sexes was also positively (p < 0.05) related to the Se:Hg ratio. Relative weight was positively related to the Se:Hg ratio for females during all seasons (p = 0.014), but only during spring and summer for males (p < 0.007). A low Se:Hg value was associated with an elevation in ARA for both sexes and a reduced hepatosomatic index in males. Data suggested that females transferred muscle stores of Se and Hg to developing oocytes during spring. This study generates hypotheses regarding the physiological drivers of seasonal and sexual variability in Hg, Se, and FA in LMB that may be applicable to other species and have implications for fisheries health and management.
 
Top-cited authors
Cornelis A M van Gestel
  • Vrije Universiteit Amsterdam
Mommaerts Veerle
  • Biobest Sustainable Crop Management
Guy Smagghe
  • Ghent University
Nicolas Desneux
  • INRA (French National Institute for Agricultural Research)
Tjeerd Blacquière
  • Blacqbee Consultancy