The widespread and indiscriminate application of insecticides within agricultural systems results in phytotoxic effects on non-target crops. Furthermore, the processes by which plants adapt and develop resistance to these agricultural chemicals are still not fully understood. This study provided a detailed analysis of the antioxidant enzyme responses, growth, photosynthetic activity, and pigment content under insecticide imidacloprid exposure on rapeseed (Brassica napus L.) plants to shed light on this issue. It has been observed that imidacloprid causes phytotoxicity in rapeseed, especially at high concentrations. The insecticide significantly affected growth parameters, pigment amounts, Fv/Fm ratio, H2O2 (hydrogen peroxide) and MDA (malondialdehyde) amount, and some antioxidant (APX-ascorbate peroxidase, CAT-catalase, DHAR-dehydroascorbate reductase, GPOD-guaiacol peroxidase, GR-glutathione reductase, SOD-superoxide dismutase) enzyme activities. These findings indicate that plants can adapt their physiological processes, such as enhancing antioxidant enzyme activities, modulating photosynthetic pigment composition, and adjusting osmoprotectant accumulation to withstand and endure insecticides up to a certain level. This research offers insights into how neonicotinoid insecticides affect plant health, linking directly to crop productivity and quality, as improved stress tolerance can lead to better growth performance, better photosynthetic activity, higher yield, lower reactive oxygen species levels, and enhanced nutritional value of the harvested produce.

Herbicides are one of the most heavily applied groups of pesticides globally. Whilst research on herbicides in relation to bees is growing, we still have more to learn about how bees may interact with herbicides and the subsequent consequences for bee health. As herbicides are designed to kill the plants they are applied to, bees and other pollinators may interact with them in a different way to other pesticide groups which is important to understand in the context of evaluating hazard and risk. Here, we conducted both a choice and no-choice test, to determine if bumblebees would be deterred from foraging from feeders containing commercial formulations of Roundup (Ultra and Biactive, respectively) compared to controls. We found across both experiments that bees were deterred from foraging where feeders contained above field-realistic concentrations of Roundup formulation, and that on average colonies reduced their consumption from these feeders by ~50% despite lacking other food sources. This demonstrates that, when given no choice, bees can be deterred from sucrose containing Roundup Biactive, although above expected field concentrations, even to their own nutritional detriment. Separately, individual foragers were observed avoiding feeders containing field-realistic levels of Roundup Ultra compared to controls, showing a preference for uncontaminated feed when given a choice. As this was an experimental setup using high concentrations of Roundup with sucrose solution rather than real flowers, more work is needed to understand this phenomenon under field conditions. This work provides useful information and insights for future studies investigating the impacts of glyphosate in the form of both active substance and formulation on bees and could also be useful in identifying future mitigation strategies for field use.

Environmental exposure to caffeine (CAF) poses potential risks to aquatic ecosystems, affecting non-target species. This study investigated the chronic effects of environmentally relevant CAF concentrations, ranging from 0.16–50 µg/L, on zebrafish behaviour. A Kohonen-type artificial neural network classified zebrafish behaviour into nine behavioural classes based on a set of movement descriptors (mean meander, mean velocity, instantaneous velocity, distance to centre point, mean angular velocity and instantaneous acceleration), while a comprehensive analysis integrated behavioural classes previously defined and biochemical markers of oxidative stress, lipid peroxidation, reserve energy content, energetic pathways, and neurotoxicity. The discriminant analysis demonstrated that behaviour descriptors and biomarkers individually explained 38% and 67% of data variation, respectively, while the combination resulted in 19 models with 100% correct diagnosis. One of the models (Model A) seemed to suit the best dose-response relationship, incorporating key biomarkers including superoxide dismutase, catalase, glutathione peroxidase activities, and behavioural characteristics such as movement distance and velocity. This suggested methodology offers a different approach to evaluating CAF’s ecological impact, highlighting behavioural analysis as a valuable complement to traditional ecotoxicological assessments. This study provides a novel framework for understanding organism-level responses to environmental stressors (e.g., several anthropogenic compounds), utilising Mahalanobis distance as an integrative response index. This approach shows promise for broader application in assessing the impact of various aquatic contaminants on aquatic organisms (from bacteria to fish), potentially extending to pharmaceuticals, pesticides, and industrial pollutants.

Surfactants are often included as co-formulants in the application of herbicides to aid in spreading and adherence to plant surfaces, but toxicity to native bees has not been extensively tested. In a set of progressive experiments, we evaluated effects of products containing glyphosate and spreading agents, as well as spreading agents alone, on bumblebees (Bombus impatiens Cresson) using parametric survival analysis. We test spreaders from multiple chemical classes including Silwet L-77© (trisiloxane), Alligare 90© (polyoxyethylene), and Southern Ag SA-50© (C10–16 alcohols). We report low lethality of high-glyphosate herbicide formulations (Rodeo©), but bee mortality increased ~20% with addition of a silicone-based spreading agent (Silwet L-77©). Spreaders alone strongly affected bee survival: effects were concentration-specific and did not differ depending on exposure method (spray application vs. application to surfaces contacted by bees). The widely used trisiloxane-based spreader Silwet L-77© was especially hazardous, and exposure to high concentrations of Silwet L-77© caused rapid and near-total mortality in B. impatiens. Analysis of whole-bee cuticle extracts after exposure revealed clear differences in the cuticular hydrocarbon profiles associated with exposure to spreading agents: the alkane n-hexacosane was present in all extracts but was detected in greater relative abundance from bees exposed to Silwet L-77© and Alligare 90©. To support wild bee conservation efforts, we recommend substituting alcohol-based spreaders for siloxane-based spreaders when possible. In addition, certain cuticular hydrocarbons may be useful as biomarkers of previous exposure to certain surfactants, which can aid investigations evaluating causes of bumblebee decline across landscapes.

Microplastics derived from biobased and biodegradable materials will increase their presence in soils as their use becomes more widespread. Research into their effects on soil fauna will help to ensure a better understanding of their environmental impacts. The aim of this work was to study the effects on the development of the earthworm Eisenia andrei (ingestion capacity, survival, growth, cocoon, and hatchling production), earthworm lysosomal stability through the neutral red retention time (NRTT), and substrate enzymatic activity of dehydrogenase (DHA) and fluorescein diacetate-hydrolysing activity (FDA) in the presence of polylactic acid (PLA), polyhydroxybutyrate (PHB) and polyethylene (PE) microplastics in laboratory tests. Three different tests were designed, one feeding test of 4 days, and two medium-term tests with 49 and 112 days. The 4-day test and the 49-day growth test were carried out using OECD artificial soil, while in the 112-day growth test, vermicompost was used as the substrate. PLA and PHB particle ingestion was demonstrated. No concentration or polymer-dependent lysosomal damage or effects on earthworm growth were observed. However, reproductive effects, such as a decrease in cocoon production and the number of juveniles, were reported upon exposure to PE and PLA during medium-term assays. These findings indicated that the toxicity of PLA bioplastic exposure is comparable to that of conventional plastic PE concerning the negative effects on the reproductive efficiency of the detritivorous earthworm E. andrei.

The investigation of the toxic potential of a newly introduced herbicide, Florpyrauxifen-benzyl (FPX), on Nile tilapia (Oreochromis niloticus) was the aim of this study. For 96 h, the median lethal concentration (LC50) was assessed in fish juveniles using the Probit analysis following the exposure to five concentrations of FPX (2–3 ppm). For investigating some mechanisms of FPX toxicity, fish were allocated into three groups (0, 0.27 and 0.54 ppm of FPX) and the cut-off intervals of the exposure were at 7 and 15 days. Liver malondialdehyde (MDA) and reduced glutathione (GSH) levels were assessed. In addition, superoxide dismutase (SOD) and catalase (CAT) were evaluated at both of transcriptional and enzymatic activity levels. Histopathological effects on the liver and erythrocytic nuclear abnormalities (ENAs) were monitored too. The 96h-LC50 was found to be 2.61 ppm, revealing the toxic potential of the FPX on Nile tilapia. Concentrations of FPX induced oxidative stress in fish by altering activities of antioxidant enzymes and their transcripts. The genotoxic effect of FPX was evidenced by a significant (P < 0.05) increase in micronuclei (MNs) and ENA frequencies. Significant liver histopathological alterations were observed at both FPX concentrations, with the highest effects at a concentration of 0.54 ppm FPX. Results suggest that FPX may exert oxidative, genotoxic, and histopathological effects on non-targeted species such as Nile tilapia if it is used improperly. Although fish could be used as an indicator for toxic materials in the aquatic habitat, future studies on other organisms, FPX concentrations or durations are recommended.

This study examines earthworm behaviour by combining locomotion-based motility assessments with evaluations of acetylcholinesterase (AChE) inhibition. Motility analysis revealed significant differences in the two-dimensional movement patterns of earthworms exposed to carbamate pesticides compared to those in the control group, indicating altered trajectories. AChE assays demonstrated a pronounced inhibitory effect on enzyme activity in exposed earthworms relative to unexposed individuals. Both univariate and multivariate analyses confirmed that the pesticide contaminant significantly affects AChE activity as well as the quantitative and directional characteristics of earthworm movement. These results suggest that behavioural testing in earthworms is a valuable tool for understanding the impact of pesticides on non-target organisms and the environment.

The use of pesticides has notably increased in recent years globally. However, sensitive organisms exposed to these environmental pollutants, such as amphibians, may experience adverse effects. The insecticide imidacloprid (IM) and the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) are two pesticides commonly used in Colombia, but their toxic impacts on tropical anurans remain poorly understood. In this study, we tested the acute toxic effects of IM and 2,4-D on the survival, total length, and burst swimming speed of tadpoles from two anuran species. Under laboratory conditions, the tadpoles of Boana platanera and Engystomops pustulosus were independently exposed to each pesticide for 96 h. We found that the tadpoles of E. pustulosus were more sensitive to both IM and 2,4-D than those of B. platanera. However, the LC50 values were higher than the reported field concentrations for these pesticides. IM led to a reduction in the total length of B. platanera tadpoles and induced total immobility in surviving individuals of both species. In contrast, the herbicide 2,4-D did not affect the total length or the swimming speed of tadpoles from the two species. In conclusion, based on the results and the reported field concentrations, IM and 2,4-D are not lethal to the studied anurans. Nevertheless, it is important to consider that IM caused strong negative sublethal effects on tadpoles, which could compromise their survival in the future. Finally, we also found that the insecticide IM showed notably greater toxicity to the tested species than did the herbicide 2,4-D.

Monitoring the dynamics of contaminants in ecosystems helps understand their potential effects. Seabirds have been used as biomonitors of marine ecosystems for this purpose. However, exposure and vulnerability to pollutants are understudied in tropical species, and the relationships between various pollutants and the trophic ecology of seabirds are poorly understood. In this study, we quantified mercury (Hg), lead (Pb), cadmium (Cd), and organochlorine pesticide (OC) concentrations in the blood of Laughing Gulls and Magnificent Frigatebirds breeding in Bahía Santa María, México. Using carbon and nitrogen isotopic ratios (δ13C and δ15N), we examined the interaction between contaminants and trophic ecology. Laughing Gulls exhibited higher concentrations of dichlorodiphenyltrichloroethane and its metabolites (ΣDDTs), endrins (ΣDrins), and chlordanes, while Magnificent Frigatebirds had elevated levels of Hg and hexachlorocyclohexane isomers (ΣHCHs). Both species displayed temporal and sex-related variations in isotopic signatures. Some blood pollutant concentrations in Laughing Gulls were explained by diet: ΣOCs in plasma were directly related to trophic levels, indicating biomagnification, whereas higher Hg levels were associated with changes in habitat use. In contrast, the differences in sex-related isotopic signatures in Magnificent Frigatebirds did not reflect pollutant accumulation patterns, possibly due to their opportunistic feeding habits.

Plastic is widely used worldwide due to its durability and relatively low production costs. However, its durability also has significant drawbacks - plastic is a slowly degrading material and greatly contributes to the environmental pollution. Increasing body of evidence shows that contamination of the environment with plastic negatively affects plants and other living organisms. The aim of present research was to determine whether short-term exposure to polystyrene nanoparticles (PSNP) has toxic effect on soybean seedlings (Glycine max L). In the first stage of the research, the effect of two hour long incubation in PSNP solutions (10 and 100 mgl−1) on the germination of soybean seeds was determined. In the second part of the study, the potential cytotoxic effect of PSNP on young seedlings was measured. The results indicate that incubation in PSNP solutions inhibits the germination of soybean seeds by approx. 10% (at p = 0.05). However, this effect was only observed after 48 and 72 h of germination and by lower PSNP concentrations, 10 mgl−1. In turn, in young soybean seedlings exposure to PSNP had no effect on growth, cell viability or oxidative status by p = 0.05. The results indicate that germination is a PSNP-sensitive process. In turn, already germinated seedlings are relatively resistant to the short-term exposure to this stressor.