Thallium (Tl) is a highly toxic heavy metal. It is widely spread in soil. However, the effects of Tl on soil invertebrates have received limited attention. Eisenia fetida, a sensitive and widely used bioindicator, is important in assessing ecological risks in soil ecosystems. It is conceivable that the stress resistance of E. fetida may vary depending on its diet, potentially influencing the assessment of ecological risks associated with contaminants. This study aims to assess the toxicological effects of Tl in soil on E. fetida, focusing on mechanisms involving Tlinduced oxidative stress, disruption of antioxidant defenses, and diet-mediated differences in physiological tolerance. E. fetida was nourished with yogurt waste or cow dung as their primary food source before exposure. The research showed a significant correlation between the increase in soil Tl levels and its bioaccumulation in E. fetida. The highest Tl accumulation was observed in E. fetida fed with yogurt waste (5.55 mu g g-1), exceeding those fed with cow dung (4.77 mu g g-1). Tl inhibited the growth of E. fetida and induced oxidative stress responses. The activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) initially increased at lower concentrations and earlier time points but were suppressed at higher Tl concentrations and longer exposures. In contrast, glutathione S-transferase (GST) and glutathione peroxidase (GPx) activities were generally elevated, especially in yogurt waste-fed worms. Additionally, reduced glutathione (GSH) levels declined over time, while malondialdehyde (MDA) levels increased significantly, indicating lipid peroxidation and oxidative damage. Furthermore, the Integrated Biomarker Response index indicated that cow dung-fed E. fetida exhibited a higher level of toxic stress when compared to those fed with yogurt waste. In a comparative analysis, despite accumulating more Tl, yogurt waste-fed E. fetida exhibited a lower overall toxic response than their cow dung-fed counterparts. Our results suggest that the diet, specifically yogurt waste, can enhance Tl tolerance in E. fetida. Hence, when assessing the ecological risk of Tl concerning earthworms, it is imperative to consider their dietary sources to increase the scientific validity of evaluation results.

Arsenic (As) in soil, such as mining waste, is a concern for communities with legacy contamination. While the chronic health effects of As exposure through drinking water are well documented, the association between As in soil and population-wide health impacts is complex, involving factors like soil accessibility, soil properties, and exposure modes. This review summarizes evidence of associations between As in soil and human health, as well as biomarker and bioaccessibility evidence of exposure pathways. Fourteen studies were included in the final analysis. Reviewed studies reported associations between As in soil and birth outcomes, neurological effects, DNA damage, and cancer. Some of these health outcomes are not known to be linked to As in drinking water and were reported over a range of soil concentrations, indicating inconsistencies. Higher soil As concentrations are associated with higher As in human biospecimens, suggesting direct and indirect soil ingestion as primary exposure pathways. The subpopulations more likely to be exposed include younger children and those involved in soil-based activities. Future research should focus on standardized epidemiological studies, longitudinal studies, soil exposure and mitigating factors, combined exposure biomarker studies, the behavior of the different As species, soil dose related to bioavailability/bioaccessibility, and effects with other elements.

This study investigated the sub-lethal effects of four commercial fungicides-two foliar (Amistar (R) Xtra and Mirador (R)) and two ear fungicides (Prosaro (R) and Icarus (R))-applied alone and in combination to wheat crops on caged earthworms (Eisenia fetida). We measured biomarkers that included detoxification responses (glutathione S-transferase, GST), oxidative stress levels (lipid peroxidation, LPO, and catalase, CAT), DNA damage (comet assay), energy reserves (lactate dehydrogenase, LDH), and immune response (lysozyme activity, LYS). The absence of significant differences in catalase and lipid peroxidation levels suggested no oxidative stress due to fungicide exposure. However, the foliar fungicide Amistar (R) Xtra induced the highest GST activity and DNA fragmentation, suggesting synergistic effects between its active ingredients and undisclosed co-formulants. Similar effects observed with the Amistar (R) Xtra-Prosaro (R) mixture confirmed the greater toxicity of Amistar (R) Xtra. This study provides novel insights into the sub-lethal effects of single and combined commercial fungicides on a standard toxicity test organism, shedding light on the ecological implications of fungicide use in agroecosystems and reinforcing the need for pesticide reduction.

In recent years, there has been increasing interest in the study of extremophilic microorganisms, which include halophiles and halotolerants. These microorganisms, able to survive and thrive optimally in a wide range of environmental extremes, are polyextremophiles. In this context, one of the main reasons for studying them is to understand their adaptative mechanisms to stress caused by extreme living conditions. In this paper, a fungal strain Penicillium chrysogenum P13, isolated from saline soils around Pomorie Lake, Bulgaria, was used. The effect of elevated concentrations of sodium chloride on the growth and morphology as well as on the physiology of the model strain was investigated. P. chrysogenum P13 demonstrated high tolerance to NaCl, showing remarkable growth in liquid and agar media. In order to establish the relationship between salt- and oxidative stress, changes in the cell biomarkers of oxidative stress, such as oxidatively damaged proteins, lipid peroxidation, and levels of reserve carbohydrates of the studied strain were evaluated. The involvement of antioxidant enzyme defense in the adaptive strategy of the halotolerant strain against elevated NaCl concentrations was investigated.

Within an identical soil environment, various pesticides may be commonly identified, but their collective toxicological traits have not been thoroughly investigated. This research sought to elucidate the potential consequences of concurrent exposure to multiple pesticides on soil organisms, with a specific emphasis on examining alterations in transcript and enzyme levels induced by the co-presence of acetamiprid (ACE) and tetraconazole (TET) in earthworms (Eisenia fetida). The results indicated that the joint presence of ACE and TET exhibited an acute synergistic impact on the organisms. Notably, there was a significant elevation in the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), coupled with a substantial suppression of caspase-9 and caspase-3 contents observed in the majority of both individual and combined groups. These findings suggested the occurrence of oxidative stress and cell death. Furthermore, the study revealed a substantial up-regulation of three genes (gst, sod, and crt) and down-regulation of one gene (mt) after exposure to individual pesticides and their mixtures. This pointed towards dysregulation of detoxification processes and oxidative damage. Collectively, the study underscored that the widespread application of these two pesticides might pose potential ecotoxicological risks to the soil ecosystem. In essence, these discoveries enriched our insights into the potential hazards linked to the simultaneous use of multiple pesticides in real-world settings. They underscored the significance of taking into account both synergistic effects and employing judicious pesticide management strategies to alleviate ecological impacts.

The sub-lethal ecotoxicity of field-contaminated soils toward small soil fauna, such as enchytraeids, remains understudied but holds paramount importance in soil pollution assessment. This study employed Enchytraeus crypticus to evaluate metal-contaminated soils from a mining area across various levels of biological organization, including individual level responses (survival, growth, reproduction, Cd/Pb/Zn accumulation), cellular level effects (peroxidase (POD), superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), acetylcholinesterase (AChE), lipid peroxidation malondialdehyde (MDA)) and genetic alterations (olive tail moment (OTM) and tail DNA%). The study revealed considerable Cd and Pb accumulation, exerting adverse impacts on the reproduction and growth of the enchytraeids after a 21-day exposure. Changes in cellular and genetic parameters occurred with increasing exposure concentration and duration, indicating heightened lipid peroxidation and DNA damage in enchytraeids. A noteworthy metal detoxification process, evident at a physical level, was identified in E. crypticus, , characterized by an initial escalation in toxicity followed by a subsequent decline. A distinctive complementary mechanism governing oxidative damage was detected in the enchytraeids, with an initial suppression of CAT activity, followed by inductions in SOD, POD, and GSH activity. Over the exposure duration, MDA content and DNA damage in the enchytraeids exhibited concentration-dependent shifts indicating their potential as efficient early-warning indicators for assessing the impact of Pb-Zn mining soils. This study contributes to a comprehensive understanding of the toxicological implications of metal-contaminated soils within the soil-enchytraeid framework.

Microplastics (MPs), which are widely dispersed in terrestrial environments, threaten crop growth and human food security. However, plant accumulation and phytotoxicity related to the size effects of MPs remain insufficiently explored. This study investigated the accumulation and toxicity of two sizes of MPs on Capsicum annuum Linn. (C. annuum) through fluorescence tracing and antioxidant defense system assessment. The results revealed that the size of MPs significantly impacts their accumulation characteristics in C. annuum roots, leading to variations in toxic mechanisms, including oxidative stress and damage. Smaller MPs and higher exposure concentrations result in more pronounced growth inhibition. C. annuum roots have a critical size threshold for the absorption of MPs of approximately 1.2 mu m. MPs that enter the root tissue exhibit an aggregated form, with smaller-sized MPs displaying a greater degree of aggregation. MP exposure induces oxidative stress in root tissues, with high concentrations of smaller MPs causing lipid peroxidation. Analysis of the IBR values revealed that C. annuum roots utilize ascorbic acid (ASA) to prevent oxidative damage caused by larger MPs. Conversely, smaller MPs primarily induce superoxide dismutase (SOD) and glutathione (GSH). These results emphasize the significant impact of MP size on plant antioxidant defense response mechanisms, laying the foundation for further investigating the implications for human health.

The use of sewage sludge as a soil improver has been promoted in agroecosystems. However, sludges can contain toxic trace elements because of suboptimal wastewater treatment. Nonetheless, field studies investigating the negative effects of these practices on pollinators are lacking. We collected honeybees from an area where sewage sludge use is widespread, and one where it is precluded. Trace elements in soils and bees were quantified. Cadmium, chromium, lead, mercury, and nickel were investigated because they were the least correlated elements to each other and are known to be toxic. Their levels were related to oxidative stress and energy biomarkers, midgut epithelial health, body size and wing asymmetry of honeybees. We found increased carbohydrate content in sites with higher cadmium levels, increased histological damage to the midgut epithelium in the sewage sludge area, and the presence of dark spherites in the epithelium of bees collected from the sites with the highest lead levels. Finally, we found that honeybees with the highest lead content were smaller, and that wing fluctuating asymmetry increased in sites with increasing levels of mercury. To the best of our knowledge, this is the first comprehensive study of the concentration and effects on honeybees of trace elements potentially deriving from soil amendment practices.

Purpose The aim of this study was to evaluate the toxic potential of mining residues by 1) evaluating the concentrations of heavy metals and arsenic in soil and earthworm's samples from impacted and reference sites in Charcas and Villa de la Paz, San Luis Potos & iacute;, M & eacute;xico; and 2) evaluating effects by laboratory bioassays and the comet assay in the earthworm Eisenia andrei. Methods The quantification of metals in soils was carried out by the Thermo Scientific Niton XL3t Gold Serie 500 environmental analyzer for X-ray fluorescence (XRF), and in the earthworm tissue through ICP-MS. The evaluation of the genotoxic potential of soils was assessed through movility and exposure bioassays with earthworms, determining DNA damage using the comet assay at the end of the bioassays. Results In Charcas, the concentrations in soils of heavy metals from highest to lowest were: Pb > Cu > Mn > Cd (Impacted); and Mn > Pb (Reference). In Villa de la Paz, the concentrations were: As > Mn > Cu > Pb (Impacted) and Mn > Pb > As (Reference). The exposure pattern to heavy metals in earthworms in Charcas was: Pb > As (Impacted and Reference); and in Villa de la Paz it was: As > Mn > Pb > Cu > Cd (Impacted), y Pb > As (Reference). In both mining districts, the magnitude of DNA damage in earthworms was: Impacted > Reference > Control. Conclusion The results indicate that the impacted soils of both sites represent a significant source of exposure to edaphic organisms, with a notable genotoxic potential.

The toxicity of nanoparticles has attracted much attention, but the toxicity of nanoparticle types to soil fauna remains unclear. In this study, the earthworm (Eisenia fetida) was selected as a representative soil fauna to evaluate the toxicity of nano-hydroxyapatite (n-HAP), -zeolite (n-zeolite), and -iron tetroxide (n-Fe3O4) to soil fauna. The results showed that the skin ultrastructure, mortality, growth, antioxidant systems, and genetic material of the earthworms were affected to varying degrees by different nanoparticles. A filter paper test indicated that dermal exposure to nanoparticles primarily caused lesions in the cuticle, microvilli, and nucleus of the epithelial cells of earthworm skin. Soil incubation experiments showed that all types of nanoparticles could cause weight loss in earthworms, but only n-Fe3O4 resulted in their death. The reactive oxygen species and glutathione contents in earthworms exposed to n-Fe3O4 were much higher than those in earthworms exposed to n-HAP and n-zeolite. All nanoparticles stimulated the catalase and lactate dehydrogenase activity and damaged the DNA of earthworms. Integrated biomarker responses showed that the toxicity to earthworms increased in the following order: n-HAP < n-zeolite < n-Fe3O4. The characterization results indicated that the differences in surface hydroxyl groups and surface charge may be the cause of the differences in toxicity between n-HAP and n-zeolite with similar properties. The highest toxicity of n-Fe3O4 could be due to the size, spherical morphology, positive surface charge and the presence of Fe(II).