Species-specific Cd-detoxification mechanisms in lumbricid earthworms Eisenia andrei, Eisenia fetida and their hybrids

Assessment of toxic effects of thallium on the earthworm Eisenia fetida using the biomarker response index

Thallium (Tl), though not essential for biological systems, is widely used in industrial activities, resulting in soil pollution and adverse effects on soil biota. Systematic toxicological studies on Tl, especially concerning soil organisms, are relatively rare. This research evaluates the toxic effects of Tl on earthworms by measuring oxidative stress biomarkers, such as superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG), and by assessing the expression of functional genes, such as heat shock protein 70 (Hsp70), metallothionein (MT), and annetocin (ANN). Additionally, this study employs the Biomarker Response Index (BRI) and two-way ANOVA to comprehensively assess the cumulative toxicity of Tl in earthworms. The findings indicate that Tl exposure significantly exacerbates oxidative stress and cellular damage in earthworms, particularly under conditions of high concentration and prolonged exposure. BRI results demonstrate a continuous decline in the physiological state of earthworms with increasing Tl concentration and exposure duration. Two-way ANOVA reveals significant dose-responsive increases in SOD and CAT activities, as well as in ANN gene expression. Apart from GST activity, other biomarkers significantly increased over time, and the changes in biomarkers such as SOD, CAT, MDA, and 8-OHdG were significantly influenced by dose and time. LSD post hoc tests show significant effects of dose, time, and their interactions on all biomarkers except for GST. These findings are valuable for gaining a deeper understanding of the ecological risks of Tl in soil environments and its potential threats to soil biota, aiding in the management of ecological risks associated with Tl-contaminated soils.

Advances in understanding and mitigating Atrazine's environmental and health impact: A comprehensive review

Atrazine is a widely used herbicide in agriculture, and it has garnered significant attention because of its potential risks to the environment and human health. The extensive utilization of atrazine, alongside its persistence in water and soil, underscores the critical need to develop safe and efficient removal strategies. This comprehensive review aims to spotlight atrazine's potential impact on ecosystems and public health, particularly its enduring presence in soil, water, and plants. As a known toxic endocrine disruptor, atrazine poses environmental and health risks. The review navigates through innovative removal techniques across soil and water environments, elucidating microbial degradation, phytoremediation, and advanced methodologies such as electrokinetic-assisted phytoremediation (EKPR) and photocatalysis. The review notably emphasizes the complex process of atrazine degradation and ongoing scientific efforts to address this, recognizing its potential risks to both the environment and human health.

Spent coffee grounds as a suitable alternative to standard soil in ecotoxicological tests

Eisenia andrei is considered in OECD and ISO guidelines to be a suitable replacement for Eisenia fetida in ecotoxicological assays. This suggests that other alternative materials and methods could also be used in standard procedures for toxicity testing. The guidelines also favor using less time-consuming procedures and reducing costs and other limitations to ecotoxicological assessments. In recent years, spent coffee grounds (SCG) have been used to produce vermicompost and biochar and as an additive to organic fertilizers. In addition, the physicochemical characteristics of SCG indicate that the material is a suitable substrate for earthworms, with the organisms performing as well as in natural soil. In the present study, a battery of ecotoxicological tests was established with unwashed and washed SCG and a natural reference soil (LUFA 2.2). The test substrates were spiked with different concentrations of silver nitrate. Survival and reproduction of the earthworm E. andrei were assessed under different conditions, along with substrate basal respiration (SBR) as a proxy for microbial activity. Seedling emergence and the germination index of Lepidium sativum were also determined, following standard guidelines. Exposure to silver nitrate had similar effects on earthworm survival and reproduction, as the estimated effective concentrations (EC10 and EC50) in unwashed SCG and LUFA 2.2 overlapped. A hormetic effect was observed for SBR in LUFA 2.2 spiked with 12.8 mg/kg but not in unwashed SCG. Both SBR and root development were inhibited by similar concentrations of silver nitrate in washed SCG. The findings indicate that unwashed SCG could potentially be used as a substrate in E. andrei toxicity tests and support the eventual inclusion of this material in the standard guidelines.

Effect of different exposure times and doses of cyantraniliprole on oxidative stress and genotoxicity in earthworms (Eisenia fetida)

Cyantraniliprole, the second generation of diamide insecticides, is widely used to control various pests, which will certainly result in adverse effects on earthworms in soil. In this study, after exposure with six doses of cyantraniliprole (0, 0.5, 1, 2.5, 5, and 10 mg kg^-1) by artificial soil method, six biomarkers, four functional genes, and histopathological changes of Eisenia fetida were measured on the 7th, 14th, 21st, and 28th days. The comprehensive toxicity was assessed by the IBR version 2 (IBRv2) method. The results showed that the reactive oxygen species (ROS) level was induced significantly. The superoxide dismutase (SOD) activity was activated in 7-28 days. The catalase (CAT) and glutathione S-transferases (GST) activities were also activated in the initial 14 days. The 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) contents in the high treatment increased until the late stage of exposure. On the 28th day, the metallothionein (MT) and calreticulin (CRT) genes were up-regulated, the transcriptionally controlled tumor protein (TCTP) gene was down-regulated. The SOD gene showed a good correlation with SOD activity. Extensive histopathological damage was found in the endoderm and ectoderm of E. fetida. The 5 and 10 mg kg^-1 treatments showed higher comprehensive toxicity than the 0.5, 1, and 2.5 mg kg^-1 treatments on the 28th day. These results suggest that cyantraniliprole exerted certain subchronic toxic effects of oxidative stress, DNA damage, and histopathological changes to E. fetida, which provided theoretical basis for rational use of cyantraniliprole and evaluation of its safety to soil environment.

Reproductive damage and compensation of wild earthworm Metaphire californica from contaminated fields with long-term heavy metal exposure

Reproduction is a significant biological process for organisms responding to environmental stresses, however, little is known about the reproductive strategies of invertebrates under long-term exposure to contaminations. In this study, earthworm Metaphire californica (Kinberg, 1867) from contaminated fields with an increased metal gradient were collected to investigate their reproductive responses. The results showed heavy metals (Cd, Cu, Zn, and Pb) induced histological damage to earthworms' seminal vesicles, including tissue disorders and cavities, and decreases in mature spermatozoa. Sperm morphology analysis indicated deformity rates were up to13.2% (e.g. head swollen or missing) for worms from the most contaminated site, which coincided with DNA damages. Furthermore, the computer-assisted sperm analysis (CASA) system was employed for the evaluation of sperm kinetic traits. Results suggested earthworms exposed to higher contamination showed a lower sperm viability rate but faster sperm velocity after re-exposure with Cd solution (like the curvilinear velocity and straight-line velocity paraments) compared with those from relatively clean sites. The activities of lactate dehydrogenase and sorbitol dehydrogenase showed the highest 32.5% and 12.5% up-regulation respectively with the increased metal gradient. In conclusion, this study elucidated the earthworm reproductive toxicity, underlying reproductive compensation, metal stress-induced damages, and adaptive responses caused by heavy metal exposure, while also providing the possibility of sperm trait analysis (CASA) for related earthworm toxicological studies.

Modelling polycyclic aromatic hydrocarbon bioavailability in historically contaminated soils with six in-vitro chemical extractions and three earthworm ecotypes

Accurate prediction of organic contaminant bioavailability for risk assessment in ecological applications is hindered by limited validation on relevant bioassay species. Here, six in-vitro chemical extraction methods (butanol, non-buffered and buffered hydroxypropyl-β-cyclodextrin (HPCD, Buf-HPCD), Tenax, potassium persulfate oxidation, polyoxymethylene solid phase extraction (POM)) were tested for PAH bioaccumulation prediction in three earthworm ecotypes with dissimilar exposures, Amynthas sp., Eisenia fetida, and Lumbricus terrestris, in historically contaminated soils from manufactured gas plant (MGP) sites. Extractions were compared directly and modelled in a calculation approach using equilibrium partitioning theory (EqPT) with a novel combination of different organic carbon/octanol-water partitioning parameters (K_OC and K_OW). In the direct comparison approach Buf-HPCD showed the closest prediction of accumulation for burrowing Amynthas sp. and L. terrestris (within 1.5 and 3.1, respectively), but Tenax and POM showed the closest approximation for E. fetida (within 1.1 and 0.9, respectively). The optimum method for predicting PAH bioaccumulation in the calculation approach depended on earthworm species and the partitioning parameters used in equations of the four models, but overall POM, which was independent of K_OC, showed the closest approximation of accumulation, within a factor of 2.5 across all species. This work effectively identifies the optimum in-vitro based approaches for PAH bioavailability prediction in earthworms as a model soil health indicator for ecological risk assessment within regulatory and remediation decision frameworks.

Air Pollution, Oxidative Stress, and the Risk of Development of Type 1 Diabetes

Despite multiple studies focusing on environmental factors conducive to the development of type 1 diabetes mellitus (T1DM), knowledge about the involvement of long-term exposure to air pollution seems insufficient. The main focus of epidemiological studies is placed on the relationship between exposure to various concentrations of particulate matter (PM): PM1, PM2.5, PM10, and sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (O3), versus the risk of T1DM development. Although the specific molecular mechanism(s) behind the link between increased air pollution exposure and a higher risk of diabetes and metabolic dysfunction is yet unknown, available data indicate air pollution-induced inflammation and oxidative stress as a significant pathway. The purpose of this paper is to assess recent research examining the association between inhalation exposure to PM and associated metals and the increasing rates of T1DM worldwide. The development of modern and more adequate methods for air quality monitoring is also introduced. A particular emphasis on microsensors, mobile and autonomous measuring platforms, satellites, and innovative approaches of IoT, 5G connections, and Block chain technologies are also presented. Reputable databases, including PubMed, Scopus, and Web of Science, were used to search for relevant literature. Eligibility criteria involved recent publication years, particularly publications within the last five years (except for papers presenting a certain novelty or mechanism for the first time). Population, toxicological and epidemiological studies that focused particularly on fine and ultra-fine PM and associated ambient metals, were preferred, as well as full-text publications.

Polymorphic microsatellite markers demonstrate hybridization and interspecific gene flow between lumbricid earthworm species, Eisenia andrei and E. fetida

The lumbricid earthworms Eisenia andrei (Ea) and E. fetida (Ef) have been used as model organisms for studies on hybridization. Previously they have been identified by species specific sequences of the mitochondrial COI gene of maternal origin ('a' or 'f') and the nuclear 28S gene of maternal/paternal origin ('A' or 'F'). In experimental crosses, these hermaphroditic species produce progeny of genotypes Ea (aAA), Ef (fFF) and hybrids (aAF and fFA) originating by self-fertilization or cross-fertilization. To facilitate studies on new aspects of the breeding biology and hybridization of earthworms, polymorphic microsatellite markers were developed based on 12 Ea and 12 Ef specimens and validated on DNA samples extracted from 24 genotyped specimens (aAA, fFF, aAF and fFA) from three laboratory-raised families and 10 of them were applied in the present study. The results indicate that microsatellite markers are valuable tools for tracking interspecific gene flow between these species.

The Effects of Wastewater Treatment Plant Failure on the Gulf of Gdansk (Southern Baltic Sea)

In August 2019 and during August/September 2020, the main collection system of the Wastewater Treatment Plant (WWTP) in Warsaw, Poland, malfunctioned. During that system failure, over 4.8 million m³ of untreated wastewater was dropped directly into the Vistula River in just a few days. It is currently considered as one of the largest known failures of WWTP worldwide. In order to assess the environmental impact, water samples were collected from 2 spots at the Vistula river estuary (406 and 415 km from the discharge location, respectively), and 4 spots at the Gulf of Gdansk, situated on the southern shore of the Baltic Sea. The sampling was conducted before the wastewater wave reached the Vistula river’s mouth, followed by daily sampling during 21 days after the malfunction occurred. The study showed the decline in water quality at the Vistula river estuary and the Baltic shore waters as the wave of wastewater reached those points, despite being situated over 400 km downstream from the place of the accident. Those changes included the reduction in the dissolved oxygen content (by 0.69-fold at its peak), the increase in Total Organic Carbon (TOC) (by 1.28-fold at its peak), nitrate-nitrogen (N-NO₃) (by 1.68-fold at its peak), phosphorous (P) (by 2.41-fold at its peak), conductivity (by 16.8-fold at its peak), and Chemical Oxygen Demand (COD) (by 1.84-fold). In the samples from the Vistula river, the decline in water quality was seen as incidental and lasted 2–3 days. Subsequently, the levels of physical and chemical parameters returned to the levels from before the accident. However, the changes in the Gulf of Gdańsk lasted significantly longer, especially on the West side of the Vistula river, where, even after 21 days from the initial accident, some parameters remained altered.

Reveal the metal handling and resistance of earthworm Metaphire californica with different exposure history through toxicokinetic modeling

Toxicokinetic (TK) model provides a new approach to mechanistically elucidate the natural variation of metal handling strategy by adaptive and sensitive earthworm populations. Here, TK model was applied to explore the metal handling and resistance strategy of wild Metaphire californica with different historical exposure history through a 12-day re-exposure and another 12-day elimination incubation. M. californica populations showed different kinetic strategies for non-essential metals (Cd and Pb) and essential metals (Zn and Cu), which were closely related to their exposure history. M. californica from the most serious Cd-contaminated soil showed the fastest kinetic rates of both Cd uptake (K₁ = 0.78 g_soil/g_worm/day) and elimination (K₂ = 0.23 day^-1), and also had the lowest Cd half-life (t_1/2 = 3.01 day), which demonstrated the potential Cd-resistance of wild M. californica from Cd-contaminated soils. Besides, the comparative experiment showed totally different metal kinetics of laboratory Eisenia fetida from field M. californica, suggesting the impacts of distinct exposure history and species-specifical sensitivities. These findings provide a novel approach to identify and quantify resistance using TK model and also imply the risk of overlooking existing exposure background and interspecies extrapolation in eco-toxicological studies and risk assessments.