Earthworm Mortality Research Articles

Effectiveness of copper oxychloride coated with iron nanoparticles against earthworms

This study examines the potential of iron nanoparticle-coated copper oxychloride in mitigating its toxic effects on earthworms, a key component of sustainable agriculture due to their role in enhancing soil quality and promoting plant growth. While earthworms and their coelomic fluid play a crucial role in enhancing soil health and promoting plant growth. Copper oxychloride, a commonly used fungicide, induces oxidative stress by disrupting antioxidant defense mechanisms in living systems. Through probit analysis, the median lethal concentration (LC50) of copper oxychloride was determined to be 2511.9 mg/kg. Artificial soil was treated with copper oxychloride at 60% and 80% of LC50, but the addition of iron nanoparticle-coated fungicide successfully reduced earthworm mortality to 0%. These findings offer promising insights into protecting non-target organisms from fungicide toxicity while maintaining agricultural productivity. The findings present a potential breakthrough in sustainable agriculture by demonstrating how nanotechnology can mitigate the harmful effects of fungicides on essential soil fauna. The use of iron nanoparticle-coated fungicides not only protects earthworms but also offers a path to maintaining ecological balance and enhancing crop productivity without compromising soil health.

Влияние катионоактивного, анионоактивного и неионогенного поверхностно-активных веществ на почвенные олигохеты Eisenia fetida andrey (Bouche, 1972)

Results of studying the main types of surfactants effect on earthworms Eisenia fetida andrey (Bouche, 1972) are presented. The worms were tested for survival and preference-avoidance behavioral reactions. Earthworms avoided sodium dodecyl sulfate (SDS) at 0.02 g/kg and above, cetyltrimethylammonium bromide – at 0.1 g/kg and above, and polysorbate 80 – at 30 mL/kg and above. The 100% mortality of earthworms occurred at 0.001, 0.01 and 0.02 g/kg of SDS on day 30, at 1 g/kg – on day 25, and at 1 g/kg – on day 2 of the experiment. Сetyltrimethylammonium bromide at 0.001 and 0.01 g/kg caused the 100% mortality of worms on day 30; at 0.1 g/kg – on day 25; at 0.5 g/kg – on day 5; and at 1.0 g/kg already on day 2 of the experiment. The 100% mortality of worms occurred at 0.1, 1 and 10 mL/kg of polysorbate 80 on day 30 of incubation; at 20 or 30 mL/kg – on day 20; at 50 mL/kg – on day 10 of experience. The following toxicity series (both in terms of g/L and in terms of g/mol) of the tested surfactants for earthworms was constructed on the basis of the results obtained (increasing toxicity): polysorbate 80 (non-ionic surfactant) < cetrimonium bromide (cationic surfactant) < sodium dodecyl sulfate (anion-active surfactant).

Biodegradation of oily waste sludge using vermiremediation and composting process bioaugmentated with isolated hydrocarbon-degrading bacteria: Performance and ecotoxicity assessment

Degradation of petroleum hydrocarbons (PHs) contents of oily waste sludge (OWS) is necessary in order to prevent the related environmental pollution. The present study aimed to investigate the degradation of total petroleum hydrocarbons (TPHs) from OWS using bioaugmentated composting (BC) with hydrocarbon-degrading bacterial consortium (HDBC) as pre-treatment followed by vermicomposting (VC) by Eisenia fetida. After isolating two indigenous bacterial strains from OWS, the ability of their consortium in degradation of crude oil was tested in Bushnell-Haas medium (BHM). Then, biodegradation of OWS was measured in the VC alone, BC alone, simultaneous BC and VC (BCVC), and BC followed by VC (BCFVC) containing high levels (30 g/kg) of TPHs. Toxicity tests including the mortality of mature earthworms and the numbers of juveniles were conducted at the TPHs of 0–40 g/kg. The obtained results indicated that the HDBC removed 18–64 % of TPHs of crude oil (1–5 %) in BHM after 7 days of incubation. After a period of 12 weeks, the removal rates of TPHs in the VC, BC, BCVC, and BCFVC experiments were 23.7, 79.5, 85.2, and 91.8 %, respectively, verifying the efficacy of simultaneous application of HDBC and worms in bioremediation of OWS. The TPHs contents of OWS exhibited toxic effects on E. fetida at some concentrations and the median lethal concentration (LC50) of TPHs was computed to be 14.5 g/kg after 28 days. This study demonstrated the effectiveness of composting bioaugmentated with HDBC as a pre-treatment step followed by vermicomposting in bioremediation of OWS.

Valorization of Fecal Sludge Stabilization via Vermicomposting in Microcosm-Enriched Substrates Using Organic Plant-Derived Materials and Agricultural Soil for Compost Production

The enormous generation of fecal sludge without proper treatment is a major sanitation problem. Vermicomposting of fecal sludge is an innovative way of producing value added compost called vermicompost. A vermicomposting technique that involves augmenting vermibed substrates with organic rich materials to provide additional nutrients and underlying layers needed for microcosm development to produce desirable vermicompost is mostly referred to as substrate enrichment. This study investigated the substrate enrichment of using plant-derived materials, which include coconut coir, palm coir and saw dust, combined with agricultural soil for the production of vermicompost from fecal sludge. Enriched substrates were prepared with 80 g of agricultural soil as amending material, 120 g of fecal matter (65-70% dry matter) and 160 g of the plant-derived materials. The treatments were labeled T1-T3, thus, T1 contained coconut coir, T2 contained palm coir and T3 contained saw dust, followed by a control treatment (T4) that had no plant-derived material. Treatments were triplicated and about 3-week-old 20 clitellated, E. fetida (live weight ∼255–275 mg) were used in the vermicomposting for 12 wk. Physicochemical parameters such as pH, Organic Carbon (Corg), Total Nitrogen (Ntot), Available Phosphorus (Pavail), Exchangeable Calcium (Caexch), Iron (Fe), Lead (Pb) and Aluminum (Al) test were performed. Vermicompost at T1 had the most Corg mineralization, most enhancement in Ntot, Pavail, Caexch, and least concentration of Fe, Pb and Al. Less than 20% earthworm mortality was recorded in all treatments except T4 (28.38 ± 8.71%). The enriched substrates were suitable for vermiculture with a worm weight ranged from 593.77 to 569.39 ± 2.30 mg and the vermicompost recorded high nutrient contents. The nutritious nature and the reduced metal concentration of the produced vermicompost might be safe and productive for agricultural use. However, further studies on the effectiveness of the vermicompost on plants growth and yield needs to be investigated.

Safety and efficacy indicators of guarana and Brazil nut extract carried in nanoparticles of coenzyme Q10: Evidence from human blood cells and red earthworm experimental model

This study characterized a nanosupplement based on coenzyme Q10 containing guarana (Paullinia cupana) and Brazil nuts oil (Bertholetia excelsa) (G-Nut). Determined cytotoxic and oxi-immunomodulatory effects on human peripheral blood mononuclear cells (PBMCs) and its effect on mortality of red Californian earthworms (Eisenia fetida) and on the immune efficiency of its coelomocytes immune by in vitro exposure to yeast dead microorganism. The cytotoxic and immunomodulatory effects of G-Nut and the GN-Free extract (0.25–3 mg/mL) were determined in PBMC cultures. Apoptotic, oxidative, and inflammatory markers were determined using biochemical, immunological, and molecular protocols. The effects of G-Nut and GN-Free extracts on mortality and immune efficiency were investigated in earthworms. G-Nut and GN-Free did not induce cytotoxic events in PBMCs, triggering the decrease in apoptotic (caspases 3 and 8) gene expression, lipid and protein oxidation levels, or pro-inflammatory cytokine levels. G-Nut and GN-Free did not trigger earthworm mortality and improved coelomocyte immune efficiency by increasing Eisenia neutrophil extracellular DNA traps and brown body formation when exposed to dead yeasts. The G-Nut nanoformulation is safe and can be used as a new form of food supplement by oral or transdermal delivery.

Exopolysaccharides from Rhizobium Tropici mitigate aluminum bioaccumulation and toxicity in earthworm Lumbricus Terrestris

Aluminum is one of the most abundant elements in earth’s crust and soils. Global soil acidification has occurred with industrialization and enhances Al solubility in acidic soils, resulting in Al phytoxicity and reducing crop production. Earthworms play an important role in nutrient recycling in soils and maintaining soil health. Rhizosphere microorganism excretes exopolysaccharides (EPS) into the rhizosphere. The objectives of this study is to examine effects of EPS from Rhizobium Tropici on aluminum uptake and ecotoxicity to earthworms in soils and litters. Overall this study provides the scientific understanding of the EPS in alleviation of Al toxicity to earthworms in soils. Results showed the clear mitigation of EPS in reducing earthworm mortality rate and increasing its reproductivity under Al stress. EPS significantly decreased Al uptake from soil and litters, and decreased Al in subcellular distribution (cell membrane, cytosol and organelle fractions) in earthworms from soils. Al in purges was found to be mainly present in the residual fraction, while EPS slightly increased Al in water soluble and exchangeable fractions in purges. Overall water soluble and organic matter bound Al in soils were correlated well with Al in earthworms, but Al in earthworms were controlled by total Al in purges. The current study concluded that earthworm Lumbricus Terrestre may be a potential bio-indicator of Al ecotoxicity in soils and EPS from Rhizobium Tropici effectively mitigated Al ecotoxicity in soils.

Quinones-enhanced humification in food waste composting: A novel strategy for hazard mitigation and nitrogen retention

The harmless and high-value conversion of organic waste are the core problems to be solved by composting technology. This study introduced an innovative method of promoting targeted humification and nitrogen retention in composting by adding p-benzoquinone (PBQ), the composting without any additives was set as control group (CK). The results indicated that the addition of exogenous quinones led to a 30.1% increase in humic acid (HA) content during the heating and thermophilic phases of composting. Spectroscopic analyses confirmed that exogenous quinones form the core skeleton structure of amino-quinones in HA through composting biochemical reactions. This accelerated the transformation of quinones into recalcitrant HA in the early stages of composting, and reduced CO2 and NH3 by 8% and 78%, respectively. Redundancy analysis (RDA) revealed that the decrease in carbon and nitrogen losses primarily correlated with quinones enhancing HA formation and greater nitrogen incorporation into HA (P < 0.05). Furthermore, the compost treated with quinones demonstrated a decrease in phytotoxicity and earthworm mortality, alongside a significant increase in the relative abundance of actinobacteria, which are associated with the humification process. This research establishes and proposes that co-composting with quinones-containing waste is an effective approach for the sustainable recycling of hazardous solid waste.

Potential toxicity of iron ore tailings after the overflow of a mining dam in Nova Lima (Minas Gerais State, Brazil)

In January 2022, the Pau Branco Mine dam in Nova Lima (MG), under the responsibility of Vallourec, overflowed after intense rainfall and iron ore tailings impacted surrounding soils and aquatic ecosystems. These tailings can alter the natural composition of soils and rivers, poising risks on soil biota. This study consists of a preliminary evaluation of potential toxicity of terrigenous materials impacted by tailings from the Pau Branco Mine, based on acute bioassays with earthworms (Eisenia andrei) and germination tests with lettuce (Lactuca sativa). The physical and chemical characterization and determination of toxic metals in the samples supported the interpretation of the ecotoxicological data. The results indicated that the tailing deposition induced the increase in particle density, due to the increase in iron concentrations in the samples. As a consequence, the water holding capacity (WHC) of the materials and organic matter concentrations were dramatically reduced. Given that the mining tailings exhibit fine texture, their depositions on soils increased the percentage of fines particles (silt) in the samples. Metal determination revealed geochemical anomalies for nickel, copper and chromium, whose concentrations exceeded the threshold limits defined by Brazilian law for soil and aquatic sediment quality. The bioassays with earthworms showed no significant earthworm mortality, indicating low acute toxicity. However, earthworm biomass was significantly reduced, suggesting that they were submitted to some stress induced by the exposure to contaminants and/or by the reduction of the organic matter contents (food scarcity) and WHC (water scarcity). The bioassays with lettuce showed no significant effects on germination levels. However, the seedling biomass was significantly reduced due, possibly, to the reduction of WHC and especially due to the increase of fines particles in the samples, which tends to inhibit the establishment of the root systems.

Effects of pyroligneous acid on acute, chronic, and cyto-genotoxicity to earthworms (Eisenia fetida)

The pyroligneous acid (PA), or wood vinegar, is a byproduct of wood carbonization during the slow pyrolysis process. PA is recognized globally as a safe compound for agriculture due to its various beneficial properties, such as antioxidant, antibacterial, antifungal, and termiticidal properties. However, the impact of different PA concentrations on beneficial soil organisms, such as earthworms has not been investigated. The present study aims to understand the effects of different PA concentrations on earthworm Eisenia fetida. The earthworms were exposed to nine different concentrations of PA in soils, including their control. The acute toxicity assay was performed after 14 days of exposure, and the chronic toxicity assay was performed up to 8 weeks after exposure. The results from the acute toxicity assay demonstrated no significant effect on earthworm mortality. The chronic toxicity assay showed that lower PA concentrations (0.01–0.2% of weight/weight PA in soil) promoted cocoon and juvenile production in soils, whereas higher PA concentrations (0.5 and 1%) had a negative effect. These findings highlight the potential of PA to enhance soil fertility at lower concentrations, up to 0.2%, by stimulating worm activity and subsequent manure production. The outcomes of this study have significant implications for the careful management of PA concentrations within agricultural operations.

Eco-toxicity assessment of fossil fuel tainted soil before phytoremediation trial

The research objective was to assess the extent of fossil fuel toxicity in the contaminated soil for an improved appraisal before phytoremediation trial and eco-safety of the soil. We used Bonny light fossil fuel to contaminate soil at different percentage levels of concentrations (5%, 3%, 1% and 0%). We assessed earthworm weight change and survival rate and plant response of Zea mays to the various treatments. Our results show that soil treated at concentration level of 5% had the highest earthworm mortality rate while the control soils had the highest earthworm survival rate. In addition, there was a noticeable change in the body weight of surviving earthworms in the 5% and 3% treated soil. Germination, shoot length and root length of the experimental plant was not totally inhibited in all the different concentrations. There was greater germination percentage obtained in 3%, 1% and 0% fossil fuel concentrations. The study verifies that high fossil fuel contamination percentage affects the biota of the soil by inhibiting plant germination and growth as well as reducing the survival and body mass of earthworms in the soil. The petroleum oil percentages utilized in this investigation can support phytoremediation trial and proposes that petroleum oil soil contamination ≤ 3% is ecologically safe for plants and animals’ survival as well as development.

Responses of &lt;em&gt;Selenastrum capricornutum&lt;/em&gt;, &lt;em&gt;Eisenia fetida&lt;/em&gt;, &lt;em&gt;Brassica nigra&lt;/em&gt; and &lt;em&gt;Sorghum bicolor&lt;/em&gt; to sent phone battery toxicity

Indiscriminate release of spent phone battery in the environment poses a danger to human and animal life. Assessment of their toxicity using bioassays, therefore, becomes imperative. In this study, the Organization for Economic Co-Operation and Development (OECD) standardized toxicity tests exhibited a high degree of sensitivity in evaluating various endpoints across different trophic levels and taxonomic groups. These tests encompass a range of parameters, including mortality rate (h), growth inhibition (ECx), germination, and root length (ECx), providing a comprehensive assessment of spent phone battery toxicity. The responses of Selenastrum capricornutum, Eisenia fetida, Brassica nigra and Sorghum bicolor to spent phone battery toxicity were investigated. Standard methods of analysis for heavy metal, microalgal toxicity, earthworm mortality and phytotoxicity were adopted. S. capricornutum, B. nigra and S. bicolor seeds were exposed for 72 h and 5 d at concentrations ranging from 0 to 100 mg/L or mg/kg while Eisenia fetida exposed for 48 h and 14 d at concentrations ranging from 0 mg/L to 2.10 LC50 mg/kg for Gionee phone battery and 0 mg/L to 3.50 LC50 mg/kg for Lenovo battery samples. The result showed that all the spent phone battery samples (Gionee and Lenovo) had WHO and FEPA exceeded the limits of the heavy metals analyzed. The order of toxicity to S. capricornutum growth is Lenovo &gt; Gionee &gt; positive control K2Cr2O7 after 72 h exposure. On E. fetida, Gionee &gt; Lenovo after 48 h and 14th-day treatments while boric acid &gt; Gionee &gt; Lenovo as well as boric acid &gt; Lenovo &gt; Gionee were observed on B. nigra and S. bicolor, respectively after 5 d exposure. The responses of the model organisms in this study necessitate the establishment of stringent implemental management measures by government and environmental policymakers to effectively address the problems and challenges associated with e-waste.

A biodegradable oxidized starch/carboxymethyl chitosan film coated with pesticide-loaded ZIF-8 for tomato fusarium wilt control

Film mulching is one of the most important methods to control soil-borne diseases. However, the traditional mulch may cause microplastic pollution and soil ecological damage. Herein, a biodegradable film was developed using oxidized starch and carboxymethyl chitosan and incorporated ZIF-8 carrying fludioxonil to sustainably control soil-borne disease. The microstructure, mechanical properties, optical properties, and water barrier properties of the composite films (Flu@ZIF-8-OS/CMCS) were investigated. The results show that Flu@ZIF-8-OS/CMCS had a smooth and uniform surface and excellent light transmittance. The excellent mechanical properties of the films were verified by tensile strength, elongation at break and Young's modulus. Higher contact angle and lower water vapor permeability indicate water retention capacity of the soil was improved through using Flu@ZIF-8-OS/CMCS. Furthermore, the release properties, biological activity, degradability and safety to soil organisms of Flu@ZIF-8-OS/CMCS was determined. The addition of ZIF-8 significantly improved the film's ability to retard the release of Flu, while the Flu@ZIF-8-OS/CMCS has good soil degradability. In vitro antifungal assays and pot experiments demonstrated excellent inhibitory activity against Fusarium oxysporum f. sp. Lycopersici. Flu@ZIF-8-OS/CMCS caused only 13.33 % mortality of earthworms within 7 d. This research provides a new approach to reducing microplastic pollution and effectively managing soil-borne diseases.

The environmental impact of mask-derived microplastics on soil ecosystems

During the COVID-19 pandemic, a significant increased number of masks were used and improperly disposed of. For example, the global monthly consumption of approximately 129 billion masks. Masks, composed of fibrous materials, can readily release microplastics, which may threaten various soil ecosystem components such as plants, animals, microbes, and soil properties. However, the specific effects of mask-derived microplastics on these components remain largely unexplored. Here, we investigated the effects of mask-derived microplastics (grouped by different concentrations: 0, 0.25, 0.5, and 1 % w/w) on soil physicochemical properties, microbial communities, growth performance of lettuce (Lactuca sativa L. var. ramosa Hort.) and earthworm (Eisenia fetida) under laboratory conditions for 80 days. Our findings suggest that mask-derived microplastics reduced soil bulk density while increasing the mean weight diameter of soil aggregates and modifying nutrient levels, including organic matter, potassium, nitrogen, and phosphorus. An increase in the abundance of denitrification bacteria (Rhodanobacteraceae) was also observed. Mask-derived microplastics were found to reduce lettuce germination, and a hormesis effect of low-concentration stimulation and high-concentration inhibition was observed on biomass, chlorophyll, and root activity. While the mortality of earthworms was not significantly affected by the mask-derived microplastics, but their growth was inhibited. Collectively, our results indicate that mask-derived microplastics can substantially impact soil properties, plant growth, and earthworm health, with potential implications for soil ecosystem functionality.

Effects of diclofenac, sulfamethoxazole, and wastewater from constructed wetlands on Eisenia fetida: impacts on mortality, fertility, and oxidative stress.

Soil contamination with micropollutants is an important global problem and the impact of these pollutants on living organisms cannot be underestimated. The effects of diclofenac (DCF) and sulfamethoxazole (SMX), their mixture (MIX), and wastewater containing these drugs on the mortality and reproduction of Eisenia fetida were investigated. The impact on the activities of antioxidant enzymes in earthworm cells was also assessed. Furthermore, the influence of the following parameters of the vertical flow constructed wetlands on wastewater toxicity was investigated: the dosing system, the presence of pharmaceuticals and the plants Miscanthus giganteus. The compounds and their mixture significantly affected the reproduction and mortality of earthworms. The calculated values of LC50,28 days values were 3.4 ± 0.3 mg kg-1 for DCF, 1.6 ± 0.3 mg kg-1 for SMX, and 0.9 ± 0.1 mg kg-1 for MIX. The EC50 (reproduction assay) for DCF was 1.2 ± 0.2 mg kg-1, whereas for SMX, it was 0.4 ± 0.1 mg kg-1, and for MIX, it was 0.3 ± 0.1 mg kg-1, respectively. The mixture toxicity index (MTI) was calculated to determine drug interactions. For both E. fetida mortality (MTI = 3.29) and reproduction (MTI = 3.41), the index was greater than 1, suggesting a synergistic effect of the mixture. We also observed a negative effect of wastewater (raw and treated) on mortality (32% for raw and 8% for treated wastewater) and fertility (66% and 39%, respectively) of E. fetida. It is extremely important to analyze the harmfulness of microcontaminants to organisms inhabiting natural environments, especially in the case of wastewater for irrigation of agricultural fields.

Effects of biochar on earthworms during remediation of potentially toxic elements contaminated soils

With the widespread use of biochar for soil remediation and improvement, its effects on soil organisms are receiving increased attention. The impacts of biochar on earthworms are still poorly understood. This study aimed to assess the potential ecotoxicity of rice husk biochar (RB) and sludge biochar (SB) on earthworms during potentially toxic elements (PTEs) contaminated soil remediation. The results showed that high rates of RB addition (5% and 10%) caused earthworm mortality, but SB addition did not affect earthworm survival. When added at non-lethal rates (3%), RB and SB addition did not affect survival, weight loss, and PTEs accumulation of earthworms, while resulting in apparent avoidance behavior and oxidative stress response. Among them, RB addition was more likely to cause avoidance behavior, while SB addition had a more pronounced stress effect on earthworms. Additionally, the bacterial communities in the earthworm gut were more sensitive to biochar addition than those in soil. SB addition had a greater impact on earthworm gut bacterial communities than RB addition. The addition of RB and SB increased the abundance of Bacillaceae while decreasing the abundance of Rhizobiaceae in the earthworm gut. This change in the composition of bacterial community may impact the nitrogen cycle and organic matter degradation functions of earthworms. The study suggests that RB and SB may have different effects on earthworms during PTEs-contaminated soil remediation, depending on their properties. It will assist us to understand the potential ecotoxicity of biochar and provide several guidance for its safe application.

Effect of bio-based microplastics on earthworms Eisenia andrei

The contribution of bio-based plastics in the global market is gradually growing and diversifying. Therefore, it is necessary to assess their environmental impact including the biotic parts of ecosystems. Earthworms are regarded as functionally essential and useful bioindicators of ecological disturbances in the terrestrial ecosystems.The purpose of this study was to evaluate the impact of three innovative bio-based plastics on earthworms Eisenia andrei in the long-term experiments. It comprised the mortality, body mass and reproduction ability of earthworms as well as the oxidative stress response. Regarding the latter the activities of catalase (CAT) and superoxide dismutase (SOD) involved in the antioxidant system of earthworms were determined. Two out of three bio-based materials tested were polylactic acid-based (PLA-based) plastics, while one was poly(hydroxybutyrate-co-valerate)-based (PHBV-based) plastic.Neither mortality nor weight of adult earthworms was affected even at high concentration of the bio-based plastics up to 12.5 % w/w in the soil. Reproduction ability occurred to be more sensitive endpoint than mortality or body mass. At the concentration of 12.5 % w/w each of the studied bio-based plastics contributed to the decrease of the earthworm reproduction at statistically significant level. PLA-based plastics exerted stronger effect on earthworm reproduction ability than PHBV-based plastic did. CAT activity turned out to be a good indicator of the cellular response against oxidative stress induced by bio-based plastics in earthworms. The activity of this enzyme increased in the response to the exposure to the bio-based plastics compared to the level achieved in the control tests. It was from 16 % to about 84 % dependent on the material tested and its concentration in the soil. Finally, the reproduction ability and catalase activity are recommended to be used in the evaluation of the potential impacts of bio-based plastics on earthworms.

Environmental toxicity of organic UV filters at predicted no-effect concentrations in soil organism, Eisenia fetida

Organic UV filters (OUVFs) are categorized as emerging environmental contaminants (EECs) owing to their extensive use and widespread occurrence. Recent findings indicate their potential adverse effects on biota inhabiting different ecological niches. The present work was carried out to investigate the environmental toxicity of OUVFs at predicted no-effect concentrations (PNEC) derived from lethal concentrations and ascertain the accuracy of the application factor to derive PNEC in soil ecotoxicology. Results of acute toxicity revealed that benzophenone-type OUVFs are found to be significantly toxic [Benzophenone (BP)>Oxybenzone (BP-3)>Octocrylene (OC)=4-Methylbenzylidene camphor (4-MBC)] than camphor and cinnamic acid derivatives during acute exposures. Based on the LC50, PNEC has been derived by applying 1000 as the soil application factor. Using the derived PNEC, the RQ for the selected OUVFs was found to be OC>4-MBC>BP-3>BP. The short and long-term exposure at PNEC (BP: 0.17 mg/Kg; BP-3: 0.36 mg/Kg; OC: 2 mg/Kg); 4-MBC: 2 mg/Kg) showed no significant changes (p>0.05) in earthworm mortality, biomass, and reproduction in terms of hatchling and cocoon production and cocoon weight during the single and combined exposures of PNEC. Nonetheless, at the cellular level, single exposure has negligible effects on oxidative stress and neurotoxicity markers to BP and OC OUVFs and invariably reduced activity on ROS, showing earthworms adaptation to OUVFs toxicity at PNECs, whereas combined exposure resulted in antagonistic effects. Based on the present experimental investigation, the null hypothesis is rejected, and the accuracy of the application factor to derive PNEC in soil ecotoxicology is validated.

Ecotoxicity of Single-Use Plastics to Earthworms

The excessive use of plastics in recent years, especially so-called single-use plastics, has led to an incipient increase in the presence of this material in the soil. As soil is the essential production factor in agriculture, this study aims to test the toxicity to earthworms of different concentrations of plastics using the same substrate for each sample. Earthworms are the main bioindicator of soil quality and are of particular ecological value because their disappearance or loss in population would have disastrous consequences for the environment. This study examines the growth, mortality and reproductive cycle of individual earthworms. The species to be studied is Eisenia fetida and during the test, individuals are immersed in five different concentrations: 1 mg/kg; 10 mg/kg; 100 mg/kg; 1000 mg/kg; and 2000 mg/kg. Bioplastic OK industrial compost (that meet the requirements established to comply with compostability according to EN 13432) was used. Whether the plastic in any of those concentrations is harmful to the worm population was then be checked. The test shows the mixture of PLA and PBAT (biodegradable plastic) studied has no significant effect on the population of Eisenia fetida. None of the variables studied yields significant data on this plastic and the effect it causes on the population of earthworms, Eisenia fetida.

Assessment of the acute toxicity of agrochemicals on earthworm (Aporrectodea caliginosa) using filter paper contact and soil mixing tests

Abstract. El-Aswad AF, Fouad MR, Aly MI. 2023. Assessment of the acute toxicity of agrochemicals on earthworm (Aporrectodea caliginosa) using filter paper contact and soil mixing tests. Asian J Agric 7: 14-19. Earthworms are suitable bioindicators of chemical contamination in terrestrial ecosystems. Therefore, adult earthworms (Aporrectodea caliginosa Savigny, 1826), which are common in Egyptian rice fields were used to study the side effects of fenitrothion and thiobencarb. Also, it was used two common Egyptian soil types; alluvial soil (clay soil) and the calcareous soil (sandy clay loam soil). Two tests were used; filter paper contact test at 24, 48 and 72 h, and the soil mixing test at 5 and 10 days. The effect of both pesticides on mortality of earthworm was insignificant at 24 h with a low mortality percentage. LC50 value of fenitrothion and thiobencarb were 83.16, 288.26, 24.67, and 39.98 µg a.i mL-1 at 48 and 72 h, respectively. Based on the LC50 values, fenitrothion was 3.5 and 1.6 times more toxic than thiobencarb at 48 and 72 h, respectively. At 5 and 10 days after treatment, respectively, the LC50 for fenitrothion in the soil mixing test decreased from 334.27 to 55.45 in clay soil and from (415.90) to (25.00) in sandy soil. Regarding to fenitrothion in soil mixing test, the LC50 was reduced from 334.27 to 55.45 in clay soil and from 415.90 to 25.00 in sandy soil at 5 and 10 days after treatment, respectively. Also, the LC50 of thiobencarb in clay soil was decreased from 0.93 to 0.41 and from 55.28 to 10.65 at 5 and 10 days, respectively. In general, a positive relation was recorded between the tested pesticide toxicity on earthworm and concentrations, and also exposure time. Fenitrothion was more toxic on earthworm in contact filter paper test than thiobencarb. While, in clay soil, fenitrothion was least toxic to the earthworm in soil mixing test, this could be attributed to the slow degradation in the worms and subsequently less elimination of the metabolites as well as attributed to its higher adsorption and lower desorption in soil.

Effects of elevated temperature and decreased soil moisture content on triclosan ecotoxicity to earthworm E. fetida.

Emerging pollutants and climate change are two main challenges affecting soil organisms today. Changes in temperature and soil moisture with climate change are key factors determining activity and fitness of soil dwelling organisms. The occurrence and toxicity of antimicrobial agent triclosan (TCS) in terrestrial environment is of high concern, while no data are available on TCS toxicity changes to terrestrial organisms under global climate change. The study's aim was to assess the impact of elevated temperature, decreased soil moisture content, and their complex interaction on triclosan-induced changes in Eisenia fetida life cycle parameters (growth, reproduction, and survival). Eight-week TCS-contaminated soil (10-750 mg TCS kg-1) experiments with E. fetida were performed at four different treatments: C (21 °C + 60% water holding capacity (WHC)); D (21 °C and 30% WHC); T (25 °C + 60% WHC); and T + D (25 °C + 30% WHC). TCS had negative impact on the earthworm mortality, growth, and reproduction. Changing climate conditions have altered TCS toxicity to E. fetida. Drought and drought in combination with elevated temperature enhanced the adverse effects of TCS on earthworm survival, growth rate, and reproduction, while single elevated temperature slightly reduced TCS lethal toxicity as well as toxicity to growth rate and reproduction.