The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform

Cornelis A M Gestel - One of the best experts on this subject based on the ideXlab platform.

  • multigeneration toxicity of imidacloprid and thiacloprid to Folsomia Candida
    Ecotoxicology, 2017
    Co-Authors: Cornelis A M Gestel, Cláudia De Lima E Silva, Jacco Koekkoek, M H Lamoree, Rudo A. Verweij
    Abstract:

    In a recent study, we showed that the springtail Folsomia Candida was quite sensitive the neonicotinoid insecticides imidacloprid and thiacloprid. This study aimed at determining the toxicity of both compounds to F. Candida following exposure over three generations, in natural LUFA 2.2 standard soil. In the first generation, imidacloprid was more toxic than thiacloprid, with LC50s of 0.44 and 9.0 mg/kg dry soil, respectively and EC50s of 0.29 and 1.5 mg/kg dry soil, respectively. The higher LC50/EC50 ratio suggests that thiacloprid has more effects on reproduction, while imidacloprid shows lethal toxicity to the springtails. In the multigeneration tests, using soil spiked at the start of the first generation exposures, imidacloprid had a consistent effect on survival and reproduction in all three generations, with LC50s and EC50s of 0.21–0.44 and 0.12–0.29 mg/kg dry soil, respectively, while thiacloprid-exposed animals showed clear recovery in the second and third generations (LC50 and EC50 > 3.33 mg/kg dry soil). The latter finding is in agreement with the persistence of imidacloprid and the fast degradation of thiacloprid in the test soil.

  • the effect of ph and calcium on copper availability to the springtail Folsomia Candida in simplified soil solutions
    Pedobiologia, 2014
    Co-Authors: Masoud M. Ardestani, Cornelis A M Gestel
    Abstract:

    Abstract The effect of pH and calcium on copper bioavailability to the springtail Folsomia Candida was determined by assessing uptake kinetics upon copper exposure for 15 days in simplified soil solutions. A slight bioaccumulation of copper was observed in all treatments and controls. The effect of exposure concentration and calcium level on copper accumulation was not significant. Although pH and time slightly but significantly affected copper concentrations in the body, copper uptake rates were not significantly different from zero. This suggests that copper uptake in F. Candida exposed to sub-lethal copper concentrations in soil pore water is not affected by pH and calcium.

  • using a toxicokinetics approach to explain the effect of soil ph on cadmium bioavailability to Folsomia Candida
    Environmental Pollution, 2013
    Co-Authors: Masoud M. Ardestani, Cornelis A M Gestel
    Abstract:

    Abstract The aim of this study was to improve our understanding of metal bioavailability in soil by linking the biotic ligand approach with toxicokinetics modelling. We determined cadmium bioaccumulation kinetics in Folsomia Candida (Collembola) as a function of soil pH. Animals were exposed for 21 days to LUFA 2.2 soil at 5 or 20 μg Cd g −1 dry soil followed by 21 days elimination in clean soil. Internal cadmium concentrations were modelled using a first-order one-compartment model, relating uptake rate constants ( k 1 ) to total soil, water or 0.01 M CaCl 2 extractable and porewater concentrations. Based on total soil concentrations, k 1 was independent of soil pH while it strongly increased with increasing pH based on porewater concentrations explaining the reduced competition of H + ions making cadmium more bioavailable in pore water at high pH. This shows that the principles of biotic ligand modelling are applicable to predict cadmium accumulation kinetics in soil-living invertebrates.

  • cadmium affects toxicokinetics of pyrene in the collembolan Folsomia Candida
    Ecotoxicology, 2012
    Co-Authors: Mieke Broerse, Hilde Oorsprong, Cornelis A M Gestel
    Abstract:

    Since toxicity is time dependent, short-term toxicity tests may overlook mixture effects, because chemical accumulation within an organism takes time. We therefore studied the effects of cadmium on the toxicokinetics of pyrene and its metabolites in the soil-dwelling collembolan Folsomia Candida exposed through Lufa 2.2 soil. Single pyrene was rapidly taken up and steady state was reached within the 337-h exposure period. Simultaneous exposure to cadmium significantly decreased the pyrene uptake and elimination rate, resulting in a prolonged half life. Kinetics of the first phase metabolite OH-pyrene was also significantly influenced by cadmium. Cadmium increased the hydroxylation rate of pyrene but slowed down its further metabolization, again resulting in a prolonged half life. We showed that pyrene accumulation and metabolization are significantly influenced by the presence of cadmium. Our results suggest that mixture effects may be dependent on exposure time.

  • application of bioassays with enchytraeus crypticus and Folsomia Candida to evaluate the toxicity of a metal contaminated soil before and after remediation
    Journal of Soils and Sediments, 2011
    Co-Authors: Veronica Gonzalez, Maria Diezortiz, M Simon, Cornelis A M Gestel
    Abstract:

    Purpose A contaminated soil was amended to reduce bioavailability of metals (As, Cd, Cu, Pb, and Zn) and to modify its potential environmental impacts. Reproduction toxicity tests using two different soil invertebrates, Enchytraeus crypticus and Folsomia Candida, were used to evaluate efficiency of soil amendments to reduce metal availability.

Susana Loureiro - One of the best experts on this subject based on the ideXlab platform.

  • copper toxicity to Folsomia Candida in different soils a comparison between nano and conventional formulations
    Environmental Chemistry, 2019
    Co-Authors: Joana Neves, Diogo N Cardoso, Catarina Malheiro, Amadeu M V M Soares, Frederick J Wrona, Susana Loureiro
    Abstract:

    Environmental context Nanotechnology has great potential for managing agricultural plant disease. This study compares effects of various nano and conventional copper formulations on Collembola Folsomia Candida, a model arthropod often used to test soil pollutants. Although toxicity varied between formulations, with a nanopesticide showing one of the highest toxicities, the differences were mainly due to the active copper compound rather than its nano formulation. Abstract Nanotechnology has recently become a major asset in agricultural practices owing to the improvement and provision of solutions for plant disease management, especially in the form of nanopesticides. These products are considered as one of the main direct sources of nanomaterials in terrestrial ecosystems, and for that reason, it is essential to understand and evaluate their behaviour and toxicity in the environment. In addition, the panoply of similar compounds makes it difficult to accurately evaluate if different formulations may induce different effects on non-target organisms. We aim to compare the toxicity and bioavailability of different copper formulations (nano and non-nano) applied to the soil using the model organism Folsomia Candida. Reproduction tests were performed in two different soils (Lufa 2.1 and 2.2) with two equilibrium times after spiking (0 and 48 h). Depending on the copper form present in the formulation, the half maximal effective concentration (EC50) values of the non-nano pesticides varied from 274 mg Cu kg−1 in Champion® to 3030 mg Cu kg−1 in Cupravit® in Lufa 2.2 and 48 h equilibrium. The nano formulation displayed one of the highest toxicities to collembolans, with an EC50 of 156 mg Cu kg−1. Regarding the soil type, a higher toxicity in Lufa 2.1 was observed probably related to the soil characteristics, namely lower pH and lower organic content, which increase the metal solubility and consequently the bioavailability. The only exception was the nanopesticide Kocide 3000®, whose toxicity was higher in Lufa 2.2. This study emphasises the importance of understanding the links between metal bioavailability and toxicity to support the more robust environmental risk assessment of different Cu fungicide formulations.

  • toxic effects of human pharmaceuticals to Folsomia Candida a multigeneration approach
    Science of The Total Environment, 2018
    Co-Authors: Miguel Oliveira, Diogo N Cardoso, Amadeu M V M Soares, Susana Loureiro
    Abstract:

    Abstract The study of the effects of human pharmaceuticals has been considered a priority in terms of environmental safety. However, the available information concerning soil organisms is scarce. To decrease this knowledge gap, the effects of carbamazepine and fluoxetine (0.04, 0.4, 4 and 40 mg·kg− 1 of soil) were assessed on the springtail Folsomia Candida, for three consecutive generations. The assessed endpoints included survival, reproduction and biomarkers associated with biotransformation, neurotransmission and peroxidative damage. A light avoidance behavior test was performed, in the third generation. The obtained data demonstrate that both pharmaceuticals may affect Collembola populations after three generational exposures, as showed by the decrease trend for both survival and reproduction. The effects of carbamazepine were however, more pronounced. After the third generational exposure to all carbamazepine tested concentrations and the three highest concentrations of fluoxetine, F. Candida displayed altered light avoidance behavior. The biochemical endpoints also revealed that carbamazepine and fluoxetine may exert toxic effects to F. Candida through the induction of oxidative stress and impairment in neurotransmission with an apparent higher potential for carbamazepine. Overall, data show that the effects of pharmaceuticals throughout different generations should be considered in risk assessment studies.

  • effects of short term exposure to fluoxetine and carbamazepine to the collembolan Folsomia Candida
    Chemosphere, 2015
    Co-Authors: Miguel Oliveira, Diogo N Cardoso, Amadeu M V M Soares, Susana Loureiro
    Abstract:

    Abstract Pharmaceuticals, emerging environmental contaminants, have their ecotoxicological effects to non-target organisms in soil largely unknown. This study assessed short-term effects of two human pharmaceuticals, carbamazepine and fluoxetine, to Folsomia Candida. Avoidance to spiked soils was assessed after 48 and 96 h exposure and biochemical changes (acetylcholinesterase and glutathione S-transferase activities, and lipid peroxidation levels) after 96 h. F. Candida avoided soils spiked with 0.04, 0.4 and 4 mg carbamazepine kg−1 after 48 h. However, higher number of organisms were found in soils with 40 mg carbamazepine kg−1, a behavior also displayed for 40 mg fluoxetine kg−1 spiked soils. After 96 h, F. Candida showed avoidance behavior to soils with 4 and 40 mg carbamazepine kg−1. Acetylcholinesterase activity decreased in 0.4 mg fluoxetine kg−1 exposed organisms. Peroxidative damages were detected in organisms exposed to 4 and 40 mg kg−1 carbamazepine and glutathione S-transferase inhibition was observed at 40 mg kg−1. Data suggests that carbamazepine and fluoxetine may pose risk to soil collembolan.

  • Short-term exposure to carbaryl and UV radiation increases the reproduction output of the collembolan Folsomia Candida
    Journal of Soils and Sediments, 2014
    Co-Authors: Diogo N Cardoso, Amadeu M V M Soares, Ana Catarina Bastos, Susana Loureiro
    Abstract:

    Purpose Ecotoxicological risk assessment of chemical compounds is considered more accurate when mixtures of chemicals and/or interactions between chemicals and natural stressors are considered. To further simulate natural conditions, under which organisms are often exposed to combinations of natural and anthropogenic stressors, the combined exposure of a widely used insecticide, carbaryl, under UV radiation was evaluated. It is more than likely that soil organisms are confronted with a combination of chemical exposure and increasing UV irradiance on the terrestrial habitat. Considering the heterogeneity of contamination in field soils and the probability of collembolan to avoid contaminated soil (less time under exposure), combined effects of carbaryl and ultraviolet radiation were evaluated, by using a short exposure to Folsomia Candida.

  • assessing single and joint effects of chemicals on the survival and reproduction of Folsomia Candida collembola in soil
    Environmental Pollution, 2012
    Co-Authors: Monica J B Amorim, Amadeu M V M Soares, Cecilia Manuela Silva Pereira, V B Menezesoliveira, Bruno Campos, Susana Loureiro
    Abstract:

    Abstract Chemicals are often found in the environment as complex mixtures. There has been a large effort in the last decade to assess the combined effect of chemicals, using the conceptual models of Concentration Addition and Independent Action, but also including synergistic, antagonistic, dose-level and dose–ratio dependent deviations from these models. In the present study, single and mixture toxicity of atrazine, dimethoate, lindane, zinc and cadmium were studied in Folsomia Candida , assessing survival and reproduction. Different response patterns were observed for the different endpoints and synergistic patterns were observed when pesticides were present. Compared with the previously tested Enchytraeus albidus and Porcellionides pruinosus , the mixture toxicity pattern for F. Candida was species specific. The present study highlights the importance of studying toxicity of chemicals mixtures due to the observed potentiation of effects and confirms that for an adequate ecologically relevant risk assessment different organisms and endpoints should be included.

Dick Roelofs - One of the best experts on this subject based on the ideXlab platform.

  • Draft Genome Sequence of Bacillus toyonensis VU-DES13, Isolated from Folsomia Candida (Collembola: Entomobryidae).
    Genome Announcements, 2017
    Co-Authors: Thierry K. S. Janssens, Nico M Van Straalen, Tjalf E. De Boer, Valeria Agamennone, Niels Zaagman, Dick Roelofs
    Abstract:

    ABSTRACT We present here the draft genome of Bacillus toyonensis VU-DES13, which was isolated from the midgut of the soil-living springtail Folsomia Candida. Previous research revealed the presence of gene clusters for the biosynthesis of various secondary metabolites, including β-lactam antibiotics, in the host9s genome. The genome data are discussed in the light of the antimicrobial properties against fungi and oomycetes and a high level of β-lactam resistance of the isolate.

  • the microbiome of Folsomia Candida an assessment of bacterial diversity in a wolbachia containing animal
    FEMS Microbiology Ecology, 2015
    Co-Authors: Valeria Agamennone, Dick Roelofs, Nico M Van Straalen, Dennis Jakupovic, James T Weedon, Wouter Suring, Wilfred F M Roling
    Abstract:

    The springtail Folsomia Candida is an important model organism for soil ecology, ecotoxicology and ecogenomics. The decomposer activities of soil invertebrates like Folsomia depend on their relationship with microbial communities including gut symbionts. In this paper, we apply high-throughput sequencing to provide a detailed characterization of the bacterial community associated with parthenogenetic F. Candida . First, we evaluated a method to suppress the amplification of DNA from the endosymbiont Wolbachia , to prevent it from interfering with the identification of less abundant operational taxonomic units (OTUs). The suppression treatment applied was effective against Wolbachia and did not interfere with the detection of the most abundant OTUs (59 OTUs, contributing over 87% of the reads). However, this method did affect the inferred community composition. Significant differences were subsequently observed in the composition of bacterial communities associated with two different strains of F. Candida . A total of 832 OTUs were found, of which 45% were only present in one strain and 17% only in the other. Among the 20 most abundant OTUs, 16 were shared between strains. Denaturing gradient gel electrophoresis and clone libraries, although unable to capture the full diversity of the bacterial community, provided results that supported the NGS data.

  • Transcriptional profiling of the soil invertebrate Folsomia Candida in pentachlorophenol‐contaminated soil
    Environmental Toxicology and Chemistry, 2015
    Co-Authors: Min Qiao, Dick Roelofs, Guangpeng Wang, Cai Zhang, Nico M Van Straalen
    Abstract:

    Pentachlorophenol (PCP), a widely used pesticide, is considered to be an endocrine disruptor. The molecular effects of chemicals with endocrine-disrupting potential on soil invertebrates are largely unknown. In the present study, the authors explored the transcriptional expression changes of collembola (Folsomia Candida) in response to PCP contamination. A total of 92 genes were significantly differentially expressed at all exposure times, and the majority of them were found to be downregulated. In addition to the transcripts encoding cytochrome P450s and transferase enzymes, chitin-binding protein was also identified in the list of common differentially expressed genes. Analyses of gene ontology annotation and enrichment revealed that cell cycle-related transcripts were significantly induced by PCP, indicating that PCP can stimulate cell proliferation in springtail, as has been reported in human breast cancer cells. Enrichment of functional terms related to steroid receptors was observed, particularly in 20 significant differentially expressed genes involved in chitin metabolism in response to PCP exposure. Combined with confirmation by quantitative polymerase chain reaction, the results indicate that the adverse effects on reproduction of springtails after exposure to PCP can be attributed to a chemical-induced delay in the molting cycle and that molting-associated genes may serve as possible biomarkers for assessing toxicological effects. Environ Toxicol Chem 2015;34:1362–1368. © 2015 SETAC

  • Expression of mtc in Folsomia Candida indicative of metal pollution in soil
    Environmental Pollution, 2011
    Co-Authors: Benjamin Nota, Nico M Van Straalen, Riet Vooijs, Dick Roelofs
    Abstract:

    The soil-living springtail Folsomia Candida is frequently used in reproduction bioassays to assess soil contamination. Alternatively, the response of genes to contamination is assessed. In this study the expression of F. Candida’s gene encoding the deduced metallothionein-like motif containing protein (MTC) was assessed, using quantitative PCR, in response to six different metals, each at two concentrations in soil. The expression of mtc was induced after exposure to all metals, except for one chromium concentration. Exposure to soil originating from metal-contaminated field sites also induced mtc, while the expression did not change in response to a polycyclic aromatic hydrocarbon. Since this transcript is induced by most of the tested metals, it may potentially be a good indicator of metal contamination. The presented gene expression assay might become a useful tool to screen potentially polluted sites, in order to identify the ones that need further ecotoxicological investigation.

  • gene expression microarray analysis of heat stress in the soil invertebrate Folsomia Candida
    Insect Molecular Biology, 2010
    Co-Authors: Benjamin Nota, Bauke Ylstra, N M Van Straalen, Dick Roelofs
    Abstract:

    Sudden temperature changes in soil can induce stress in soil-dwelling invertebrates. Hyperthermic conditions have an impact on gene expression as one of the first steps. We use a transcriptomics approach using microarrays to identify expression changes in response to heat in the springtail Folsomia Candida. An elevation of temperature (Δ 10 °C) altered the expression of 142 genes (116 up-, 26 down-regulated). Many up-regulated genes encoded heat shock proteins, enzymes involved in ATP synthesis, oxidative stress responsive enzymes and anion-transporting ATPases. Down-regulated were glycoside hydrolases, involved in catalysis of disaccharides. The small number of altered transcripts suggest a mild response to heat in this soil invertebrate, but further research is needed to confirm this. This study presents Candidate genes for future functional studies concerning thermal stress in soil-dwelling invertebrates. © 2010 The Royal Entomological Society.

Martin Holmstrup - One of the best experts on this subject based on the ideXlab platform.

  • Recovery period of Folsomia Candida influence the impact of nonylphenol and phenanthrene on the tolerance of drought and heat shock.
    Environmental Pollution, 2019
    Co-Authors: Nanna Mikkelsen, Martin Holmstrup, Gustav Holm Mikkelsen, John Jensen
    Abstract:

    Abstract Soil organisms are exposed to natural and anthropogenic stressors, such as xenobiotics. However, to simplify and make laboratory experiments easily reproducible, natural stressors are often excluded from ecotoxicological studies and risk assessment. This might underestimate the effect of chemicals, since synergistic interactions between chemicals and natural stressors might occur, creating a more severe impact than expected. Several studies have addressed simultaneous exposure to natural and chemical stressors, but very little is known of about the persistence of these interactions during recovery. Here, we examined if recovery after chemical stress exposure was important for the ability of springtails (Folsomia Candida) to tolerate subsequent drought- and heat stress. Nonylphenol (NP) and phenanthrene (PHE) was tested and their isolated toxicity resulted in LC50 values of 206 mg NP kg−1 dry soil and 109 mg PHE kg−1 dry soil in a 7-day test. Elimination of NP and PHE was rapid and only trace amounts remained in springtail tissues after 3–7 days of recovery. Isolated studies of drought and heat shock on Folsomia Candida resulted in a lethal effect for 50% of the animals (LRH50) at a relative humidity (RH) of 97.9%, and 190 min at 34 °C was shown to be lethal for 50% of the test species (LT50). The results showed, as expected, significant synergistic interactions between the effects of the chemicals and the effects of drought and heat stress. The negative effects of NP and PHE on the drought tolerance disappeared within 7 days post exposure. Springtails exposed to PHE also recovered their heat tolerance within 7 days post exposure, while NP exposed animals had not fully recovered their heat tolerance 14 days after exposure. Overall, a recovery period post chemical exposure was found to be very important for springtails in order to cope with natural stressors like heat and drought.

  • recovery of reproduction after drought in the soil living Folsomia Candida collembola
    Soil Biology & Biochemistry, 2011
    Co-Authors: Dorthe Waagner, Mark Bayley, Martin Holmstrup
    Abstract:

    Abstract Soil dwelling (euedaphic) Collembola have evolved to live in soil pores where the atmosphere is saturated with water vapour. Here we show that reproduction in the euedaphic Folsomia Candida ceases during drought where soil water potentials are lower than −7 bar (∼99.4% RH). Recovery of the moulting cycle after cessation of drought showed increasing delay with increasing previous drought pressure. However, reproduction was rapidly resumed. Only in F. Candida recovering from the most severe drought (−55 bar, 96% RH) was the time lapse between drought and resumed reproduction significantly different from the control (99.4% RH). Furthermore, the final numbers of eggs were unaffected by the degree of drought exposure. Hence, these results suggest that while even very mild drought will stop the reproductive cycle, subsequent recovery is rapid and complete.

  • the effect of soil ph and temperature on Folsomia Candida transcriptional regulation
    Journal of Insect Physiology, 2010
    Co-Authors: Tjalf E. De Boer, Nico M Van Straalen, Martin Holmstrup, Dick Roelofs
    Abstract:

    Abstract Differences in abiotic factors like temperature and soil pH can have a significant physiological impact on soil dwelling invertebrates and may confound results in ecotoxicological testing. In this study we exposed Folsomia Candida to a range of two abiotic stress treatments (pH and temperature) for 3 days and measured gene expression of a panel of nine stress response genes with real-time Q-PCR. The exposure to different pH values had a minimal effect on the expression of the nine selected genes: only V-ATPase expression was significantly increased due to decreasing pH. ATPase expression was up-regulated, possibly due to increased proton trafficking across the cell membrane, at a lower pH. HSP70 was up-regulated in collembolans exposed to 30 °C, and along with HSP40 at 0 °C. We speculate that the minor pH effect on gene expression, compared to the temperature treatment, can be explained by the spatial restricted exposure to the external pH in the gut. Our data showed that only 1 or 2 stress response genes were transcriptionally affected by pH and temperature thus exerting minimal effects. The physiological effects of these treatments on F. Candida might indicate interesting novel molecular mechanisms.

  • Sugar sweet springtails: on the transcriptional response of Folsomia Candida (Collembola) to desiccation stress.
    Insect Molecular Biology, 2009
    Co-Authors: M.j.t.n. Timmermans, Dick Roelofs, Benjamin Nota, Bauke Ylstra, Martin Holmstrup
    Abstract:

    Several species of Collembola survive stressful desiccating conditions by absorbing water vapour from the environment. To obtain insight into the transcriptomic responses underlying this ‘water vapour absorption’ mechanism we subjected Folsomia Candida (Collembola) to transcriptome profiling. We show that ecologically relevant desiccation stress leads to strong time-dependent transcriptomic changes. Exposure of F. Candida to 98.2% relative humidity over an interval of 174 h resulted in a high number of gene transcripts being differentially expressed (up to 41%; P-value < 0.05). Additional Gene Ontology analyses suggest that carbohydrate transport, sugar catabolism and cuticle maintenance are biological processes involved in combating desiccation. However, many additional pathways seem to be affected; additional experiments are needed to elucidate which responses are primarily linked to desiccation resistance.

  • Exposure to mercury reduces cold tolerance in the springtail Folsomia Candida
    Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2008
    Co-Authors: Martin Holmstrup, Aurore Aubail, Christian Damgaard
    Abstract:

    Abstract We investigated how mercury (Hg) as an example of a widespread pollutant, can influence the tolerance of low temperature stress in the springtail, Folsomia Candida . Springtails were exposed to aqueous solutions with a range of concentrations of HgCl 2 and subsequently exposed to a range of low temperatures (cold shock) in order to model the dose–response surface (using survival as toxicity parameter). The data fitted a multiplicative model well ( R 2  = 0.99), and there was a highly significant synergistic interaction between Hg and cold shock. Our results indicate that the assessment of the toxicity of Hg by traditional laboratory studies where test organisms are exposed to only one stress factor and otherwise optimal conditions, may well underestimate the impact of the pollutant on the survival of field populations if stressful climatic conditions prevail. This conclusion is likely to apply to many other species and possibly other toxic chemicals as well. We propose that the present and similar research is needed for improvement of the scientific basis for setting safety factors in sound risk assessment of polluting chemicals.

Amadeu M V M Soares - One of the best experts on this subject based on the ideXlab platform.

  • copper toxicity to Folsomia Candida in different soils a comparison between nano and conventional formulations
    Environmental Chemistry, 2019
    Co-Authors: Joana Neves, Diogo N Cardoso, Catarina Malheiro, Amadeu M V M Soares, Frederick J Wrona, Susana Loureiro
    Abstract:

    Environmental context Nanotechnology has great potential for managing agricultural plant disease. This study compares effects of various nano and conventional copper formulations on Collembola Folsomia Candida, a model arthropod often used to test soil pollutants. Although toxicity varied between formulations, with a nanopesticide showing one of the highest toxicities, the differences were mainly due to the active copper compound rather than its nano formulation. Abstract Nanotechnology has recently become a major asset in agricultural practices owing to the improvement and provision of solutions for plant disease management, especially in the form of nanopesticides. These products are considered as one of the main direct sources of nanomaterials in terrestrial ecosystems, and for that reason, it is essential to understand and evaluate their behaviour and toxicity in the environment. In addition, the panoply of similar compounds makes it difficult to accurately evaluate if different formulations may induce different effects on non-target organisms. We aim to compare the toxicity and bioavailability of different copper formulations (nano and non-nano) applied to the soil using the model organism Folsomia Candida. Reproduction tests were performed in two different soils (Lufa 2.1 and 2.2) with two equilibrium times after spiking (0 and 48 h). Depending on the copper form present in the formulation, the half maximal effective concentration (EC50) values of the non-nano pesticides varied from 274 mg Cu kg−1 in Champion® to 3030 mg Cu kg−1 in Cupravit® in Lufa 2.2 and 48 h equilibrium. The nano formulation displayed one of the highest toxicities to collembolans, with an EC50 of 156 mg Cu kg−1. Regarding the soil type, a higher toxicity in Lufa 2.1 was observed probably related to the soil characteristics, namely lower pH and lower organic content, which increase the metal solubility and consequently the bioavailability. The only exception was the nanopesticide Kocide 3000®, whose toxicity was higher in Lufa 2.2. This study emphasises the importance of understanding the links between metal bioavailability and toxicity to support the more robust environmental risk assessment of different Cu fungicide formulations.

  • toxic effects of human pharmaceuticals to Folsomia Candida a multigeneration approach
    Science of The Total Environment, 2018
    Co-Authors: Miguel Oliveira, Diogo N Cardoso, Amadeu M V M Soares, Susana Loureiro
    Abstract:

    Abstract The study of the effects of human pharmaceuticals has been considered a priority in terms of environmental safety. However, the available information concerning soil organisms is scarce. To decrease this knowledge gap, the effects of carbamazepine and fluoxetine (0.04, 0.4, 4 and 40 mg·kg− 1 of soil) were assessed on the springtail Folsomia Candida, for three consecutive generations. The assessed endpoints included survival, reproduction and biomarkers associated with biotransformation, neurotransmission and peroxidative damage. A light avoidance behavior test was performed, in the third generation. The obtained data demonstrate that both pharmaceuticals may affect Collembola populations after three generational exposures, as showed by the decrease trend for both survival and reproduction. The effects of carbamazepine were however, more pronounced. After the third generational exposure to all carbamazepine tested concentrations and the three highest concentrations of fluoxetine, F. Candida displayed altered light avoidance behavior. The biochemical endpoints also revealed that carbamazepine and fluoxetine may exert toxic effects to F. Candida through the induction of oxidative stress and impairment in neurotransmission with an apparent higher potential for carbamazepine. Overall, data show that the effects of pharmaceuticals throughout different generations should be considered in risk assessment studies.

  • effects of short term exposure to fluoxetine and carbamazepine to the collembolan Folsomia Candida
    Chemosphere, 2015
    Co-Authors: Miguel Oliveira, Diogo N Cardoso, Amadeu M V M Soares, Susana Loureiro
    Abstract:

    Abstract Pharmaceuticals, emerging environmental contaminants, have their ecotoxicological effects to non-target organisms in soil largely unknown. This study assessed short-term effects of two human pharmaceuticals, carbamazepine and fluoxetine, to Folsomia Candida. Avoidance to spiked soils was assessed after 48 and 96 h exposure and biochemical changes (acetylcholinesterase and glutathione S-transferase activities, and lipid peroxidation levels) after 96 h. F. Candida avoided soils spiked with 0.04, 0.4 and 4 mg carbamazepine kg−1 after 48 h. However, higher number of organisms were found in soils with 40 mg carbamazepine kg−1, a behavior also displayed for 40 mg fluoxetine kg−1 spiked soils. After 96 h, F. Candida showed avoidance behavior to soils with 4 and 40 mg carbamazepine kg−1. Acetylcholinesterase activity decreased in 0.4 mg fluoxetine kg−1 exposed organisms. Peroxidative damages were detected in organisms exposed to 4 and 40 mg kg−1 carbamazepine and glutathione S-transferase inhibition was observed at 40 mg kg−1. Data suggests that carbamazepine and fluoxetine may pose risk to soil collembolan.

  • Short-term exposure to carbaryl and UV radiation increases the reproduction output of the collembolan Folsomia Candida
    Journal of Soils and Sediments, 2014
    Co-Authors: Diogo N Cardoso, Amadeu M V M Soares, Ana Catarina Bastos, Susana Loureiro
    Abstract:

    Purpose Ecotoxicological risk assessment of chemical compounds is considered more accurate when mixtures of chemicals and/or interactions between chemicals and natural stressors are considered. To further simulate natural conditions, under which organisms are often exposed to combinations of natural and anthropogenic stressors, the combined exposure of a widely used insecticide, carbaryl, under UV radiation was evaluated. It is more than likely that soil organisms are confronted with a combination of chemical exposure and increasing UV irradiance on the terrestrial habitat. Considering the heterogeneity of contamination in field soils and the probability of collembolan to avoid contaminated soil (less time under exposure), combined effects of carbaryl and ultraviolet radiation were evaluated, by using a short exposure to Folsomia Candida.

  • assessing single and joint effects of chemicals on the survival and reproduction of Folsomia Candida collembola in soil
    Environmental Pollution, 2012
    Co-Authors: Monica J B Amorim, Amadeu M V M Soares, Cecilia Manuela Silva Pereira, V B Menezesoliveira, Bruno Campos, Susana Loureiro
    Abstract:

    Abstract Chemicals are often found in the environment as complex mixtures. There has been a large effort in the last decade to assess the combined effect of chemicals, using the conceptual models of Concentration Addition and Independent Action, but also including synergistic, antagonistic, dose-level and dose–ratio dependent deviations from these models. In the present study, single and mixture toxicity of atrazine, dimethoate, lindane, zinc and cadmium were studied in Folsomia Candida , assessing survival and reproduction. Different response patterns were observed for the different endpoints and synergistic patterns were observed when pesticides were present. Compared with the previously tested Enchytraeus albidus and Porcellionides pruinosus , the mixture toxicity pattern for F. Candida was species specific. The present study highlights the importance of studying toxicity of chemicals mixtures due to the observed potentiation of effects and confirms that for an adequate ecologically relevant risk assessment different organisms and endpoints should be included.