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Inorganic forms of As (arsenite - As(III) and arsenate - As(V)) are prevalent in soil and recognized for their high toxicity. Once in the soil, these forms of As can compromise key organisms for ecological processes, such as earthworms. The aim of the study was to evaluate the toxicity of arsenite and arsenate in the Californian earthworm Eisenia andrei exposed in natural soil and tropical artificial soil (TAS). Adverse effects were evaluated using avoidance test, acute toxicity test, and a sublethal concentration test to assess biochemical parameters. LC50 values for arsenite were 21.27 mg/kg in natural soil and 19.0 mg/kg in TAS and for arsenate were 76.18 mg/kg in natural soil and above 120 mg/kg in TAS. In the avoidance test, this behavior was shown to be significantly higher in the natural soil and for earthworms exposed to arsenite, while total antioxidant capacity, glutathione levels, lipid damage, and DNA damage were significantly higher in animals exposed to arsenite, but without differences in relation to the two types of soil tested. Animals exposed to As(V) showed increased activity of enzymes related to glutathione metabolism. The results obtained in the present study show the impact of As exposure on the health of the Californian earthworm E. andrei, especially in the form of arsenite, and alert the public authorities that legal limits should, whenever possible, consider the soil properties and also the different chemical species of the contaminants.

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The aim of this study was to assess the effect of temperature on the toxicity of fipronil toward earthworms (Eisenia andrei) in two Brazilian soils (Entisol and Oxisol) with contrasting textures. In the case of Entisol, the influence of soil moisture content on toxicity was also investigated. Earthworms were exposed for 56 days to soils spiked with increasing concentrations of fipronil (8.95, 19.48, 38.22, 155.61, and 237.81 mg kg-1 for Entisol; 12.99, 27.94, 48.42, 204.67, and 374.29 mg kg-1 for Oxisol) under scenarios with different combinations of temperature (20, 25 and 27 °C) and soil moisture content (60 and 30% of water holding capacity (WHC) for Entisol and 60% WHC for Oxisol). The number of juveniles produced was taken as the endpoint, and a risk assessment was performed based on the hazard quotient (HQ). In Entisol, at 60% WHC the fipronil toxicity decreased at 27 °C compared with the other temperatures tested (EC50 = 52.58, 48.48, and 110 mg kg-1 for 20, 25, and 27 °C, respectively). In the case of Oxisol at 60% WHC, the fipronil toxicity increased at 27 °C compared with other temperatures (EC50 = 277.57, 312.87, and 39.89 mg kg-1 at 20, 25, and 27 °C, respectively). An increase in fipronil toxicity was also observed with a decrease in soil moisture content in Entisol at 27 °C (EC50 = 27.95 and 110 mg kg-1 for 30% and 60% WHC, respectively). The risk of fipronil was only significant at 27 °C in Entisol and Oxisol with water contents of 30% and 60% WHC, respectively, revealing that higher temperatures are able to increase the risk of fipronil toxicity toward earthworms depending on soil type and soil moisture content. The results reported herein show that soil properties associated with climatic shifts could enhance the ecotoxicological effects and risk of fipronil for earthworms, depending on the type of soil.

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We evaluated the toxicity and risk (via toxicity exposure ratio approach - TER) of the insecticide fipronil to collembolan's growth and reproduction in three tropical soils, under increasing atmospheric temperatures. Chronic toxicity tests were performed with Folsomia candida in tropical artificial soil (TAS), oxisol, and entisol spiked with increasing concentrations of fipronil, at three room temperature scenarios: a standard (20 ± 2 °C), a tropical condition (25 ± 2 °C) and a global warming simulation (27 ± 2 °C). Temperatures influenced the fipronil effects on the species reproduction differently between soil types. In TAS and oxisol the highest toxicities (EC50-based) were found at 27 °C (EC50 TAS = 0.81, 0.70, 0.31 mg kg-1; EC50 OXISOL = 0.52, 0.54, 0.40 mg kg-1; at 20, 25, and 27 °C, respectively). In entisol, the toxicity at 27 °C was lower compared to 25 and 20 °C (EC50 ENTISOL = 0.33, 0.24, 0.12 mg kg-1, respectively). Fipronil concentrations also increased the proportion of small juveniles (growth reduction) in all tested soils. However, this effect was greater (EC10-based) at higher temperatures (25 and/or 27 °C), regardless of the soil type. TER approach revealed a significant risk of fipronil in entisol, regardless of the tested temperature, while in other soils the risk was found significant only at the higher temperatures (25 and 27 °C for TAS, and 27 °C for oxisol). These results indicate that exposures to fipronil at high temperatures (e.g., those resulting from climate change) can threaten F. candida populations, depending on the soil type.

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This study assessed the influence of three tropical soil types and soil moisture content on the toxicity and risk of the insecticide fipronil to collembolans Folsomia candida. Chronic toxicity tests were performed in a Tropical Artificial Soil (TAS), an Oxisol and an Entisol spiked with increasing concentrations of fipronil to assess the effects on the reproduction and growth of the species. The soil moisture contents were kept at 60% (standard condition) and 30 or 45% (water restriction) of their water holding capacity (WHC). The toxicity of fipronil on collembolans reproduction was about three times higher in Entisol compared to TAS or Oxisol. Higher toxicities were also found in the drier TAS (EC50 30%WHC = 0.20 vs EC50 60%WHC = 0.70 mg kg-1) and Oxisol (EC50 45%WHC = 0.27 vs EC50 60%WHC = 0.54 mg kg-1), while in Entisol lower impacts were found in the drier samples (EC50 30%WHC = 0.41 vs EC50 60%WHC = 0.24 mg kg-1). For all tested soils, the size of generated collembolans was reduced by the fipronil concentrations, regardless of soil moisture. However, the drier condition increased the effect on the growth in TAS and Entisol for some concentrations. A significant risk of exposure was found in TAS and Oxisol at drier conditions and, for Entisol, regardless of the soil moisture. The toxic effects and risk of fipronil on collembolans were higher in the natural sandy soil. The soil moisture content increase or decrease the toxicity of the insecticide for collembolans, depending on soil type.

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Given the essential role of arbuscular mycorrhizal fungi (AMF) in soil systems and agriculture, their use as biological indicators has risen in all fields of microbiology research. However, AMF sensitivity to chemical pesticides is poorly understood in field conditions, and not explored in ecotoxicology protocols. Hence, the goal of this study was to evaluate the effects of different concentrations of glyphosate (Roundup®) and diuron+paraquat (Gramocil®) on the germination of spores of Gigaspora albida and Rhizophagus clarus in a tropical artificial soil. This study was conducted in 2019 at the Soil Ecology and Ecotoxicology Laboratory of the Universidade do Estado de Santa Catarina. The nominal concentrations of glyphosate were 0, 10, 50, 100, 250, 500, 750 and 1000 mg a.i. kg-1. For diuron+paraquat, the concentrations tested were 0, 10 + 20, 50 + 100, 100 + 200, 250 + 500, 500 + 1000, 750 + 1500 and 1000 + 2000 mg a.i. kg-1. Glyphosate did not alter germination of G. albida, but germination inhibition of R. clarus spores was of 30.8% at 1000 mg kg-1. Diuron+paraquat inhibited by 8.0% germination of G. albida, but only at the highest concentration tested. On the other hand, effects on R. clarus were detected at 50 + 100 mg kg-1 concentration and above, and inhibition was as high as 57.7% at the highest concentration evaluated. These results suggest distinct response mechanisms of Rhizophagus and Gigaspora when exposed to herbicides, with the former being more sensitive than the later.

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Produced water (PW) is a mixture of formation water and injected water from oil and gas reservoirs, which contain a complex composition of dissolved and particulate organic and inorganic chemicals. High quantities of PW are extracted with the oil, which can be discharged into the environment, re-injected into the wells or treated for reuse. The present study aimed to evaluate the soil ecotoxicity under an irrigation system using treated PW (water-oil separation, sand filter, activated charcoal filter, reverse osmosis) for sunflower production, predicting conditions for PW reuse in the semi-arid region of Brazil. The experiment was conducted in a greenhouse using natural soil in vessels. Water from public water supply was used as control. Soil samples from two production cycles of sunflowers were assessed using ecotoxicity tests with soil invertebrate's species representing macro and mesofaunal groups: Eisenia andrei (earthworms), Folsomia candida (collembolans) and Enchytraeus crypticus (enchytraeids). Leachates samples were evaluated with aquatic ecotoxicity tests to assess the soil retention function. Results showed impact of irrigation with PW in all treatments except reverse osmosis. Significant negative correlations were found among reproduction of soil invertebrates, high Na+ concentrations and electrical conductivity. The effects of other contaminants not analyses should not be discarded. It is important to highlight that salinity is not usually included in target values of soil quality. This study reinforces the importance of ecotoxicity tests in predictive and retrospective risk assessment, joining effects of contaminant mixtures or even that contaminants not considered in chemical scope of analysis or legislation.

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Isoxaflutole (IFT) é um herbicida utilizado para o controle em pré-emergência de uma ampla variedade de plantas daninhas de folha larga e gramíneas, especialmente quando há resistência a outros herbicidas, como glyphosate e atrazine. Apesar de seu potencial como herbicida ter sido identificado no início dos anos 90, IFT ainda é considerado um ingrediente ativo novo no Brasil e pouco se sabe sobre seus efeitos, principalmente acerca da ecotoxicidade dos produtos formulados para grupos da macro e mesofauna do solo. Este estudo teve como objetivo avaliar efeitos comportamentais, agudos e crônicos (fuga, letalidade e reprodução) do produto comercial Provence® 750 WG (750 g i.a. L-1 isoxaflutole) nos organismos de teste Eisenia andrei (minhoca) e Folsomia candida (colêmbolo) usando normas padronizadas ISO. Os resultados mostraram que as minhocas apresentam comportamento de fuga apenas em doses >300 vezes a dose de campo e redução na reprodução em doses >150 vezes a dose de campo. Para os colêmbolos não foi obtida resposta de fuga, letalidade ou reprodução nas doses avaliadas. A partir dos resultados de laboratório, presume-se que o produto comercial Provence® não apresenta toxicidade para minhocas e colêmbolos, mesmo em doses muito acima à dose de campo, garantindo a segurança das comunidades do solo.

Isoxaflutole (IFT) is a pre-emergence herbicide used to control of a wide range of broadleaf and grass weeds, especially those resistant to other herbicide classes, such as glyphosate and atrazine. Although its herbicidal potential was identified in the early 90s, IFT is still a new active ingredient in Brazil and little is known about its effects, mainly regarding to ecotoxicity of formulated products to soil macro and mesofauna groups. This study aimed to assess behavioral, acute, and chronical effects (avoidance, lethality, and reproduction) of the commercial product ProvenceTM 750 WG (750 g a.i. L-1 isoxaflutole) on the test organisms Eisenia andrei (earthworms) and Folsomia candida (collembolans) using standardized ISO guidelines. The results showed the avoidance of the earthworm species only at >300 times the predicted field doses, as well as a decrease in reproduction over >150 times the predicted field dose. Neither the avoidance, nor lethality or reproduction response were found for the collembolan species. The laboratory results showed that it is possible to assume that ProvenceTM is not toxic to earthworms and collembolans, even at the highest field dose applied, ensuring the safety of soil communities.

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Isoxaflutole (IFT) é um herbicida utilizado para o controle em pré-emergência de uma ampla variedade de plantas daninhas de folha larga e gramíneas, especialmente quando há resistência a outros herbicidas, como glyphosate e atrazine. Apesar de seu potencial como herbicida ter sido identificado no início dos anos 90, IFT ainda é considerado um ingrediente ativo novo no Brasil e pouco se sabe sobre seus efeitos, principalmente acerca da ecotoxicidade dos produtos formulados para grupos da macro e mesofauna do solo. Este estudo teve como objetivo avaliar efeitos comportamentais, agudos e crônicos (fuga, letalidade e reprodução) do produto comercial Provence® 750 WG (750 g i.a. L-1 isoxaflutole) nos organismos de teste Eisenia andrei (minhoca) e Folsomia candida (colêmbolo) usando normas padronizadas ISO. Os resultados mostraram que as minhocas apresentam comportamento de fuga apenas em doses >300 vezes a dose de campo e redução na reprodução em doses >150 vezes a dose de campo. Para os colêmbolos não foi obtida resposta de fuga, letalidade ou reprodução nas doses avaliadas. A partir dos resultados de laboratório, presume-se que o produto comercial Provence® não apresenta toxicidade para minhocas e colêmbolos, mesmo em doses muito acima à dose de campo, garantindo a segurança das comunidades do solo.(AU)

Isoxaflutole (IFT) is a pre-emergence herbicide used to control of a wide range of broadleaf and grass weeds, especially those resistant to other herbicide classes, such as glyphosate and atrazine. Although its herbicidal potential was identified in the early 90s, IFT is still a new active ingredient in Brazil and little is known about its effects, mainly regarding to ecotoxicity of formulated products to soil macro and mesofauna groups. This study aimed to assess behavioral, acute, and chronical effects (avoidance, lethality, and reproduction) of the commercial product ProvenceTM 750 WG (750 g a.i. L-1 isoxaflutole) on the test organisms Eisenia andrei (earthworms) and Folsomia candida (collembolans) using standardized ISO guidelines. The results showed the avoidance of the earthworm species only at >300 times the predicted field doses, as well as a decrease in reproduction over >150 times the predicted field dose. Neither the avoidance, nor lethality or reproduction response were found for the collembolan species. The laboratory results showed that it is possible to assume that ProvenceTM is not toxic to earthworms and collembolans, even at the highest field dose applied, ensuring the safety of soil communities.(AU)

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Based on the hypothesis that urban activities can deposit chemical contaminants in soil and consequently have an impact on the vitality of key organisms of the ecosystem, the aim of the present study was to analyse genotoxicity in earthworm's coelomocytes in urban soil samples in comparison to soil samples from protected areas. Earthworms (Eisenia andrei) were exposed to soil samples for 14 days, subsequently the coelomocytes were extracted with an 10% ethanol solution and used in single cell gel electrophoresis (SCGE) assay and the micronucleus (MN) assay. The levels of copper, cadmium, lead, zinc, and arsenic were measured in monitored soil samples. Earthworms exposed to urban soils had higher levels of DNA damage, according to the results of the SCGE assay, than earthworms exposed to protected area soils. The frequency of micronuclei did not differ between the studied soil samples. There was an association between % DNA (SCGE assay) and arsenic and zinc levels. Copper, lead and zinc levels in urban soil samples exceeded the limits of legal values in Brazil. Our findings show that the genotoxicity markers we tested are sensitive to contamination and this association should be taken into account by regulatory agencies.

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Mancozeb is a dithiocarbamate non-systemic fungicide widely used to control fungal diseases of plants, commonly applied in apple orchards in Brazil. Instead of its common use, there are no reports about the risk to non-target organisms in Brazilian soils. We studied the risk of Mancozeb (in the commercial formulation Dithane® NT) for standard invertebrate species (Folsomia candida, Eisenia andrei and Enchytraeus crypticus) in two subtropical Brazilian soils, Oxisol and Ultisol, which are representative of apple production areas in Brazil. Reproduction and survival tests were carried out following ISO guidelines. Results showed that Mancozeb in Oxisol reduced the survival and reproduction of collembolans (LC50 54.43 and EC50 2.72 mg a.i. kg-1) and enchytraeids (LC50 6.97 and EC50 3.56 mg a.i. kg-1), in lowest values than those observed in Ultisol (F. candida LC50 > 1000 and EC50 > 100 mg a.i. kg-1; E. crypticus LC50 280.21 and EC50 29.67). Effects to E. andrei were similar in both soils and indicated a lower sensitivity of this species to Mancozeb. The species F. candida and E. crypticus were more sensitive than E. andrei. These results reinforce the need to include other soil organisms besides earthworms, using chronical endpoints and considering different types of soils, to better predict the risk of pesticides for subtropical soils.

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Reference substances are recommended to evaluate the quality of laboratory test species and the reliability of ecotoxicity data. Boric acid (BA) has been recommended as reference substance in some standardized tests in OECD soil, but no data are available for Tropical Artificial Soil (TAS). For this purpose, avoidance tests with Eisenia andrei, lethality tests with E. andrei and Folsomia candida, and reproduction tests with E. andrei, Enchytraeus crypticus and F. candida were carried out in TAS (5% organic matter), following ISO guidelines, and compared between two laboratories. Collembolans were more sensitive than earthworms in lethality tests (LC50 = 342 and > 1000 mg kg-1, respectively). For both laboratories, the EC50 values were similar for reproduction of oligochaeta species (165 mg kg-1 for E. crypticus; 242 and 281 mg kg-1 for E. andrei), but significantly different for reproduction of F. candida (96 and 198 mg kg-1). Present results suggest that boric acid could replace the current pesticides recommended by ISO guidelines as reference substances on reproduction tests with soil invertebrates in TAS. Concerning avoidance tests, additional investigations should be performed with other substances that cause no neurotoxic effects on soil organisms.

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BACKGROUND: Urban forests are usually affected by several types of atmospheric contaminants and by abnormal variations in weather conditions, thus facilitating the biotic homogenization and modification of ecosystem processes, such as nutrient cycling. Peri-urban forests and even natural forests that surround metropolitan areas are also subject to anthropogenic effects generated by cities, which may compromise the dynamics of these ecosystems. Hence, this study advances the hypothesis that the forests located at the margins of the Metropolitan Region of São Paulo (MRSP), Brazil, have high concentrations of atmospheric contaminants leading to adverse effects on litter fall stock. METHODS: The production, stock and decomposition of litter fall in two forests were quantified. The first, known as Guarapiranga forest, lies closer to the urban area and is located within the MRSP, approximately 20km from the city center. The second, Curucutu forest, is located 70km from the urban center. This forest is situated exactly on the border of the largest continuum of vegetation of the Atlantic Forest. To verify the reach of atmospheric pollutants from the urban area, levels of heavy metals (Cd, Pb, Ni, Cu) adsorbed on the litter fall deposited on the soil surface of the forests were also quantified. RESULTS: The stock of litter fall and the levels of heavy metals were generally higher in the Guarapiranga forest in the samples collected during the lower rainfall season (dry season). Non-metric multidimensional scaling multivariate analysis showed a clear distinction of the sample units related to the concentrations of heavy metals in each forest. A subtle difference between the units related to the dry and rainy seasons in the Curucutu forest was also noted. Multivariate Analysis of Variance revealed that both site and season of the year (dry or rainy) were important to differentiate the quantity of heavy metals in litter fall stock, although the analysis did not show the interaction between these two factors. Precipitation appeared to be an important factor to disperse air pollutants; one method to better regulate this process is the development and integration of green infrastructure at city level, which might contribute to nature-based solutions. CONCLUSIONS: Results suggest that although the Curucutu forest is not very far from the MRSP, which could result in heavy metal levels similar to those observed in the Guarapiranga forest, the weather conditions, geographic location and rainfall rates might act as efficient physical barriers against the dispersion of pollutants in the urban area. However, it is important to highlight that in the period studied (2012-2013), MRSP presented unusual features during the winter period marked by the highest levels of precipitation which was due to several numbers of frontal systems and also due to their permanence for a couple days in the region. Thus, it is recommended to continue this study in order to obtain a database for characterizing the seasonal variation of air pollution levels in the litter fall and their adverse effects on ecosystem processes in these remnants of the Atlantic Forest.

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Soils from some Latin American countries support the highest biodiversity levels on the planet and simultaneously have some of the most serious environmental impacts attributed to both historical and current agricultural practices and industrial activities. Soil contamination has resulted from intensive use of pesticides, extensive mining and other industrial activities, and uncontrolled management of waste within inappropriate regulatory frameworks. The present study presents an overview of the scientific research on soil ecotoxicology conducted in Latin America, summarizing the recent advances and highlighting the needs for further refinements in this research field. Most of the contributions to the scientific literature have been from Brazil. The most investigated issue is the ecotoxicity of pesticides and earthworms, which were the organisms most frequently used as test species. Needs identified by Latin American researchers include methods and procedures for: 1) identifying and collecting natural soils to be used as reference test-substrates in tests, 2) identifying and discerning the range of sensitivities of native test species to soil contaminants, 3) developing environmental guidelines applicable to tropical/subtropical conditions, and 4) developing methods and procedures for higher tier testing for full development and implementation of environmental risk assessment schemes. The protection of Latin American soils, including provision of goods and services, is currently framed in legislation and other regulations, but implementation requires significant improvement and additional training programs. Environ Toxicol Chem 2017;36:1795-1810. © 2017 SETAC.

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The current use and development of applications with silver nanoparticles (Ag NPs) could lead to potential inputs of these NPs to soils. Consequently, it is crucial to understand the ecotoxicological risks posed by Ag NPs in the terrestrial compartment. In the present investigation, the effects produced by PVP-PEI coated Ag NPs were assessed in Eisenia fetida earthworms in comparison with the soluble form (AgNO3). Earthworms were exposed for 1, 3 and 14 days to a range of sublethal concentrations of Ag (0, 0.05 and 50mg/kg) and at each exposure time, apart from mortality and weight loss of individuals, metallothionein (MT) protein concentration and catalase (CAT) activity were quantified in earthworm tissues. In addition, cellular and molecular level endpoints (cell viability, absolute and relative trophic indices and transcription levels of catalase-cat- and metallothionein-mt-) were measured in coelomocytes extruded from exposed earthworms. Despite the lack of effects in traditional endpoints (mortality and weight loss), Ag NPs and AgNO3 posed changes at lower levels of biological complexity (biochemical, cellular and molecular levels). Both Ag forms induced similar changes in the metal detoxification mechanism (MT, mt) and in the antioxidant response system (CAT, cat) of E. fetida. In contrast, Ag form dependant cytotoxicity and subpopulation ratio alterations (eleocytes/amoebocytes) were recorded in extruded coelomocytes. Complementarily, the use of coelomocytes to assess molecular level endpoints represented a relevant alternative for development of non-invasive biomarkers.

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Biosolids have been applied as soil amendments to improve and maintain the soil fertility and faster plant growth. In spite of its beneficial use, the potential risks of land disposal should be analyzed, considering potential ecological receptors in soil and water. This work describes the use of an early warning laboratory microcosm system to evaluate the integrated ecotoxicological potential of two biosolids: BIO-1 and BIO-2 (18 and 28 months after landfarming, respectively), from an effluent treatment station in a petrochemical and industrial district. The endpoints related to habitat function were: a) germination, growth and biomass of Phaseolus vulgaris; b) survival, biomass and number of cocoons of Eisenia andrei (Oligochaeta) and; c) reproduction of Folsomia candida (Collembola). The retention function was evaluated by testing the leachates using the tropical cladoceran Latonopsis australis (Cladocera) in a 48-h acute toxicity test, and growth of the aquatic plant Lemna minor in a 7-d chronic test. Tropical artificial soil (TAS) and a natural soil (NS) from the region were used as control soils. Results showed no chronic toxicity of BIO-1 and BIO-2 to the soil organisms tested, but acute toxicity of BIO-1 in the leachate for 50% of L. australis, and chronic toxicity of both biosolid leachates to L. minor (inhibition of growth rate), indicating potential risks to aquatic ecosystems. The results confirmed the ability of this microcosm system as a rapid tool to assess biosolid toxicity over time and its potential for hazardous waste characterization in environmental risk assessment, in a screening phase.

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Soil ecotoxicology has been motivated by the increasing global awareness on environmental issues. Northern Hemisphere has been the main driver of this science branch; however, the number and quality of contributions from the Southern Hemisphere are increasing quickly. In this case study, Brazil is taken as an example of how soil ecotoxicology has developed over the last 30 years. It starts with a brief historical overview depicting the main events on soil ecotoxicology in the country. Following, an overview on the Brazilian legislation related to soil ecotoxicology is given, covering regulations with prospective focus, mainly on the registration of pesticides. Regulations with retrospective focus in contaminated areas are also given. Then, an outline of the actors in soil ecotoxicology and examples of prospective ecotoxicological studies performed with soil organisms and plants are given by stressor groups: pesticides, pharmaceuticals, metals, and residues. Experiences from retrospective studies, mainly looking at the assessment of industrial sites, are also covered. Emphasis is given on methodological aspects, pointing to needed actions, mainly regarding the different biotic and abiotic conditions of a tropical country. Finally, the last session discusses how soil ecotoxicology could be improved in methodological adaptations as well as legal requirements.

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