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Land use changes threaten the maintenance of water quality and challenge the management of tropical reservoirs. In particular, eutrophication alters several ecosystem functions and services, compromising multiple uses of water. For example, in the Lajeado Reservoir (Araraquara, São Paulo, Brazil), aquatic macrophytes rapidly spread and occupied more than 90% of the system's surface area (from 2016 to 2019). In such a scenario, this research aimed to evaluate the eutrophication causes and impacts to provide technical and scientific support to public agencies and propose remediation alternatives. First, a diagnosis of the study area was performed, using available data on land use, water quality, and climate (between 2010 and 2018). Second, water and sediment samples were collected for physical, chemical, and ecotoxicological analyses. The Ecological Risk Assessment consisted of a triad of Lines of Evidence, including physical-chemical, chemical, and ecotoxicological results. The expansion of agricultural activities (e.g., sugarcane cultivation) and diffuse pollution were highlighted among possible causes, and water quality was affected by increases in the concentration of nutrients (e.g., nitrogen and phosphorus), metals (e.g., iron), and emerging contaminants (e.g., pesticides and caffeine). As a result, the Lajeado Reservoir presented a high ecological risk, and alternatives for macrophyte removal are needed. This research involved several stakeholders (i.e., community, government agencies, and universities) who participated more effectively in environmental monitoring and recovery.

The continuous growth in global population since the beginning of the 20th century result in the necessity of food and energy provision favoring the intensive use of agricultural products such as pesticides. Although pesticides are important to prevent losses in the conventional chemically based agriculture, they frequently present side effects, which goes against agricultural production. The use of pesticides cause direct and indirect effects to soil organisms unbalancing essential soil processes (e.g. primary production, organic matter decomposition, nutrient cycling). Under tropical conditions, very little is known regarding the effects of pesticides to terrestrial organisms. Hence, the aim of the present study was to assess the ecotoxicological effects of the herbicide DMA® 806 BR (active ingredient: 2,4-D) and the insecticide Regent® 800 WG (active ingredient: fipronil), on terrestrial plant species (the dicot Raphanus sativus var. acanthioformis and the monocot Allium cepa), and soil invertebrates (the collembolan Folsomia candida and the enchytraeid Enchytraeus crypticus), using natural (NS) and artificial soils (TAS). For both pesticides, negative effects on non-target species were observed at concentrations lower than the doses recommended to prevent pests in sugarcane fields. For both soils, the dicot species was the most affected by the herbicide (R. sativus > A. cepa > F. candida > E. crypticus) and the collembolan species was the most affected by the insecticide (F. candida > E. crypticus = R. sativus = A. cepa). Although the order of the organisms’ sensitivity for both pesticides was the same in both soils, results showed that the extent of the effects was soil dependent. Considering the ecologically relevant concentrations tested, and their severe effects to non-target organisms, it may be concluded that the use of fipronil and 2,4-D under recommended conditions may pose a risk to the terrestrial environment.

The frequent exposure of bees to a wide variety of fungicides, on crops where they forage, can be considered a stressor factor for these pollinators. The organisms are exposed both to the fungicide active ingredients and to the adjuvants of commercial formulations. All these ingredients are brought to the hive by bee foragers through contaminated pollen and nectar, thus exposing also immature individuals during larval phase. This work aimed to compare the effects of larval exposure to the fungicide pyraclostrobin (active ingredient and commercial formulation) and its influence on the cytotoxicity to midguts in adults, which were inoculated with the Nosema ceranae spores in the post-emergence stage. Under laboratory conditions, Apis mellifera larvae received an artificial diet containing fungicide solution from the third to the sixth day of the feeding phase. One-day-old adult workers ingested 100,000 infectious N. ceranae spores mixed in sucrose solution. Effects on midgut were evaluated through cellular biomarkers of stress and cell death. The exposure to the fungicide (active ingredient and commercial formulation) did not affect the larval post-embryonic development and survival of adult bees. However, this exposure induced cytotoxicity in the cells of the midgut, showed by the increase in DNA fragmentation and alteration in the HSP70 immunolabeling pattern. Without the pathogen, the midgut cytotoxic effects and HSP70 immunolabeling of the organisms exposed to the commercial formulation were lower when compared to the exposure to its active ingredient. However, in the presence of the pathogen, the cytotoxic effects of the commercial formulation to the adult bees’ midgut were potentialized. The pathogen N. ceranae increased the damage to the intestinal epithelium of adult bees. Thus, realistic doses of pyraclostrobin present in beebread consumed by larvae can affect the health and induce physiological implications to the midgut functions of the adult bees.

Pesticides are widely used in agricultural fields to control plant diseases, weeds, and pests; however, the unforeseeable consequences of releasing these compounds into the soil and their effects on terrestrial invertebrates are matters of grave concern. The aim of the present study was to determine the direct impact of 2 pesticides, KRAFT® 36 EC (an insecticide; a.i. abamectin) and SCORE® (a fungicide; a.i. difenoconazole), on nontarget terrestrial invertebrates. Ecotoxicological tests were performed to evaluate the chronic and acute toxicity of these compounds to a potworm (Enchytraeus crypticus), a collembolan (Folsomia candida), and a mite (Hypoaspis aculeifer). The results showed that, for both pesticides, the collembolan F. candida was the most sensitive species, followed by the enchytraeid E. crypticus and the mite H. aculeifer. Effect concentrations at 50% of organisms' reproduction calculated for F. candida, E. crypticus, and H. aculeifer were 0.06, 2.8, and >32 mg of abamectin/kg dry weight soil and 28.9, 125, and 145.5 mg of difenoconazole/kg dry weight soil, respectively. Environmentally relevant concentrations of both pesticides significantly affected the collembolan species. The existence of a potential risk from abamectin and difenoconazole for soil invertebrates even at recommended doses could be identified. Environ Toxicol Chem 2018;37:2919-2924. © 2017 SETAC.

Besides being toxic to enchytraeids, pesticides may also affect microbial communities, which are the main diet of enchytraeids. This study aimed to analyze the individual and combined effects of the insecticide Kraft® 36 EC (abamectin) and the fungicide Score® 250 EC (difenoconazole) to soil microbial communities and Enchytraeus crypticus populations. The abamectin and difenoconazole effects to the microbial community metabolism, as revealed by qCO2 increase in the first two periods of exposure, might indicate an acute effect of pesticides, which might result in lowered microbial biomass once microorganisms spend more energy in detoxification processes than in microbial growth. E. crypticus juvenile production was not affected at the different conditions tested. However, the importance of microorganisms on the enchytraeids diet was ratified. Besides, it is important to emphasize that only one recommended dose of the pesticides was tested in this study. Hence, other situations (e.g. pesticides over application or a slower process of pesticides degradation) may result in a different scenario of effects and should be further investigated.

The present research employs the Ecological Risk Assessment (ERA) method to evaluate the probability of adverse effects in the water supply of Bom Repouso (MG), a city where the agriculture has caused an advanced degree of degradation of its sources. The methodology is based on the integration of different variables, divided into three Lines of Evidence (chemical, physical-chemical and ecotoxicological), and allows for the evaluation of risk assessment between 0.0 and 1.0 in the sampled environment. Five sampling points were evaluated in three periods, with the results varying between the four possible ratings (from low to very high), and it was not possible to identify a pattern of risk evolution between them. Thus, the method used proved to be efficient in assessing the degree of degradation of the environment, however, additional studies are required to improve this type of systemic impact assessment, based on the evaluation of the environmental degradation.

Considering the need to understand the effects that pesticides pose tonon-target soil organisms, the effects of two pesticides, commonly used ontomato crops (Lycopersicon lycopersicum), were investigated considering germination and growth of the plants as measurement parameters. Natural,dried and defaunated soil was inoculated with a microbial substrate andcontaminated with the insecticide (Active Ingredient (AI) abamectin), thefungicide (AIdifenoconazole) and a mixture of both products. The tests wereperformed after 0, 28, 56 and 84 days from soil contamination, according toOECD 208 and ISO 11269-2guidelines. Plants height, fresh and dry mass, andalso microbial biomass carbon were measured.The parameters exhibited anincrease over time for all treatments, showing no toxicity to the organismstested under the above conditions. Considerando a necessidade de compreender os efeitos de agrotóxicos sobreorganismos não alvo, os efeitos de dois agrotóxicos, comumente utilizadosna cultura de tomate (Lycopersicon lycopersicum), foram analisadosconsiderando a germinação e o crescimento de plantas como parâmetrosde medida. Solo natural, seco e desfaunado foi inoculado com um substratomicrobiano e contaminado com as doses recomendadas do inseticida(Ingrediente Ativo (IA) abamectina), do fungicida (IA difenoconazol) e amistura de ambos. Após 0, 28, 56 e 84 dias da contaminação do solo, foramrealizados testes de germinação e crescimento de plântulas, conformeadaptações dos protocolos OECD 208 e ISO 11269-2. Em cada teste, forammensuradas a altura, a massa fresca e a massa seca das plântulas, alémda biomassa microbiana de carbono do solo. Em todos os tratamentos, osparâmetros apresentaram um crescimento não evidenciando toxicidadepara os organismos testados nas condições citadas.

Pesticides are widely used in agricultural fields to control plant diseases, weeds, and pests; however, the unforeseeable consequences of releasing these compounds into the soil and their effects on terrestrial invertebrates are matters of grave concern. The aim of the present study was to determine the direct impact of 2 pesticides, KRAFT® 36 EC (an insecticide; a.i. abamectin) and SCORE® (a fungicide; a.i. difenoconazole), on nontarget terrestrial invertebrates. Ecotoxicological tests were performed to evaluate the chronic and acute toxicity of these compounds to a potworm (Enchytraeus crypticus), a collembolan (Folsomia candida), and a mite (Hypoaspis aculeifer). The results showed that, for both pesticides, the collembolan F. candida was the most sensitive species, followed by the enchytraeid E. crypticus and the mite H. aculeifer. Effect concentrations at 50% of organisms' reproduction calculated for F. candida, E. crypticus, and H. aculeifer were 0.06, 2.8, and32 mg of abamectin/kg dry weight soil and 28.9, 125, and 145.5 mg of difenoconazole/kg dry weight soil, respectively. Environmentally relevant concentrations of both pesticides significantly affected the collembolan species. The existence of a potential risk from abamectin and difenoconazole for soil invertebrates even at recommended doses could be identified. Environ Toxicol Chem 2018;37:2919-2924. © 2017 SETAC.