Bees are considered as important providers of ecosystem services, acting via pollination process in crops and native plants, and contributing significantly to the maintenance of biodiversity. However, the decrease of bee's population has been observed worldwide and besides other factors, this collapse is also related to the extensive use of pesticides. In this sense, studies involving the assessment of adverse effects and the uptake of pesticides by bees are of great concern. This work presents an analytical method for the determination of the insecticide abamectin and the fungicide difenoconazole in the stingless bee Melipona scutellaris exposed via oral and topic to endpoints concentrations of active ingredients (a.i.) alone and in commercial formulations and the discussion about its mortality and uptake. For this purpose, QuEChERS (Quick, Easy, Cheap, Efficient, Rugged and Safe) acetate modified method was used for extraction and pesticides were determined by LC-MS/MS. The validation parameters have included: a linear range between 0.01 and 1.00 μg mL⁻¹; and LOD and LOQ of 0.038 and 0.076 μg g⁻¹ for abamectin and difenoconazole, respectively. The uptake of tested pesticides via oral and topic was verified by the accumulation in adult forager bees, mainly when the commercial product was tested. Mortality was observed to be higher in oral exposure than in topic tests for both pesticides. For abamectin in a commercial formulation (a.i.) no differences were observed for oral or topic exposure. On the other hand, for difenoconazole, topic exposure had demonstrated higher accumulation in bees, according to the increase of received dose. Through the results, uptake and the possible consequences of bioaccumulated pesticides are also discussed and can contribute to the knowledge about the risks involving the exposure of bees to these compounds.

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous analysis of 6 ectoparasiticides – 2 synthetic pyrethroids (deltamethrin, cypermethrin) and 4 macrocyclic lactones (abamectin, doramectin, ivermectin and eprinomectin) in biosolids. The method was used to investigate the occurrence of these ectoparasiticides in beef cattle feedlot wastes in Australia from 5 commercial feedlot operations which employ varying waste management practices. Deltamethrin and cypermethrin were not detected in any of the samples while abamectin, ivermectin, doramectin and eprinomectin were detected in some of the samples with concentrations ranging from 1 to 36 μg/kg dry weight (d.w.) freeze dried feedlot waste. Levels of macrocyclic lactones detected in the feedlot wastes varied and were dependent on sample type. The effect of seasonal variations and waste management practices were also investigated in this study.

Pistachio is an economically valuable crop, and Iran is among the biggest producers, exporters, and consumers of this product in the world. During the growing season, pistachios are subjected to multiple sprayings with various pesticides, which result in the accumulation of their residues in nuts. These residues have raised concerns regarding consumers’ health. In this research, uptake and dissipation kinetics of insecticides imidacloprid (IMI), thiacloprid (THI), thiamethoxam (THX), and abamectin (ABA) were investigated in pistachio nuts. Field experiments were conducted in a pistachio orchard. Pistachio trees were sprayed with the recommended dose of each insecticide formulation and water as the control. Samplings were performed for up to 49 days. Based on the results, pesticides uptake and dissipation kinetics were best fitted to first-order exponential growth (FOEG) and single first-order kinetic (SFOK) models, respectively. Variations in pesticides uptake/dissipation rates were mostly related to their water solubility, pKₐ, and log Kₒw. THX showed a higher uptake rate (0.16 ± 0.04) compared to IMI (0.10 ± 0.01) and THI (0.06 ± 0.01). The fastest dissipation rates were observed for IMI (0.04 ± 0.002 day⁻¹) and THX (0.03 ± 0.001 day⁻¹), while the slowest belonged to THI (0.02 ± 0.003 day⁻¹). ABA residues were below the quantification limit (LOQ) throughout the experiment. Based on FOEG and SFOK model predictions, multiple sprayings with THI and THX resulted in final concentrations exceeding the maximum residue limit (MRL). Hazard quotients for all pesticides were <1, indicating no risk to humans via consumption of the pistachio nut.

Owls are outstanding environmental quality bioindicators due to their position at the top of the food chain and susceptibility to pollutant accumulation. Exposure to chemical contaminants is often a risk for these animals. Moreover, studies addressing the bioaccumulation of trace elements and pesticide residues in tropical nocturnal raptor species are scarce. We analyzed the 26 organs (heart, liver, and kidney) of Tyto furcata (n=3), Megascops spp. (n=5), Pulsatrix koeniswaldiana (n=1), and Asio stygius (n=1) carcasses, collected from June 2018 to May 2019 in the Southern region of Brazil. The original vegetation consisted of areas of Araucaria forests and grassy-woody steppes with gallery forests, which were greatly modified by the introduction of agriculture. In four animals and eight organs, the pesticides abamectin, atrazine, chlorpyrifos-ethyl, and diurom were analyzed through high-performance liquid chromatography coupled with a mass detector. In six animals and eighteen organs, the trace elements cadmium, lead, chromium, and nickel were identified via atomic absorption spectrophotometry. Chlorpyrifos-ethyl was detected in the livers of the genus Megascops. Chromium was found at high concentrations in all matrices analyzed for this trace element. Moreover, P. koeniswaldiana presented lead levels indicative of high exposure. The bioaccumulation of these toxics in owls described here can impact the population levels of these species, impact on its ecological function, and consequently unbalance the ecosystem. Moreover, owls are considered bioindicators; therefore, the occurrence of bioaccumulation indirectly gives us information about the quality of the environment.

Farm worker and consumers are vulnerable to the potentially toxic pesticides accumulated in the environment and food. Nonetheless, few studies have investigated the pesticide pollution and risk in the medlar planting site at a large scale. Hereupon, this study focused on the pesticide contamination distribution, their potential risk assessment of contaminated sites and dietary. The 11 pesticide pollution sources were collected from the five systems of fruit, leaf, soil, groundwater, and honey based on a systematic review in medlar planting site. Seventy-six samples were analyzed by chromatography technique. Residues of 4 (36.7%) compounds were found in the samples. The most distributed pesticides were imidacloprid for all samples, followed by avermectin for leaf, soil, groundwater, and honey, and carbendazim for leaf, glyphosate for soil, and those with the highest average concentrations were carbendazim (3.8–8.4 mg/kg of leaf) and glyphosate (0.21–1.3 mg/kg of soil). The vertical migration characteristic of imidacloprid was relatively stable, and the residual concentration gradually declined with the increase of burial depth. However, glyphosate tended to accumulate gradually or was close to the surface concentration with the increase of burial depth. The distribution of abamectin had no obvious regularity. Imidacloprid was lower than the MRL in fruit and honey. Imidacloprid, avermectin, and glyphosate no MRL in soil and groundwater are set. Using the monitoring data, potential health risk come from fruit, soil, and groundwater was evaluated. The HI and HQ could be considered safe for pesticide residues in fruit, soil, and groundwater. Even if these results are in general safe to eat, the effects of insecticide on human health, especially on genetic toxicity, have gradually aroused more attention. To minimize the increasing human health risk, this study suggests that authorities must regulate the usage of agrochemicals, to strengthen the controls for effective implementation of the pesticide bans.

Honeybee (Apis mellifera L.) provides not only bee products of immense value but also render invaluable free service as cross-pollination and propagation of several cultivated and wild species, thereby, maintaining biological diversity. Bee larvae and adults might be killed or suffer various sublethal effects when placed in contact with pollen and nectar contaminated with insecticides. The present work was conducted to investigate the toxicity of seven insecticides on laboratory using oral toxicity test and their side effects on A. mellifera in cotton fields. Results indicated that lambda-cyhalothrin was the most toxic-tested pesticide, recording the lowest LC₅₀ and LC₉₀ values at all tested periods and the lowest LT₅₀ and LT₉₀ at all tested concentrations, followed by abamectin, spinosad, chlorpyrifos, and emamectin benzoate. On the other side, dipel and pyridalyl recording the highest LC₅₀ and LC₉₀ at all tested periods and the highest LT₅₀ and LT₉₀ at all tested concentrations. As for the application of pesticides in cotton fields, the tested pesticides significantly increased the number of dead workers in comparison with control. The tested pesticides significantly decreased bee foraging activities, i.e., number of foraging workers, number of worker collecting nectar, number of worker gathering pollen grains, area of broad workers, and honey bee yields. Dipel and pyridalyl were the most safety pesticides on honey bee workers in laboratory and field, so it could be introduced as a component in IPM programs of cotton pests.

In conventional agriculture, several pesticides can be applied at the same stage of plant development, either individually or in mixtures and these compounds also reach aquatic ecosystems. The aim of the present study was to investigate the short-term effects of the insecticide Kraft® 36 EC (active ingredient — a.i. abamectin) and the fungicide Score® 250 EC (a.i. difenoconazole) on the zooplankton community in outdoor freshwater microcosms. The potential risks related to the exposure to both compounds, isolated and in mixture, likely to occur in the field after runoff and spray drift events of their recommended doses were assessed in these microcosms through integrative analyses of the effects on the composition, density, and functional diversity of zooplankton. Namely, these endpoints were evaluated for eight different exposures, which were (1) Runoff control — RC; (2) Kraft-contaminated runoff — RK; (3) Score-contaminated runoff — RS; (4) Kraft and Score-contaminated runoff — RKS; (5) Spray drift Control — SC; (6) Kraft spray drift — SK; (7) Score spray drift — SS; and (8) Kraft and Score spray drift — SKS. Zooplankton taxa responded quickly to physical, chemical, and biological changes in the aquatic ecosystems. The principal response curves (PRC) analyses of the zooplankton community in the microcosms indicated significant effects after all insecticide treatments, both when applied individually and in a mixture with the fungicide. The insecticide treatment (RK and SK) demonstrated a decrease in the number of unique species (sing.sp) of zooplankton in the microcosms, and RK also decreased the functional divergence (FDiv). However, it was the treatment of mixtures (SKS) that caused a decrease in functional diversity (FD) and in the functional diversity indexes (divergence and richness) and sing.sp. Thus, the results showed the risk of the insecticide and their mixture to aquatic ecosystems.

Application of an agricultural residue (rice husk, RH) as a raw material for catalyst support for advanced oxidative processes (AOPs) was evaluated. The supported catalyst was produced by the calcination of TiCl₄ impregnated in RH, thereby providing a composite TiO₂/Si-C, which was characterized by elemental analysis (CHN), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX), X-ray photoelectron spectroscopy (XPS), UV/VIS diffuse reflectance spectroscopic (DRS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), atomic force microscopy (AFM), SEM, and nitrogen adsorption–desorption isotherms (BET and BJH). Catalytic photodecomposition of methylene blue (MB), naphthalene, phenol, and abamectin and acid drainage of a mine by a titania-based catalyst composite were investigated. For comparative purposes, a commercial photocatalyst (TiO₂) was also employed. Photocatalytic degradation of MB, phenol, naphthalene, abamectin, and from coal mining effluent ranged from 8 to 93 % of the initial concentration. Performances of both catalysts were comparable. Additionally, in these evaluated systems, the toxicity of the effluent decreased after photocatalysis, either for Daphnia magna or for Scenedesmus subspicatus (employed as bioindicators).

With the advancement of technology and the development of agriculture, the use of pesticides in this industry has also increased. The aim of this study was to investigate the effects of Abamectin toxin on survival and intestinal tissue of Caspian Roach as one of the valuable species in the Caspian Sea. For this purpose, 126 fingerlings fish were exposed to a different level of Abamectin for 96 h. Data analyzed showed that there was a significant correlation between fish mortality rate and Abamectin concentrations. Histological assays showed some typical tissue damages such as vaculation, necrosis, bleeding, epithelial degeneration, the intestinal villi destruction, deformation, and destruction of epithelial cells. Moreover, some clinical signs occurred like increasing operculum movement, swimming near the water surface, anxiety, and death with open mouth. The results of the present study showed that Abamectin can have toxicity effects on Caspian roach, also to sub-lethal concentrations, leading to several tissue damages and reduced survival rate of fish.

In the current study, the toxicity bioassay of three pollutants abamectin (ABM), thiamethoxam (TMX), and acrylamide (ACR) against land snails Theba pisana was measured. Also, the ecotoxicological effects of dietary exposure to sublethal concentration (1/20 LC₅₀) of these pollutants for 2-week exposure and 1-week recovery on some physiological endpoints evaluated as feeding activity, growth response, and carbonic anhydrase activity as a marker in charge of shell formation and seromucoid level as a marker in charge of mucus synthesis of the snails were studied. The results exhibited that the 48-h LC₅₀ values were 0.91, 313.8, and 45.7 μg/g dry food for ABM, TMX, and ACR, respectively. The sublethal concentrations of these pollutants in the diet after 2-week exposure were found to reduce the food consumption and inhibit growth rate of the snails. Also, the data illustrated that carbonic anhydrase activity was significantly decreased. On the other hand, there was a significant increase in the seromucoid level as a marker responsible for mucus synthesis in ABM- and TMX-exposed snails, while ACR showed significantly decreased level when compared to control. After 1-week recovery, the tested endpoints of treated snails were slightly repaired but still less than that of the untreated animals. The overall outcome of this investigation suggests the utility of this animal as a good bioindicator organism for ABM, TMX, and ACR exposure in pollution monitoring studies.