Measurement of pesticides in hair samples from pemphigus foliaceus and pemphigus vulgaris patients in Southeastern Brazil.

BACKGROUND: Pesticides, mainly organophosphates (OP), have been related to increased risk of pemphigus vulgaris (PV) and pemphigus foliaceus (PF), nevertheless, their measurement has not been determined in pemphigus patients. OBJECTIVE: To evaluate pesticide exposure and pesticide measurement, comparing PV, PF and control groups in Southeastern Brazil. METHODS: Information about urban or rural residency and exposure to pesticides at the onset of pemphigus was assessed by questionnaire interview; hair samples from the scalp of PV, PF, and controls were tested for OP and organochlorines (OC) by gas-phase chromatography coupled to mass spectrometry. RESULTS: The minority of PV (2 [7.1%] of 28) and PF (7 [18%] of 39), but none of the 48 controls, informed living in rural areas at the onset of pemphigus (p = 0.2853). PV (33.3%), PF (38.5%), and controls (20%) informed exposure to pesticides (p = 0.186). Twenty-one (14.8%) of 142 individuals tested positive for OP and/or OC: PV (2 [6.3%] of 32) and PF (11 [25.6%] of 43) had similar pesticides contamination as controls (8 [11.9%] of 67) (p = 0.4928; p = 0.0753, respectively), but PF presented higher contamination than PV (p = 0.034). PV did not present any positivity for OP. Three (7%) PF tested positive for both OP and OC. Some PF tested positive for three or four OP, mainly diazinon and dichlorvos. STUDY LIMITATION: Lack of data for some controls. CONCLUSION: Although the frequency of PV and PF patients exposed to pesticides was similar, pesticides were more frequently detected in hair samples from PF compared to PV. The cause-effect relationship still needs to be determined.

Measurement of pesticides in hair samples from pemphigus foliaceus and pemphigus vulgaris patients in Southeastern Brazil

Abstract Background Pesticides, mainly organophosphates (OP), have been related to increased risk of pemphigus vulgaris (PV) and pemphigus foliaceus (PF), nevertheless, their measurement has not been determined in pemphigus patients. Objective To evaluate pesticide exposure and pesticide measurement, comparing PV, PF and control groups in Southeastern Brazil. Methods Information about urban or rural residency and exposure to pesticides at the onset of pemphigus was assessed by questionnaire interview; hair samples from the scalp of PV, PF, and controls were tested for OP and organochlorines (OC) by gas-phase chromatography coupled to mass spectrometry. Results The minority of PV (2 [7.1%] of 28) and PF (7 [18%] of 39), but none of the 48 controls, informed living in rural areas at the onset of pemphigus (p = 0.2853). PV (33.3%), PF (38.5%), and controls (20%) informed exposure to pesticides (p = 0.186). Twenty-one (14.8%) of 142 individuals tested positive for OP and/or OC: PV (2 [6.3%] of 32) and PF (11 [25.6%] of 43) had similar pesticides contamination as controls (8 [11.9%] of 67) (p = 0.4928; p = 0.0753, respectively), but PF presented higher contamination than PV (p = 0.034). PV did not present any positivity for OP. Three (7%) PF tested positive for both OP and OC. Some PF tested positive for three or four OP, mainly diazinon and dichlorvos. Study limitation Lack of data for some controls. Conclusion Although the frequency of PV and PF patients exposed to pesticides was similar, pesticides were more frequently detected in hair samples from PF compared to PV. The cause-effect relationship still needs to be determined.

Diazinon toxicity in hepatic and spleen mononuclear cells is associated to early induction of oxidative stress.

Diazinon is an organophosphorus pesticide, which may have potential toxic effects on the liver and immune system; however, the underlying mechanisms remain mostly unidentified. This work is aimed at evaluating the oxidative stress and cell cycle alterations elicited by low-dose diazinon in a rat liver cell line (BRL-3A) and spleen mononuclear cells (SMC) from Wistar rats. Diazinon (10-50 µM) caused early reactive oxygen species (ROS) generation (from 4 h) as well as increased O2•- level (from 0.5 h), which led to subsequent lipid peroxidation at 24 h, in BRL-3A cells. In SMC, diazinon (20 µM) produced similar increases in ROS levels, at 4 and 24 h, with the highest O2•- level being found at 4 h. Low-dose diazinon induced G1-phase arrest and cell death in hepatic cells and SMC. Therefore, diazinon could affect the liver and the immunological system through the premature oxidative stress induction.Abbreviations: O2•-: superoxide anion radical; ROS: reactive oxygen species; SMC: spleen mononuclear cells; TBARS: thiobarbituric acid reactive substances.

Diazinon impairs bioenergetics and induces membrane permeability transition on mitochondria isolated from rat liver.

Diazinon (DZN) is a broad-spectrum insecticide extensively used to control pests in crops and animals. Several investigators demonstrated that DZN produced tissue toxicity especially to the liver. In addition, the mitochondrion was implicated in DZN-induced toxicity, but the precise role of this organelle remains to be determined. The aim of this study was thus to examine the effects of DZN (50 to 150 µM) on the bioenergetics and mitochondrial permeability transition (MPT) associated processes in isolated rat liver mitochondria. DZN inhibited state-3 respiration in mitochondria energized with glutamate plus malate, substrates of complex I, and succinate, substrate of complex II of the respiratory chain and decreased the mitochondrial membrane potential resulting in inhibition of ATP synthesis. MPT was estimated by the extent of mitochondrial swelling, in the presence of 10 µM Ca2+. DZN elicited MPT in a concentration-dependent manner, via a mechanism sensitive to cyclosporine A, EGTA, ruthenium red and N-ethylmaleimide, which was associated with mitochondrial Ca2+ efflux and cytochrome c release. DZN did not result in hydrogen peroxide accumulation or glutathione oxidation, but this insecticide oxidized endogenous NAD(P)H and protein thiol groups. Data suggest the involvement of mitochondria, via apoptosis, in the hepatic cytotoxicity attributed to DZN.

Performance of a continuous stirred tank bioreactor employing an immobilized actinobacteria mixed culture for the removal of organophosphorus pesticides.

In this study, we evaluated polyurethane foam (PF), volcanic rock (VR), and a modified plastic cap (MPC) as supports for the immobilization of organophosphorus (OP) pesticide-degrading actinobacterial strains. The colonization and activity of four streptomycetes were favoured by PF, which was selected as the carrier to use in a continuous stirred tank bioreactor (CSTR) that can be operated at increasing inflows of a pesticide mixture that contains the insecticides chlorpyrifos (CP) and diazinon (DZ). Our results demonstrate that the CSTR can be operated at flow rates of 10 and 40 mL h-1 with greater than 85% removal of the pesticides in the short term. A significant decrease in the efficiency of CP removal was observed at the highest inflows into the reactor. The CP and DZ loading rates in the bioreactor ranged from 0.44 to 1.68 mg L-1 h-1 and from 0.50 to 2.17 mg L-1 h-1, respectively. Although the treated wastewater exhibited moderate toxicity for Raphanus sativus, a bioreactor inoculated with a mixed culture formed by Streptomyces spp. strains AC5, AC9, GA11 and ISP13 may provide an effective biotechnological strategy for the reduction of OP pesticide residues produced during agronomic and manufacturing practices and therefore prevent environmental pesticidal pollution.

Toxicity bioassay and sub-lethal effects of diazinon on blood profile and histology of liver, gills and kidney of catfish, Clarias gariepinus / Toxicidade bioensaio e efeitos sub-letais do diazinon no perfil sangüíneo e histologia do fígado, brânquias e rim de peixe-gato, clarias gariepinus

Abstract The catfish, Clarias gariepinus, was exposed to different acute concentrations (5-10 mg/l) of diazinon and the Lc50 value was recorded as high as 7.3 mg/l for 96 hours. The fishes exposed to three sub-lethal levels of diazinon (0.73, 1.095 and 1.46 mg/l) for 30 days showed that the pesticide induces changes in different blood parameters. Number of red blood cells (RBC), haemoglobin level and haematocrit values were elevated whereas white blood cells (WBC) count was reduced. Various blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobine (MCH) and mean corpuscular haemoglobine concentration (MCHC) vary insignificantly in the fish treated with diazinon. Glucose level and activity level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was increased in Clarias gariepinus exposed to diazinon. Protein level in plasma of fish treated with pesticide was changed but the change was insignificant. Histological changes in the liver, gills and kidney of fishes exposed to diazinon were apparent when compared to control. Hepatocytes necrosis and bleeding were more distinct in the fishes exposed to pesticide. Glomerulus hypertrophy and bleeding in kidneys; and fusion and degeneration of secondary lamellae and epithelial hyperplasia in gills were also observed in the exposed fish.

Resumo O peixe-gato, Clarias gariepinus, foi exposto a diferentes concentrações agudas (5-10 mg / l) de diazinon e o valor de Lc50 foi registrado tão alto quanto 7,3 mg / l por 96 horas. Os peixes expostos a três níveis sub-letais de diazinon (0,73, 1,095 e 1,46 mg / l) por 30 dias mostraram que o pesticida induz mudanças nos diferentes parâmetros sanguíneos. O número de glóbulos vermelhos, o nível de hemoglobina e os valores do hematócrito foram elevados, enquanto a contagem de leucócitos foi reduzida. Vários índices sanguíneos, como volume corpuscular médio (VCM), hemoglobina corpuscular média (HCM) e concentração de hemoglobina corpuscular média (CHCM) variam insignificantemente nos peixes tratados com diazinon. Nível de glicose e nível de atividade de AST e ALT foi aumentado em Clarias gariepinus expostos a diazinon. O nível de proteína no plasma de peixes tratados com pesticidas foi alterado, mas a mudança foi insignificante. Alterações histológicas no fígado, brânquias e rins de peixes expostos ao diazinon foram aparentes quando comparados ao controle. A necrose e o sangramento de hepatócitos foram mais distintos nos peixes expostos ao agrotóxico. Hipertrofia do glomérulo e sangramento nos rins; e fusão e degeneração de lamelas secundárias e hiperplasia epitelial em brânquias também foram observadas nos peixes expostos.

Phagocytosis and ROS production as biomarkers in Nile tilapia (Oreochromis niloticus) leukocytes by exposure to organophosphorus pesticides.

Organophosphorus pesticides (OPs) are broad-spectrum insecticides. One of the commonly used OPs is diazinon (DZN). The aim of this study was to evaluate the immunotoxic effect of DZN on phagocytic parameters of blood leukocytes using the teleost fish Oreochromis niloticus as a study model. For this purpose, fish were exposed in vivo to 0.97, 1.95 and 3.97 mg/L of DZN for 6 and 24 h. Our results indicated that phagocytic active cells decreased in fish exposed in vivo to 0.97 and 1.95 mg/L of DZN for 6 and 24 h. Regarding ROS production, H2O2 and O2- levels were higher on fish exposed to 1.95 mg/L for 6 and 24 h, while H2O2 production increased at 0.97 mg/L for 24 h. From this we can conclude that phagocytic parameters are sensitive to assess the effect of acute intoxication with organophosphorus pesticides on Nile tilapia.

Toxicity bioassay and sub-lethal effects of diazinon on blood profile and histology of liver, gills and kidney of catfish, Clarias gariepinus / Toxicidade bioensaio e efeitos sub-letais do diazinon no perfil sangüíneo e histologia do fígado, brânquias e rim de peixe-gato, clarias gariepinus

The catfish, Clarias gariepinus, was exposed to different acute concentrations (5-10 mg/l) of diazinon and the Lc50 value was recorded as high as 7.3 mg/l for 96 hours. The fishes exposed to three sub-lethal levels of diazinon (0.73, 1.095 and 1.46 mg/l) for 30 days showed that the pesticide induces changes in different blood parameters. Number of red blood cells (RBC), haemoglobin level and haematocrit values were elevated whereas white blood cells (WBC) count was reduced. Various blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobine (MCH) and mean corpuscular haemoglobine concentration (MCHC) vary insignificantly in the fish treated with diazinon. Glucose level and activity level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was increased in Clarias gariepinus exposed to diazinon. Protein level in plasma of fish treated with pesticide was changed but the change was insignificant. Histological changes in the liver, gills and kidney of fishes exposed to diazinon were apparent when compared to control. Hepatocytes necrosis and bleeding were more distinct in the fishes exposed to pesticide. Glomerulus hypertrophy and bleeding in kidneys; and fusion and degeneration of secondary lamellae and epithelial hyperplasia in gills were also observed in the exposed fish.(AU)

O peixe-gato, Clarias gariepinus, foi exposto a diferentes concentrações agudas (5-10 mg / l) de diazinon e o valor de Lc50 foi registrado tão alto quanto 7,3 mg / l por 96 horas. Os peixes expostos a três níveis sub-letais de diazinon (0,73, 1,095 e 1,46 mg / l) por 30 dias mostraram que o pesticida induz mudanças nos diferentes parâmetros sanguíneos. O número de glóbulos vermelhos, o nível de hemoglobina e os valores do hematócrito foram elevados, enquanto a contagem de leucócitos foi reduzida. Vários índices sanguíneos, como volume corpuscular médio (VCM), hemoglobina corpuscular média (HCM) e concentração de hemoglobina corpuscular média (CHCM) variam insignificantemente nos peixes tratados com diazinon. Nível de glicose e nível de atividade de AST e ALT foi aumentado em Clarias gariepinus expostos a diazinon. O nível de proteína no plasma de peixes tratados com pesticidas foi alterado, mas a mudança foi insignificante. Alterações histológicas no fígado, brânquias e rins de peixes expostos ao diazinon foram aparentes quando comparados ao controle. A necrose e o sangramento de hepatócitos foram mais distintos nos peixes expostos ao agrotóxico. Hipertrofia do glomérulo e sangramento nos rins; e fusão e degeneração de lamelas secundárias e hiperplasia epitelial em brânquias também foram observadas nos peixes expostos.(AU)

Biological impacts of organophosphates chlorpyrifos and diazinon on development, mitochondrial bioenergetics, and locomotor activity in zebrafish (Danio rerio).

The objectives of this study were to compare the biological responses in developing zebrafish to two organophosphate insecticides, chlorpyrifos (CPF) and diazinon (DZN). Zebrafish embryos were exposed to either solvent control (0.1% DMSO, v/v), or one dose of 0.1, 1.0, 10.0 and 25.0 µM CPF, as well as one dose of 0.1, 1.0, 10.0 and 100.0 µM DZN for 96 h. CPF at 10.0 and 25.0 µM caused 70-80% and 100% mortality in embryos after 96 h exposure, whereas embryos treated with 10.0 and 100.0 µM DZN showed 30-40% and 70-80% lethality. CPF at 10.0 µM significantly decreased cumulative hatching rate, whereas hatching rate was significantly reduced in embryos treated with 100.0 µM DZN. Spinal lordosis was primarily observed in larvae exposed to 1.0 and 10.0 µM CPF, whereas pericardial edema was mainly detected with 10.0 and 100.0 µM DZN exposure. Embryo exposed to 1.0, 10.0 and 25.0 µM CPF exhibited no mitochondrial dysfunction; exposure to 100.0 µM DZN significantly inhibited mitochondrial bioenergetics. To determine if CPF and DZN affected larval activity, dark photokinesis response was assessed in larvae following 7 days exposure to 0.1 and 1.0 µM CPF, as well as to 0.1 1.0, and 10.0 µM DZN. Larvae exposed to 1.0 µM CPF showed hypoactivity, whereas the activity in the dark was not overtly changed in larvae exposed to DZN. In summary, CPF showed higher developmental toxicity compared to DZN. Moreover, based on the types of morphological deformities noted, as well as differences in locomotor activity, we conclude that OPs have unique chemical-specific modes of action that can result in varied biological responses during early development.

Degradation kinetics of chlorpyrifos and diazinon in volcanic and non-volcanic soils: influence of cyclodextrins.

The intensive use of insecticides such as chlorpyrifos (CPF) and diazinon (DZN) in the agricultural activities worldwide has produced contamination of soils and/or transport to non-target areas including their distribution to surface and groundwaters. Cyclodextrins (CDs) have been proposed as an alternative in remediation technologies based on the separation of contaminants from soils because they could allow a higher bioavailability for their degradation with a low environmental impact. In this work, the degradation pattern of CPF and DZN and the formation and dissipation of the major degradation products 3,5,6-trichloro-2-pyridinol (TCP) and 2-isopropyl-6-methyl-4-pyrimidinol (IMPH) was established in four agricultural volcanic and non-volcanic soils belonging to Andisol, Ultisol, and Mollisol orders. Both pesticides were highly adsorbed in these soils, consequently, with a greater probability of contaminating them. In contrast, the adsorption of their two main metabolites was low or null; therefore, they are potential groundwater contaminants. The degradation processes were studied in the natural and amended soils with ß-cyclodextrin (ß-CD) and methyl-ß-cyclodextrin (Mß-CD) for CPF and DZN, respectively. A slow degradation of CPF and DZN was obtained for volcanic soils with observable residues until the end of the incubation time (150-180 days). In Mollisols, the higher degradation rate of CPF was favored by the neutral to basic pH, and for DZN it was related to the lower adsorption and higher bioavailability. The amendment of soils with CDs produced slower degradation rates which led to a greater concentration of the compounds at the end of the incubation time. This effect was more pronounced for DZN. The exception was the Andisol, with no significant changes for both compounds regarding the unamended soil. No residues of TCP were observed for this soil in both conditions during the whole incubation time; nevertheless, the accumulation of TCP was significant in the Ultisol and Mollisols, but the concentrations were lower for the amended soils. The accumulation of IMPH was important in Mollisol amended soils; however, their residues were observed in the volcanic soils during the whole incubation period in the natural and amended soils. An important enhancement of the microbial activity occurred in the system ß-CD/CPF in Mollisols, without a more effective degradation of the insecticide. The opposite effect was observed in the system Mß-CD/DZN mainly in the oxidative activity in all soils. The higher degradation of DZN and IMPH in natural Mollisols was related to the higher hydrolytic and oxidative activities. The stability of the inclusion complexes formed could play an important role for explaining the results obtained with the amendments.

Organophosphorus pesticide mixture removal from environmental matrices by a soil Streptomyces mixed culture.

The current study aimed to evaluate the removal of a pesticide mixture composed of the insecticides chlorpyrifos (CP) and diazinon (DZ) from liquid medium, soil and a biobed biomixture by a Streptomyces mixed culture. Liquid medium contaminated with 100 mg L-1 CP plus DZ was inoculated with the Streptomyces mixed culture. Results indicated that microorganisms increased their biomass and that the inoculum was viable. The inoculum was able to remove the pesticide mixture with a removal rate of 0.036 and 0.015 h-1 and a half-life of 19 and 46 h-1 for CP and DZ, respectively. The sterilized soil and biobed biomixture inoculated with the mixed culture showed that Streptomyces was able to colonize the substrates, exhibiting an increase in population determined by quantitative polymerase chain reaction (q-PCR), enzymatic activity dehydrogenase (DHA) and acid phosphatase (APP). In both the soil and biomixture, limited CP removal was observed (6-14%), while DZ exhibited a removal rate of 0.024 and 0.060 day-1 and a half-life of 29 and 11 days, respectively. Removal of the organophosphorus pesticide (OP) mixture composed of CP and DZ from different environmental matrices by Streptomyces spp. is reported here for the first time. The decontamination strategy using a Streptomyces mixed culture could represent a promising alternative to eliminate CP and DZ residues from liquids as well as to eliminate DZ from soil and biobed biomixtures.

Assesment of the Genotoxic Effect of the Diazinon on Root Cells of Allium cepa (L.)

ABSTRACT Organophosphorous pesticides (OPs) posses a great potential of acute toxicity for exposed animals and men. To evaluate the toxic potential of the organophosphate diazinon on root meristematic cells of Allium cepa L., was created two groups: In group 1 (control group), was not given any chemical. In group 2 (diazinon-treatment group), different doses (10, 40, 80 and 160 ppm) and times periods (24, 48 and 72 h) were administered. After exposure, cell death, effective concentration (EC50), mitotic index, cellular /chromosome aberrations, DNA damage by comet assay and RAPD-PCR were assessed at exposure times. EC50 value of diazinon was detected approximately 80 ppm. Hyperchromasia, later segragation, micronucleus, pulverised nucleus, nuclear cytoplasmic shrinkage and cell death, cytoplasmic vacuolation were detected in meristem cells as chromosome/celular aberrations for 72 h at 80 ppm. DNA damage was identified using tail DNA%, tail lengths and tail moment from these cells. Increasing exposure doses of diazinon caused increasing tail DNA% and tail lengths at 72 h. DNA bands of increasing concentrations treated groups were more distant to compare with the control group according to RAPD-PCR method. Diazinon cause cytotoxic and genotoxic on A. cepa root and could be considered for further toxicological evaluations.

Toxicity bioassay and sub-lethal effects of diazinon on blood profile and histology of liver, gills and kidney of catfish, Clarias gariepinus

Abstract The catfish, Clarias gariepinus, was exposed to different acute concentrations (5-10 mg/l) of diazinon and the Lc50 value was recorded as high as 7.3 mg/l for 96 hours. The fishes exposed to three sub-lethal levels of diazinon (0.73, 1.095 and 1.46 mg/l) for 30 days showed that the pesticide induces changes in different blood parameters. Number of red blood cells (RBC), haemoglobin level and haematocrit values were elevated whereas white blood cells (WBC) count was reduced. Various blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobine (MCH) and mean corpuscular haemoglobine concentration (MCHC) vary insignificantly in the fish treated with diazinon. Glucose level and activity level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was increased in Clarias gariepinus exposed to diazinon. Protein level in plasma of fish treated with pesticide was changed but the change was insignificant. Histological changes in the liver, gills and kidney of fishes exposed to diazinon were apparent when compared to control. Hepatocytes necrosis and bleeding were more distinct in the fishes exposed to pesticide. Glomerulus hypertrophy and bleeding in kidneys; and fusion and degeneration of secondary lamellae and epithelial hyperplasia in gills were also observed in the exposed fish.

Resumo O peixe-gato, Clarias gariepinus, foi exposto a diferentes concentrações agudas (5-10 mg / l) de diazinon e o valor de Lc50 foi registrado tão alto quanto 7,3 mg / l por 96 horas. Os peixes expostos a três níveis sub-letais de diazinon (0,73, 1,095 e 1,46 mg / l) por 30 dias mostraram que o pesticida induz mudanças nos diferentes parâmetros sanguíneos. O número de glóbulos vermelhos, o nível de hemoglobina e os valores do hematócrito foram elevados, enquanto a contagem de leucócitos foi reduzida. Vários índices sanguíneos, como volume corpuscular médio (VCM), hemoglobina corpuscular média (HCM) e concentração de hemoglobina corpuscular média (CHCM) variam insignificantemente nos peixes tratados com diazinon. Nível de glicose e nível de atividade de AST e ALT foi aumentado em Clarias gariepinus expostos a diazinon. O nível de proteína no plasma de peixes tratados com pesticidas foi alterado, mas a mudança foi insignificante. Alterações histológicas no fígado, brânquias e rins de peixes expostos ao diazinon foram aparentes quando comparados ao controle. A necrose e o sangramento de hepatócitos foram mais distintos nos peixes expostos ao agrotóxico. Hipertrofia do glomérulo e sangramento nos rins; e fusão e degeneração de lamelas secundárias e hiperplasia epitelial em brânquias também foram observadas nos peixes expostos.

Direct immersion single drop micro-extraction method for multi-class pesticides analysis in mango using GC-MS.

Due the negative effects of pesticides on environment and human health, more efficient and environmentally friendly methods are needed. In this sense, a simple, fast, free from memory effects and economical direct-immersion single drop micro-extraction (SDME) method and GC-MS for multi-class pesticides determination in mango samples was developed. Sample pre-treatment using ultrasound-assisted solvent extraction and factors affecting the SDME procedure (extractant solvent, drop volume, stirring rate, ionic strength, time, pH and temperature) were optimized using factorial experimental design. This method presented high sensitive (LOD: 0.14-169.20µgkg-1), acceptable precision (RSD: 0.7-19.1%), satisfactory recovery (69-119%) and high enrichment factors (20-722). Several obtained LOQs are below the MRLs established by the European Commission; therefore, the method could be applied for pesticides determination in routing analysis and custom laboratories. Moreover, this method has shown to be suitable for determination of some of the studied pesticides in lime, melon, papaya, banana, tomato, and lettuce.

Toxicity bioassay and sub-lethal effects of diazinon on blood profile and histology of liver, gills and kidney of catfish, Clarias gariepinus

Abstract The catfish, Clarias gariepinus, was exposed to different acute concentrations (5-10 mg/l) of diazinon and the Lc50 value was recorded as high as 7.3 mg/l for 96 hours. The fishes exposed to three sub-lethal levels of diazinon (0.73, 1.095 and 1.46 mg/l) for 30 days showed that the pesticide induces changes in different blood parameters. Number of red blood cells (RBC), haemoglobin level and haematocrit values were elevated whereas white blood cells (WBC) count was reduced. Various blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobine (MCH) and mean corpuscular haemoglobine concentration (MCHC) vary insignificantly in the fish treated with diazinon. Glucose level and activity level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was increased in Clarias gariepinus exposed to diazinon. Protein level in plasma of fish treated with pesticide was changed but the change was insignificant. Histological changes in the liver, gills and kidney of fishes exposed to diazinon were apparent when compared to control. Hepatocytes necrosis and bleeding were more distinct in the fishes exposed to pesticide. Glomerulus hypertrophy and bleeding in kidneys; and fusion and degeneration of secondary lamellae and epithelial hyperplasia in gills were also observed in the exposed fish.

Resumo O peixe-gato, Clarias gariepinus, foi exposto a diferentes concentrações agudas (5-10 mg / l) de diazinon e o valor de Lc50 foi registrado tão alto quanto 7,3 mg / l por 96 horas. Os peixes expostos a três níveis sub-letais de diazinon (0,73, 1,095 e 1,46 mg / l) por 30 dias mostraram que o pesticida induz mudanças nos diferentes parâmetros sanguíneos. O número de glóbulos vermelhos, o nível de hemoglobina e os valores do hematócrito foram elevados, enquanto a contagem de leucócitos foi reduzida. Vários índices sanguíneos, como volume corpuscular médio (VCM), hemoglobina corpuscular média (HCM) e concentração de hemoglobina corpuscular média (CHCM) variam insignificantemente nos peixes tratados com diazinon. Nível de glicose e nível de atividade de AST e ALT foi aumentado em Clarias gariepinus expostos a diazinon. O nível de proteína no plasma de peixes tratados com pesticidas foi alterado, mas a mudança foi insignificante. Alterações histológicas no fígado, brânquias e rins de peixes expostos ao diazinon foram aparentes quando comparados ao controle. A necrose e o sangramento de hepatócitos foram mais distintos nos peixes expostos ao agrotóxico. Hipertrofia do glomérulo e sangramento nos rins; e fusão e degeneração de lamelas secundárias e hiperplasia epitelial em brânquias também foram observadas nos peixes expostos.

Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement.

Removal of the insecticide diazinon from liquid media by free and immobilized Streptomyces sp. isolated from agricultural soil.

From an agricultural soil that had received continuous applications of organophosphorus pesticides, 30 actinobacteria strains were isolated. Two strains, identified as Streptomyces sp. AC1-6 and Streptomyces sp. ISP4, were selected because of their tolerance to diazinon and based on the relationship between diazinon removal and microbial growth. In liquid medium with diazinon at concentrations of 25 and 50 mg L(-1), both strains were able to remove approximately 40-50% and 70-90% of the initial diazinon after 24 and 96 h of incubation, respectively. This diazinon removal was accompanied by microbial growth of the strains, an initial pH decrease, and glucose consumption in the liquid medium. Evaluation of the diazinon removal achieved by the free actinobacteria and Streptomyces sp. AC1-6 immobilized on alginate beads revealed that the immobilized cells exhibited a 60% higher diazinon removal compared with the free cells. The reusability of the encapsulated biomass was confirmed, and a diazinon removal rate of more than 50% was obtained after the second batch. This work constitutes one of the few reports that describe Streptomyces strains as diazinon degraders. Given the high diazinon removal found, the streptomycetes exhibit suitable potential as diazinon-degrading actinobacteria for elimination of diazinon from liquid residues.

Sub-lethal Effects of Diazinon on Hematological Indices and Blood Biochemical Parameters in Indian Carp, Cirrhinus mrigala (Hamilton)

Indian carp (Cirrhinus mrigala) exposed to two sub-lethal concentrations (0.815 mg/L and 1.63 mg/L) of diazinon for 30 days showed a significant decrease in erythrocyte count, hemoglobin concentration, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, plasma levels of total protein, albumin, globulin, activity of enzyme acetylcholinesterase and a significant increase in plasma glucose levels when compared with controlled fish (P<0.05). Compared to the controlled fish, leukocyte count decreased significantly in fish exposed to both sub-lethal concentrations and the plasma activities of enzyme asparate aminotransferase and alanine aminotransferase increased significantly after 20 and 30 days in fish exposed to 0.815 mg/L of diazinon, while the activities of these enzymes in fish exposed to 1.63 mg/L of diazinon increased significantly at all sampling periods (P<0.05). On the other hand, the plasma activity of the enzyme lactate dehydrogenase decreased significantly in both diazinon treated fish groups after 10 days of exposure (P<0.05) and returned to the normal value after 20 and 30 days of exposure. In conclusion, long-term exposure to diazinon at sub-lethal concentrations induces severe physiological alterations in C. mrigala that may potentially disrupt their survival in their natural habitat.

Uso inadequado de organofosforados: uma prática de risco para bovinos no Sul do Rio Grande do Sul / Misuse of organophosphate: potential risk to cattle in Southern Brazil

Com o objetivo de determinar as causas para o súbito aumento no número de surtos de intoxicação por organofosforados foram analisados nove surtos da intoxicação diagnosticados em bovinos no Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (LRD/UFPel) entre novembro de 2013 e fevereiro de 2014. Em todos os surtos os animais foram tratados com concentrações entre duas e 151 vezes maiores que a concentração recomendada de diazinon para banho carrapaticida utilizado nas diferentes propriedades. Contribuíram, ainda, para o grande número de casos de intoxicação a via de adminstração pour on não recomendada para os produtos utilizados e o intenso calor registrado na época de ocorrência dos surtos.

In order to determine the cause of the sudden increase in the number of outbreaks of organophosphate poisoning, nine outbreaks diagnosed in cattle were analyzed at the Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Universidade Federal de Pelotas (LRD/UFPel) between November 2013 and February 2014. In all outbreaks the animals were treated with concentration from two to 151 times higher than the concentration recommended of diazinon for tick treatment. The incorrect route of application, and the intense heat recorded at the time of the outbreaks also contributed to the large number of poisoning.

Uso inadequado de organofosforados: uma prática de risco para bovinos no Sul do Rio Grande do Sul / Misuse of organophosphate: potential risk to cattle in Southern Brazil

Com o objetivo de determinar as causas para o súbito aumento no número de surtos de intoxicação por organofosforados foram analisados nove surtos da intoxicação diagnosticados em bovinos no Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (LRD/UFPel) entre novembro de 2013 e fevereiro de 2014. Em todos os surtos os animais foram tratados com concentrações entre duas e 151 vezes maiores que a concentração recomendada de diazinon para banho carrapaticida utilizado nas diferentes propriedades. Contribuíram, ainda, para o grande número de casos de intoxicação a via de adminstração pour on não recomendada para os produtos utilizados e o intenso calor registrado na época de ocorrência dos surtos.(AU)

In order to determine the cause of the sudden increase in the number of outbreaks of organophosphate poisoning, nine outbreaks diagnosed in cattle were analyzed at the Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Universidade Federal de Pelotas (LRD/UFPel) between November 2013 and February 2014. In all outbreaks the animals were treated with concentration from two to 151 times higher than the concentration recommended of diazinon for tick treatment. The incorrect route of application, and the intense heat recorded at the time of the outbreaks also contributed to the large number of poisoning.(AU)