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Wrobel MH, Mlynarczuk J, Rekawiecki R. Effects of commonly used carbamates (carbaryl and thiram) on the regulatory, secretory and motor functions of bovine cervixes in vitro. Theriogenology 2024; 218:183-192. [PMID: 38330862 DOI: 10.1016/j.theriogenology.2024.01.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/10/2024]
Abstract
Previously studied classes of pesticides, including organochlorines, organophosphates and pyrethroids disturb the mechanism that causes bovine myometrial contractions. Hence, the aim of this study was to investigate the effects of carbaryl and thiram, which are representative carbamate pesticides commonly used in global agriculture, on the motor and secretory functions of bovine cervixes. Additionally, the impacts of these pesticides on intra- and intercellular signaling in vitro were estimated. In this study, cervical cells or strips were obtained from cows at days 18-20 of the estrous cycle and were treated with carbaryl or thiram. Neither carbamate (10 or 100 ng/ml) exerted cytotoxic effects. Carbaryl increased the level of mRNA (at a dose of 0.1 ng/ml) and protein (at both doses, 1 and 10 ng/ml) expression for the oxytocin receptor (OXTR), while thiram (at 0.1 and 10 ng/ml or 0.1-10 ng/ml, respectively) caused the opposite effects. Moreover, the level of the second messenger inositol-trisphosphate (IP3) was decreased by carbaryl (10 ng/ml) but increased by thiram (10 ng/ml). Only thiram decreased prostaglandin-endoperoxide synthase 2 (PTGS2; 0.1 ng/ml) and aldo-keto reductase family 1, member B1 (AKR1B1; 0.1 ng/ml), and prostaglandin E synthase 2 (PTGES2; 0.1-10 ng/ml) mRNA expression, while thiram (0.1-10 ng/ml) and carbaryl (0.1 and 10 ng/ml) both decreased the release of PGF2α. Carbaryl (10 ng/ml) and thiram (10 ng/ml) also decreased the level of a gap junction protein (GAP). Moreover, carbaryl (10 ng/ml) decreased the level of myosin light chain kinase (MLCK). However, the strength of cervical contractions was increased by thiram (1 and 10 ng/ml) but decreased by carbaryl (1 and 10 ng/ml). Carbaryl increased the receptivity of cervical cells to oxytocin (OXT), but inhibited further transduction (IP3) of this signal. Hence, direct inhibition of cervical strip contraction may occur. In contrast, thiram mostly decreased the receptivity of cervical cells to OXT, while it stimulated the contraction of cervical strips. Moreover, compared to carbaryl, thiram more greatly affected the synthesis and release of prostaglandins. These results suggest that carbaryl and thiram disturb OXT signaling, PG secretion and cervical contraction in vitro.
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Affiliation(s)
- Michal Hubert Wrobel
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima Street 10, 10-748, Olsztyn, Poland.
| | - Jaroslaw Mlynarczuk
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima Street 10, 10-748, Olsztyn, Poland
| | - Robert Rekawiecki
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima Street 10, 10-748, Olsztyn, Poland
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Mohapatra B, Phale PS. Microbial Degradation of Naphthalene and Substituted Naphthalenes: Metabolic Diversity and Genomic Insight for Bioremediation. Front Bioeng Biotechnol 2021; 9:602445. [PMID: 33791281 PMCID: PMC8006333 DOI: 10.3389/fbioe.2021.602445] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/09/2021] [Indexed: 12/21/2022] Open
Abstract
Low molecular weight polycyclic aromatic hydrocarbons (PAHs) like naphthalene and substituted naphthalenes (methylnaphthalene, naphthoic acids, 1-naphthyl N-methylcarbamate, etc.) are used in various industries and exhibit genotoxic, mutagenic, and/or carcinogenic effects on living organisms. These synthetic organic compounds (SOCs) or xenobiotics are considered as priority pollutants that pose a critical environmental and public health concern worldwide. The extent of anthropogenic activities like emissions from coal gasification, petroleum refining, motor vehicle exhaust, and agricultural applications determine the concentration, fate, and transport of these ubiquitous and recalcitrant compounds. Besides physicochemical methods for cleanup/removal, a green and eco-friendly technology like bioremediation, using microbes with the ability to degrade SOCs completely or convert to non-toxic by-products, has been a safe, cost-effective, and promising alternative. Various bacterial species from soil flora belonging to Proteobacteria (Pseudomonas, Pseudoxanthomonas, Comamonas, Burkholderia, and Novosphingobium), Firmicutes (Bacillus and Paenibacillus), and Actinobacteria (Rhodococcus and Arthrobacter) displayed the ability to degrade various SOCs. Metabolic studies, genomic and metagenomics analyses have aided our understanding of the catabolic complexity and diversity present in these simple life forms which can be further applied for efficient biodegradation. The prolonged persistence of PAHs has led to the evolution of new degradative phenotypes through horizontal gene transfer using genetic elements like plasmids, transposons, phages, genomic islands, and integrative conjugative elements. Systems biology and genetic engineering of either specific isolates or mock community (consortia) might achieve complete, rapid, and efficient bioremediation of these PAHs through synergistic actions. In this review, we highlight various metabolic routes and diversity, genetic makeup and diversity, and cellular responses/adaptations by naphthalene and substituted naphthalene-degrading bacteria. This will provide insights into the ecological aspects of field application and strain optimization for efficient bioremediation.
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Affiliation(s)
- Balaram Mohapatra
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Prashant S Phale
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
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Chemical cues of an invasive turtle reduce development time and size at metamorphosis in the common frog. Sci Rep 2020; 10:7978. [PMID: 32409709 PMCID: PMC7224366 DOI: 10.1038/s41598-020-64899-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/24/2020] [Indexed: 11/16/2022] Open
Abstract
In aquatic systems, chemical cues are one of the major sources of information through which animals can assess local predation risk. Non-native red-eared sliders (Trachemys scripta elegans) have the potential to disrupt aquatic ecosystems in Central Europe because of their superior competitive abilities and omnivorous diets. In this study, we examined whether continuous predator-borne cues are tied to changes in the developmental rates, growth rates and sizes at metamorphosis of common frog tadpoles (Rana temporaria). Our results show rather rarely documented types of amphibian prey responses to caged predators. The presence of turtles shortened the time at metamorphosis of tadpoles from 110 ± 11.7 days to 93 ± 13.0 days (mean ± S.D.). The first metamorphosed individuals were recorded on the 65th day and on the 80th day from hatching in the predator treatment and in the control group, respectively. The froglets were significantly smaller (12.8 ± 0.99 mm) in the presence of the predator than in the control treatment (15.2 ± 1.27 mm). The growth rate trajectories were similar between the predator treatment and the control. Thus, predator-induced tadpole defences were evident in higher developmental rates and smaller sizes at metamorphosis without significant changes in growth.
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Phale PS, Shah BA, Malhotra H. Variability in Assembly of Degradation Operons for Naphthalene and its derivative, Carbaryl, Suggests Mobilization through Horizontal Gene Transfer. Genes (Basel) 2019; 10:genes10080569. [PMID: 31357661 PMCID: PMC6723655 DOI: 10.3390/genes10080569] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/11/2019] [Accepted: 07/11/2019] [Indexed: 01/14/2023] Open
Abstract
In the biosphere, the largest biological laboratory, increased anthropogenic activities have led microbes to evolve and adapt to the changes occurring in the environment. Compounds, specifically xenobiotics, released due to such activities persist in nature and undergo bio-magnification in the food web. Some of these compounds act as potent endocrine disrupters, mutagens or carcinogens, and therefore their removal from the environment is essential. Due to their persistence, microbial communities have evolved to metabolize them partially or completely. Diverse biochemical pathways have evolved or been assembled by exchange of genetic material (horizontal gene transfer) through various mobile genetic elements like conjugative and non-conjugative plasmids, transposons, phages and prophages, genomic islands and integrative conjugative elements. These elements provide an unlimited opportunity for genetic material to be exchanged across various genera, thus accelerating the evolution of a new xenobiotic degrading phenotype. In this article, we illustrate examples of the assembly of metabolic pathways involved in the degradation of naphthalene and its derivative, Carbaryl, which are speculated to have evolved or adapted through the above-mentioned processes.
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Affiliation(s)
- Prashant S Phale
- Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Powai, Mumbai-400 076, India.
| | - Bhavik A Shah
- Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Powai, Mumbai-400 076, India
| | - Harshit Malhotra
- Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Powai, Mumbai-400 076, India
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Vasconcelos AM, Daam MA, de Resende JC, Casali-Pereira MP, Espíndola ELG. Survival and development of bullfrog tadpoles in microcosms treated with abamectin. ECOTOXICOLOGY (LONDON, ENGLAND) 2017; 26:729-737. [PMID: 28409414 DOI: 10.1007/s10646-017-1804-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/05/2017] [Indexed: 05/22/2023]
Abstract
As compared to other aquatic taxonomic groups, few studies have been conducted so far evaluating the potential risks of pesticides to amphibians. Furthermore, most existing studies with amphibians consist of acute laboratory toxicity tests that mostly only evaluated single peak pesticide exposure. In the present study, potential chronic effects of single and repeated abamectin applications on the survival and development of L. catesbeianus tadpoles under (semi-) field conditions were evaluated. To this end, tadpoles were housed in microcosms treated with single or repeated applications of abamectin (as the commercial product Vertimec® 18 EC). The single application level corresponded to the previously established laboratory 96 h LC50 of the test organism, whereas the repeated application was based on abamectin concentrations likely to occur in runoff water from agricultural areas where Vertimec® 18 EC is applied. Under semi-field conditions, toxicity after the single application was greater than would be expected from the laboratory toxicity value. Although the repeated application did not exert direct effects on tadpole survival, the observed delay in development may have pronounced effect on the fitness and survival of anuran populations in edge-of-field water bodies.
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Affiliation(s)
- Ana M Vasconcelos
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil
| | - Michiel A Daam
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil.
- CENSE, Department of Environmental Sciences and Engineering, Faculty of Sciences and Technology, New University of Lisbon, Quinta da Torre, Caparica, 2829-516, Portugal.
| | - Juliana C de Resende
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil
| | - Maressa P Casali-Pereira
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil
| | - Evaldo L G Espíndola
- NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, Av. Trabalhador São Carlense, 400, 13.560-970, São Carlos, Brazil
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De Jesús Andino F, Lawrence BP, Robert J. Long term effects of carbaryl exposure on antiviral immune responses in Xenopus laevis. CHEMOSPHERE 2017; 170:169-175. [PMID: 27988452 PMCID: PMC5205582 DOI: 10.1016/j.chemosphere.2016.12.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/04/2016] [Accepted: 12/05/2016] [Indexed: 05/06/2023]
Abstract
Water pollutants associated with agriculture may contribute to the increased prevalence of infectious diseases caused by ranaviruses. We have established the amphibian Xenopus laevis and the ranavirus Frog Virus 3 (FV3) as a reliable experimental platform for evaluating the effects of common waterborne pollutants, such as the insecticide carbaryl. Following 3 weeks of exposure to 10 ppb carbaryl, X. laevis tadpoles exhibited a marked increase in mortality and accelerated development. Exposure at lower concentrations (0.1 and 1.0 ppb) was not toxic, but it impaired tadpole innate antiviral immune responses, as evidenced by significantly decreased TNF-α, IL-1β, IFN-I, and IFN-III gene expression. The defect in IFN-I and IL-1β gene expression levels persisted after metamorphosis in froglets, whereas only IFN-I gene expression in response to FV3 was attenuated when carbaryl exposure was performed at the adult stage. These findings suggest that the agriculture-associated carbaryl exposure at low but ecologically-relevant concentrations has the potential to induce long term alterations in host-pathogen interactions and antiviral immunity.
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Affiliation(s)
| | - B Paige Lawrence
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA; Department of Environmental Medicine, University of Rochester Medical Center, Rochester, USA
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA; Department of Environmental Medicine, University of Rochester Medical Center, Rochester, USA.
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Leomanni A, Schettino T, Calisi A, Gorbi S, Mezzelani M, Regoli F, Lionetto MG. Antioxidant and oxidative stress related responses in the Mediterranean land snail Cantareus apertus exposed to the carbamate pesticide Carbaryl. Comp Biochem Physiol C Toxicol Pharmacol 2015; 168:20-7. [PMID: 25451076 DOI: 10.1016/j.cbpc.2014.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/20/2014] [Accepted: 11/20/2014] [Indexed: 10/24/2022]
Abstract
The aim of the present work was to study the alterations of the antioxidant defenses and the overall susceptibility to oxidative stress of the terrestrial snail Cantareus apertus exposed to the carbamate pesticide Carbaryl at a low environmentally realistic concentration. The animals were exposed to Lactuca sativa soaked for 1h in 1μM Carbaryl. The temporal dynamics of the responses was assessed by measurements at 3, 7 and 14days of exposure. C. apertus exposed to Carbaryl activates a number of enzymatic antioxidant responses, represented by the early induction of catalase, glutathione peroxidase, glutathione reductase, followed by a delayed induction of superoxide dismutase. Concomitantly, a derangement of the total oxyradical scavenging of the tissues was observed, suggesting an overall impairment of the tissue capability to neutralize ROS probably resulting from the overall negative balance between enzymatic antioxidant defense capability and oxidative stress intensity. This negative balance exposed the animals to the risk of oxidative stress damages including genotoxic damage. Compared to acetylcholinesterase inhibition, the antioxidant responses developed to Carbaryl exposure at the low concentration utilized showed a greater percentage variation in exposed organisms. The results pointed out the high sensitivity of the antioxidant and oxidative stress related responses to Carbaryl exposure at an environmental realistic concentration, demonstrating their usefulness in environmental monitoring and risk assessment. The study highlights also the usefulness of the terrestrial snail C. apertus as potential bioindicator species for assessing the risk of pesticide environmental contamination.
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Affiliation(s)
- A Leomanni
- Dip.to di Scienze e Tecnologie Biologiche e Ambientali (DiSTeBA), Università del Salento, Via prov.le Lecce-Monteroni, 73100 Lecce, Italy
| | - T Schettino
- Dip.to di Scienze e Tecnologie Biologiche e Ambientali (DiSTeBA), Università del Salento, Via prov.le Lecce-Monteroni, 73100 Lecce, Italy
| | - A Calisi
- Dip.to di Scienze e Tecnologie Biologiche e Ambientali (DiSTeBA), Università del Salento, Via prov.le Lecce-Monteroni, 73100 Lecce, Italy
| | - S Gorbi
- Dip.to di Genetica Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Via Ranieri 65, Montedago, 60131 Ancona, Italy
| | - M Mezzelani
- Dip.to di Genetica Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Via Ranieri 65, Montedago, 60131 Ancona, Italy
| | - F Regoli
- Dip.to di Genetica Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Via Ranieri 65, Montedago, 60131 Ancona, Italy
| | - M G Lionetto
- Dip.to di Scienze e Tecnologie Biologiche e Ambientali (DiSTeBA), Università del Salento, Via prov.le Lecce-Monteroni, 73100 Lecce, Italy.
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Peltzer PM, Lajmanovich RC, Attademo AM, Junges CM, Cabagna-Zenklusen MC, Repetti MR, Sigrist ME, Beldoménico H. Effect of exposure to contaminated pond sediments on survival, development, and enzyme and blood biomarkers in veined treefrog (Trachycephalus typhonius) tadpoles. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 98:142-151. [PMID: 24080097 DOI: 10.1016/j.ecoenv.2013.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 08/28/2013] [Accepted: 09/03/2013] [Indexed: 06/02/2023]
Abstract
Sediments are important elements of aquatic ecosystems and in general sediments accumulate diverse toxic substances. Amphibians potentially have a greater risk of exposure to contaminants in sediments, and the test of sediments provides first lines of evidences. Sediment outdoor microcosm experiments were conducted to analyze biological endpoints (survival, development, growth, and morphological and organ malformation), enzyme activity (butyrylcholinesterase, BChE; glutathione-S-transferase, GST; and catalase, CAT) and blood biomarkers in veined treefrog Trachycephalus typhonius tadpoles, a widespread neotropical species. Hatching (stage 23) of T. thyphonius was exposed until they reached metamorphosis (stage 46). Sediment tests were performed and four different treatments were used: three ponds (LTPA, ISP, and SSP) influenced by industrial and agricultural activities and a reference treatment from a forest (RFS). Physical and chemical variables and concentration of nutrients, pesticide residues, and metals were determined. One treatment was metal-rich (LPTA) and two were nutrient-rich (ISP and SSP). Sediment treatments had no significant effect on survival; in contrast they had significant sublethal effects on T. typhonius larval development and growth rates, and affected overall size and shape at stage 38. Principally, in LPTA animals were significantly larger than in RFS, exhibiting swollen bodies, tail muscles and tail fin. In addition, metamorphs from LPTA, ISP, and SSP were smaller and showed signs of emaciation by the end of the experiment. Statistical comparisons showed that the proportions of each type of morphological abnormalities (swollen bodies and diamond shape, gut uncoiling, diverted gut, stiff tails, polydactyly, and visceral and hindlimb hemorrhaging) were significantly greater in metal- and nutrient-rich sediment treatments. Moreover, activities of BChE, GST and CAT, as well as and presence of micronuclei, immature, mitotic, anucleated erythrocytes varied significantly among treatments. Our biological effects-based sediment study highlights the use of different biological endpoints and biomarkers on anuran larvae at sites where pond sediment is risky and sediment management should be considered. Finally, the information of those biological endpoints and biomarkers would be useful as a management tool to decide if there are sufficient exposures of tadpoles to suspected pollutants on sediment.
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Affiliation(s)
- Paola M Peltzer
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1033AAJ Buenos Aires, Argentina; Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral (ESS-FBCB-UNL), 3000 Santa Fe, Argentina.
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Çakici Ö. Carbaryl-induced histopathologic alterations in the digestive tract of the Levantine frog, Pelophylax bedriagae (Anura: Ranidae). Toxicol Pathol 2013; 42:1032-40. [PMID: 24067672 DOI: 10.1177/0192623313503517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this study, histopathologic changes following carbaryl exposure for 96 hr were investigated in the digestive tract of Levantine frog, Pelophylax bedriagae. Adult frogs were exposed to carbaryl once by oral gavage in concentrations of 0.05, 0.1, and 0.2 mg/g. Histopathological changes were more prominent in medium- (0.1 mg/g) and high-dose (0.2 mg/g) groups than in the low-dose (0.05 mg/g) group. Esophageal cells showed vacuolization, cellular swelling, nuclear pyknosis, karyolysis, and necrosis. Additionally, esophageal glandular atrophy and infiltration of inflammatory cells around esophageal glands were observed at medium and high doses. In the stomach, there were prominent histopathologic defects such as cellular swelling and necrosis in gastric glands, necrotic cells within the interstitial spaces, separation of epithelial cell layer, congested vessels, and hemorrhage at medium and high doses. In the intestine, detachment of epithelial layer, epithelial cell disorganization, inflammation, and necrosis were detected at medium and high doses. The results of this study showed that carbaryl caused adverse effects on the digestive tract of the Levantine frog, P. bedriagae.
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Affiliation(s)
- Özlem Çakici
- Department of Biology, Zoology Section, Science Faculty, Ege University, İzmir, Turkey
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Moreira JC, Peres F, Simões AC, Pignati WA, Dores EDC, Vieira SN, Strüssmann C, Mott T. [Groundwater and rainwater contamination by pesticides in an agricultural region of Mato Grosso state in central Brazil]. CIENCIA & SAUDE COLETIVA 2012; 17:1557-68. [PMID: 22699646 DOI: 10.1590/s1413-81232012000600019] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 04/24/2012] [Indexed: 11/22/2022] Open
Abstract
This study sought to analyze groundwater and rainwater contamination by pesticides in two municipalities (Lucas do Rio Verde and Campo Verde) of Mato Grosso state. The area is Brazil's mid-west situated among the major soybean, corn and cotton producers in the state and the country. The analytical methodology combined chromatographic techniques on groundwater and rainwater samples with eco-toxicological analyses of the impacts of contamination by pesticide on bio-indicator species. The results revealed the presence of different pesticide residues in the groundwater and rainwater samples collected in the two municipalities. In conjunction with this data, results of the eco-toxicological tests revealed the presence of anomalies in a bio-indicator species collected in one of the two study sites compatible with exposure to pesticides. The results presented and discussed here highlight the degradation of water resources in the region, caused by the intensive use of pesticides in agriculture, including the contamination of drinking water sources and rain, broadening the risk of contamination beyond the cultivated areas.
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Affiliation(s)
- Josino Costa Moreira
- Centro de Estudos da Saúde do Trabalhador e Ecologia Humana, Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, 21041-210 Rio de Janeiro, RJ.
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Boone MD, Sullivan NH. Impact of an insecticide changes with amount of leaf litter input: implications for amphibian populations. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2012; 31:1518-1524. [PMID: 22488856 DOI: 10.1002/etc.1832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 01/04/2012] [Accepted: 02/08/2012] [Indexed: 05/31/2023]
Abstract
Changes in percentage of forest cover can influence nutrient levels in aquatic systems and change abiotic conditions that may influence species. The authors examined how increasing amounts of leaf litter influenced toxicity of the insecticide carbaryl using larval green frogs (Rana clamitans) in outdoor mesocosm ponds. Insecticides can have direct negative effects on individual physiology and behavior and indirect effects on the food web, which can result in trophic cascades. They predicted that direct effects of the insecticide would dominate when nutrients were low (resulting in negative impacts on amphibian development and survival), whereas indirect effects could offset direct effects when nutrients were more abundant through a trophic cascade that leads to more food for tadpoles (resulting in positive effects on amphibian development and survival). The authors found support for this hypothesis: first, total green frog survival was greatest with increased leaf litter input in the presence of carbaryl. Additionally, most green frogs that reached metamorphosis were from ponds with high leaf litter input and carbaryl. Second, the impact of carbaryl on developmental stage and tadpole mass varied depending on the amount of leaf litter present. With high amounts of leaf litter, carbaryl had a positive impact on development and growth; in contrast, with low amounts of leaf litter, carbaryl had negative or no effects on tadpole development and mass. The present study suggests that differences in nutrient levels between ponds exposed to pesticides could play a role in amphibian population dynamics.
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