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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Limiar de recuperação de ovos de Toxocara canis em solo por técnica de centrífugo-flutuação / Threshold of Toxocara canis eggs recovery from soil by a centrifuge-flotation technique

Xavier, Iara Giordano Rosa 09 February 2009 (has links)
Made available in DSpace on 2016-01-26T18:55:27Z (GMT). No. of bitstreams: 1 Dissertacao Iara.pdf: 237584 bytes, checksum: e46da405eef70428aeccd508feab545f (MD5) Previous issue date: 2009-02-09 / The purpose of this study was to evaluate the threshold of a technique of centrifuge-flotation used to recovery Toxocara canis eggs from artificially contaminated soil with 1, 3, 5, 10, 25, 50, 100 and 200 eggs. Soil samples were previously sterilized. Aliquots of one gram were contaminated with 20 µL of a solution containing the eggs. For each trial, 10 contaminated samples were tested. Threshold was evaluated based on a centrifuge-flotation technique by using zinc sulphate (Zn2SO4) and sodium nitrate solutions (Na2NO3), specific gravity 1.20. The recovery of eggs was directly proportional to the number of eggs. By using both solutions, it was possible to reach the success in samples containing three eggs. Only Zn2SO4 showed efficacy in soil contaminated with a single egg. The recovery of 100% in all tests was obtained for samples containing 10 and 25 eggs, respectively, for Zn2SO4 and Na2NO3. There was no difference in the mean of recovered eggs both for the efficacy of solutions and for the repetition of evaluations in a same trial. The centrifuge-flotation technique shows efficiency even in samples containing low number of eggs. / O objetivo do estudo foi avaliar o limiar de detecção de ovos de Toxocara canis em amostras de solo previamente esterilizadas e contaminadas com 1, 3, 5, 10, 25, 50, 100 e 200 ovos. As amostras de solo foram divididas em alíquotas de um grama e contaminadas com 20 µL de solução contendo os ovos. O limiar foi avaliado por uma técnica de centrífugo-flutuação, utilizando-se as soluções de sulfato de zinco (Zn2SO4) e nitrato de sódio (Na2NO3), na densidade 1.20. A recuperação foi diretamente proporcional ao número de ovos na amostra. Observou-se a contaminação em amostras contendo três ovos para ambas as soluções. No caso do Zn2SO4, foi possível detectar a contaminação em duas alíquotas contendo apenas um ovo. Considerando-se o número de repetições positivas, o sucesso de 100% foi observado com o sulfato para amostras contendo a partir de 10 ovos, enquanto que para o Na2NO3, ele foi verificado em amostras que possuíam a partir de 25 ovos. Não houve diferença significativa na recuperação dos ovos quando as soluções e as leituras foram comparadas entre si. A técnica de centrífugo-flutuação é eficiente na recuperação de ovos mesmo em material com baixa contaminação.
72

Limiar de recuperação de ovos de Toxocara canis em solo por técnica de centrífugo-flutuação / Threshold of Toxocara canis eggs recovery from soil by a centrifuge-flotation technique

Xavier, Iara Giordano Rosa 09 February 2009 (has links)
Made available in DSpace on 2016-07-18T17:53:05Z (GMT). No. of bitstreams: 1 Dissertacao Iara.pdf: 237584 bytes, checksum: e46da405eef70428aeccd508feab545f (MD5) Previous issue date: 2009-02-09 / The purpose of this study was to evaluate the threshold of a technique of centrifuge-flotation used to recovery Toxocara canis eggs from artificially contaminated soil with 1, 3, 5, 10, 25, 50, 100 and 200 eggs. Soil samples were previously sterilized. Aliquots of one gram were contaminated with 20 µL of a solution containing the eggs. For each trial, 10 contaminated samples were tested. Threshold was evaluated based on a centrifuge-flotation technique by using zinc sulphate (Zn2SO4) and sodium nitrate solutions (Na2NO3), specific gravity 1.20. The recovery of eggs was directly proportional to the number of eggs. By using both solutions, it was possible to reach the success in samples containing three eggs. Only Zn2SO4 showed efficacy in soil contaminated with a single egg. The recovery of 100% in all tests was obtained for samples containing 10 and 25 eggs, respectively, for Zn2SO4 and Na2NO3. There was no difference in the mean of recovered eggs both for the efficacy of solutions and for the repetition of evaluations in a same trial. The centrifuge-flotation technique shows efficiency even in samples containing low number of eggs. / O objetivo do estudo foi avaliar o limiar de detecção de ovos de Toxocara canis em amostras de solo previamente esterilizadas e contaminadas com 1, 3, 5, 10, 25, 50, 100 e 200 ovos. As amostras de solo foram divididas em alíquotas de um grama e contaminadas com 20 µL de solução contendo os ovos. O limiar foi avaliado por uma técnica de centrífugo-flutuação, utilizando-se as soluções de sulfato de zinco (Zn2SO4) e nitrato de sódio (Na2NO3), na densidade 1.20. A recuperação foi diretamente proporcional ao número de ovos na amostra. Observou-se a contaminação em amostras contendo três ovos para ambas as soluções. No caso do Zn2SO4, foi possível detectar a contaminação em duas alíquotas contendo apenas um ovo. Considerando-se o número de repetições positivas, o sucesso de 100% foi observado com o sulfato para amostras contendo a partir de 10 ovos, enquanto que para o Na2NO3, ele foi verificado em amostras que possuíam a partir de 25 ovos. Não houve diferença significativa na recuperação dos ovos quando as soluções e as leituras foram comparadas entre si. A técnica de centrífugo-flutuação é eficiente na recuperação de ovos mesmo em material com baixa contaminação.
73

SPATIAL INTERPOLATION OF HEAVY METAL CONCENTRATIONS IN SOILS OF BUMPUS COVE, TN

Magno, Melissa A, Luffman, Ingrid, Nandi, Arpita, Evanshen, Brian G 05 April 2018 (has links)
Mining processes generate waste rock, tailings, and slag that can increase heavy metal concentrations in soils. Un-reclaimed, abandoned mine sites are particularly prone to leaching these contaminants, which may accumulate and pose significant environmental and public health concerns. The characterization and spatial delineation of heavy metals of such soils is vital for risk assessment and soil reclamation. Bumpus Cove, once one of the richest mineralized districts of eastern TN, is home to at least 47 abandoned, un-reclaimed mines that were all permanently closed by the 1950s. This study evaluated 52 soil samples collected within a 0.67 km2 study area containing 6 known abandoned Pb, Zn, and Mn mines at the headwaters of Bumpus Cove Creek for heavy metal concentrations. Soil samples were analyzed for Zn, Mn, Pb, Cu, and Cd by means of microwave-assisted acid digestion and flame atomic absorption spectrometry (FAAS). Using the measured values and digital elevation model (DEM) derived from lidar data, ordinary kriging and cokriging interpolation techniques were used to predict the trend of heavy metal concentrations throughout the study area. Concentrations for Zn, Mn, and Pb show significant variability between sample sites (ranges of 12 – 1,354 mg/kg Zn, 6 – 2,574 mg/kg Mn, 33 – 2,271 mg/kg Pb). Cu and Cd were much less variable, with ranges of 1 - 65 mg/kg and 7 – 40 mg/kg, respectively. Of the measured heavy metals, only Zn and Pb exceed permissible limits in soils. Results show that ordinary kriging interpolation methods produced improved results over ordinary cokriging with and without lognormal transformations for all metals. Mn and Pb were found to transport further downhill following the natural drainage, whereas Zn, Cu and Cd concentrations exhibit localized variability without a clear transportation path. This study can provide a reference for state and local entities responsible for heavy metal monitoring in Bumpus Cove, TN.
74

Stress responses of Eisenia andrei and Enchytraeus doerjesi (Oligochaeta) to combined effects of temperature and metal contamination

Otomo, Patricks Voua 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: The terrestrial Oligochaete species Eisenia andrei and Enchytraeus doerjesi were exposed to different concentration series of Cd and Zn, both separately and in mixtures for 28 days in artificial OECD soil at 15, 20 and 25°C. At the end of the four week exposure period, survival and reproduction were assessed in E. doerjesi and survival, reproduction, biomass change, metal uptake and biomarker responses (MTT and comet assays) in E. andrei. Survival results for both E. andrei and E. doerjesi indicated that the lethality of Cd increased at higher temperatures, whereas the opposite was observed for Zn.Cadmium LC50 values were the highest at 15°C and the lowest at 25°C. In the Zn exposures LC50 increased with increasing temperature. Mixture results in both test organisms indicated that mixtures were less lethal than the metals separately. Effects of mixtures on survival, nonetheless, increased with increasing temperature. In the Cd experiment, reproduction in E. andrei was only recorded in the control treatments at the three temperatures investigated. However, the deleterious effect of Zn on the reproduction of both E. andrei and E. doerjesi decreased with increasing temperature and Zn EC50 for reproduction increased with increasing temperature. Results for exposures to mixtures indicated in both test organisms that the interaction between Cd and Zn were antagonistic. In both E. andrei and E. doerjesi, the effect of mixture exposures on reproduction decreased with increasing temperatures. The highest mixture EC50 values for reproduction were found at higher temperature. In E. doerjesi (using reproduction results in MixToxModules) Cd and Zn interactions were dose level dependent at the three temperatures investigated. Antagonism was the predominant interaction at lower mixture concentrations whereas synergism occurred at mixture concentrations equal to or higher than the mixtures’ EC50 values. Biomass loss increased with increasing temperature in the Cd exposures (p 9 0.05) but not in the Zn exposures in E. andrei. In this species mixture results indicated antagonistic interactions between Cd and Zn at all temperatures investigated. The deleterious effect of mixtures on the biomass of E. andrei increased with increasing temperature. When Cd and Zn interactions were further investigated in E. andrei (using biomass results in MixToxModules) it was found that they were dose level dependent at the three temperatures investigated. Antagonism was the predominant interaction at lower mixture concentrations whereas synergism occurred at mixture concentrations higher than the mixtures EC50 values. The assessment of metal uptake in E. andrei revealed a temperature dependent Cd uptake with higher Cd body burdens occurring at higher exposure concentrations and temperatures (p ≤ 0.05). In the case of Zn, although uptake was lower at higher temperature, there was no statistical difference in uptake between exposure concentrations and between temperatures. Mixture results however indicated that in mixture exposures less Cd was accumulated by E. andrei than in single Cd exposures (p ≤ 0.05). Inversely, in mixture exposures more Zn was accumulated by E. andrei than in single Zn exposures (p ≤ 0.05). Biomarker studies revealed that Cd and Zn were both cytotoxic and genotoxic whether in single or mixture exposures. Factorial ANOVA analyses of the effects of temperature and metals on the reduction of MTT by E. andrei indicated that temperature rather than the metals was the most important factor controlling mitochondrial activity (p < 0.001). In both Cd and Zn exposures significant deleterious metal effects on mitochondrial processes were found to increase with temperature (p ≤ 0.01). Mixture exposures indicated decreasing cytotoxicity with increasing temperature (p ≤ 0.05) and possible antagonism between Cd and Zn at cellular level. Results of the comet assay showed that the genotoxic profile of Cd was the opposite of the genotoxic profile of Zn. Cd was less genotoxic at lower temperature and increasingly deleterious at higher temperature while Zn was more genotoxic at lower than higher temperature (p ≤ 0.05). The results of mixture exposures indicated decreasing mixture genotoxicity with increasing temperature and suggested that the interactions between Cd and Zn at molecular level were probably antagonistic. / AFRIKAANSE OPSOMMING: Eisenia andrei en Enchytraeus doerjesi is aan verskillende konsentrasiereekse van Cd en Zn, afsonderlik en in mengsels, vir 28 dae in OECD kunsmatige grond onderskeidelik by 15, 20 en 25°C blootgestel Die volgende eindpunte is aan die einde van die vier weke blootstellingsperiode gemeet: oorlewing en voortplanting (by E. doerjesi) en oorlewing, voortplanting, biomassaverandering, metaalopname, MTT en komeettoetse (by E. andrei). Oorlewingsresultate by beide E. andrei en E. doerjesi het getoon dat toenemende temperatuur die letale toksisiteit van Cd laat toeneem terwyl die teenoorgestelde waar was vir Zn. By die Cd blootstellings was die LK50 waardes die hoogste by 15°C en die laagste by 25°C. By die blootstellings aan Zn het die LK50 waardes toegeneem by hoër temperatuur. Resultate by die mengsels by beide toestspesies het aangetoon dat die mengsels minder letaal was as die afsonderlike metale. Effekte van mengsels op oorlewing het nietemin toegeneem met toenemende temperatuur. By die Cd blootstellings is voortplanting slegs by die kontroles en in die geval van E. andrei by die drie onderskeie temperature ondersoek. Die nadelige uitwerking van Zn op voortplanting by beide E. andrei en E. doerjesi het afgeneem met stygende temperatuur en die Zn LK50 vir voortplanting het toegeneem met toenemende temperatuur. Resultate van die blootstellings aan mengsels het getoon dat die wisselwerking tussen Cd en Zn by beide spesies antagonisties was. By beide spesies het die invloed van die mengsels op voortplanting afgeneem met stygende temperatuur. Die hoogste mengsel LK50 waardes vir voortplanting is by hoër temperature gevind. By E. doerjesi was Cd en Zn wisselwerkings by blootstelling aan mengsels (voortplantingsresultate ondersoek deur van MixToxModules gebruik te maak) dosisvlak verwant by die drie temperature wat ondersoek is. Antagonisme was die oorwegende wisselwerking by laer mengsel konsentrasies terwyl sinergisme voorgekom het by mengsel konsentrasies gelyk aan of hoër as die LK50 waardes van die mengsels. In die geval van die Cd blootstellings by E. andrei het biomassaverlies toegeneem met toenemende temperatuur (p ≤ 0.05) maar nie by die Zn blootstellings nie. Resultate van blootstellings aan mengsels het getoon dat die uitwerking van mengsels op die biomassa van E. fetida toegeneem het met toenemende temperatuur. By die verdere ondersoek van Cd en Zn wisselwerkings, waar gekyk is na dosis verhouding of dosisvlak antagonisme (deur van biomassa resultate in MixToxModules gebruik te maak), is gevind dat Cd en Zn wisselwerkings dosisvlak afhanklik was by die drie temperature wat ondersoek is. Antagonisme was die oorwegende wisselwerking by laer mengselkonsentrasies terwyl sinergisme voorgekom het by mengselkonsentrasies hoër as die mengsel EK50 konsentrasies. Die bepaling van metaalopname deur E. andrei het ’n temperatuurafhanklike opname van Cd getoon met hoër Cd liggaamskonsentrasies by hoër blootstellingskonsentrasies en temperature (p ≤ 0.05). Alhoewel Zn opname laer was by hoër temperatuur was daar geen statisties betekenisvolle verskille in opname tussen blootstellingskonsentrasies of temperature nie. Die bepaling van metaalopname by wurms wat aan mengsels blootgestel is, het getoon dat minder Cd deur E. andrei opgeneem is as waneer die wurms aan Cd as enkelmetaal blootgestel is (p ≤ 0.05), Daarteenoor het die teenoorgestelde gebeur in die geval van Zn, Meer van die metaal is opgeneem wanneer E. andrei aan mengsels blootgestel is as aan die enkelmetaal. Biomerkerstudie het getoon dat Cd en Zn beide sito- en genotoksies kan wees ongeag of dit as enkelmetale of in mengsels toegedien is. Faktoriale ANOVA analises van die effekte van temperatuur en metale op die verlaging van MTT by E. andrei het getoon dat temperatuur ’n belangriker faktor was as metaalbesoedeling by die kontrole van mitochondriale aktiwiteit. (p ≤ 0.001). By beide Cd en Zn blootstellings was daar in elk geval statisties betekenisvolle metaaleffekte op mitochondriale prosesse met toename in temperatuur (P ≤ 0.01). By blootstellings aan mengsels is gevind dat sitotoksisiteit afgeneem het met toenemende temperatuur (p ≤ 0.05) asook ’n moontlike antagonisme tussen Cd en Zn op sellulêre vlak. Resultate van die komeettoets het getoon dat die genotoksiese profiel van Cd die teenoorgestelde was as die van Zn. Cd was minder genotoksies by laer temperature en meer en meer skadelik by hoër temperature terwyl Zn meer genotoksies was by laer as by hoër temperature (p ≤ 0.05). Die resultate van blootstlling aan mengsels het laer genotoksisiteit getoon met toename in temperatuur. Dit dui daarop dat wisselwerkings tussen Cd en Zn op molekulêre vlak moontlik antagonisties was.
75

Soil-to-plant transfer of heavy metals and an assessment of human health risks in vegetable-producing areas of São Paulo state / Transferência solo-planta de metais pesados e avaliação de risco à saúde humana em áreas olerícolas do estado de São Paulo

Santos-Araujo, Sabrina Novaes dos 24 February 2015 (has links)
While contaminated food products are known to be a leading source of exposure to potentially toxic elements (PTEs), for the general population, few studies have been carried out to examine PTEs levels in soils and plants in wet tropical regions such as Brazil. While the most commonly used index for estimating PTEs accumulation in vegetables and the subsequent exposure to humans who eat them is the bioconcentration factor (BCF) - the ratio between the concentration of metals in the edible portions of produce and their total concentration in soils - the BCF does not provide an adequate description of soil-to-plant metal transfers. A better understanding of such transfers requires information about the soil attributes that influence the availability of PTEs to plants. The state of São Paulo (SP) is the largest consumer of vegetables in Brazil, as well as the largest and most diversified producer. Studies are therefore needed on PTEs concentrations in soils and vegetables, in order to assess their quality under guidelines established by Brazilian legislation. It is likewise crucial to establish critical limits of these elements in soils, via models that assess risks to human health, based on data that reflect current conditions in the soils of São Paulo. The objectives in this study were: (i) to characterize and to evaluate the relations between the concentrations of Cd, Cu, Ni, Pb and Zn in soils and in vegetables from the \"Green Belt\" of the state of São Paulo, Brazil, taking the limits established by legislation into account; (ii) to develop empiric models to derive appropriate soil screening values and to provide an accurate risk assessment for tropical regions; (iii) to develop proposals for improved human health-based screening values for Cd, Cu, Ni, Pb and Zn in São Paulo soils, using soil - vegetable relations. With the exception of Cd, there was a positive correlation between pseudototais and bioavailable contents of PTEs. Cd and Pb content in plants, moreover, not significantly correlated with any of the variables studied. All models of random forests and trees were good predictors of results generated from a regression model and provided useful information about which covariates were important to forecast only for the zinc concentration in the plant. The soil-plant transfer models proposed in this study had a good performance and are useful for eight of the ten combinations (five metals versus two species). SP data combined with NL data for Cd in lettuce and for Ni and Zn in lettuce and in carrot when pH, organic carbon - OC and clay contents were included in the model. Including such soil properties results in improved relations between PTEs concentrations in soils and in vegetables to derive appropriate screening values for SP State. The model in which pH, OC and clay contents were included gave the most useful results with SP and NL data set combined for Cu, Pb, Zn in lettuce and for Cd and Cu in carrot. Our setup did not work for Ni and for Pb in carrot because the data models gave an inconsistent result and the combination of datasets did not or insufficiently improve the results. / Uma das principais vias de exposição de elementos potencialmente tóxicos (EPT) para a maioria da população é por meio da ingestão de alimentos, mas poucos são os estudos relacionados às concentrações de EPTs em solos e em vegetais de regiões tropicais úmidas, sobretudo no Brasil. O índice mais comumente utilizado para estimar o acúmulo de EPTs em vegetais e a subsequente exposição humana pelo consumo de vegetais é o fator de bioconcentração (BCF), que é a razão entre a concentração de metais em partes comestíveis de hortaliças e da concentração total do metal no solo. Porém, o BCF não descreve adequadamente a transferência solo-planta de metais. Assim, a utilização de relações envolvendo os principais atributos dos solos que influenciam a disponibilidade dos EPTs às plantas pode explicar com mais detalhe as relações solo-planta. O estado de São Paulo é o maior mercado consumidor, além de ser o maior e mais diversificado produtor olerícola no Brasil. Assim, são necessárias pesquisas referentes às concentrações de metais pesados em solos e hortaliças, para avaliação da qualidade dos mesmos em relação aos limites estabelecidos pela legislação. Os objetivos neste trabalho foram: (i) caracterizar e avaliar as relações solo-planta entre as concentrações de Cd, Cu, Ni, Pb e Zn em solos e olerícolas de folhas e raiz no estado de São Paulo, tendo em vista os limites estabelecidos pela legislação; (ii) desenvolver modelos empíricos para poder derivar adequados limites críticos do solo e fornecer uma avaliação de risco precisa para regiões tropicais; (iii) desenvolver propostas para melhorar os limites críticos baseados na saúde humana para Cd, Cu, Ni, Pb e Zn em solos de São Paulo, utilizando relações solo-planta adequadas para as condições tropicais. Com exceção do Cd, houve correlação positiva entre os teores pseudototais e biodisponíveis dos EPTs. Os teores de Cd e de Pb nas plantas, por outro lado, não correlacionaram significativamente com nenhuma das variáveis estudadas. Os modelos de florestas aleatórias e árvores foram bons preditores de resultados gerados a partir de um modelo de regressão e forneceram informações úteis sobre quais covariáveis foram importantes para previsão apenas para o teor de Zn na planta. A aplicação de modelos de transferência solo-planta proposto neste estudo tiveram bom desempenho e foram úteis para oito das dez combinações (cinco metais contra duas espécies). O conjunto de resultados de SP pode ser combinado com o da Holanda usando o modelo em que se incluem pH, teor de carbono orgânico - CO e teor de argila para Cd em alface e para Ni e Zn na alface e na cenoura. O modelo foi mais eficiente com os conjunto de resultados combinados para Cu, Pb, Zn, em alface e para Cd e Cu na cenoura. A abordagem não foi eficiente para Ni e para Pb em cenoura, com resultados incoerentes para os conjuntos de resultados combindados ou separados, para os quatro modelos testados.
76

Frequência de anticorpos anti-Toxocara spp em escolares do município de Fernandópolis- SP, Brasil e análise da contaminação do solo por ovos do parasito / Frequency of anti-Toxocara spp antibody in school children from Fernandópolis-SP, Brazil and analysis of soil contamination by parasite eggs

Cassenote, Alex Jones Flores 20 October 2010 (has links)
A toxocaríase é uma zoonose muito difundida em todo o mundo. Trata-se da infecção humana, em especial pelas larvas de Toxocara canis, um nematóide comum de cães. O objetivo do presente estudo foi levantar a soropositividade a anticorpos anti-Toxocara spp, identificar os fatores de risco em grupos de escolares da cidade de Fernandópolis/SP e avaliar a contaminação do solo por ovos desse e de outros geo-helmintos entre os anos de 2007 e 2008. Foi realizado um estudo transversal utilizando-se amostragem complexa e estratificada, por renda, para a avaliação da toxocaríase humana. O método diagnóstico empregado foi o teste de ELISA para detecção de anticorpos IgG anti-Toxocara spp. O estudo da contaminação do solo deu-se por meio da avaliação de amostras de solo de praças, parques públicos e escolas municipais e pela avaliação de amostras de fezes provenientes de 10 praças públicas. Foram avaliados 252 indivíduos em dois estratos, o primeiro representando baixa renda com 120 (47,6%) crianças e o segundo com 132 (52,4%) representando renda elevada. A frequência geral de positividade ao antígeno TES foi de 15,4% (39), sendo 28,3% (34) para o primeiro estrato contra 3,7% (5) do segundo (p<0,000). A exposição à geofagia (exposto OR ajustado 14,65 - IC95% = 2,14 a 89,25 e muito expostos OR ajustado 19,15 a IC95% = 2,96 a 123,94), o hábito de levar objetos à boca (exposto OR ajustado 9,31 - IC95% = 1,63 a 53,03 e muito expostos OR ajustado 42,29 a IC95% = 5,49 a 326,01) e a presença de mais de dois cães em domicílio (OR ajustado 21,25 = 1,7 a 264,87) foram variáveis associadas à positividade. O hábito de lavar as mãos antes das refeições (OR ajustado 0,01 - IC95% 0,00 a 0,05) representou importante fator de proteção. Foram avaliadas 225 amostras de solo, sendo 71% (160) provenientes de praças e parques públicos e 29% (65), de escolas municipais. Foi observado alto grau de contaminação de praças e parques públicos 28,4% (64), ao passo que nas escolas a positividade foi de 1,7% (6). Os parasitos encontrados com maior frequência foram de Toxocara spp 79,6% (47), Trichuris spp 13,5% (8) e ancilostomídeo 6,4% (4). Foram avaliadas ainda 400 amostras de fezes de cães, e observou-se uma positividade de 23,7% (95). Os parasitos observados com maior frequência nas amostras positivas foram ancilostomídeo símile 74,7% (71) e Toxocara canis, 53,6% (51). A positividade a anticorpos anti-Toxocara spp em indivíduos de 1 a 12 anos de idade, provenientes de cinco escolas do município de Fernandópolis/SP, foi relativamente baixa. Os principais fatores de risco/proteção dizem respeito às questões modificáveis como a geofagia, o hábito de levar objetos à boca, a existência de mais de dois cães em domicílio e o hábito de lavar as mãos antes das refeições. Os solos de praças e parques públicos de Fernandópolis/SP e amostras de fezes recolhidas em ambiente estavam altamente contaminados com geo-helmintos zoonóticos e representam fonte de infecção relevante para a população / Toxocariasis is a zoonosis of worldwide occurrence. It is defined as the human infection by larvae of nematodes, especially Toxocara canis, common intestinal parasite of dogs. The aim of this study was to estimate the frequency of anti-Toxocara spp antibodies, identify risk factors in groups of school children from the city of Fernandópolis/SP and evaluate soil contamination by eggs of this and other geohelminths between 2007 and 2008. It was conducted a cross-sectional study using complex sampling for the assessment of human toxocariasis. The diagnostic method used was the ELISA test for detection of IgG anti-Toxocara spp antibodies. The study of soil contamination was done through evaluation of soil samples from public places, sand boxes of municipal schools and evaluation of dogs stool samples from 10 public places. Two hundred and fifty two children were evaluated in two strata, the first with 120 children (47.6%) from low income families and the second with 132 (52.4%) from high income ones. The overall frequency of antibodies anti-Toxocara spp was 15.4% (39), being 28.3% (34) for the first stratum compared with 3.7% (5) of the second (p <0.000). The exposure to geophagy (exposed: adjusted OR 14.65 - CI 95% = 2.14 to 89.25; very exposed: adjusted OR 19.15 - CI 95%= 2.96 to 123.94), the habit of rising objects up to the mouth (exposed: adjusted OR 9.31 1.63 to 53.03; very exposed: adjusted OR 42.29 - CI 95%= 5.49 to 326.01) and the presence of more than two dogs at home (adjusted OR 21.25 - 1.7 to 264.87) were variables associated with positivity. The habit of washing hands before meals (adjusted OR 0.01 - CI 95% = 0.00 to 0.05) represented an important protective factor. Were evaluated 225 samples of soil: 71% (160) from public places and 29% (65) of municipal schools. It was observed a high contamination of public places with 28.4% (64) being positive, while in school positivity was 1.7% (6). The most frequent parasites eggs found were Toxocara spp 79.6% (47), Trichuris spp 13.5% (8) and Ancylostomatidae 6.4% (4). They were also evaluated 400 fecal samples of dogs and observed a positivity of 23.7% (95). The most frequent parasites observed in positive samples were Ancylostoma simile 74.7% (71) and Toxocara canis 53.6% (51). The anti-Toxocara spp antibodies positivity in school children from Fernandópolis/SP was relatively low. The main factors of risk/protection concern to modifiable issues like geophagy, the habit of rising objects up to the mouth, the existence of more than two dogs at home and the habit of washing hands before meals. The soil of public places of Fernandópolis/SP and feces samples collected from the environment were highly contaminated with zoonotic helminths and represent important source of infection for the population
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Metabolismo e qualidade da bebida em cafeeiro expostos ao cádmio, níquel e zinco / Metabolism and beverage quality of coffee plants exposed to cadmium, nickel and zinc

Tezotto, Tiago 02 February 2011 (has links)
A contaminação ambiental por metais pesados, entre os quais o cádmio (Cd), níquel (Ni) e zinco (Zn), tanto nos solos cultivados quanto nos produtos agrícolas, demanda constante monitoramento do solo, bem como a quantificação desses elementos nos diferentes órgãos dos vegetais. No manejo da adubação e outras práticas culturais, há contaminação indesejável de metais pesados que se acumulam nos solos ao longo dos anos, podendo causar danos ao crescimento vegetal, produção e/ou qualidade do produto agrícola. Considerando a relevância da problemática dos metais pesados nos sistemas agrícolas, é essencial o conhecimento da ação do Cd, Ni e Zn nos processos metabólicos no cafeeiro. A proposta desta pesquisa foi verificar a influência das aplicações de doses crescentes de Cd, Ni e Zn sobre as características nutricionais, fisiológicas e bioquímicas em plantas de cafeeiro em produção e na qualidade da bebida. Por meio dos parâmetros analisados até 128 dias, a ordem crescente de toxidez é de Ni, Zn e Cd. A distribuição de Cd é maior nos ramos, grãos e folha; Ni nas folhas, ramos e grãos e Zn nos ramos, folhas e grãos. O estado nutricional do cafeeiro não é afetado pela aplicação dos metais, com exceção do nitrogênio e do fósforo, que reduz nas maiores doses de Cd e Zn. A produtividade e qualidade da bebida são reduzidas em razão da aplicação dos metais. / Environmental contamination by heavy metals, including Cd, Ni and Zn, in both cultivated soils and agricultural products, takes constant monitoring of soils and the quantification of these elements in different plant parts. The management of fertilizer and other cultural practices, there are undesirable contamination of heavy metals that accumulate in soils over the years, causing damage to plant growth, production and/or quality of products. Considering the growing concern with heavy metals in agricultural systems is essential research focused on the physiological mechanism of Cd, Ni and Zn in coffee plants. Therefore, to evaluate the translocation of metals to coffee beans, the monitoring and the quantification of these elements in soils and different organs of coffee plants are required. The aim of this study was to evaluate the influence of applications times and rates of Cd, Ni and Zn on the nutritional, physiological and biochemical changes in coffee plants as well as cup quality drink under field condition. According to the results evaluated up to 128 days exposure to metals, the order of increasing toxicity was Ni>Zn>Cd. The distribution of Cd was higher in the plagiotropic branches>grain>leaf; Ni in leaves>stems>grains, and Zn in stems>leaves>grains, respectively. The nutritional status of coffee plants was not affected by the application of metals, except nitrogen and phosphorus, which reduced the highest levels of Cd and Zn. The coffee yield and cup quality drink decreased due to metals exposition.
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Caracterização físico-química de solos de mangue e avaliação de sua contaminação por esgoto doméstico via traçadores fecais. / Physicochemical characterization of mangrove soils and evaluation of contamination by domestic sewage by faecal tracers.

Firme, Lilian Pittol 29 September 2003 (has links)
Os manguezais são ecossistemas que portam comunidades vegetais típicas de ambientes alagados, resistentes à alta salinidade da água e do solo. Não são muito ricos em espécies, porém, destacam-se pela grande importância ecológica que desempenham. Por isso podem ser considerados um dos mais produtivos ambientes naturais do Brasil. Os solos do subsistema estuarino do manguezal são pouco conhecidos e a ênfase em sua descrição e estudo neste trabalho surgiu do fato de que no Estado de São Paulo inúmeras áreas de mangue vêm sendo alvo de constante pressões sócio-econômicas. No município do Guarujá, assim como em grande parte da Baixada Santista os solos de mangue vêm sofrendo crescente degradação devido à ocupação urbana de alta intensidade e saneamento básico precário. Este trabalho teve como objetivo estudar as características mineralógicas e fisico-químicas em uma transeção de solos de mangue do rio Crumahú, no município do Guarujá, junto ao bairro Morrinhos, e determinar a distribuição horizontal e vertical de poluentes em função da descarga de efluentes urbanos. Os perfis foram amostrados, utilizando amostrador para solos inundados, em 3 profundidades numa transeção de 160m, que vai da margem do canal do rio Crumahú até a restinga, e com pontos de coleta a cada 10 m. No laboratório, foram realizadas análises físicas, químicas e mineralógicas. A mineralogia das frações areia, silte e argila foi estudada por meio de difratogramas de raio-X. Para a distribuição de poluentes gerados em função da descarga pontual de esgoto doméstico foram utilizados traçadores fecais fazendo uso da relação coprostanol/colesterol entre outras, para confirmação da contaminação. Análises com os traçadores foram feitas por cromatografia gasosa. A análise granulométrica evidencia mudanças do regime de sedimentação recente. O microrrelevo do maguezal é dinâmico e isso foi evidenciado pela distribuição granulometrica. O fluxo e refluxo da maré influenciou alguns atributos do solo ao longo da transeção como a concentração de cátions e ânions solúveis e a condutividade elétrica. Com o secamento das amostras de solo, houve uma oxidação induzida o que levou à diminuição do pH, aumento de sulfato e liberação de Al trocável. Foram encontrados minerais como caulinita, mica, esmectita, ortoclásio e quartzo. Os maiores índices de contaminação foram encontrados na profundidade de 30-50 cm, enquanto que, na profundidade de 60-80 cm esta não foi detectada. A zona de contato mangue-restinga caracteriza-se como local de acúmulo de contaminantes Foi verificada a diminuição das relações de esteróis no sentido do prolongamento da transeção. Toda a área estudada está contaminada por esgoto doméstico podendo colocar em risco todo o ecossistema local. / Mangroves are ecosystems that carry typical biological communities, adapted to flooded environments, which are resistant to water and soils salinity. Although they are not very rich in species, they stand out for their great ecological importance. Hence, they can be considered one of the most productive natural environments of Brazil. Little is known about the soils in a mangrove ecosystem, and the emphasis on its study in the present work came about as a consequence of the fact that in São Paulo State many of these ecosystems are continuously suffering from antropic impacts. In Guarujá municipal district, as well as in a large part of Baixada Santista, mangrove soils are suffering from degradation due to the high-density urban occupation and precarious sanitary conditions. The objective of this work was to study the mineralogical and physicochemical characteristics of mangroves soils located on a transect in the Crumahú river, in Guarujá municipal district; and to determine the horizontal and vertical distribution of pollutant. Profiles were sampled at 3 different depths along a transect of 160m, using a sampler for flooded soils. The physical, chemical and mineralogical analyses were carried out in the Laboratory. X-ray diffractions were used for the characterization of sand, silt and clay fraction mineralogy. Faecal tracers (coprostanol/cholesterol) were used to characterize the pollutant distribution along the transect. Faecal tracer analyses were made by gaseous chromatography. The granulometric analysis showed recent changes in the sedimentation pattern. The mangrove microrelief is dynamic and this could be observed by the granulometric distribution. The tides influenced some soil attributes along the transect such as soluble cations and anions concentration and electrical conductivity. After the samples were dried, there was an induced oxidation resulting in a pH decrease, sulphate increase and exchangeable aluminum liberation. Kaolinite, mica, smectite, orthoclase and quartz were found in the samples. The largest indexes of contamination were found at the depth of 30-50cm while, at the depth of 60-80cm, no contamination was detected. The area where the mangrove meets the "restinga" (coastal reef) is characterized by an accumulation of pollutants. Sterols rate decreased along the transect. The whole studied area is polluted by domestic sewage what could put in risk the whole local ecosystem.
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Indústria carboní­fera no Distrito de Moatize, Província de Tete, Moçambique e sua influência ambiental dos solos por elementos potencialmente tóxicos / Carboniferous industry in Moatize District, Tete Province, Mozambuique and its environmental influence of soils by potentially toxic elements

Passe, José João 20 December 2018 (has links)
Sendo o solo, um recurso natural com multiplicidade de funções, torna-se urgente e necessário protegê-lo de todas as fontes de contaminação. A concentração e distribuição de metais na superfície dos solos são dependentes da natureza da rocha a partir da qual o solo foi derivado, dos processos intempéricos e pedogenéticos. Porém, o crescimento industrial e populacional em Moatize tem influenciado os teores de metais pesados nos solos, impactando a qualidade deste recurso. A presente Tese tem como principal objetivo caracterizar o grau de comprometimento ambiental dos solos por elementos potencialmente tóxicos (Co, Cr, Cu, Mn, Ni, Pb, Sr, Ti, V, Zn e Zr) já determinados no conteúdo dos carvões decorrentes da industrialização no distrito de Moatize, Província de Tete, Moçambique. Nessa pesquisa foram coletadas 5 pontos de amostras de solo na área 1 (uma das mineradoras que atuam na área), 12 pontos de amostras na área 2 (uma segunda mineradora nessa região), 2 pontos de amostras de poeira nas casa de habitantes próxima a atividade mineira, 5 pontos de amostras de solo em áreas com mínima atividade antrópica para determinar as concentrações naturais de metais no solo (área 3) e 2 amostras de carvão mineral designadas UCS e LCS, provenientes da mineradora Vale Moçambique. A caracterização química das amostras foi realizada através das técnicas de Fluorescência de Raio-X (FRX) e por Espectrômetro de Emissão Atômica com Plasma Indutivamente Acoplado (ICP-OES). Os resultados de solos obtidos por ICP-OES foram comparados com os teores de metais considerados naturais \"background\" obtidos em Moatize e os teores das legislações CONAMA (2009) e CETESB (2016). Os resultados obtidos por FRX indicam que os solos assim como o carvão são constituídos majoritariamente por SiO2 e Al2O3. Pode-se notar ainda, uma concentração significativa nas amostras do carvão mineral e solos do SO3. Dos metais potencialmente tóxicos analisados por FRX, o Cr2O3 apresentou valores relativamente altos em todos os pontos de coleta de solo e nas amostras de carvão para os compostos com CuO e ZnO. Os elementos Ti, Mn, Ni, Ba, Pb, Zn, Co, Cr, V e Sr apresentaram concentrações superiores em relação aos teores de background encontrados nos solos em Moatize principalmente para os 12 pontos de amostras na área 2. Importa salientar ainda que os resultados apresentados apontam para alterações de alguns elementos químicos nos solos estudados como o Ni, Ba, Co e Cr, quando comparados com os valores de referência estabelecidos pelas legislações CONAMA (2009) e CETESB (2016). / Being the soil, a natural resource with multiplicity of functions, it becomes urgent and necessary to protect it from all sources of contamination. The concentration and distribution of metals in the soil surface are dependent on the nature of rock from which the soil was derived from, the intemperic and pedogenetic processes. However, industrial and population growth in Moatize has influenced the levels of heavy metals that impacting the quality of the soil. The main objective of this thesis is to characterize the degree of environmental compromise of soils by potentially toxic elements (Co, Cr, Cu, Mn, Ni, Pb, Sr, Ti, V, Zn and Zr) already determined in the contents of the industrialization in Moatize district, Tete province, Mozambique. In this research 5 soil samples were collected in area 1(one of the miners working in the area), 12 were collected in area 2 (a second mining company in this region), 2 samples were collected with dust collection at house of inhabitants next to mining activity, 5 samples in areas with minimal anthropic activity to determine the natural levels of metals in the soil (area 3) and 2 samples of mineral coal designated UCS and LCS from the mining company Vale Mozambique. The chemical characterization of the samples was performed using X-Ray Fluorescence (FRX) and Inductively Coupled Plasma Atomic Emission Spectrometers (ICP-OES). The results obtained by ICP-OES were compared to the levels of metals considered as natural background obtained in Moatize, the contents of the laws CONAMA (2009) and CETESB (2016). The results obtained by FRX indicate that the soils as well as the coal are constituted mainly by SiO2 and Al2O3. It is also possible to note a significant concentration in samples of mineral coal and SO3 soils. From the potentially toxic metals analyzed by FRX or Cr2O3, it presented relatively high values at all collection points and in the samples of coal for the compounds with CuO and ZnO. Ti, Mn, Ni, Ba, Pb, Zn, Co, Cr, V and Sr showed higher concentrations than the background contents found in Moatize soils mainly for 12 samples were collected in the vicinity of Minas Moatize Ltda. It is important to point out that the results presented point to changes in some chemical elements in the studied soils such as Ni, Ba, Co and Cr, when compared with the reference values established by CONAMA (2009) and CETESB (2016).
80

Indústria carboní­fera no Distrito de Moatize, Província de Tete, Moçambique e sua influência ambiental dos solos por elementos potencialmente tóxicos / Carboniferous industry in Moatize District, Tete Province, Mozambuique and its environmental influence of soils by potentially toxic elements

José João Passe 20 December 2018 (has links)
Sendo o solo, um recurso natural com multiplicidade de funções, torna-se urgente e necessário protegê-lo de todas as fontes de contaminação. A concentração e distribuição de metais na superfície dos solos são dependentes da natureza da rocha a partir da qual o solo foi derivado, dos processos intempéricos e pedogenéticos. Porém, o crescimento industrial e populacional em Moatize tem influenciado os teores de metais pesados nos solos, impactando a qualidade deste recurso. A presente Tese tem como principal objetivo caracterizar o grau de comprometimento ambiental dos solos por elementos potencialmente tóxicos (Co, Cr, Cu, Mn, Ni, Pb, Sr, Ti, V, Zn e Zr) já determinados no conteúdo dos carvões decorrentes da industrialização no distrito de Moatize, Província de Tete, Moçambique. Nessa pesquisa foram coletadas 5 pontos de amostras de solo na área 1 (uma das mineradoras que atuam na área), 12 pontos de amostras na área 2 (uma segunda mineradora nessa região), 2 pontos de amostras de poeira nas casa de habitantes próxima a atividade mineira, 5 pontos de amostras de solo em áreas com mínima atividade antrópica para determinar as concentrações naturais de metais no solo (área 3) e 2 amostras de carvão mineral designadas UCS e LCS, provenientes da mineradora Vale Moçambique. A caracterização química das amostras foi realizada através das técnicas de Fluorescência de Raio-X (FRX) e por Espectrômetro de Emissão Atômica com Plasma Indutivamente Acoplado (ICP-OES). Os resultados de solos obtidos por ICP-OES foram comparados com os teores de metais considerados naturais \"background\" obtidos em Moatize e os teores das legislações CONAMA (2009) e CETESB (2016). Os resultados obtidos por FRX indicam que os solos assim como o carvão são constituídos majoritariamente por SiO2 e Al2O3. Pode-se notar ainda, uma concentração significativa nas amostras do carvão mineral e solos do SO3. Dos metais potencialmente tóxicos analisados por FRX, o Cr2O3 apresentou valores relativamente altos em todos os pontos de coleta de solo e nas amostras de carvão para os compostos com CuO e ZnO. Os elementos Ti, Mn, Ni, Ba, Pb, Zn, Co, Cr, V e Sr apresentaram concentrações superiores em relação aos teores de background encontrados nos solos em Moatize principalmente para os 12 pontos de amostras na área 2. Importa salientar ainda que os resultados apresentados apontam para alterações de alguns elementos químicos nos solos estudados como o Ni, Ba, Co e Cr, quando comparados com os valores de referência estabelecidos pelas legislações CONAMA (2009) e CETESB (2016). / Being the soil, a natural resource with multiplicity of functions, it becomes urgent and necessary to protect it from all sources of contamination. The concentration and distribution of metals in the soil surface are dependent on the nature of rock from which the soil was derived from, the intemperic and pedogenetic processes. However, industrial and population growth in Moatize has influenced the levels of heavy metals that impacting the quality of the soil. The main objective of this thesis is to characterize the degree of environmental compromise of soils by potentially toxic elements (Co, Cr, Cu, Mn, Ni, Pb, Sr, Ti, V, Zn and Zr) already determined in the contents of the industrialization in Moatize district, Tete province, Mozambique. In this research 5 soil samples were collected in area 1(one of the miners working in the area), 12 were collected in area 2 (a second mining company in this region), 2 samples were collected with dust collection at house of inhabitants next to mining activity, 5 samples in areas with minimal anthropic activity to determine the natural levels of metals in the soil (area 3) and 2 samples of mineral coal designated UCS and LCS from the mining company Vale Mozambique. The chemical characterization of the samples was performed using X-Ray Fluorescence (FRX) and Inductively Coupled Plasma Atomic Emission Spectrometers (ICP-OES). The results obtained by ICP-OES were compared to the levels of metals considered as natural background obtained in Moatize, the contents of the laws CONAMA (2009) and CETESB (2016). The results obtained by FRX indicate that the soils as well as the coal are constituted mainly by SiO2 and Al2O3. It is also possible to note a significant concentration in samples of mineral coal and SO3 soils. From the potentially toxic metals analyzed by FRX or Cr2O3, it presented relatively high values at all collection points and in the samples of coal for the compounds with CuO and ZnO. Ti, Mn, Ni, Ba, Pb, Zn, Co, Cr, V and Sr showed higher concentrations than the background contents found in Moatize soils mainly for 12 samples were collected in the vicinity of Minas Moatize Ltda. It is important to point out that the results presented point to changes in some chemical elements in the studied soils such as Ni, Ba, Co and Cr, when compared with the reference values established by CONAMA (2009) and CETESB (2016).

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