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Registro Completo |
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Biblioteca(s): |
Embrapa Pantanal. |
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Data corrente: |
01/10/1998 |
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Data da última atualização: |
28/03/2017 |
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Autoria: |
LIPFERT, F. W. |
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Título: |
Estimating exposure to methylmercury: effects of uncertainties. |
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Ano de publicação: |
1997 |
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Fonte/Imprenta: |
Water, Air & Soil Pollution, v.97, n.1/2, p.119-145, 1997. |
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Idioma: |
Inglês |
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Conteúdo: |
Uncertainties in exposures can lead to biased estimates of slopes and thresholds in the exposure-response relationships that are developed from regression analysis. This paper reviews published exposure and epidemiological studies of methylmercury (meHg) from the perspective of the accuracy and precision of the estimates used to represent the actual doses received. Sources of such uncertainties, collectively referred to as exposure errors, include instrumental and analytical erros, sampling and survey uncertainties and individual variability in the relationships between the exposure metrics and the actual doses to target organs. Because the relationship between maternal intake and the consequent dose to the fetal brain varies among individuals, epidemiological stidues of the effects of prenatal exposure must necessarily be accompanied by larger exposure uncertainties than comparable studies of effects on the mothers. The increased exposure errors typically result in attnuated slopes of the dose-response functions and under-estimates of thresholds, so that part of the apparent increased sensitivity of the fetus that has been developed from epidemiological studies may in fact be due to their inherently less certain exposures. Sources and magnitudes of exposure error found in the literature are discussed and their statistical ramifications are explored with Monte Carlo simulations. The paper also finds that, after adjusting for exposure error, the relationship between dietary intake and blood concentration is consistent with an average half-life shorter than has typically been used and that using population averages yields a consistent but-linear relationship between dietary intake of Hg and hair concentration. Investigators are urged to obtain (and present) data on more than one exposure metric, so that their relative uncertainties may be assessed indenpendently. MenosUncertainties in exposures can lead to biased estimates of slopes and thresholds in the exposure-response relationships that are developed from regression analysis. This paper reviews published exposure and epidemiological studies of methylmercury (meHg) from the perspective of the accuracy and precision of the estimates used to represent the actual doses received. Sources of such uncertainties, collectively referred to as exposure errors, include instrumental and analytical erros, sampling and survey uncertainties and individual variability in the relationships between the exposure metrics and the actual doses to target organs. Because the relationship between maternal intake and the consequent dose to the fetal brain varies among individuals, epidemiological stidues of the effects of prenatal exposure must necessarily be accompanied by larger exposure uncertainties than comparable studies of effects on the mothers. The increased exposure errors typically result in attnuated slopes of the dose-response functions and under-estimates of thresholds, so that part of the apparent increased sensitivity of the fetus that has been developed from epidemiological studies may in fact be due to their inherently less certain exposures. Sources and magnitudes of exposure error found in the literature are discussed and their statistical ramifications are explored with Monte Carlo simulations. The paper also finds that, after adjusting for exposure error, the relationship between dietary i... Mostrar Tudo |
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Palavras-Chave: |
Cabelo humano; Human hair; Incertezas estatisticas; Methylmercury; Metilmercurio; Monte Carlo simulation; Reino Unido; Simulacao de Monte Carlo; Statistical uncertainties. |
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Thesagro: |
Dieta; Peixe. |
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Thesaurus Nal: |
diet; fish; United Kingdom. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02663naa a2200289 a 4500
001 1793047
005 2017-03-28
008 1997 bl --- 0-- u #d
100 1 $aLIPFERT, F. W.
245 $aEstimating exposure to methylmercury$beffects of uncertainties.
260 $c1997
520 $aUncertainties in exposures can lead to biased estimates of slopes and thresholds in the exposure-response relationships that are developed from regression analysis. This paper reviews published exposure and epidemiological studies of methylmercury (meHg) from the perspective of the accuracy and precision of the estimates used to represent the actual doses received. Sources of such uncertainties, collectively referred to as exposure errors, include instrumental and analytical erros, sampling and survey uncertainties and individual variability in the relationships between the exposure metrics and the actual doses to target organs. Because the relationship between maternal intake and the consequent dose to the fetal brain varies among individuals, epidemiological stidues of the effects of prenatal exposure must necessarily be accompanied by larger exposure uncertainties than comparable studies of effects on the mothers. The increased exposure errors typically result in attnuated slopes of the dose-response functions and under-estimates of thresholds, so that part of the apparent increased sensitivity of the fetus that has been developed from epidemiological studies may in fact be due to their inherently less certain exposures. Sources and magnitudes of exposure error found in the literature are discussed and their statistical ramifications are explored with Monte Carlo simulations. The paper also finds that, after adjusting for exposure error, the relationship between dietary intake and blood concentration is consistent with an average half-life shorter than has typically been used and that using population averages yields a consistent but-linear relationship between dietary intake of Hg and hair concentration. Investigators are urged to obtain (and present) data on more than one exposure metric, so that their relative uncertainties may be assessed indenpendently.
650 $adiet
650 $afish
650 $aUnited Kingdom
650 $aDieta
650 $aPeixe
653 $aCabelo humano
653 $aHuman hair
653 $aIncertezas estatisticas
653 $aMethylmercury
653 $aMetilmercurio
653 $aMonte Carlo simulation
653 $aReino Unido
653 $aSimulacao de Monte Carlo
653 $aStatistical uncertainties
773 $tWater, Air & Soil Pollution$gv.97, n.1/2, p.119-145, 1997.
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Registro original: |
Embrapa Pantanal (CPAP) |
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| Registros recuperados : 7 | |
| 2. |  | KARVATTE JUNIOR, N.; ALVES, F. V.; ALMEIDA, R. G. de; MIYAGI, E. S.; RAMOS, C. E. C. de O.; BARRTO, C. D.; MASTELARO, A. P.; FERRARI, B. Multiple factor analysis to identify correlated variable among microclimate, thermal comfort and infrared thermography in agroforestry systems. In: CONGRESO INTERNACIONAL DE SISTEMAS SILVOPASTORILES 10., 2019, Asunción. Por una produción sostenible: Libro de Actas. Asunción: CIPAV, 2019. p. 56-64| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Gado de Corte. |
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| 3. | | LEAL, T. T. B.; NASCIMENTO, A. S. do; RAMOS, C. E. C. de O.; BARBOSA, F. S. Bioatividade de extratos de sisal (Agave Sisalana Perrine ex Engelm) sobre a oviposição de Ceratitis Capitata (Wiedemann, 1824) (DípTERA: Tephritidae). In: REUNIÃO ANUAL DE CIÊNCIA, TECNOLOGIA, INOVAÇÃO E CULTURA NO RECÔNCAVO DA BAHIA - RECONCITEC, 3., Cruz das Almas. Anais.... Cruz das Almas, Universidade Federal do Recôncavo da Bahia, 2014. E-Book.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Mandioca e Fruticultura. |
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| 4. | | ROSA, M. S.; FANCELLI, M.; MEDEIROS, N. G. F. de; RAMOS, C. E. C. de O.; SILVA, J. N. da; RGÔLO, R. da S.; FERREIRA, C. F.; LEDO, C. A. da S. Efeito do protótipo emissor de ondas mecânicas sobre o comportamento de Diaphorina citri Kuwayama (Hemiptera: Liviidae) In: JORNADA CIENTÍFICA EMBRAPA MANDIOCA E FRUTICULTURA, 17., 2017 Ciência e Empreendedorismo : resumos. Cruz das Almas, BA: Embrapa Mandioca e Fruticultura, 2017. 137p. 1p. Manejo das principais doenças e insetos-praga| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Mandioca e Fruticultura. |
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| 5. | | SALES, A. C.; RAMOS, C. E. C. de O.; SOUZA, K. N. de; FANCELLI, M.; NASCIMENTO, A. S. do. Infestação de Diaphorina citri (Hemiptera: Liviidae) em plantas de citros e murta (Murraya paniculata) no Recôncavo da Bahia. In: JORNADA CIENTÍFICA EMBRAPA MANDIOCA E FRUTICULTURA, 10., 2016: Cruz das Almas, BA. Traduzindo ciência para o mundo : resumos. Brasília, DF : Embrapa, 2016.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Mandioca e Fruticultura. |
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| 7. | | SALES, A. C.; RAMOS, C. E. C. de O.; SOUZA, K. N. de; FANCELLI, M.; NASCIMENTO, A. S. do. Taxa de parasitismo de Diaphorina citri (Hemiptera: Liviidae) por Tamarixia radiata (Hymenoptera: Eulophidae), nos hospedeiros citros e murta, no Recôncavo da Bahia. In: JORNADA CIENTÍFICA EMBRAPA MANDIOCA E FRUTICULTURA, 10., 2016: Cruz das Almas, BA. Traduzindo ciência para o mundo : resumos. Brasília, DF : Embrapa, 2016.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Mandioca e Fruticultura. |
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| Registros recuperados : 7 | |
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| Nenhum registro encontrado para a expressão de busca informada. |
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