Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Chronologically matched toenail-Hg to hair-Hg ratio: temporal analysis within the Japanese community (U.S.)
Thomas Hinners, Ami Tsuchiya, Alan H Stern, Thomas M Burbacher, Elaine M Faustman, Koenraad Mari?n
Environmental Health , 2012, DOI: 10.1186/1476-069x-11-81
Abstract: As part of the Arsenic Mercury Intake Biometric Study, toenail clippings were collected at three time points over a period of one year amongst females from within the population of Japanese living near Puget Sound in Washington State (US). Variability in temporal intra-individual toenail-Hg levels was examined and chronologically matched hair and toenail samples were compared to more accurately define the toxicokinetic variability of Hg levels observed between the two compartments.Mean toenail-Hg values (n=43) for the 1st, 2nd and 3rd visits were 0.60, 0.60 and 0.56 ng/mg. Correlations were as follows: r=0.92 between 1st and 2nd clinic visits, r=0.75 between 1st and 3rd visits and r=0.87 between 2nd and 3rd visits. With few exceptions, toenail-Hg values from any visit were within 50-150% of the individual’s mean toenail-Hg level. Nearly all participants had less than a two-fold change in toenail-Hg levels across the study period. A regression model of the relationship between toenail-Hg and hair-Hg (n = 41) levels representing the same time period of exposure, gave a slope (Hg ng/mg) of 2.79 for hair relative to toenail (r=0.954).A chronologically matched hair-Hg to toenail-Hg ratio has been identified within a population that consumes fish regularly and in quantity. Intra-individual variation in toenail-Hg levels was less than two-fold and may represent dietary-based fluctuations in body burden for individuals consuming various fish species with different contaminant levels. The chronologically matched ratio will be useful for relating MeHg exposure and dose–response derived from toenail-Hg measurements to those derived from hair-Hg measurements in other studies, and may be useful in future investigations as an indicator of stable MeHg body burden within a population.As most human exposures to methylmercury (MeHg) result from fish consumption, federal and state consumption advisories have been released as a public health protective measure [1,2]. Most state and fed
Proyecto Altamira  [cached]
para Altamira, Consorcio
Informes de la Construccion , 1997,
Abstract: Up to the North of Spain, in Cantabria, Altamira, place of great importance a hundred thousand years ago, let us know how prehistoric days were when Mary, Marcelino Sanz de Sautuola's daughter, discovers in 1879, among the excavations her father was doing, the prehistoric paintings. Since then the Cave of Altamira became the paradigm of rupestrian art all over the world. In the seventies, due to the excessive increase of visitors that imperil the paintings, strong restricted measures were taken. Since 1982, only 8.500 people per year are allowed to visit the Cave. Then, the idea of an Altamira's reproduction was born. The "Altamira Project", a very important architectural unit being managed and promoted by a partnership created on that purpose is ordered to the renowned architect Navarro Baldeweg. In 1999, being at a new millennium's door, Altamira will receive again all the visitors looking for prehistoric times. En Cantabria, al N. de Espa a, Altamira, enclave de gran importancia y concentración humana hace 100.000 a os, nos abre las puertas de la prehistoria cuando María, en las excavaciones que realizaba su padre, D. Marcelino Sanz de Sautuola, en 1879, descubre las pinturas rupestres de lo que a partir de entonces será la "Cueva de Altamira", uno de los conjuntos rupestres más importantes del mundo. La masiva afluencia de visitantes de las últimas décadas comienza a poner en peligro las pinturas, tomándose fuertes medidas restrictivas, que tan sólo permiten el acceso a 8.500 personas al a o, desde 1982. Surge entonces la idea de la reproducción facsimilar de la cueva, englobada en el "Proyecto Altamira", conjunto arquitectónico de primer orden encargado al arquitecto Navarro Baldeweg. En 1999, a las puertas de un nuevo milenio, Altamira podrá acoger de nuevo a cuantos visitantes quieran acercarse a la prehistoria.
Prevalence of nits and lice in sampls of cut hair from floors of barbershop and beauty parlors in Belo Horizonte, Minas Gerais state, Brazil
Linardi, Pedro Marcos;Maria, Mário de;Botelho, José Ramiro;Cunha, Horácio Capistrano;Ferreira, Jo?o Batista;
Memórias do Instituto Oswaldo Cruz , 1988, DOI: 10.1590/S0074-02761988000400013
Abstract: a louse survey based on samples of cut hair collected from floors of barbershops and beauty parlors was conducted in belo horizonte, minas gerais state, brazil, from october 1984 to april 1985, as an alternative way to determine the prevalence of pediculosis capitis in the population. of 475 samples examined for nits, nymphs, or adults of pediculus capitis, 140 were infested (29.5%). a total of 58 lice and 3.553 nits were found in 33.632.9 g of hair collected, giving a ratio of 0.10 nit/g. almost 29% of the nits were viable and capable of being transmitted after hatching. there was significant difference among the infestation rates by socioeconomic levels, and samples from barbershops with male customers were the most infested. based upon the number of haircuts in each sample, we estimated that 5 or 6% of the population might be infested by this species.
Levels of Metals in Hair in Childhood: Preliminary Associations with Neuropsychological Behaviors  [PDF]
Margarita Torrente,Mireia Gascon,Martine Vrijheid,Jordi Sunyer,Joan Forns,José L. Domingo,Martí Nadal
Toxics , 2014, DOI: 10.3390/toxics2010001
Abstract: For more than 100 years, an electrochemical plant has been operating in Flix (Catalonia, Spain) by the Ebro River. Its activities have originated a severe accumulation of environmental contaminants (metals, organochlorinated pesticides and radionuclides) in sediments of the Flix reservoir, while mercury (Hg) has been also frequently released to the air. Environmental exposure to industrial pollutants has been associated with decreased intelligence and behavioral problems. In the present study, we assessed, in 53 children living in the village of Flix and the surroundings, the relationships between the concentrations of a number of trace elements (As, Be, Cd, Cs, Hg, Mn, Ni, Pb, Sn, Tl, U and V) in hair and the levels of testosterone in blood, with respect to potential neuropsychological alterations. Lead (Pb) and Hg showed the highest mean concentrations in hair samples. However, the current Hg levels were lower than those previously found in children living in the same zone, while the concentration of the remaining elements was similar to those reported in the scientific literature. The outcomes of certain neuropsychological indicators showed a significant correlation with metals, such as Pb and uranium (U). More specifically, these elements were negatively correlated with working memory and hit reaction time, suggesting impulsivity. In summary, although Pb and U concentrations in hair were within standard levels, both metals could be correlated with certain, but minor, neuropsychological alterations in the childhood population of Flix. These findings should be confirmed by future birth cohort studies, with bigger study populations and using more complex statistical analyses, focused on human exposure to these specific elements.
Determination of Cd, Cu, Pb, Hg by Reversed Phase High Performance Liquid Chromatography

Ding Chaowu,Li Huabin,

色谱 , 1998,
Abstract: The chromatographic behaviors of Me(n+)-Dz (dithizone) have been studied with RP-HPLC. A method for the determination of Cd, Cu, Pb and Hg has been established. The chromatographic conditions were: column: Shim-pack CLC-ODS, 150 mm x 6.0 mm i.d.; mobile phase: V(methanol): V(water): V (chloroform) (containing volume fraction 1% triethylamine) = 80:12:8; flow rate: 1 mL/min; column temperature: 35 degrees C; detection wavelength: 254 nm. The linear ranges were from 0.01 mg/mL to 2.0 mg/mL with correlation coefficients of 0.9993-0.9998. The detection limits of Cd, Cu, Pb, Hg were from 2.4 micrograms/L to 5.0 micrograms/L. The RSDs were in the range from 1.8% to 9.7%, and the recoveries ranged from 94% to 103% (except Hg). The method has been applied to the analysis of hair.
El proyecto científico Los Tiempos de Altamira : primeros resultados  [PDF]
J.A. Lasheras Corruchaga,R. Montes Barquín,Emilio Mu?oz Fernández,P. Rasines del Río
Munibe Antropologia-Arkeologia , 2005,
Abstract: El Museo de Altamira viene desarrollando un proyecto científico centrado en el estudio de 4 cavidades con ocupaciones y arte rupestre del Solutrense y el Magdaleniense, todas ellas situadas en el entorno inmediato de la cueva de Altamira. Los yacimientos son las cuevas de Cualventi, El Linar y Las Aguas (Alfoz de Lloredo, Cantabria) y la propia cueva de Altamira (Santillana de Mar). En este trabajo se aportan los primeros resultados obtenidos.
Uranium and other contaminants in hair from the parents of children with congenital anomalies in Fallujah, Iraq
Samira Alaani, Muhammed Tafash, Christopher Busby, Malak Hamdan, Eleonore Blaurock-Busch
Conflict and Health , 2011, DOI: 10.1186/1752-1505-5-15
Abstract: Levels of Ca, Mg, Co, Fe, Mn, V, Zn, Sr, Al, Ba, Bi, Ga, Pb, Hg, Pd and U (for mothers only) were significantly higher than published mean levels in an uncontaminated population in Sweden. In high excess were Ca, Mg, Sr, Al, Bi and Hg. Of these only Hg can be considered as a possible cause of congenital anomaly. Mean levels for Uranium were 0.16 ppm (SD: 0.11) range 0.02 to 0.4, higher in mothers (0.18 ppm SD 0.09) than fathers (0.11 ppm; SD 0.13). The highly unusual non-normal Fallujah distribution mean was significantly higher than literature results for a control population Southern Israel (0.062 ppm) and a non-parametric test (Mann Whitney-Wilcoxon) gave p = 0.016 for this comparison of the distribution. Mean levels in Fallujah were also much higher than the mean of measurements reported from Japan, Brazil, Sweden and Slovenia (0.04 ppm SD 0.02). Soil samples show low concentrations with a mean of 0.76 ppm (SD 0.42) and range 0.1-1.5 ppm; (N = 18). However it may be consistent with levels in drinking water (2.28 μgL-1) which had similar levels to water from wells (2.72 μgL-1) and the river Euphrates (2.24 μgL-1). In a separate study of a sub group of mothers with long hair to investigate historic Uranium excretion the results suggested that levels were much higher in the past. Uranium traces detected in the soil samples and the hair showed slightly enriched isotopic signatures for hair U238/U235 = (135.16 SD 1.45) compared with the natural ratio of 137.88. Soil sample Uranium isotope ratios were determined after extraction and concentration of the Uranium by ion exchange. Results showed statistically significant presence of enriched Uranium with a mean of 129 with SD5.9 (for this determination, the natural Uranium 95% CI was 132.1 < Ratio < 144.1).Whilst caution must be exercised about ruling out other possibilities, because none of the elements found in excess are reported to cause congenital diseases and cancer except Uranium, these findings suggest the enrich
The Boars from Altamira: Solving an Identity Crisis
Patricia C. Rice
Papers from the Institute of Archaeology , 1992, DOI: 10.5334/pia.34
Abstract: Most scholars of prehistoric European cave art would regard correct species identification of depicted animals as the first step toward explaining the presence of animals in prehistoric imagery. Whether one is attempting explanation via quantitative or qualitative means, via inductive or deductive methods, knowing the relative proportions of animals depicted in single caves or in all caves is a logical starting point, since the vast majority of identifiable images in cave art are of animals. But inventories of animals in caves differ from expert to expert due to numbers of images involved, and because the lack of preservation or poor technical rendition make identification difficult in many cases. Using the most recent counts is no indication of accuracy. The reluctance of governments to allow surveys to be made by any but their own nationals has complicated the issue, with the results that most scholars must use the counts of others, inevitably reinforcing errors. The underlying message remains clear: we can explain only as accurately as our data allow. It is with this in mind that I question part of the recent reinterpretation of the Altamira ceiling by Leslie Freeman (1987). I do not question his goal of reinventorying the animal images; he is to be applauded for this venture. I do, however, question his conclusion that the three animals identified by Breuil in 1935 as 'wild boars' are bison (1987:81).
Segmental hair mercury evaluation of a single family along the Upper Madeira Basin, Brazilian Amazon
Boischio, Ana Amélia Peixoto;Cernichiari, Elsa;Henshel, Diane;
Cadernos de Saúde Pública , 2000, DOI: 10.1590/S0102-311X2000000300016
Abstract: mercury pollution (mehg) up the aquatic food chains in the amazonian ecosystems has been a major concern in environmental health. riverside people (ribeirinhos) along the upper madeira river are heavy fish eaters. hair is the best biomarker for mehg exposure. by assuming a constant hair growth rate, it is possible to evaluate a temporal profile of hg exposure over the recent defined past. in this paper we present the segmental total hair hg concentrations from a single family from which some of the 10 persons investigated had high hair hg concentrations (peak of 339 ppm). we also presented the hair mehg content from 4 out of the 10 family members investigated. there was a wide variation in total hair hg concentrations (8 to 339 ppm) among these individuals, who were mostly sharing their meals; there was also a wide variation in total hg concentrations in the same individual over time (136 to 274 ppm). hg speciation showed a mean and standard deviation in the mehg content of 62% and 6%, respectively. the wide variation in total hair hg concentration strongly indicated that it is possible to mitigate critical hg exposure levels by conducting a fish advisory.
Segmental hair mercury evaluation of a single family along the Upper Madeira Basin, Brazilian Amazon  [cached]
Boischio Ana Amélia Peixoto,Cernichiari Elsa,Henshel Diane
Cadernos de Saúde Pública , 2000,
Abstract: Mercury pollution (MeHg) up the aquatic food chains in the Amazonian ecosystems has been a major concern in environmental health. Riverside people (ribeirinhos) along the Upper Madeira river are heavy fish eaters. Hair is the best biomarker for MeHg exposure. By assuming a constant hair growth rate, it is possible to evaluate a temporal profile of Hg exposure over the recent defined past. In this paper we present the segmental total hair Hg concentrations from a single family from which some of the 10 persons investigated had high hair Hg concentrations (peak of 339 ppm). We also presented the hair MeHg content from 4 out of the 10 family members investigated. There was a wide variation in total hair Hg concentrations (8 to 339 ppm) among these individuals, who were mostly sharing their meals; there was also a wide variation in total Hg concentrations in the same individual over time (136 to 274 ppm). Hg speciation showed a mean and standard deviation in the MeHg content of 62% and 6%, respectively. The wide variation in total hair Hg concentration strongly indicated that it is possible to mitigate critical Hg exposure levels by conducting a fish advisory.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.