نتایج جستجو برای: الگریتم pb

تعداد نتایج: 36430  

Journal: :British journal of industrial medicine 1976
G I Benson W H George M H Litchfield D J Seaborn

Biochemical measurements were carried out on 20 workers entering employment in a lead industry. Blood lead (Pb-B) urinary delta-aminolevulinic acid (ALA), and coproporphyrin (CP) levels were determined before entry and then at approximately weekly intervals for the first 12 weeks of employment. Levels of blood lead began to increase in all men within one week rising from an average pre-employme...

2011
Marisela Rubio-Andrade Francisco Valdés-Pérezgasga J Alonso Jorge L Rosado Mariano E Cebrián Gonzalo G García-Vargas

BACKGROUND To study the changes of children lead exposure in the city of Torreon during the last five years, after environmental and public health interventions, using the timeline of lead in blood concentration as the biomarker of exposure and its relation to lead in soil concentrations. METHODS This follow-up study started in 2001 and consisted of 232 children living in nine neighborhoods i...

Journal: :Environmental science & technology 2015
Hong-Bo Li Kai Chen Albert L Juhasz Lei Huang Lena Q Ma

Fingerprinting based on stable isotopes of lead (Pb) in blood and environmental media helps to identify Pb exposure pathways in children. However, previous studies used stable isotopes of total Pb in media. In this study, a wire rope production town in China (Zhuhang) was selected for investigating the effectiveness of using isotope ratios in bioaccessible Pb to identify childhood Pb exposure p...

Journal: :Environmental pollution 2011
Guo-Xin Sun Xin-Jun Wang Qin-Hong Hu

Lead isotopes and heavy metal concentrations were measured in two sediment cores sampled in estuaries of Xiangjiang and Lishui Rivers in Hunan province, China. The presence of anthropogenic contribution was observed in both sediments, especially in Xiangjiang sediment. In the Xiangjiang sediment, the lower (206)Pb/(207)Pb and higher (208)Pb/(206)Pb ratio, than natural Pb isotope signature (1.19...

Journal: :The Science of the total environment 2009
Neal Michelutti Antonio Simonetti Jason P Briner Svend Funder Robert A Creaser Alexander P Wolfe

Concentrations and stable isotope ratios of lead (Pb) from lake sediments were used to quantify temporal patterns of anthropogenic Pb pollution in the Clyde River region of Baffin Island, Arctic Canada. Surface sediments from eight lakes on eastern Baffin Island and one from northern-most Greenland, spanning a gradient of 20 degrees latitude, showed great variability with respect to Pb concentr...

2014
Howard W. Mielke Christopher Gonzales Eric Powell Paul W. Mielke

In 2012 the U.S. Centers for Disease Control (CDC) set the blood Pb reference value at ≥5 µg/dL. Clinical analysis of children's blood Pb levels is the common way to diagnose environmental Pb contamination, and intervention ensues with education and household dust cleanup. Recent review indicates that education and household dust cleanup are not effective at reducing children's Pb exposure. Her...

Journal: :The Science of the total environment 2015
N Walraven M Bakker B J H van Os G Th Klaver J J Middelburg G R Davies

In human risk assessment, ingestion of soil is considered a major route of toxic Pb exposure. A large body of research has focussed on the measurement of the 'total' Pb contents in sediment, soil and dust as a measure for the exposure to lead. We report that Pb bioaccessibility (i.e. the maximum bioavailability), determined with an in vitro test, does not necessarily depend on the total Pb cont...

Journal: :Analytica chimica acta 2015
Maxence Paul Luke Bridgestock Mark Rehkämper Tina van DeFlierdt Dominik Weiss

A new method for the determination of seawater Pb isotope compositions and concentrations was developed, which combines and optimizes previously published protocols for the separation and isotopic analysis of this element. For isotopic analysis, the procedure involves initial separation of Pb from 1 to 2L of seawater by co-precipitation with Mg hydroxide and further purification by a two stage ...

2015
Yan Wang Hong Shen Liang Xu Xianwen Zhu Chao Li Wei Zhang Yang Xie Yiqin Gong Liwang Liu

Lead (Pb), a ubiquitous but highly toxic heavy metal (HM), is harmful to human health through various pathways including by ingestion of contaminated vegetables. Radish is a worldwide root vegetable crop with significant health and nutritional benefits. However, little is known about Pb translocation and distribution within radish plants after its uptake by the roots. In this study, Pb stress w...

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