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Bothell, WA, United States

Gunduz O.,Dokuz Eylul University | Bakar C.,Canakkale Onsekiz Mart University | Simsek C.,Dokuz Eylul University | Baba A.,Izmir Institute of Technology | And 4 more authors.
Archives of Environmental and Occupational Health | Year: 2015

The purpose of this research was to compare the causes of death in 5 villages situated in Simav Plain, Turkey, during 2005-2010 where different arsenic levels were detected in drinking water supplies. Since groundwater in Simav Plain had arsenic concentrations that ranged between 7.1 and 833.9 ppb, a two-phase research was formulated. In the first phase, public health surveys were conducted with 1,003 villagers to determine the distribution of diseases. In the second phase, verbal autopsy surveys and official death records were used to investigate the causes of death. In total, 402 death cases were found in the study area where cardiovascular system diseases (44%) and cancers (15.2%) were major causes. Cancers of lung (44.3%), prostate (9.8%), colon (9.8%), and stomach (8.2%) were comparably higher in villages with high arsenic levels in drinking water supplies. Furthermore, the majority of cases of liver, bladder, and stomach cancers were observed in villages with high arsenic levels. © 2015 Taylor and Francis Group, LLC. Source


Gunduz O.,Dokuz Eylul University | Gurleyuk H.,Applied Speciation and Consulting LLC | Cakir A.,Dokuz Eylul University | Elci A.,Dokuz Eylul University | And 2 more authors.
Journal of Environmental Engineering (United States) | Year: 2013

The accurate speciation analysis of arsenic is a serious concern for water quality monitoring programs. Because the preservation of sample integrity until analysis is one of the most important aspects of speciation, this study aims to compare the performance of four different sample preservation methods under diverse conditions of sample quality. Natural samples with different characteristics were collected into the following containers to study their effectiveness: (1) standard high-density polyethylene bottle with no preservative; (2) empty, sterile Vacuette tube with no preservative; (3) sterile tripotassium ethylenediaminetetraacetic acid (K3EDTA) Vacuette tube with K3EDTA additive; and (4) empty, sterile Vacuette tube with added hydrochloric acid (HCl). Known concentrations of arsenite [As(III)] were also added to each container to monitor the oxidation of As(III) to arsenate [As(V)]. The results revealed recovery ratios exceeding 95% in all containers with sterile vacuum conditions. In particular, the K3EDTA Vacuette tube yielded a recovery very close to 100% of the spiked As(III), which is known to rapidly oxidize to As(V). Overall, collecting the sample into a container under sterile vacuum conditions and using a universally accepted preserving agent such as EDTA or HCl significantly improved the preservation of the original species distribution in the water matrix studied, compared to sampling without the use of preservation methods. After validation by future research, these sterile vacuum tubes can possibly be utilized for collecting and storing samples for the routine speciation analysis of other elements such as selenium, chromium, and antimony. © 2013 American Society of Civil Engineers. Source


Kerger B.D.,Exponent, Inc. | Gerads R.,Applied Speciation and Consulting LLC | Gurleyuk H.,Applied Speciation and Consulting LLC | Urban A.,Cardno ChemRisk | Paustenbach D.J.,Cardno ChemRisk
Toxicological and Environmental Chemistry | Year: 2015

Inductively coupled plasma with mass spectrometric detection (ICP-MS) has been used for clinical analysis of cobalt (Co) due to its sensitivity and specificity; however, media-specific validation studies are lacking. This study provides data on performance variables affecting differences between selected analytical platforms (Perkin Elmer and Agilent), tissue sample preparation, storage, and interferences affecting measurements in whole blood, serum, and synovial fluid. The limits of detection (LOD) range from 0.2–0.5 µg/L in serum and synovial fluid, and 0.6–1.7 µg Co/L in whole blood. The Agilent platform with collision reaction cell is more sensitive, while the Perkin Elmer platform with dynamic reaction cell demonstrates more polyatomic interferences near the LOD for serum and whole blood. Split sample analysis showed good accuracy, precision, and reproducibility between serum Co measurements using acid digestion or detergent dilution preparations for persons with metal hip implants or following supplement intake. The results demonstrated reliability of the ICP-MS methodology across the two analytical platforms and between two commercial laboratories for Co concentrations above 5 µg Co/L, but digestion procedures and polyatomic interferences may affect measurements in some media at lower concentrations. These studies validate the described ICP-MS methodology for clinical purposes with precautions at low cobalt concentrations (<5 µg Co/L). © 2015 Taylor & Francis. Source


Kerger B.D.,ChemRisk LLC | Gerads R.,Applied Speciation and Consulting LLC | Gurleyuk H.,Applied Speciation and Consulting LLC | Thuett K.A.,ChemRisk LLC | And 2 more authors.
Toxicological and Environmental Chemistry | Year: 2013

A method utilizing size exclusion liquid chromatography (SEC) was developed to separate and quantify large molecular cobalt (Co) (e.g., albumin-Co) from cyanocobalamin (vitamin B12) and small molecular Co (e.g., glutathione-Co and free Co) in human serum. Highly selective and sensitive detection using inductively coupled plasma-mass spectrometry was coupled with SEC to provide a method with reliable accuracy, precision, recoveries, stability, and a detection limit of 0.037 μg/L in undiluted serum. Other divalent metal cations known to compete with Co(II) for serum albumin-binding sites (such as iron, zinc, manganese, cadmium, copper, nickel, and lead) did not significantly alter Co(II) quantification. Co-protein binding capacity determination of individual serum samples indicated that addition of 2500 μg Co/L to undiluted human serum resulted in approximately 90% distribution to the large molecular Co peak, consistent with Co binding to high-affinity divalent metal binding sites on albumin. Since serum albumin binding partially sequesters biologically active Co(II) ions, this method provides an important tool for better understanding the kinetics and toxicology of Co compounds. Thus, the proposed method might play an important role in establishing Co dose-response relationships that affect the equilibrium concentrations of free ionic Co(II). © 2013 Copyright Taylor and Francis Group, LLC. Source


Ito K.,New York State Department of Health | Ito K.,University at Albany | Goessler W.,University of Graz | Gurleyuk H.,Applied Speciation and Consulting LLC | And 6 more authors.
Journal of Analytical Atomic Spectrometry | Year: 2011

A limited interlaboratory study for arsenic speciation analysis of whole blood was conducted in conjunction with the New York State Department of Health's (NYS DOH's) proficiency testing (PT) program for total arsenic in whole blood. Four laboratories were able to report values for up to five arsenic species in blood materials representing typical environmental concentrations. The arsenic species were very challenging to measure, due to the low concentrations ( Source

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