Selenium status during pregnancy and child psychomotor development-Polish Mother and Child Cohort study.

BACKGROUND: The studies on the impact of selenium (Se) levels in different pregnancy periods on child psychomotor functions are limited. The aim of this study was to evaluate the impact of prenatal Se on child neurodevelopment. METHODS: The study population consisted of 410 mother-child pairs from Polish Mother and Child Cohort. Se levels were measured in each trimester of pregnancy, at delivery, and in cord blood by graphite furnace atomic absorption spectrometry. Psychomotor development was assessed in children at the age of 1 and 2 y using the Bayley Scales of Infant and Toddler Development. RESULTS: Plasma Se levels decreased through pregnancy (from 48.3 ± 10.6 µg/l in the first trimester to 38.4 ± 11.8 µg/l at delivery; P < 0.05). A statistically significant positive association between Se levels in the first trimester of pregnancy and motor development (ß = 0.2, P = 0.002) at 1 y of age, and language development (ß = 0.2, P = 0.03) at 2 y of age was observed. The positive effect of Se levels on cognitive score at 2 y of age was of borderline significance (ß = 0.2, P = 0.05). CONCLUSION: Prenatal selenium status was associated with child psychomotor abilities within the first years of life. Further epidemiological and preclinical studies are needed to confirm the association and elucidate the underlying mechanisms of these effects.

Useful and Fast Method for Blood Lead and Cadmium Determination Using ICP-MS and GF-AAS; Validation Parameters.

BACKGROUND: In case of clinical analysis, especially in blood lead (Pb-B) and cadmium (Cd-B) determination, the accuracy and precision of the method are crucial. The objective of this article is to present a simple and useful method for Pb-B and Cd-B determination using ICP-MS (inductively coupled plasma-mass spectrometry) as well as GF-AAS (graphite furnace-atomic absorption spectrometry). METHODS: The principle of the method is based on the deproteinization of blood samples by addition of 5% nitric acid that eliminates the presence of the protein in the samples, thereby excluding the influence of the organic matrix on the result determinations. A comparison of the two techniques ICP-MS and GF-AAS was established for Pb and Cd determinations in the same 40 blood samples collected from lead workers. RESULTS: The results showed that validation parameters for ICP-MS and GF-AAS were similar, however better for ICP-MS for Pb-B determinations. The detection limit (3×SD) for Pb-B determinations for ICP-MS and GF-AAS was, respectively, 0.16 and 1.0 µg/l, and for Cd-B it was, respectively, 0.08 and 0.02 µg/l. Correlation coefficients (rs) for comparable Pb-B and Cd-B determinations, using these two techniques, showed very good statistically significant correlations and were r = 0.9988, P < 0.0001 for Pb-B and r = 0.9949, P < 0.0001 for Cd-B. CONCLUSIONS: The obtained results indicate that the method of deproteinization of blood samples is still the best way to eliminate spectral interferences and influence of the organic matter. The elaborated method is especially dedicated to clinical laboratories and determined low concentrations of lead and cadmium in biological samples.

[Selenium determination in plasma/serum by inductively coupled plasma mass spectrometry (ICP-MS): comparison with graphite furnace atomic absorption spectrometry (GF-AAS)]. / Oznaczanie selenu w surowicy/osoczu technika spektrometrii mas z plazma indukcyjnie sprzezona (ICP-MS): porównanie ztechnika bezplomieniowej absorpcyjnej spektrometrii atomowej (GF-AAS).

BACKGROUND: The present study was aimed at comparing two techniques of selenium (Se) determination in serum/plasma samples: inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption (GF-AAS). MATERIALS AND METHODS: Blood samples were collected by venipuncture, using Venosafe closed blood sampling system. The samples were centrifuged. The measurements were performed by Elan DRC-e mass spectrometry, Perkin Elmer, SCIEX, USA and Unicam Solar 989 QZ atomic absorption spectrometry. Reference material, Clincheck Serum Control Level 1 (Recipe, Germany), was used to verify the determinations. The Laboratory participates in external quality control (G-EQUAS). RESULTS: Analytical parameters for both techniques are respectively: ICP-MS--precision 5.9%, limit of detection 0.19 microg/l, repeatability 5.5%, trueness 2.4%, bias 97.6%, GF-AAS--precision 8%, limit of detection 3.4 microg/l, repeatability 7.2%, trueness 6.8%, bias 93.2%. CONCLUSIONS: The benefits of the ICP-MS technique are high accuracy, low detection limits and the possibility of multi-element analysis.

[Mercury in hair--an indicator of environmental exposure]. / Rtec we wlosach--wskaznik narazenia srodowiskowego.

Mercury concentration in human hair is used as an indicator of long-term environmental exposure to mercury. Over 90% of mercury in hair occur in the metylmercury form. Exposure to mercury almost entirely results from the consumption of seafood and meat of big sea mammals. This paper presents a review of toxic effects of mercury, biological monitoring of exposure to mercury and biological levels of mercury in hair and blood of people consuming a variety of fish diets. It also describes the methods most often used for preliminary sample preparation and applied to determining mercury hair levels. Validation parameters of the method for the determination of mercury in hair, developed and applied by the Nofer Institute of Occupational Medicine, is also presented.

Exposure to mercury vapors in dental workers in Poland.

OBJECTIVES: The study aimed at assessing the effect of low-level exposure to mercury (Hg) vapor from amalgam fillings among dental surgery staff in the city of Lódz, Poland. MATERIALS AND METHODS: The study group was composed of 51 workers (mean age, 39.25+/-11.05 years) employed in dental surgeries; the control group comprised 16 white-collar workers (mean age, 40.05+/-10.57 years) of the Nofer Institute of Occupational Medicine, Lódz, who had no or a few amalgam dental fillings. Total urine mercury (Hg-U) concentration was determined with cold vapor atomic absorption spectrometry (CV-AAS) based on tin (II) chloride mercury reduction after overnight digestion of urine sample with potassium permanganate in sulfuric acid solution. The reliability of mercury determinations was verified by measuring Hg concentration in the reference material and via participation in the external quality assessment scheme. RESULTS: No statistically significant differences were found in geometric mean of urine Hg concentrations between the study and control groups (GM+/-SD, 0.44+/-0.440 and 0.5+/-0.270 mug/g creatinine, respectively, p = 0.242). Among different factors affecting Hg exposure in dental surgeries, only the duration of dental practice showed a statistically significant influence on total Hg-U (r = 0.3000; p = 0.024). Having divided the subjects into two groups, with and without amalgam fillings, we noted a statistically significant difference in urine Hg concentrations (0.60 +/- 0.720, n = 38; 0.36 +/- 0.650, n = 29; p = 0.004) between these two groups. CONCLUSIONS: The results of biological monitoring of dental surgery staff did not reveal current exposure to Hg vapors from amalgam fillings. However, these dental workers may have been the subject to such an exposure in the past. The only statistically significant correlation was that between total Hg-U concentrations and the duration of dental practice.

Multi-element analysis of urine using dynamic reaction cell inductively coupled plasma mass spectrometry (ICP-DRC-MS) - a practical application.

OBJECTIVES: The method for the determination of As, Al, Cd, Ni, Pb (toxic elements) and Cr, Co, Cu, Fe, Mn, Zn (essential elements) in human urine by the use of Inductively Coupled Plasma Mass Spectrometry (quadrupole ICP-MS DRCe Elan, Perkin Elmer) with the dynamic reaction cell (DRC) was developed. MATERIALS AND METHODS: The method has been applied for multi-element analysis of the urine of 16 non-exposed healthy volunteers and 27 workers employed in a copper smelter. The analysis was conducted after initial 10-fold dilution of the urine samples with 0,1% nitric acid. Rhodium was used as an internal standard. The method validation parameters such as detection limit, sensitivity, precision were described for all elements. Accuracy of the method was checked by the regular use of certified reference materials ClinCheck®-Control Urine (Recipe) as well as by participation of the laboratory in the German External Quality Assessment Scheme (G-EQUAS). RESULTS: The detection limits (DL 3s) of the applied method were 0.025, 0.007, 0.002, 0.004, 0.004, 0.086, 0.037, 0.009, 0.016, 0.008, 0.064 (µg/l) for Al, As, Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb, Zn in urine, respectively. For each element linearity with correlation coefficient of at least 0.999 was determined. Spectral interferences from some of the ions were removed using DRC-e with addition of alternative gas: methane for cobalt, copper, cadmium, chromium, iron, manganese, nickel and rhodium, and oxygen for arsenic. CONCLUSIONS: The developed method allows to determine simultaneously eleven elements in the urine with low detection limits, high sensitivity and good accuracy. Moreover, the method is appropriate for the assessment of both environmental and occupational exposure.