| 1. |
- Barany, E, et al.
(författare)
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Trace element levels in whole blood and serum from Swedish adolescents
- 2002
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Ingår i: Science of the Total Environment. - 1879-1026 .- 0048-9697. ; 286:1-3, s. 129-141
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Tidskriftsartikel (refereegranskat)abstract
- Blood and serum samples from 372 15-year-old adolescents were collected in two cities in Sweden and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The objective was to (1) determine the levels of 13 elements in blood and serum from the teenagers; and (2) for each element, investigate the correlation between the concentrations in blood and serum. The concentrations in blood and serum were generally in line with that usually reported for the essential elements Co, Cu, Zn and Se, and generally low for the 'non-essential' elements Cd, Hg, Pb. The median concentrations were in blood and serum, respectively: of Co 031 and 0.48 mug/l, Cu 0.92 and 1.0 mg/l, Zn 6.1 and 0.99 mg/l, Se 110 and 100 mug/l, Rb 2.8 and 0.24 mg/l, Hg 1.1 and 0.44 mug/l, Pb 16 and 0.33 mug/l. The median concentration of W in blood was < 0.2 mug/l (below the detection limit) and in serum 0.087 mug/l. The median concentrations of Cd, Rh, Pd, Pt and TI were below the detection limits. Statistically significant correlations were found between the concentrations in blood and serum for Co, Cu, Zn, Se, Rb, W, Hg and Pb. The levels presented in this study constitute baseline levels or levels generally not exceeded in adolescents for 13 elements, including essential, ubiquitous toxic, and rare elements.
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| 2. |
- Fatolazadeh, Farzam, et al.
(författare)
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A new approach for generating optimal GLDAS hydrological products and uncertainties
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 730
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Tidskriftsartikel (refereegranskat)abstract
- This study proposes a new approach that can be used to generate the optimal surface state information and associated uncertainties from the estimates provided by the six land surface models used by the Global Land Data Assimilation System (GLDAS). The Förstner and best quadratic unbiased variance component estimators are used simultaneously with the least-squares method to calculate optimal values and the associated uncertainties. To demonstrate the concept, the research focused on three GLDAS hydrological products, namely soil moisture (SM), snow water equivalent (SWE), and canopy water (CAN) over the Canadian Prairies. When the Förstner estimator is applied, the estimated SM and SWE differ from their corresponding mean values by 26 mm and 9 mm respectively. Almost similar result was found with the best quadratic estimator. The estimated maximum uncertainties of each component including SM, SWE and CAN vary from year to year (e.g. 35 mm in 2006, 12 mm in 2007 and 2009 and 0.1 mm in 2001, respectively). The uncertainties of the total water storage (TWS) are almost similar to that of SM, which contributes more importantly to TWS in the area considered. The results obtained by the two proposed estimators were compared to the waterGAP hydrological models (WGHM), and to the Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage anomalies. The optimal SWE anomalies generated from GLDAS using the proposed approach show a maximum correlation of r = 0.97 with the WGHM SWE anomalies. The optimal TWS anomalies have a correlation of r = 0.91 with WGHM, and r = 0.71 with GRACE. However, the correlation jumps to r = 0.81 when GRACE TWS is corrected for groundwater signals (with a mean RMSE of 8.5 mm). The RMSE and mean absolute error between our proposed methods and WGHM and GRACE are better than those obtained with each individual LSM or their average value. No significant mean bias error is observed in each case. Finally, the analysis of the time-lag characteristics of the resonance period between the results and their coherence was done by using a cross wavelet transform and a wavelet coherence analysis.
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