1. |
- Covaci, Adrian, et al.
(författare)
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Urinary BPA measurements in children and mothers from six European member states: Overall results and determinants of exposure.
- 2015
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Ingår i: Environmental Research. - : Elsevier BV. - 1096-0953 .- 0013-9351. ; 141:Oct 13, s. 77-85
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Tidskriftsartikel (refereegranskat)abstract
- For the first time in Europe, both European-wide and country-specific levels of urinary Bisphenol A (BPA) were obtained through a harmonized protocol for participant recruitment, sampling and quality controlled biomarker analysis in the frame of the twin projects COPHES and DEMOCOPHES. 674 child-mother pairs were recruited through schools or population registers from six European member states (Belgium, Denmark, Luxembourg, Slovenia, Spain and Sweden). Children (5-12y) and mothers donated a urine sample. Information on socio-demographic characteristics, life style, dietary habits, and educational level of the parents was provided by mothers. After exclusion of urine samples with creatinine values below 300mg/L or above 3000mg/L, 653 children and 639 mothers remained for which BPA was measured. The geometric mean (with 95% confidence intervals) and 90th percentile were calculated for BPA separately in children and in mothers and were named "European reference values". After adjustment for confounders (age and creatinine), average exposure values in each country were compared with the mean of the "European reference values" by means of a weighted analysis of variance. Overall geometric means of all countries (95% CI) adjusted for urinary creatinine, age and gender were 2.04 (1.87-2.24) µg/L and 1.88 (1.71-2.07) µg/L for children (n=653) and mothers (n=639), respectively. Multiple regression analysis was used to identify significant environmental, geographical, personal or life style related determinants. Consumption of canned food and social class (represented by the highest educational level of the family) were the most important predictors for the urinary levels of BPA in mothers and children. The individual BPA levels in children were significantly correlated with the levels in their mothers (r=0.265, p<0.001), which may suggest a possible common environmental/dietary factor that influences the biomarker level in each pair. Exposure of the general European population was well below the current health-based guidance values and no participant had BPA values higher than the health-based guidance values.
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2. |
- Huber, Jürgen, et al.
(författare)
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Experimental asset markets with endogenous choice of costly asymmetric information
- 2011
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Ingår i: Experimental Economics. - 1386-4157. ; 14:2, s. 223-240
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Tidskriftsartikel (refereegranskat)abstract
- Asymmetric distribution of information, while omnipresent in real markets, is rarely considered in experimental financial markets. We present results from experiments where subjects endogenously choose between five information levels (four of them costly). We find that (i) uninformed traders earn the highest net returns, while average informed traders always perform worst even when information costs are not considered; (ii) over time traders learn to pick the most advantageous information levels (full information or no information); and (iii) market efficiency decreases with higher information costs. These results are mostly in line with the theoretical predictions of Grossman and Stiglitz (Am. Econ. Rev. 70:393–408, 1980) and provide additional insights that studies with only two information levels cannot deliver.
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3. |
- Schindler, Birgit Karin, et al.
(författare)
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The European COPHES/DEMOCOPHES project: Towards transnational comparability and reliability of human biomonitoring results.
- 2014
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Ingår i: International Journal of Hygiene and Environmental Health. - : Elsevier BV. - 1618-131X .- 1438-4639. ; 217:6, s. 653-661
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Tidskriftsartikel (refereegranskat)abstract
- COPHES/DEMOCOPHES has its origins in the European Environment and Health Action Plan of 2004 to "develop a coherent approach on human biomonitoring (HBM) in Europe". Within this twin-project it was targeted to collect specimens from 120 mother-child-pairs in each of the 17 participating European countries. These specimens were investigated for six biomarkers (mercury in hair; creatinine, cotinine, cadmium, phthalate metabolites and bisphenol A in urine). The results for mercury in hair are described in a separate paper. Each participating member state was requested to contract laboratories, for capacity building reasons ideally within its borders, carrying out the chemical analyses. To ensure comparability of analytical data a Quality Assurance Unit (QAU) was established which provided the participating laboratories with standard operating procedures (SOP) and with control material. This material was specially prepared from native, non-spiked, pooled urine samples and was tested for homogeneity and stability. Four external quality assessment exercises were carried out. Highly esteemed laboratories from all over the world served as reference laboratories. Web conferences after each external quality assessment exercise functioned as a new and effective tool to improve analytical performance, to build capacity and to educate less experienced laboratories. Of the 38 laboratories participating in the quality assurance exercises 14 laboratories qualified for cadmium, 14 for creatinine, 9 for cotinine, 7 for phthalate metabolites and 5 for bisphenol A in urine. In the last of the four external quality assessment exercises the laboratories that qualified for DEMOCOPHES performed the determinations in urine with relative standard deviations (low/high concentration) of 18.0/2.1% for cotinine, 14.8/5.1% for cadmium, 4.7/3.4% for creatinine. Relative standard deviations for the newly emerging biomarkers were higher, with values between 13.5 and 20.5% for bisphenol A and between 18.9 and 45.3% for the phthalate metabolites. Plausibility control of the HBM results of all participating countries disclosed analytical shortcomings in the determination of Cd when using certain ICP/MS methods. Results were corrected by reanalyzes. The COPHES/DEMOCOPHES project for the first time succeeded in performing a harmonized pan-European HBM project. All data raised have to be regarded as utmost reliable according to the highest international state of the art, since highly renowned laboratories functioned as reference laboratories. The procedure described here, that has shown its success, can be used as a blueprint for future transnational, multicentre HBM projects.
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