| 1. |
- Lindh, Christian, et al.
(författare)
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Blood serum concentrations of perfluorinated compounds in men from Greenlandic Inuit and European populations.
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 88:11, s. 1269-1275
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Tidskriftsartikel (refereegranskat)abstract
- Perfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are used in large quantities. They are persistent and found in measurable levels in human serum around the world. They have been associated with developmental, hepatic, and carcinogenic effects in animal studies. The aim of the present study was to describe levels of PFCs in serum among Inuits from Greenland and inhabitants from Warsaw, Poland and Kharkiv, Ukraine. Furthermore, the aim was to define social- and lifestyle related determinants of exposure for these compounds. Serum levels of seven PFCs were analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The concentrations of PFOS and PFOA were the highest of all PFCs in all three populations with a total amount of almost 90% of the PFCs. The mean levels of PFOS and PFOA were in the Greenlandic Inuits 52 and 4.8ngmL(-1), in Poland 19 and 5.2ngmL(-1), and in Ukraine 8.1 and 1.9ngmL(-1), respectively. Thus, levels of PFCs in the serum of Inuits on Greenland were among the highest described in a general population whereas the levels in Poland were similar to other industrialized countries. The exposure in Ukraine was rather low. In the Greenlandic Inuit population, intake of seafood, tea, age and area of living were significant determinants of PFOS concentrations and explained about 22% of the variation. For the other populations no strong determinants were found.
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| 2. |
- Norén, Erika, et al.
(författare)
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Temporal trends, 2000–2017, of perfluoroalkyl acid (PFAA) concentrations in serum of Swedish adolescents
- 2021
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 155
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Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluoroalkyl substances (PFAS) have been extensively used as surfactants because of their high stability and good water/oil-repellent properties. PFASs, especially perfluoroalkyl acids (PFAAs), have long biological half-lives, and exposure may cause adverse health effects in humans. We assessed temporal trends of concentrations of eight PFAAs in serum of Swedish adolescents (age 16–21 years) from the general population, and estimated the stability of PFAAs and serum samples after 6 years of storage. Repeated cross-sectional sampling was performed on five occasions (covering in total 1213 individuals, 83% males) in southern Sweden between 2000 and 2017. We analyzed serum for perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), and perfluorododecanoic acid (PFDoDA) using liquid chromatography-tandem mass spectrometry. We assessed time trends using linear regression, long-term stability was assessed by reanalyzing samples collected 2013, and the comparison was done using Pearson correlation and Bland-Altman plots. PFHxS, PFOS, and PFOA decreased by 6.7% (CI: –7.0, –6.3%), 12.6% (CI: –12.9, –12.3%), and 6.5% (CI: –6.8, –6.1%) per year, respectively, and year of sampling explained 48–81% of the variation in concentrations. PFNA and PFDA seemed to increase up to 2009 and decrease thereafter. The trends were consistent after sensitivity analyses excluding women. Strong correlations of 94–97% were observed for concentrations of all compounds, except PFHxS, after storage. The observed trends closely followed the timing of manufacturers’ voluntary phase-out initiatives, and of regulatory measures governing the compounds implemented in the EU and USA. This indicates that these actions mitigated the population's exposure to PFHxS, PFOS, and PFOA and, in recent years, to PFNA and PFDA, in southern Sweden. Furthermore, the results suggest that PFAAs remain stable in serum samples after long-term storage.
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| 3. |
- Ode, Amanda, et al.
(författare)
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Determinants of maternal and fetal exposure and temporal trends of perfluorinated compounds.
- 2013
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 1614-7499 .- 0944-1344. ; 20:11, s. 7970-7978
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, some perfluorinated compounds (PFCs) have been identified as potentially hazardous substances which are harmful to the environment and human health. According to limited data, PFC levels in humans could be influenced by several determinants. However, the findings are inconsistent. In the present study, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were measured in paired maternal and cord serum samples (N = 237) collected between 1978 and 2001 in Southern Sweden to study the relationship between these and to investigate several potential determinants of maternal and fetal exposure to PFCs. Time trends of PFCs in Swedish women were also evaluated. The study is a part of the Fetal Environment and Neurodevelopment Disorders in Epidemiological Research project. PFOS, PFOA, and PFNA levels (median) were higher in maternal serum (15, 2.1, and 0.24 ng/ml, respectively) than in cord serum (6.5, 1.7, and 0.20 ng/ml, respectively). PFC levels were among the highest in women originating from the Nordic countries and the lowest in women from the Middle East, North Africa, and sub-Saharan Africa. Multiparous women had lower serum PFOA levels (1.7 ng/ml) than primiparous women (2.4 ng/ml). Maternal age, body mass index, cotinine levels, and whether women carried male or female fetuses did not affect serum PFC concentrations. Umbilical cord serum PFC concentrations showed roughly similar patterns as the maternal except for the gestational age where PFC levels increased with advancing gestational age. PFOS levels increased during the study period in native Swedish women. In summary, PFOS levels tend to increase while PFOA and PFNA levels were unchanged between 1978 and 2001 in our study population. Our results demonstrate that maternal country of origin, parity, and gestational age might be associated with PFC exposure.
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| 4. |
- Rylander, Lars, et al.
(författare)
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Tidstrender av PFAS-nivåer i serum hos gravida kvinnor
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Högfluorerade ämnen, eller per- och polyfluorerade alkylsyror (PFAS) är mycket stabila ämnen som pga av sina vatten- och fettavvisande egenskaper har många användningsområden. Syftet med den aktuella studien var att studera tidstrender av PFAS under perioden 1995-2014 hos gravida kvinnor.Studien inkluderade 1208 kvinnor i södra Sverige från vilka serumprover samlades in i tidig graviditet. I serumproverna analyserades koncentrationen av fyra olika PFAS, nämligen PFOS (perfluoroktansulfonat), PFOA (perfluoroktansyra), PFNA (perfluornonansyra) och PFHxS (perfluorhexasulfonat).De högsta koncentrationerna och den största minskningen (ca 9% per kalenderår) över tid observerades för PFOS där ca 33% av variationen förklarades av kalenderår. Även PFOA och PFHxS minskade (2,3-3,5% per kalenderår) under studieperioden medan PFNA ökade.Sammanfattningsvis visar studien klara minskningar över tiden av vissa PFAS, men ämnena har lång halveringstid i människa vilket innebär att halterna minskar långsamt och kommer att finnas kvar i kroppen under lång tid. Dessutom är ämnena stabila ute i naturen så människorna kommer fortsatt att exponeras för dem. Vidare är det så att vissa PFAS har förbjudits såsom PFOS vilket fått till följd att nya ämnen som PFNA vilka ersatt dessa ökade under studieperioden.
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| 5. |
- Rylander, Lars, et al.
(författare)
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Very high correlations between fresh weight and lipid-adjusted PCB-153 serum concentrations: Irrespective of fasting status, age, body mass index, gender, or exposure distributions.
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 88:7, s. 828-831
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIM: Persistent organochlorine pollutants (POPs) have in epidemiological studies been associated with health hazards. The exposure window might be crucial and it is, accordingly, important to analyze exposure concentrations in samples collected at the window of interest. This makes the use of stored blood samples extremely interesting. However, small blood volumes from stored samples in biobanks means that the researchers in epidemiological studies most often have to select a limited number of biomarkers representing the POP exposure and abstain from analyses of lipid concentrations. This raises the question of the necessity of lipid adjustment. The aim of the present study was to evaluate the correlation between fresh weight and lipid adjusted concentrations. METHODS: We included data from studies were we have used the PCB congener 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) as a biomarker for POP exposure and where fresh weight as well as lipid adjusted PCB-153 concentrations are known (n=1628). The variety of the cohort members in the different studies gave us the possibility to better understand how well these measures correlate. RESULTS: When all individuals were included in the analyses a correlation coefficient of 0.95 between fresh weight and lipid adjusted serum concentrations was obtained. Restricting the analyses to specific subgroups (based on gender, fasting status, age and BMI) gave correlation coefficients between 0.85 and 0.97. CONCLUSIONS: This study does strongly support the use of samples from biobanks in epidemiological studies for analyzing PCBs, at least regarding PCB-153, even though it is not possible to lipid adjust the results.
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| 6. |
- Winges, Johan, 1987, et al.
(författare)
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Multi-objective optimization of wireless power transfer systems with magnetically coupled resonators and nonlinear loads
- 2019
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Ingår i: Progress in Electromagnetics Research B. - 1937-6472. ; 83:2019, s. 25-42
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 Progress In Electromagnetics Research B. We present an optimization procedure for wireless power transfer (WPT) applications and test it numerically for a WPT system design with four resonant circuits that are magnetically coupled by coaxial coils in air, where the magnetic field problem is represented by a fully populated inductance matrix that includes all magnetic interactions that occur between the coils. The magnetically coupled resonators are fed by a square-wave voltage generator and loaded by a rectifier followed by a smoothing filter and a battery. We compute Pareto fronts associated with a multi-objective optimization problem that contrasts: 1) the system efficiency; and 2) the power delivered to the battery. The optimization problem is constrained in terms of: 1) the physical construction of the system and its components; 2) the root-mean-square values of the currents and voltages in the circuit; and 3) bounds on the overtones of the currents in the coils in order assure that the WPT system mainly generates magnetic fields at the operating frequency. We present optimized results for transfer distances from 0.8 to 1.6 times the largest coil radius with a maximum power transfer from 4 kW to 9 kW at 85 kHz, which is achieved at an efficiency larger than 90%.
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