| 61. |
- Gustafsson, Asa, et al.
(författare)
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Isolation and characterization of a respirable particle fraction from residential house-dust
- 2018
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Ingår i: Environmental Research. - : Academic Press Inc Elsevier Science. - 0013-9351 .- 1096-0953. ; 161, s. 284-290
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Tidskriftsartikel (refereegranskat)abstract
- Indoor air pollution has caused increasing concern in recent years. As we spend most of our lives indoors, it is crucial to understand the health effects caused by indoor air pollution. Household dust serve as good proxy for accessing indoor air pollution, especially smaller dust particles that can pass into the lungs are of interest. In this study we present an efficient method for the isolation of dust particles in the respirable size range. The respirable fraction was recovered from vacuum cleaner bags, separated by stepwise sieving, followed by characterization for size, morphology, surface area, organic content and elemental composition. The respirable fraction was obtained in a yield of 0.6% with a specific surface area of 2.5 m(2)/g and a Mass Median Aerodynamic Diameter of 3.73 +/- 0.15 mu m. Aluminum and zink were the dominating metals measured in the dust, whereas the major mineral components were found to be silicon dioxide and calcium carbonate. The fraction of organic matter in the dust was measured to be 69 +/- 1%. The organic matrix contained bacterial and fungi and a presence of skin fragments. We present here an efficient and fast method for the isolation of dust particles in the respirable size range. That is of considerable value due to the need for large quantities of respirable particle fractions to conduct toxicological studies and risk assessment work.
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| 62. |
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| 63. |
- Gyllenhammar, Irina, et al.
(författare)
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Concentrations of cadmium, cobalt, chromium, manganese, nickel, and iodine in urine from first-time mothers in Uppsala, Sweden: temporal trends 2009-2020
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sedan 1996 samlas blod- och modersmjölksprover regelbundet in från förstföderskor i Uppsala i den så kallade POPUP-studien. Sedan 2009 tas också ett urinprov. I denna rapport har tidstrender för kadmium, kobolt, krom, mangan, nickel och jod studerats i urinprov (n=371) insamlade mellan 2009 och 2020. Resultaten visade inte någon trend för kadmium vilket stämmer överens med andra studier. För nickel och krom sågs en nedåtgående trend med i medeltal 8,8 respektive 3,5 % per år. Kadmiumhalterna i denna studie var på samma nivå som hos medelålders svenska kvinnor (50-59 år) och något högre än i andra studier från Sverige på gravida kvinnor och kvinnor i åldern 19-39 år. Totalt 25 av de 371 mammorna (7%) hade halter över 0.5 μg/g kreatinin, vilket är den nivå som anses kunna öka risken för påverkan på skelettet. Alla deltagare i studien hade precis genomgått en graviditet vilket kan påverka resultaten, t ex är det vanligt med låga järnnivåer under graviditet som i sin tur kan öka upptaget av kadmium.Kadmium-halter i urin från rökare och före-detta rökare var högre jämfört med kvinnor som uppgett att de inte var rökare. Detta resultat stämmer väl med andra studier. Halter av kadmium, kobolt och jod var högre bland vegetarianer, alltså kvinnor som uppgett att de inte äter animaliskt kött, jämfört med kvinnor som äter kött. Högre halter av kadmium och kobolt kan bero på låg järnstatus och som är vanligare hos vegetarianer.
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| 64. |
- Harari, Raul, et al.
(författare)
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Exposure and toxic effects of elemental mercury in gold-mining activities in Ecuador
- 2012
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Ingår i: Toxicology Letters. - : Elsevier BV. - 1879-3169 .- 0378-4274. ; 213:1, s. 75-82
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Tidskriftsartikel (refereegranskat)abstract
- Traditional gold mining, using metallic mercury (Hg-0) to form gold amalgam, followed by burning to remove the Hg-0, is widely used in South America, Africa and Asia. The gold is sold to merchants who burn it again to eliminate remaining Hg-0. In Ecuador, 200 gold miners, 37 gold merchants and 72 referents were studied. The median Hg concentrations in urine (U-Hg) were 3.3 (range 0.23-170), 37 (3.2-420), and 1.6 (0.2-13) mu g/g creatinine, respectively, and in whole blood (B-Hg) were 5.2, 30, and 5.0 mu g/L, respectively. Biomarker concentrations among merchants were statistically significantly higher than among miners and referents; also the miners differed from the referents. Burning of gold amalgam among miners was intermittent; U-Hg decreased in the burning-free period. In computerized neuromotor examinations, B-Hg and U-Hg concentrations were associated with increases in the centre frequency of the tremor, as well as in reaction time and postural stability. Retention of Hg (B-Hg), and the elimination rate (U-Hg) appears to be modified by polymorphism in a gene of an enzyme in the glutathione synthesis (GCLM), but there were no significant genetic modifications for the associations between exposure and neurotoxicity. Thus, the gold merchants have a much higher exposure and risk than the miners, in whom the exposure varies over time. The metabolism of Hg is modified by genetic traits. The present exposure to Hg had limited neurotoxic effects. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
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| 65. |
- Hoac, Tien, et al.
(författare)
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Separation of Selenium, Zinc, and Copper Compounds in Bovine Whey Using Size Exclusion Chromatography Linked to Inductively Coupled Plasma Mass Spectrometry.
- 2007
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 55:10, s. 4237-4243
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Tidskriftsartikel (refereegranskat)abstract
- To study the role of trace elements for the quality and nutritional value of bovine milk, the distribution of selenium, zinc, and copper in whey was investigated using a method linking size exclusion chromatography to inductively coupled plasma mass spectrometry (SEC-ICP-MS). Three major peaks were detected for selenium, two peaks for zinc, and five peaks for copper. More than 65% of the selenium was found in protein fractions, mainly in fractions coinciding with the major whey proteins beta-lactoglobulin and alpha-lactalbumin. All zinc was associated with low molecular weight compounds (< 5 kDa) and one of these compounds was probably citrate. More than 60% of the copper eluted in protein fractions and two of the five major peaks probably contained metallothionein and citrate. This method was used to compare milk and whey produced by organic and conventional feeding procedures. The selenium content in whey and desalted milk produced using organic regimens was significantly lower than that in conventional samples. Moreover, the proportion of selenium in protein fractions of organic whey was significantly smaller than that in conventional whey, but the distributions of zinc and copper did not differ. This study showed that with the SEC-ICP-MS technique the distribution profiles of several trace elements in whey could be studied in the same run and that the selenium profile differed in whey produced by organic and conventional procedures.
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| 66. |
- Hoac, Tien, et al.
(författare)
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Short-term effects of selenium supplementation of cows' feed on the content and distribution of selenium, copper and zinc in bovine milk, whey and blood plasma.
- 2008
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Ingår i: Journal of Dairy Research. - 0022-0299. ; 75:3, s. 326-334
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Tidskriftsartikel (refereegranskat)abstract
- The effect of selenium supplementation of feed on the Se content in bovine milk, whey and plasma, and on the distribution of Se, Zn and Cu in whey and plasma was investigated. In a cross-over study two groups of cows were given a basal feed with 0.16 ppm selenite (approx. 3 mg Se/d) with or without 25 mg yeast Se/d for 2 weeks. In the supplemented group the Se content increased 10-fold in milk, 10-fold in whey and 2-fold in plasma, and after the cessation of the supplementation, selenium in milk decreased with a calculated half-life of 3.5 d. In another experiment, two groups of cows were given either 100 mg yeast Se/d for 1 week or only the basal feed. The increase in Se content in both whole and defatted milk was 40-50-fold, and in whey it was approx. 20-fold. Size-exclusion chromatography of whey using inductively coupled plasma mass spectrometry for detection showed that supplementation increased the proportion of Se in the beta-lactoglobulin-alpha-lactalbumin fraction. Distribution of Cu and Zn was essentially unaffected. In plasma, supplementation increased the Se content in all major Se fractions like selenoprotein P, albumin and low-molecular-weight compounds, but the distribution profiles of Zn and Cu underwent no major changes. The study showed for the first time the rapid kinetics of the Se increase and decrease in milk after the initiation and cessation of supplementation, respectively, and the preferential appearance of Se in the beta-lactoglobulin-alpha-lactalbumin fraction of whey. Milk highly enriched in selenium will be a useful tool for different research purposes.
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| 67. |
- Hrubá, Františka, et al.
(författare)
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A regional comparison of children's blood cadmium, lead, and mercury in rural, urban and industrial areas of six European countries, and China, Ecuador, and Morocco
- 2023
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Ingår i: International Journal of Occupational Medicine and Environmental Health. - Poland : Nofer Institute of Occupational Medicine. - 1232-1087 .- 1896-494X .- 2008-6520. ; 36:3, s. 349-364
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The authors aimed to evaluate whether blood cadmium (B-Cd), lead (B-Pb) and mercury (B-Hg) in children differ regionally in 9 countries, and to identify factors correlating with exposure.MATERIAL AND METHODS: The authors performed a cross-sectional study of children aged 7-14 years, living in 2007-2008 in urban, rural, or potentially polluted ("hot spot") areas (ca. 50 children from each area, in total 1363 children) in 6 European and 3 non-European countries. The authors analyzed Cd, Pb, and total Hg in blood and collected information on potential determinants of exposure through questionnaires. Regional differences in exposure levels were assessed within each country.RESULTS: Children living near industrial "hot-spots" had B-Cd 1.6 (95% CI: 1.4-1.9) times higher in the Czech Republic and 2.1 (95% CI:1.6-2.8) times higher in Poland, as compared to urban children in the same countries (geometric means [GM]: 0.13 μg/l and 0.15 μg/l, respectively). Correspondingly, B-Pb in the "hot spot" areas was 1.8 (95% CI: 1.6-2.1) times higher than in urban areas in Slovakia and 2.3 (95% CI: 1.9-2.7) times higher in Poland (urban GM: 19.4 μg/l and 16.3 μg/l, respectively). In China and Morocco, rural children had significantly lower B-Pb than urban ones (urban GM: 64 μg/l and 71 μg/l, respectively), suggesting urban exposure from leaded petrol, water pipes and/or coal-burning. Hg "hot spot" areas in China had B-Hg 3.1 (95% CI: 2.7-3.5) times higher, and Ecuador 1.5 (95% CI: 1.2-1.9) times higher, as compared to urban areas (urban GM: 2.45 μg/l and 3.23 μg/l, respectively). Besides industrial exposure, traffic correlated with B-Cd; male sex, environmental tobacco smoke, and offal consumption with B-Pb; and fish consumption and amalgam fillings with B-Hg. However, these correlations could only marginally explain regional differences.CONCLUSIONS: These mainly European results indicate that some children experience about doubled exposures to toxic elements just because of where they live. These exposures are unsafe, identifiable, and preventable and therefore call for preventive actions.
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| 68. |
- Hruba, Frantiska, et al.
(författare)
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Blood cadmium, mercury, and lead in children : An international comparison of cities in six European countries, and China, Ecuador, and Morocco
- 2012
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Ingår i: Environment International. - Oxford : Elsevier. - 0160-4120 .- 1873-6750. ; 41, s. 29-34
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Tidskriftsartikel (refereegranskat)abstract
- Children's blood-lead concentration (B-Pb) is well studied, but little is known about cadmium (B-Cd) and mercury (B-Hg), in particular for central Europe. Such information is necessary for risk assessment and management. Therefore, we here describe and compare B-Pb, B-Cd and B-Hg in children in six European, and three non-European cities, and identify determinants of these exposures. About 50 school children (7-14 years) from each city were recruited (totally 433) in 2007-2008. Interview and questionnaire data were obtained. A blood sample was analyzed: only two laboratories with strict quality control were used. The European cities showed only minor differences for B-Cd (geometric means 0.11-0.17 mu g/L) and B-Pb (14-20 mu g/L), but larger for B-Hg (0.12-0.94 mu g/L). Corresponding means for the non-European countries were 0.21-0.26, 32-71, and 0.3-3.2 mu g/L, respectively. For B-Cd in European samples, traffic intensity close to home was a statistically significant determinant, for B-Hg fish consumption and amalgam fillings, and for B-Pb sex (boys higher). This study shows that European city children's B-Cd and B-Pb vary only little between countries; B-Hg differs considerably, due to varying tooth restoration practices and fish intake. Traffic intensity seemed to be a determinant for B-Cd. The metal concentrations were low from a risk perspective but the chosen non-European cities showed higher concentrations than the cities in Europe. (C) 2011 Elsevier Ltd. All rights reserved.
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| 69. |
- Hussein, A. E., et al.
(författare)
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Laser-wakefield accelerators for high-resolution X-ray imaging of complex microstructures
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Laser-wakefield accelerators (LWFAs) are high acceleration-gradient plasma-based particle accelerators capable of producing ultra-relativistic electron beams. Within the strong focusing fields of the wakefield, accelerated electrons undergo betatron oscillations, emitting a bright pulse of X-rays with a micrometer-scale source size that may be used for imaging applications. Non-destructive X-ray phase contrast imaging and tomography of heterogeneous materials can provide insight into their processing, structure, and performance. To demonstrate the imaging capability of X-rays from an LWFA we have examined an irregular eutectic in the aluminum-silicon (Al-Si) system. The lamellar spacing of the Al-Si eutectic microstructure is on the order of a few micrometers, thus requiring high spatial resolution. We present comparisons between the sharpness and spatial resolution in phase contrast images of this eutectic alloy obtained via X-ray phase contrast imaging at the Swiss Light Source (SLS) synchrotron and X-ray projection microscopy via an LWFA source. An upper bound on the resolving power of 2.7 ± 0.3 μm of the LWFA source in this experiment was measured. These results indicate that betatron X-rays from laser wakefield acceleration can provide an alternative to conventional synchrotron sources for high resolution imaging of eutectics and, more broadly, complex microstructures.
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| 70. |
- Jiang, Zheshun, et al.
(författare)
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Circulating lung-cancer-related non-coding RNAs are associated with occupational exposure to hexavalent chromium - A cross-sectional study within the SafeChrom project
- 2024
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Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 190
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hexavalent chromium (Cr(VI)) is classified as a group 1 human carcinogen and increases the risk of lung cancer. Non-coding RNAs (ncRNAs) have key regulatory roles in lung cancer, but less is known about their relation to Cr(VI) exposure.Objectives: We aimed to 1) measure the expression of lung cancer-related circulating ncRNAs in exposed workers and controls; 2) assess associations between ncRNAs expression and Cr concentrations in red blood cells (RBC) and urine; and 3) evaluate correlations between the ncRNAs.Methods: The study included 111 Cr(VI) exposed workers and 72 controls recruited from the SafeChrom project. Cr concentrations were measured in RBC (biomarker of long-term exposure) and urine (biomarker of short-term exposure) samples. Long ncRNA (lncRNA) and microRNA (miRNA) were extracted from plasma followed by deoxyribonuclease treatment, complementary DNA synthesis, and quantitative real-time polymerase chain reaction using target-specific assays for three lncRNAs (H19, MALAT1, NORAD), and four miRNAs (miR-142-3p, miR-15b-5p, miR-3940-5p, miR-451a).Results: Expression levels of lncRNAs MALAT1 and NORAD, and all four miRNAs, were significantly lower in Cr (VI) exposed workers compared with controls, and correlated significantly with RBC-Cr concentrations (rS = -0.16 to -0.38). H19 was non-significantly increased in exposed workers but significantly correlated with miR142-3p (rS = -0.33) and miR-15b-5p (rS = -0.30), and NORAD was significantly positively correlated with all four miRNAs (rS = 0.17 to 0.46). In multivariate regression models adjusting for confounders, expressions of lncRNAs MALAT1 and NORAD and all miRNAs were still significantly lower in the exposed group compared with controls, and the expression decreased with increasing RBC-Cr concentrations. Conclusions: Cr(VI) exposure was inversely and in a dose-response manner associated with the expression of circulating non-coding RNA, which suggests ncRNAs as potential biomarkers for Cr(VI)-induced toxicity.
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