Person: Kämpfe, Alexander David
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1984
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Kämpfe
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Alexander David
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Veröffentlichung Effects of Zinc Oxide Nanoparticles on model systems of the intestinal barrier(2022) Mittag, Anna; Höra, Christian; Owesny, Patricia; Kämpfe, Alexander DavidZinc oxide nanoparticles (ZnO NP) are often used in the food sector, among others, because of their advantageous properties. As part of the human food chain, they are inevitably taken up orally. The debate on the toxicity of orally ingested ZnO NP continues due to incomplete data. Therefore, the aim of our study was to examine the effects of two differently sized ZnO NP (<50 nm and <100 nm primary particle size; 123â€Ì614 mikromol/L) on two model systems of the intestinal barrier. Differentiated Caco-2 enterocytes were grown on Transwell inserts in monoculture and also in coculture with the mucus-producing goblet cell line HT29-MTX. Although no comprehensive mucus layer was detectable in the coculture, cellular zinc uptake was clearly lower after a 24-h treatment with ZnO NP than in monocultured cells. ZnO NP showed no influence on the permeability, metabolic activity, cytoskeleton and cell nuclei. The transepithelial electrical resistance was significantly increased in the coculture model after treatment with _307 _mol/L ZnO NP. Only small zinc amounts (0.07â€Ì0.65 mikrog/mL) reached the basolateral area. Our results reveal that the cells of an intact intestinal barrier interact with ZnO NP but do not suffer serious damage. Quelle: ArtikelVeröffentlichung Release of antioxidants and their degradation products from materials in contact with drinking water(2023) Berger, Sabrina; Kalweit, Cynthia; Kämpfe, Alexander David; Rapp, ThomasVeröffentlichung Lead, cadmium, mercury, and chromium in urine and blood of children and adolescents in Germany - Human biomonitoring results of the German Environmental Survey 2014-2017 (GerES V)(2021) Doyle, Ulrike; Höra, Christian; Kämpfe, Alexander David; Kolossa-Gehring, Marike; Murawski, Aline; Rucic, Enrico; Schmied-Tobies, Maria Irene Hilde; Vogel, NinaMetals reach humans through food and drinking water intake and inhalation of airborne particles and can have detrimental health effects in particular for children. The metals presented here (lead, cadmium, chromium, and mercury) could lead to toxic effects such as neurotoxicity, mutagenicity, and have been classified as (possible) carcinogens. Using population representative data from the German Environmental Survey 2014-2017 (GerES V) from 3- to 17-year-old children on lead and cadmium in blood (n = 720) and on cadmium, chromium, and mercury in urine (n = 2250) we describe current internal exposure levels, and socio-demographic and substance-specific exposure determinants. Average internal exposure (geometric means) in blood was 9.47 (micro)g/L for lead and below 0.06 (micro)g/L (limit of quantification) for cadmium, and in urine 0.072 (micro)g/L for cadmium, 0.067 (micro)g/L for mercury, and 0.393 (micro)g/L for chromium, respectively. Younger children have higher concentrations of lead and chromium compared to 14-17-year-old adolescents, and boys have slightly higher mercury concentrations than girls. With respect to substance specific determinants, higher lead concentrations emerged in participants with domestic fuel and in non-smoking children with smokers in the household, higher levels of cadmium were associated with smoking and vegetarian diet and higher levels of mercury with the consumption of seafood and amalgam teeth fillings. No specific exposure determinants emerged for chromium. The health based guidance value HBM-I was not exceeded for mercury and for cadmium in urine it was exceeded by 0.6% of the study population. None of the exceedances was related to substantial tobacco smoke exposure. Comparisons to previous GerES cycles (GerES II, 1990-1992; GerES IV, 2003-2006) indicate continuously lower levels. © 2021 Elsevier GmbHVeröffentlichung Screening for 26 per- and polyfluoroalkyl substances (PFAS) in German drinking waters with support of residents(2023) Ingold, Vanessa; Kämpfe, Alexander David; Ruhl, Aki SebastianThe occurrence of per- and polyfluoroalkyl substances (PFAS) in water cycles poses a challenge to drinking water quality and safety. In order to counteract the large knowledge gap regarding PFAS in German drinking water, 89 drinking water samples from all over Germany were collected with the help of residents and were analyzed for 26 PFAS by high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The 20 PFAS recently regulated by sum concentration (PFASâ Ì20), as well as six other PFAS, were quantified by targeted analysis. In all drinking water samples, PFASâ Ì20 was below the limit of 0.1 ÎÌg/L, but the sum concentrations ranged widely from below the limit of quantification up to 80.2 ng/L. The sum concentrations (PFASâ Ì4) of perfluorohexanesulfonate (PFHxS), perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorononanoate of 20 ng/L were exceeded in two samples. The most frequently detected individual substances were PFOS (in 52% of the samples), perfluorobutanesulfonate (52%), perfluorohexanoate (PFHxA) (44%), perfluoropentanoate (43%) and PFHxS (35%). The highest single concentrations were 23.5 ng/L for PFHxS, 15.3 ng/L for PFOS, and 10.1 ng/L for PFHxA. No regionally elevated concentrations were identified, but some highly urbanized areas showed elevated levels. Concentrations of substitution PFAS, including 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate and 2,2,3-trifluor-3-[1,1,2,2,3,3-hexafluor-3-(trifluormethoxy)propoxy]-propanoate (anion of ADONA), were very low compared to regulated PFAS. The most frequently detected PFAS were examined for co-occurrences, but no definite correlations could be found. © 2023 The Author(s)Veröffentlichung Quantification and stability assessment of 7,9-di.tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione leaching from cross-linked polyethylene pipes using gas and liquid chromatography(2023) Berger, Sabrina; Kalweit, Cynthia; Kämpfe, Alexander David; Rapp, ThomasThis study assesses the formation and stability of the water contaminant 7,9-di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione ([1]) which repeatedly occurs in the migration waters of cross-linked polyethylene (PE-X) pipes. In aqueous solution [1] is partially transformed to 3-(3,5-di-tert-butyl-1-hydroxy-4-oxo-2,5-cyclohexadien-1-yl)propionic acid ([2]). For a better understanding of the formation of [1] and its transformation into [2] an analytical method was established to allow the analysis of both species separately. Because of thermal instability [2] cannot be detected with GC-MS. Therefore, two methods were validated for a reliable and reproducible quantification: GC-MS for [1] and HPLC-MS/MS for both [1] and [2]. Comparative measurements of migration waters from PE-X pipes using GC-MS and HPLC-MS/MS methods showed that the concentrations of [1] detected with GC-MS corresponds to the sum of [1] and [2] measured with HPLC-MS/MS. In the migration waters [1] was detected in higher concentrations than [2]. The highest concentrations of [1], detected with GC-MS, were > 300 (micro)g/L. The longer the materials are stored without contact with water, the more [1] is measured in the migration waters. Most of the previous values reported in the literature for [1] were based on semi-quantification. Hence, we compared results of the semi-quantitative determination according to EN 15768 with those of a quantitative method with a standard. The results gained with the semi-quantitative method represent less than 50% of the quantified values for the amount leaching from the pipes, which means that the semi-quantification method according to EN 15768 leads to a significant underestimation of [1]. Finally, stability assessment showed that [1] developed an equilibrium with [2] under acidic conditions, whereas it will completely be transferred to [2] at pH 10. At pH 7, it takes more than 50 days for [1] to reach an equilibrium with [2]. However, at increasing the temperature to 60 ËÌC, [1] will be rapidly transformed into [2]. Besides [1] and [2], other currently unknown degradation products are formed. As there is no comprehensive toxicological assessment for both substances available today, our findings underline the need for regulatory consequences. © 2023 Elsevier Ltd. All rights reserved.Veröffentlichung The role of dietary factors on blood lead concentration in children and adolescents - Results from the nationally representative German Environmental Survey 2014-2017 (GerES V)(2022) Hahn, Domenica; Höra, Christian; Kämpfe, Alexander David; Kolossa-Gehring, Marike; Schmied-Tobies, Maria Irene Hilde; Vogel, NinaIn industrialized nations, human lead exposure has decreased significantly in recent decades. Nevertheless, due to its toxic effects, this heavy metal remains a public health concern with children and adolescents being particularly at risk. In Europe nowadays, oral intake via food and drinking water is the predominant exposure pathway for lead. The objective of the present study was to investigate the association between dietary factors and blood lead (PbB) level of 3- to 17-year-old children and adolescents living in Germany, using data from the fifth German Environmental Health Survey (GerES V) and the Child and Adolescent Health Survey (KiGGS Wave 2). GerES V and KiGGS Wave 2 are two national population-representative studies conducted between 2014 and 2017, including measurement of lead concentrations in blood from 720 children and adolescents aged 3-17 years (mean age = 10.21, SD age = 4.36). Using multiple linear regression, sociodemographic and environmental characteristics as well as dietary factors could be identified as significant exposure determinants of PbB concentrations. Lead intake via domestic tap water was the strongest predictor of elevated PbB levels with 27.6% (p-value< .001) higher concentrations of highest compared to none lead intake via tap water. Other foods which were found to be relevant to PbB levels were meat, fruit, and fruit juice. While meat or fruit consumption were each associated with about 13% (p-value < .05) lower PbB levels, fruit juice drinking was associated with up to 12.2% (p-value = .04) higher PbB levels. In conclusion, results indicate the importance of dietary habits for lead exposure in children and adolescents. To protect vulnerable groups, it is recommended that future research and lead-reducing measures pay more attention to dietary links. © 2022 The Authors.Veröffentlichung Nebenprodukte der Desinfektion(2018) Kämpfe, Alexander DavidVeröffentlichung Brom - eine Entmystifizierung(2020) Kämpfe, Alexander DavidVeröffentlichung Bromat im Trinkwasser: Herkunft, Vorkommen und gesundheitliche Bewertung(2021) Chorus, Ingrid; El-Athman, Fatima; Kämpfe, Alexander David; Mahringer, DanielVeröffentlichung Wann ist ein Brunnen ein Nassspielplatz?(2019) Förster, Christina; Beutel, Thomas; Kämpfe, Alexander David