The Experts below are selected from a list of 42903 Experts worldwide ranked by ideXlab platform
Jorg Oehlmann - One of the best experts on this subject based on the ideXlab platform.
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endocrine disruptors in bottled mineral water total estrogenic burden and migration from plastic bottles
2009Co-Authors: Martin Wagner, Jorg OehlmannAbstract:Food consumption is an important route of human Exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by Exposure Modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination. In the present study, we analyzed commercially available mineral water in an in vitro system with the human estrogen receptor alpha and detected estrogenic contamination in 60% of all samples with a maximum activity equivalent to 75.2 ng/l of the natural sex hormone 17β-estradiol. Furthermore, breeding of the molluskan model Potamopyrgus antipodarum in water bottles made of glass and plastic [polyethylene terephthalate (PET)] resulted in an increased reproductive output of snails cultured in PET bottles. This provides first evidence that substances leaching from plastic food packaging materials act as functional estrogens in vivo. Our results demonstrate a widespread contamination of mineral water with xenoestrogens that partly originates from compounds leaching from the plastic packaging material. These substances possess potent estrogenic activity in vivo in a molluskan sentinel. Overall, the results indicate that a broader range of foodstuff may be contaminated with endocrine disruptors when packed in plastics.
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endocrine disruptors in bottled mineral water total estrogenic burden and migration from plastic bottles
2009Co-Authors: Martin Wagner, Jorg OehlmannAbstract:Background, aim, and scope Food consumption is an important route of human Exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by Exposure Modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination.
Martin Wagner - One of the best experts on this subject based on the ideXlab platform.
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endocrine disruptors in bottled mineral water total estrogenic burden and migration from plastic bottles
2009Co-Authors: Martin Wagner, Jorg OehlmannAbstract:Food consumption is an important route of human Exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by Exposure Modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination. In the present study, we analyzed commercially available mineral water in an in vitro system with the human estrogen receptor alpha and detected estrogenic contamination in 60% of all samples with a maximum activity equivalent to 75.2 ng/l of the natural sex hormone 17β-estradiol. Furthermore, breeding of the molluskan model Potamopyrgus antipodarum in water bottles made of glass and plastic [polyethylene terephthalate (PET)] resulted in an increased reproductive output of snails cultured in PET bottles. This provides first evidence that substances leaching from plastic food packaging materials act as functional estrogens in vivo. Our results demonstrate a widespread contamination of mineral water with xenoestrogens that partly originates from compounds leaching from the plastic packaging material. These substances possess potent estrogenic activity in vivo in a molluskan sentinel. Overall, the results indicate that a broader range of foodstuff may be contaminated with endocrine disruptors when packed in plastics.
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endocrine disruptors in bottled mineral water total estrogenic burden and migration from plastic bottles
2009Co-Authors: Martin Wagner, Jorg OehlmannAbstract:Background, aim, and scope Food consumption is an important route of human Exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by Exposure Modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination.
James B Young - One of the best experts on this subject based on the ideXlab platform.
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flexible marginal structural models for estimating the cumulative effect of a time dependent treatment on the hazard reassessing the cardiovascular risks of didanosine treatment in the swiss hiv cohort study
2014Co-Authors: Yongling Xiao, Michal Abrahamowicz, Erica E M Moodie, Rainer Weber, James B YoungAbstract:The association between antiretroviral treatment and cardiovascular disease (CVD) risk in HIV-positive persons has been the subject of much debate since the Data collection on Adverse events of Anti-HIV Drugs (D:A:D) study reported that recent use of two antiretroviral drugs, abacavir (ABC) and didanosine (DDI), was associated with increased risk. We focus on the potential impact of DDI use, as this drug has not been as studied intensively as ABC. We propose a flexible marginal structural Cox model with weighted cumulative Exposure Modeling (Cox WCE MSM) to address two key challenges encountered when using observational longitudinal data to assess the adverse effects of medication: (1) the need to model the cumulative effect of a time-dependent treatment and (2) the need to control for time-dependent confounders that also act as mediators of the effect of past treatment. Simulations confirm that the Cox WCE MSM yields accurate estimates of the causal treatment effect given complex Exposure effects and tim...
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flexible marginal structural models for estimating the cumulative effect of a time dependent treatment on the hazard reassessing the cardiovascular risks of didanosine treatment in the swiss hiv cohort study
2014Co-Authors: Yongling Xiao, Michal Abrahamowicz, Erica E M Moodie, Rainer Weber, James B YoungAbstract:The association between antiretroviral treatment and cardiovascular disease (CVD) risk in HIV-positive persons has been the subject of much debate since the Data collection on Adverse events of Anti-HIV Drugs (D:A:D) study reported that recent use of two antiretroviral drugs, abacavir (ABC) and didanosine (DDI), was associated with increased risk. We focus on the potential impact of DDI use, as this drug has not been as studied intensively as ABC. We propose a flexible marginal structural Cox model with weighted cumulative Exposure Modeling (Cox WCE MSM) to address two key challenges encountered when using observational longitudinal data to assess the adverse effects of medication: (1) the need to model the cumulative effect of a time-dependent treatment and (2) the need to control for time-dependent confounders that also act as mediators of the effect of past treatment. Simulations confirm that the Cox WCE MSM yields accurate estimates of the causal treatment effect given complex Exposure effects and time-dependent confounding. We then use the new flexible Cox WCE MSM to assess the association between DDI use and CVD risk in the Swiss HIV Cohort Study. In contrast to the nonsignificant results obtained with conventional parametric Cox MSMs, our new Cox WCE MSM identifies a significant short-term risk increase due to DDI use in the previous year. Supplementary materials for this article are available online.
Marloes Eeftens - One of the best experts on this subject based on the ideXlab platform.
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air pollution and lung function in dutch children a comparison of Exposure estimates and associations based on land use regression and dispersion Exposure Modeling approaches
2015Co-Authors: Meng Wang, Ulrike Gehring, Gerard Hoek, Menno Keuken, Sander Jonkers, Rob Beelen, Marloes Eeftens, Dirkje S PostmaAbstract:Background: There is limited knowledge about the extent to which estimates of air pollution effects on health are affected by the choice for a specific Exposure model. Objectives: We aimed to evaluate the correlation between long-term air pollution Exposure estimates using two commonly used Exposure Modeling techniques [dispersion and land use regression (LUR) models] and, in addition, to compare the estimates of the association between long-term Exposure to air pollution and lung function in children using these Exposure Modeling techniques. Methods: We used data of 1,058 participants of a Dutch birth cohort study with measured forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) measurements at 8 years of age. For each child, annual average outdoor air pollution Exposure [nitrogen dioxide (NO2), mass concentration of particulate matter with diameters ≤ 2.5 and ≤ 10 μm (PM2.5, PM10), and PM2.5 soot] was estimated for the current addresses of the participants by a dispersion and a LUR model. Associations between Exposures to air pollution and lung function parameters were estimated using linear regression analysis with confounder adjustment. Results: Correlations between LUR- and dispersion-modeled pollution concentrations were high for NO2, PM2.5, and PM2.5 soot (R = 0.86–0.90) but low for PM10 (R = 0.57). Associations with lung function were similar for air pollutant Exposures estimated using LUR and dispersion Modeling, except for associations of PM2.5 with FEV1 and FVC, which were stronger but less precise for Exposures based on LUR compared with dispersion model. Conclusions: Predictions from LUR and dispersion models correlated very well for PM2.5, NO2, and PM2.5 soot but not for PM10. Health effect estimates did not depend on the type of model used to estimate Exposure in a population of Dutch children.
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air pollution and lung function in dutch children a comparison of Exposure estimates and associations based on land use regression and dispersion Exposure Modeling approaches
2015Co-Authors: Meng Wang, Ulrike Gehring, Gerard Hoek, Menno Keuken, Sander Jonkers, Rob Beelen, Marloes Eeftens, Dirkje S PostmaAbstract:BackgroundThere is limited knowledge about the extent to which estimates of air pollution effects on health are affected by the choice for a specific Exposure model.ObjectivesWe aimed to evaluate t...
Paloma I Beamer - One of the best experts on this subject based on the ideXlab platform.
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a meta analysis of children s object to mouth frequency data for estimating non dietary ingestion Exposure
2010Co-Authors: Jianping Xue, Valerie Zartarian, Nicolle S Tulve, Jacqueline Moya, Natalie C G Freeman, Willa Auyeung, Paloma I BeamerAbstract:To improve estimates of non-dietary ingestion in probabilistic Exposure Modeling, a meta-analysis of children's object-to-mouth frequency was conducted using data from seven available studies representing 438 participants and approximately 1500 h of behavior observation. The analysis represents the first comprehensive effort to fit object-to-mouth frequency variability and uncertainty distributions by indoor/outdoor location and by age groups recommended by the US Environmental Protection Agency for assessing childhood Exposures. Weibull distributions best fit the observed data from studies with no statistical differences, and are presented by study, age group, and location. As age increases, both indoor and outdoor object-to-mouth frequencies decrease. Object-to-mouth frequency is significantly greater indoors (2-32 contacts/h) than outdoors (average 1-9 contacts/h). This paper compares results to a similar hand-to-mouth frequency meta-analysis. Children who tend to mouth hands indoors also tend to mouth hands outdoors; children who tend to mouth objects indoors tend to mouth objects outdoors. However, children who tend to mouth objects do not necessarily have a tendency to mouth hands. Unlike for hand-to-mouth frequency, a statistical difference was found among the various studies for object-to-mouth frequency. This could be due to different definitions for object mouthing across the studies considered. The analysis highlights the need for additional object-to-mouth data (indoors and especially outdoors) for various age groups using standardized collection and analysis.
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a meta analysis of children s hand to mouth frequency data for estimating nondietary ingestion Exposure
2007Co-Authors: Jianping Xue, Valerie Zartarian, Nicolle S Tulve, Jacqueline Moya, Natalie C G Freeman, Paloma I Beamer, Kathy Black, Stuart L ShalatAbstract:Because of their mouthing behaviors, children have a higher potential for Exposure to available chemicals through the nondietary ingestion route; thus, frequency of hand-to-mouth activity is an important variable for Exposure assessments. Such data are limited and difficult to collect. Few published studies report such information, and the studies that have been conducted used different data collection approaches (e.g., videography versus real-time observation), data analysis and reporting methods, ages of children, locations, and even definitions of "mouthing." For this article, hand-to-mouth frequency data were gathered from 9 available studies representing 429 subjects and more than 2,000 hours of behavior observation. A meta-analysis was conducted to study differences in hand-to-mouth frequency based on study, age group, gender, and location (indoor vs. outdoor), to fit variability and uncertainty distributions that can be used in probabilistic Exposure assessments, and to identify any data gaps. Results of this analysis indicate that age and location are important for hand-to-mouth frequency, but study and gender are not. As age increases, both indoor and outdoor hand-to-mouth frequencies decrease. Hand-to-mouth behavior is significantly greater indoors than outdoors. For both indoor and outdoor hand-to-mouth frequencies, interpersonal, and intra-personal variability are approximately 60% and approximately 30%, respectively. The variance difference among different studies is much bigger than its mean, indicating that different studies with different methodologies have similar central values. Weibull distributions best fit the observed data for the different variables considered and are presented in this article by study, age group, and location. Average indoor hand-to-mouth behavior ranged from 6.7 to 28.0 contacts/hour, with the lowest value corresponding to the 6 to <11 year olds and the highest value corresponding to the 3 to <6 month olds. Average outdoor hand-to-mouth frequency ranged from 2.9 to 14.5 contacts/hour, with the lowest value corresponding to the 6 to <11 year olds and the highest value corresponding to the 6 to <12 month olds. The analysis highlights the need for additional hand-to-mouth data for the <3 months, 3 to <6 months, and 3 to <6 year age groups using standardized collection and analysis because of lack of data or high uncertainty in available data. This is the first publication to report Weibull distributions as the best fitting distribution for hand-to-mouth frequency; using the best fitting Exposure factor distribution will help improve estimates of Exposure. The analyses also represent a first comprehensive effort to fit hand-to-mouth frequency variability and uncertainty distributions by indoor/outdoor location and by age groups, using the new standard set of age groups recommended by the U.S. Environmental Protection Agency for assessing childhood Exposures. Thus, the data presented in this article can be used to update the U.S. EPA's Child-Specific Exposure Factors Handbook and to improve estimates of nondietary ingestion in probabilistic Exposure Modeling.
