235 research outputs found
NO2 and PM2.5 Exposures and Lung Function in Swiss Adults: Estimated Effects of Short-Term Exposures and Long-Term Exposures with and without Adjustment for Short-Term Deviations
Background:
The impact of nitrogen dioxide (NO2) and particulate matter with an aerodynamic diameter of less than or equal to 2.5. microns (PM2.5) exposures on lung function has been investigated mainly in children and less in adults. Furthermore, it is unclear whether short-term deviations of air pollutant concentration need to be considered in long-term exposure models.
Objectives:
The aims of this study were to investigate the association between short-term air pollution exposure and lung function and to assess whether short-term deviations of air pollutant concentration should be integrated into long-term exposure models.
Methods:
Short-term (daily averages 0â7 d prior) and long-term (1- and 4-y means) NO2 and PM2.5 concentrations were modeled using satellite, land use, and meteorological data calibrated on ground measurements. Forced expiratory volume within the first second (FEV1) of forced exhalation and forced vital capacity (FVC) were measured during a LuftiBus assessment (2003â2012) and linked to exposure information from the Swiss National Cohort for 36,085 adults (ages 18â95 y). We used multiple linear regression to estimate adjusted associations, and additionally adjusted models of long-term exposures for short-term deviations in air pollutant concentrations.
Results:
A 10ÎŒg/m3 increase in NO2 and PM2.5 on the day of the pulmonary function test was associated with lower FEV1 and FVC (NO2: FEV1 â8.0âml [95% confidence interval: â13.4, â2.7], FVC â16.7âml [â23.4, â10.0]; PM2.5: FEV1 â15.3âml [â21.9, â8.7], FVC â18.5âml [â26.5, â10.5]). A 10ÎŒg/m3 increase in 1-y mean NO2 was also associated with lower FEV1 (â7.7âml; â15.9, 0.5) and FVC (â21.6âml; â31.9, â11.4), as was a 10ÎŒg/m3 increase in 1-y mean PM2.5 (FEV1: â42.2âml; â56.9, â27.5; FVC: â82.0âml; â100.1, â63.9). These associations were robust to adjustment for short-term deviations in the concentration of each air pollutant.
Conclusions:
Short- and long-term air pollution exposures were negatively associated with lung function, in particular long-term PM2.5 exposure with FVC. Our findings contribute substantially to the evidence of adverse associations between air pollution and lung function in adults. https://doi.org/10.1289/EHP752
Hard diffraction in hadron--hadron interactions and in photoproduction
Hard single diffractive processes are studied within the framework of the
triple--Pomeron approximation. Using a Pomeron structure function motivated by
Regge--theory we obtain parton distribution functions which do not obey
momentum sum rule. Based on Regge-- factorization cross sections for hard
diffraction are calculated. Furthermore, the model is applied to hard
diffractive particle production in photoproduction and in
interactions.Comment: 13 pages, Latex, 13 uuencoded figure
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Ten years of research on synergisms and antagonisms in chemical mixtures: A systematic review and quantitative reappraisal of mixture studies
Background
Several reviews of synergisms and antagonisms in chemical mixtures have concluded that synergisms are relatively rare. However, these reviews focused on mixtures composed of specific groups of chemicals, such as pesticides or metals and on toxicity endpoints mostly relevant to ecotoxicology. Doubts remain whether these findings can be generalised. A systematic review not restricted to specific chemical mixtures and including mammalian and human toxicity endpoints is missing.
Objectives
We conducted a systematic review and quantitative reappraisal of 10 yearsâ of experimental mixture studies to investigate the frequency and reliability of evaluations of mixture effects as synergistic or antagonistic. Unlike previous reviews, we did not limit our efforts to certain groups of chemicals or specific toxicity outcomes and covered mixture studies relevant to ecotoxicology and human/mammalian toxicology published between 2007 and 2017.
Data sources, eligibility criteria
We undertook searches for peer-reviewed articles in PubMed, Web of Science, Scopus, GreenFile, ScienceDirect and Toxline and included studies of controlled exposures of environmental chemical pollutants, defined as unintentional exposures leading to unintended effects. Studies with viruses, prions or therapeutic agents were excluded, as were records with missing details on chemicalsâ identities, toxicities, doses, or concentrations.
Study appraisal and synthesis methods
To examine the internal validity of studies we developed a risk-of-bias tool tailored to mixture toxicology. For a subset of 388 entries that claimed synergisms or antagonisms, we conducted a quantitative reappraisal of authorsâ evaluations by deriving ratios of predicted and observed effective mixture doses (concentrations).
Results
Our searches produced an inventory of 1220 mixture experiments which we subjected to subgroup analyses. Approximately two thirds of studies did not incorporate more than 2 components. Most experiments relied on low-cost assays with readily quantifiable endpoints. Important toxicity outcomes of relevance for human risk assessment (e.g. carcinogenicity, genotoxicity, reproductive toxicity, immunotoxicity, neurotoxicity) were rarely addressed. The proportion of studies that declared additivity, synergism or antagonisms was approximately equal (one quarter each); the remaining quarter arrived at different evaluations. About half of the 1220 entries were rated as âdefinitelyâ or âprobablyâ low risk of bias. Strikingly, relatively few claims of synergistic or antagonistic effects stood up to scrutiny in terms of deviations from expected additivity that exceed the boundaries of acceptable between-study variability. In most cases, the observed mixture doses were not more than two-fold higher or lower than the predicted additive doses. Twenty percent of the entries (N = 78) reported synergisms in excess of that degree of deviation. Our efforts of pinpointing specific factors that predispose to synergistic interactions confirmed previous concerns about the synergistic potential of combinations of triazine, azole and pyrethroid pesticides at environmentally relevant doses. New evidence of synergisms with endocrine disrupting chemicals and metal compounds such as chromium (VI) and nickel in combination with cadmium has emerged.
Conclusions, limitations and implications
These specific cases of synergisms apart, our results confirm the utility of default application of the dose (concentration) addition concept for predictive assessments of simultaneous exposures to multiple chemicals. However, this strategy must be complemented by an awareness of the synergistic potential of specific classes of chemicals. Our conclusions only apply to the chemical space captured in published mixture studies which is biased towards relatively well-researched chemicals.European Commission, Directorate-General Joint Research Centre, Service Contract CCR.F.933992.X
Use it or lose it! Cognitive activity as a protec-tive factor for cognitive decline associated with Alzheimer's disease.
Because of the worldwide aging of populations, Alzheimer's disease and other dementias constitute a devastating experience for patients and families as well as a major social and economic burden for both healthcare systems and society. Multiple potentially modifiable cardiovascular and lifestyle risk factors have been associated with this disease. Thus, modifying these risk factors and identifying protective factors represent important strategies to prevent and delay disease onset and to decrease the social burden. Based on the cognitive reserve hypothesis, evidence from epidemiological studies shows that low education and cognitive inactivity constitute major risk factors for dementia. This indicates that a cognitively active lifestyle may protect against cognitive decline or delay the onset of dementia. We describe a newly developed preventive programme, based on this evidence, to stimulate and increase cognitive activity in older adults at risk for cognitive decline. This programme, called "BrainCoach", includes the technique of "motivational interviewing" to foster behaviour change. If the planned feasibility study is successful, we propose to add BrainCoach as a module to the already existing "Health Coaching" programme, a Swiss preventive programme to address multiple risk factors in primary care
Spatial biases reduce the ability of Earth system models to simulate soil heterotrophic respiration fluxes
Heterotrophic respiration (Rh) is, at a global scale, one of the largest CO2 fluxes between the Earth's surface and atmosphere and may increase in the future. The previous generation of Earth system models (ESMs) was able to reproduce global fluxes relatively well, but at that, time no gridded products were available to perform an in-depth evaluation. The capacity of the new generation of ESMs used within the Coupled Model Intercomparison Project Phase 6 (CMIP6) to reproduce this flux has not been evaluated, meaning that the realism of resulting CO2 flux estimates is unclear. In this study, we combine recently released observational data on Rh and ESM simulations to evaluate the ability of 13 ESMs from CMIP6 to reproduce Rh. Only 4 of the 13 tested ESMs were able to reproduce the total Rh flux, but spatial analysis underlined important bias compensation for most of the ESMs, which generally showed an overestimation in tropical regions and an underestimation in arid regions. To identify the main drivers of the bias, we performed an analysis of the residuals and found that mean annual precipitation was the most important driver explaining the difference between ESM simulations and observation-derived products of Rh, with a higher bias between ESM simulations and Rh products where precipitation was high. Based on our results, next-generation ESMs should focus on improving the response of Rh to soil moisture.</p
The viscosity effect on marine particle flux: A climate relevant feedback mechanism
Oceanic uptake and long-term storage of atmospheric carbon dioxide (CO2) are strongly driven by the marine âbiological pump,â i.e., sinking of biotically fixed inorganic carbon and nutrients from the surface into the deep ocean (Sarmiento and Bender, 1994; Volk and Hoffert, 1985). Sinking velocity of marine particles depends on seawater viscosity, which is strongly controlled by temperature (Sharqawy et al., 2010). Consequently, marine particle flux is accelerated as ocean temperatures increase under global warming (Bach et al., 2012). Here we show that this previously overlooked âviscosity effectâ could have profound impacts on marine biogeochemical cycling and carbon uptake over the next centuries to millennia. In our global warming simulation, the viscosity effect accelerates particle sinking by up to 25%, thereby effectively reducing the portion of organic matter that is respired in the surface ocean. Accordingly, the biological carbon pump's efficiency increases, enhancing the sequestration of atmospheric CO2 into the ocean. This effect becomes particularly important on longer time scales when warming reaches the ocean interior. At the end of our simulation (4000âA.D.), oceanic carbon uptake is 17% higher, atmospheric CO2 concentration is 180âppm lower, and the increase in global average surface temperature is 8% weaker when considering the viscosity effect. Consequently, the viscosity effect could act as a long-term negative feedback mechanism in the global climate system
Position paper on management of personal data in environment and health research in Europe
Management of datasets that include health information and other sensitive personal information of European study participants has to be compliant with the General Data Protection Regulation (GDPR, Regulation (EU) 2016/679). Within scientific research, the widely subscribed'FAIR' data principles should apply, meaning that research data should be findable, accessible, interoperable and re-usable. Balancing the aim of open science driven FAIR data management with GDPR compliant personal data protection safeguards is now a common challenge for many research projects dealing with (sensitive) personal data. In December 2020 a workshop was held with representatives of several large EU research consortia and of the European Commission to reflect on how to apply the FAIR data principles for environment and health research (E&H). Several recent data intensive EU funded E&H research projects face this challenge and work intensively towards developing solutions to access, exchange, store, handle, share, process and use such sensitive personal data, with the aim to support European and transnational collaborations. As a result, several recommendations, opportunities and current limitations were formulated. New technical developments such as federated data management and analysis systems, machine learning together with advanced search software, harmonized ontologies and data quality standards should in principle facilitate the FAIRification of data. To address ethical, legal, political and financial obstacles to the wider re-use of data for research purposes, both specific expertise and underpinning infrastructure are needed. There is a need for the E&H research data to find their place in the European Open Science Cloud. Communities using health and population data, environmental data and other publicly available data have to interconnect and synergize. To maximize the use and re-use of environment and health data, a dedicated supporting European infrastructure effort, such as the EIRENE research infrastructure within the ESFRI roadmap 2021, is needed that would interact with existing infrastructures
Photoproduction off Nuclei and Point-like Photon Interactions Part I: Cross Sections and Nuclear Shadowing
High energy photoproduction off nuclear targets is studied within the
Glauber-Gribov approximation. The photon is assumed to interact as a
-system according to the Generalized Vector Dominance Model and as a
``bare photon'' in direct scattering processes with target nucleons. We
calculate total cross sections for interactions of photons with nuclei taking
into account coherence length effects and point-like interactions of the
photon. Results are compared to data on photon-nucleus cross sections, nuclear
shadowing, and quasi- elastic -production. Extrapolations of cross
sections and of the shadowing behaviour to high energies are given.Comment: 15 pages, 12 figure
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