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Hajat S.,London School of Hygiene and Tropical Medicine | Sheridan S.C.,Kent State University | Allen M.J.,Kent State University | Pascal M.,Institute of Veille Sanitaire | And 7 more authors.
American Journal of Public Health | Year: 2010

Objectives. We compared the ability of several heat-health warning systems to predict days of heat-associated mortality using common data sets. Methods. Heat-health warning systems initiate emergency public health interventions once forecasts have identified weather conditions to breach predetermined trigger levels. We examined 4 commonly used trigger-setting approaches: (1) synoptic classification, (2) epidemiologic assessment of the temperature-mortality relationship, (3) temperature-humidity index, and (4) physiologic classification. We applied each approach in Chicago, Illinois; London, United Kingdom; Madrid, Spain; and Montreal, Canada, to identify days expected to be associated with the highest heat-related mortality. Results. We found little agreement across the approaches in which days were identified as most dangerous. In general, days identified by temperature-mortality assessment were associated with the highest excess mortality. Conclusions. Triggering of alert days and ultimately the initiation of emergency responses by a heat-health warning system varies significantly across approaches adopted to establish triggers. Source

De Soto I.S.,Public University of Navarra | Ayora C.,Institute Diagnostico Ambiental y Estudios Del Agua | Cuevas J.,Autonomous University of Madrid
Clay Minerals | Year: 2014

Clays are commonly used as liners in urban landfills. However, the reactive processes with landfill leachates, and in particular the role of accessory minerals is poorly known. The aim of this work is to evaluate the diffusion of a synthetic urban landfill leachate through compacted natural smectite-illitic clays containing carbonates and sulfates and to predict the functioning of the clay liner for different minor mineral proportions. The leachate, characterized by acidic pH conditions and high organic matter content, is a typical aqueous solution formed in the acetogenic phase of organic matter degradation in urban landfill areas. Medium-scale (11 cm) laboratory diffusion tests were performed over 77 days. Chloride diffusion coefficients, porosity changes, cation exchange constants and the sulfate reduction rate were quantitatively assessed by means of reactive transport modelling. The exchange capacity of the clays is responsible for NH+ 4 retention. However, the presence or absence of gypsum in the initial clay rock controls the functioning of the liner. Gypsum dissolution ensures a high sulfate concentration in the porewater and enhances the acetate consumption via sulfate reduction. Gypsum dissolution and the concomitant calcite precipitation do not significantly alter the porosity of the clay rock. © 2014 Mineralogical Society. Source

Aim. To determine if women with multiple sclerosis (MS) reported an increased risk of breast cancer compared with the general female population. Patients and methods. We conducted a systematic review and meta-analysis of observational cohort studies. We performed a search in PubMed/Medline of studies where standardized incidence ratios (SIRs) were provided. Overall estimates of the SIRs (meta-SIRs) were calculated using DerSimonian-Laird random effects models. Sources of heterogeneity were explored by means sub-groups analyses. Results. Five studies met the inclusion criteria. Women with MS were not associated with increased risk of overall (meta-SIR = 0.80; 95% confidence interval, 95% CI = 0.61-1.06) and breast cancers (meta-SIR = 1.02; 95% CI = 0.75-1.40). These differences did not turn out to be statistically significant. A high degree of heterogeneity between studies was found (I2 = 88.7% and I2 = 75.3%, respectively). Conclusions. The data shown here suggest a similar risk of breast cancer in women with MS when compared to the general population. Further research is required to evaluate the role of specific risk factors at cancer sites such as effects of treatments used in the management of MS patients. © 2010 Revista de Neurología. Source

De Soto I.S.,Autonomous University of Madrid | Ruiz A.I.,Autonomous University of Madrid | Ayora C.,Institute Diagnostico Ambiental y Estudios Del Agua | Garcia R.,Autonomous University of Madrid | And 2 more authors.
Applied Geochemistry | Year: 2012

Diffusion of a synthetic urban landfill leachate through compacted natural illitic clays and the role of reactive accessory minerals (carbonates and gypsum) in the geochemical behavior of major soluble ions are evaluated. The leachate is composed of NH 4 + and Na + (0.25M) balanced by Cl - (0.25M), acetate (0.1M) and HCO3- (0.15M). The pH is 7.8 and it is typical of the mature stage of organic matter degradation within an urban landfill. Laboratory scale diffusion tests were performed over 4months (long term experiment, LT) and 2weeks (short term experiment, ST). The ST experiments were designed to allow the measurement of the Cl - gradient as a diffusion tracer in the compacted clay. In the LT experiments the chemical gradients were already at steady state, but geochemical reactions involving dissolution of gypsum and precipitation of calcite were observed. Evolution of pore-water chemistry, mineralogy, cation exchange properties, and the specific surface of clays were determined. Numerical simulations were carried out using the geochemical code RETRASO. Chloride transport, precipitation of carbonates, pH buffering, and Ca 2+/NH 4 +cation exchange reactions took place in the laboratory tests. Apparent Cl - diffusion coefficients were determined by direct modeling of the ST tests and validated with the LT experiments. These coefficients were considered in the simulation of transport coupled with experimentally calculated exchange constants and dissolution/precipitation reactions of gypsum and carbonates. Sulfate reduction coupled with acetate oxidation has been proven to be relevant in the sample with significant concentration of SO 4 2- (Bailén). This process also includes significant precipitation of carbonates (mainly calcite) and causes a decrease of SO 4 2- in the porewater. © 2012 Elsevier Ltd. Source

Matamoros V.,University of Girona | Matamoros V.,University of Barcelona | Jover E.,Institute Diagnostico Ambiental y Estudios Del Agua | Bayona J.M.,University of Barcelona
Analytical Chemistry | Year: 2010

An analytical procedure based on comprehensive two-dimensional gas chromatography (GC × GC) coupled with time-of-flight mass spectrometry (TOF-MS) for the simultaneous determination of 97 organic contaminants at trace concentration in river water is presented. The target analytes included 13 pharmaceuticals, 18 plasticizers, 8 personal care products, 9 acid herbicides, 8 triazines, 10 organophosphorous compounds, 5 phenylureas, 12 organochlorine biocides, 9 polycyclic aromatic hydrocarbons (PAHs), and 5 benzothiazoles and benzotriazoles. The best resolution of the target analytes in the contour plots was obtained when a nonpolar stationary phase was used in the first dimension and polar one in the second. However, in the opposite configuration, polar-nonpolar, the retention time in the second dimension exhibited a strong correlation with the log Kow (p < 0.01), and it was proposed as an additional identification criteria. The developed methodology is based on a polymeric solidphase extraction followed by in GC-port methylation and GC × GC/TOF-MS determination. Moreover, limits of detection (LODs) and quantification (LOQs) ranged from 0.5 to 100 ng/L and from 2 to 185 ng/L, respectively. Repeatability was always lower than 20%. Finally, the developed method has been successfully applied to the determination of incurred target analytes in four river waters subjected to a different anthropogenic pressure. © 2010 American Chemical Society. Source

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