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1.
Chemosphere ; 355: 141830, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38552801

RESUMEN

Monitoring networks show that the European Union Nitrates Directive (ND) has had mixed success in reducing nitrate concentrations in groundwater. By combining machine learning and monitored nitrate concentrations (1992-2019), we estimate the total area of nitrate hotspots in Europe to be 401,000 km2, with 47% occurring outside of Nitrate Vulnerable Zones (NVZs). We also found contrasting increasing or decreasing trends, varying per country and time periods. We estimate that only 5% of the 122,000 km2 of hotspots in 2019 will meet nitrate quality standards by 2040 and that these may be offset by the appearance of new hotspots. Our results reveal that the effectiveness of the ND is limited by both time-lags between the implementation of good practices and pollution reduction and an inadequate designation of NVZs. Substantial improvements in the designation and regulation of NVZs are necessary, as well as in the quality of monitoring stations in terms of spatial density and information available concerning sampling depth, if the objectives of EU legislation to protect groundwater are to be achieved.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Nitratos/análisis , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Europa (Continente)
2.
Environ Int ; 128: 362-370, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31078005

RESUMEN

Trapezoidal integration by linear interpolation of data points is by far the most commonly used method of cumulative flux calculations of nitrous oxide (N2O) in studies that use flux chambers; however, this method is incapable of providing accurate uncertainty estimates. A Bayesian approach was used to calculate N2O emission factors (EFs) and their associated uncertainties from flux chamber measurements made after the application of nitrogen fertilisers, in the form of ammonium nitrate (AN), urea (Ur) and urea treated with Agrotain® urease inhibitor (UI) at four grassland sites in the UK. The comparison between the cumulative fluxes estimated using the Bayesian and linear interpolation methods were broadly similar (R2 = 0.79); however, the Bayesian method was capable of providing realistic uncertainties when a limited number of data points is available. The study reports mean EF values (and 95% confidence intervals) of 0.60 ±â€¯0.63, 0.29 ±â€¯0.22 and 0.26 ±â€¯0.17% of applied N emitted as N2O for the AN, Ur and UI treatments, respectively. There was no significant difference between N2O emissions from the Ur and UI treatments. In the case of the automatic chamber data collected at one site in this study, the data did not fit the log-normal model, implying that more complex models may be needed, particularly for measurement data with high temporal resolution.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Fertilizantes/análisis , Nitrógeno/análisis , Óxido Nitroso/análisis , Teorema de Bayes , Inglaterra , Pradera , Escocia , Gales
3.
Epidemiol Infect ; 144(2): 355-62, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26112312

RESUMEN

Human adenoviruses (HAdVs) are important respiratory pathogens, found in 2-27% of acute respiratory infection (ARI) cases. Few studies have analysed the diversity of species and types of HAdVs associated with ARI in Brazil. The purpose of this study was to determine the circulation patterns of the different HAdV species and respective types associated with ARI in children in the city of Fortaleza, northeastern Brazil. HAdVs were screened by an indirect immunofluorescence assay, and subsequently identified as species and types by PCR and sequencing of the hexon gene (HVR1-HVR6). Between 2001 and 2013, a total of 290 HAdV strains were detected, 190 of which were identified as belonging to the HAdV-B, -C and -E species. Seven types of HAdVs circulated in the studied population during the analysed period, with HAdV-3 being predominant.


Asunto(s)
Infecciones por Adenovirus Humanos/epidemiología , Adenovirus Humanos/clasificación , Adenovirus Humanos/aislamiento & purificación , Infecciones del Sistema Respiratorio/epidemiología , Infecciones por Adenovirus Humanos/virología , Adenovirus Humanos/genética , Adolescente , Brasil/epidemiología , Niño , Preescolar , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Hospitalización , Humanos , Lactante , Recién Nacido , Masculino , Reacción en Cadena de la Polimerasa , Infecciones del Sistema Respiratorio/virología , Análisis de Secuencia de ADN
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