A simple and precise methodology to determine particulate matter mass in atmospheric filters; validation and application cases

In the past decades, particulate matter (PM) measurements have been used extensively in atmospheric sciences, as it allows studying the evolution of tracers for different atmospheric processes and the effects of atmospheric pollution on human health. However, measuring PM mass requires a constant control of the laboratory conditions due to its capacity to absorb humidity. For this reason, this study was focused on developing a novel, simple and precise methodology to determine the corrections of the filter mass due to humidity changes. The control and corrections are possible using a “control filter”, which is always adapted to the environmental conditions of the laboratory. To check the consistency of this method, it was proved that the mass of any problem filter and that of the control filter behave in a very similar way. This allows quantifying the mass changes of any problem filter by using the control filter, where the problem filters and the control filter must have the same chemical composition and dimensions. To validate this methodology, a comparison was made between the methodology proposed in this study (Method-1) and the one proposed by the EPA (Method-2), which is generally applied. The particulate matter mass (m) was obtained for a problem filter for different weights, achieving similar values using both methods. However, Method-1 still provided reliable mass measurements for relative humidities very different from 50%, even as low as 18%. It was also proved that the adsorption or loss of water by the particulate matter can be neglected, since m is much smaller than the blank filter mass. Method-1 was also employed in several samplings carried out using three PM10 samplers to determine contaminants, such as 7Be and 210Pb, obtaining a good agreement between all particulate masses and activities measured by the three samplers for all samplings.This research has partially funded by the projects of the Regional Government of Andalusia called “Basic processes regulating the fractionations and enrichments of natural radionuclides under acid mine drainage conditions” (Ref.: UHU-1255876), and “Treatment of acid leachates from phosphogypsum piles located at Huelva, and transport modelling of the released radionuclides” (Ref.: P20_00096), the project funded by the Spanish Ministry of Science, Innovation and Universities’ Research Agency “Development and optimization of a process for removing natural radionuclides in phosphogypsum leachates” (Ref.: PID2020-116461RB-C21), and the Project for Novel Principal Investigators “Quantitative study of the variables involved in the radon exhalation rate for granular solids; application to rafts of granular solid phosphogypsum” (Ref.: UHUPJ-00005-632). The authors acknowledge the funding for open access charge provided by Universidad de Huelva / CBUA. The authors would like to thank A.M. Padilla for his great help provided in order to make this study possible

Radon transport events associated with the impact of a NORM repository in the SW of Europe

Two radon measurement stations located to the north and south of a NORM (Naturally Occurring Radioactive Materials) repository of phosphogypsum (southwest of Europe) were used to monitor radon behavior during 2018. The stations are located at opposing sides of the repository, one in Huelva City to the north and other one in a rural area to the south. This setup aimed to identify the influence of the NORM repository on each station and use radon levels as a marker of atmospheric transport in the local area. To achieve this, a comparison was carried out with other coastal stations in the south of Spain, finding higher average concentrations in Huelva City, ~3.3 Bq m− 3 . Hierarchical clustering was applied to identify days with different radon patterns at each Huelva station, detecting possible local radon transport events from the repository. Three events were investigated with WRF (Weather Research and Forecasting) and FLEXPART-WRF (FLEXible PARTicle dispersion model). It was found that both sampling sites required atmospheric stagnant conditions to reach high radon concentration. However, under these conditions the urban station showed high radon regardless of wind direction while the rural station also required radon transport from the repository, either directly or indirect.This research was supported by the Spanish Ministry of Science, Innovation and Universities, by the project ‘Fluxes of radionuclides emitted by the PG piles located at Huelva; assessment of the dispersion, radiological risks and remediation proposals’ (Ref.: CTM2015-68628- R). It is important to reiterate the significant contribution of CSN to this research providing radon measurements from the REA network. Special thanks are given to Antonio Padilla for his invaluable technical support and know-how. Resources supporting this work were provided by the CEAFMC and Universidad de Huelva High Performance Computer (HPC@UHU) funded by ERDF/MINECO project UNHU-15CE-2848.Funding for open access charge: Universidad de Huelva / CBU

Behavior of 222Rn, 220Rn and their progenies along a daily cycle for different meteorological situations: Implications on atmospheric aerosol residence times and Rn daughters' equilibrium factors

The correct assessment of the radiological hazard from radon and daughters, external and internal doses, residence times and equilibrium factors, implies the need to properly determine 222Rn (radon), 220Rn (thoron) and their respective short-lived progenies (214Pb and 214Bi, and 212Pb and 212Bi, respectively), where the precise measurements of both progenies are quite complex due to their very short half-lives. In addition, it is important to study the temporal behavior of all these radionuclides along daily cycles. Therefore, the aim of this study was to analyze the temporal evolution of radon, thoron and their progenies, and of their activity ratios along daily cycles for two different meteorological situations (synoptic and mesoscale processes). Radon and thoron were measured using a radon monitoring system, while their respective progenies were collected onto atmospheric filters using an ASS-500 sampler, and then measured by gamma-ray spectrometry. Furthermore, the different relationships between the concentrations of radionuclides and the different meteorological variables of interest (temperature, ABL height, and speed and direction of the wind) were found. Finally, the atmospheric aerosol residence times and Rn daughters’ equilibrium factors were estimated for each sampling carried out along the two daily cycles, finding results consistent with previous studies.This research was partially funded by the University of Huelva and the Operative FEDER Program-Andalusia 2014–2020 (Refs.: UHU- 1255876, and UHU-202020), the European Regional Development Fund through the Research State Agency (Ref.: PID2020-116461RB-C21), the Andalusian Government (Ref.: PY20_00096), and the CSN (Nuclear Safety Council) projects with Refs.: SUBV-4/2022 (CLIMATOR) and SUBV-4/2021 (EXRADON).Departamento de Física Aplicad

La radiación solar: efectos en la salud y el medio ambiente

140 páginasEl incremento de cierto tipo de radiaciones ultravioletas procedentes del sol, perjudiciales para la salud y el medio ambiente es un tema de candente actualidad, a pesar de la aparente recuperación de la capa de ozono, filtro protector de la biosfera y de la calidad de vida de los seres que habitan el Planeta. La obra ha tratado de definir la situación actual de este gas a escala planetaria, analizando las causas físicas de su aparición y de su destrucción y las consecuencias que para el medio ambiente y la salud tiene el incremento de radiación ultravioleta

Caracterización y comportamiento del ozono superficial en la provincia de Huelva

El desarrollo de las actividades antropogénicas ha llevado al incremento de las concentraciones de ozono en la baja troposfera. La provincia de Huelva presenta una serie de condiciones ideales para la formación y acumulación de ozono, por ello se decide en el año 2000 realizar un estudio sobre los niveles y el comportamiento que muestra este gas. Las medidas de ozono se han realizado en cuatro puntos de la provincia. Para realizar una correcta interpretación de las medidas fue necesario estudiar la dinámica de la baja atmósfera, estudiándose los principales parámetros meteorológicos. A partir de los datos de viento se extrajeron los días con brisa costera y se pudo conocer que el comportamiento de la brisa depende de las condiciones sinópticas. La relación entre el ozono y varios parámetros meteorológicos han sido analizados. Se ha evaluado el número de superaciones de los umbrales de protección de la vegetación y de la salud humana. Se ha estudiado el comportamiento del ozono bajo diferentes escenarios meteorológicos, con concentraciones bajas de ozono bajo situaciones advectivas y episodios de ozono con condiciones de brisa costera._____________________________________________The development of antropogenic activities have increased ozone levels in the low troposphere. The province of Huelva presents a special characteristics to formation and accumulation of ozone surface, and therefore it was decided to start a study in year 2000, to know the levels and behaviour surface ozone. The network to measure ozone concentrations consists of four stations. To make a correct interpretation of ozone concentrations, it was necessary to know atmospheric dynamic, hence we have studied the main meteorological parameters. From the winds regime and after applying a criteria to extract breeze days of wind data, we have been able to study breeze regime. Sea-land breeze in Huelva does not present always the same behaviour and it depends on synoptic conditions. We have made a study to know seasonal and daily variability surface ozone in this region. The relation between ozone concentrations and several meteorological variables such as temperature, wind speed and relative humidity, and other atmospheric parameters has been analysed. We have also evaluated the number of exceedances of the different thresholds such as health protection and vegetation protection. We have studied the behaviour surface ozone under different atmospheric conditions, thus under advection situations the ozone concentrations show small cycles while under typical sea-land breezes take place the episodes of air pollution by ozone

Influence of the accumulation chamber insertion depth to measure surface radon exhalation rates

A common method to measure radon exhalation rates relies on the accumulation chamber technique. Usually, this approach only considers one-dimensional gas transport within the soil that neglects lateral diffusion. However, this lateral transport could reduce the reliability of the method. In this work, several cylindricalshaped accumulation chambers were built with different heights to test if the insertion depth of the chamber into the soil improves the reliability of the method and, in that case, if it could limit the radon lateral diffusion effects. To check this hypothesis in laboratory, two reference exhalation boxes were manufactured using phosphogypsum from a repository located nearby the city of Huelva, in the southwest of Spain. Laboratory experiments showed that insertion depth had a deep impact in reducing the effective decay constant of the system, extending the interval where the linear fitting can be applied, and consistently obtaining reliable exhalation measurements once a minimum insertion depth is employed. Field experiments carried out in the phosphogypsum repository showed that increasing the insertion depth could reduce the influence of external effects, increasing the repeatability of the method. These experiments provided a method to obtain consistent radon exhalation measurements over the phosphogypsum repository.This research was supported by the Spanish Ministry of Science, Innovation and Universities, by the project ‘Fluxes of radionuclides emitted by the PG piles located at Huelva; assessment of the dispersion, radiological risks and remediation proposals’ (Ref.: CTM2015-68628-R) and the Junta de Andalucía Regional Government by the project “Basic processes regulating the fractionation and enrichment of natural radionuclides under Acid Mine Drainage” (Ref.: UHU-1255876). Special thanks are given to Antonio Padilla for his invaluable technical support and know-how

Use of a fuzzy qualitative model to reanalyze radon relationship with atmospheric variables in a coastal area near a NORM repository

A soft computing methodology, PreFuRGe (Predictive Fuzzy Rules Generator), was applied to study atmospheric radon in relation to other meteorological variables. This algorithm is based on fuzzy clustering and generates a rule-based system that provides a qualitative model that describes the behavior of radon. Two one-year radon datasets were used to verify the consistency of the fuzzy methodology, by comparing the obtained models with published results obtained with statistical techniques. These datasets were collected in the city of Huelva, to the southwest of Europe, and were already studied in peer-reviewed publications. The proposed fuzzy methodology was able to provide results consistent with previous studies, identifying the main drivers in radon behavior, atmospheric stability and wind speed, together with a complete characterization of the daily cycle and its seasonality. PreFuRGe highlighted features that would otherwise require detailed examination combining a number of classical statistical techniques, proving to be a useful tool to characterize heterogeneous datasets.This research was supported by the Spanish Ministry of Science, Innovation and Universities, by the project ‘Fluxes of radionuclides emitted by the PG piles located at Huelva; assessment of the dispersion, radiological risks and remediation proposals’ (Ref.: CTM2015-68628-R). Funding for open access charge by Universidad de Huelva/CBUA. Thanks to Spanish Agency of Meteorology (AEMET) for the meteorological data employed at this study

Estudio físico-químico comparativo de una atmósfera próxima a una zona industrial y otra rural y su implicación en el currículo de secundaria

Resumen tomado de la publicación.Se incluyen anexos referidos en el documento.El objetivo de este trabajo es analizar y comparar una atmósfera próxima a una zona industrial (Argamasilla de Calatrava) y otra rural (Porzuna). Para ello se han medido de forma continua y en tiempo real las concentraciones de ozono, uno de los contaminantes troposféricos más importantes. Esto se ha hecho por primera vez en estas localidades donde no existen estaciones de vigilancia de la contaminación. Se pretende también particularizar los contenidos relativos a contaminación atmosférica de las materias de Física y Química en la Educación Secundaria a un episodio concreto (contaminación por ozono troposférico) e introducir a los alumnos en el método científico con el desarrollo de un trabajo de investigación específico.Consejería de Educación, Cultura y Deportes de Castilla-La ManchaCastilla La ManchaES

Meteorology during the DOMINO campaign and its connection with trace gases and aerosols

The DOMINO (Diel Oxidant Mechanisms in relation to Nitrogen Oxides) campaign was carried out from 21 November to 8 December 2008 at the El Arenosillo station (SW of Spain) in a coastal-rural environment. The main weather conditions are analysed using local meteorological variables, meteorological soundings and synoptic maps, as well as back trajectories of the air masses using the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory Model) model and a high spatial resolution of meteorological fields. Measurements of the main meteorological parameters were collected both from the surface and from a tall tower. A detailed land use analysis was performed on a 80 km scale showing the main types of vegetation and land use. Also the main anthropogenic atmospheric emission sources – both industrial-urban from Huelva and from the urban Seville area – are shown. A study to identify air mass origins and their variation with height was carried out. In this intensive campaign, air masses coming from different areas with different emission sources were observed: from the NW, with a highly industrial-urban character; continental flows from northerly directions; from the NE, with a pathway starting over the Seville metropolitan area and then continuing over the Doñana National Park; and maritime air masses coming from the Atlantic Ocean. To study the chemistry in the four atmospheric scenarios identified, gas -phase measurements of primary and secondary species such as ozone, NO, NO2 and SO2, biogenic and anthropogenic VOCs (volatile organic compounds) like benzene and isoprene, as well as total particle concentration and chemical composition of the aerosols are compared and discussed. The highest levels for total particle concentration, NO, NO2, SO2, benzene, PM10, PM2.5 and chemical elements such as As or Cu were found under flows associated with industrial-urban emissions from the Huelva–Portugal sector which are transported to the site before significant removal by chemical or deposition mechanism can occur. The air masses from the north were affected mainly by crustal elements and biogenic sources, the latter being exemplified by the biogenic species such as isoprene, particularly in the first part of the campaign. The urban air from the Seville area, before arriving at El Arenosillo, traversed the Doñana National Park and therefore was affected by industrial-urban and biogenic emissions. This aged air parcel can transport low levels of NOx, total particle concentration and SO2 as well as ozone and isoprene. Marine air masses from the Atlantic Ocean influence El Arenosillo frequently. Under these conditions, the lowest levels of almost all the species – with the exception of ozone levels associated to long-range transport – were measured