Analyses of long-term measurements (2005-2012) of 7Be concentrations in surface air aerosols

Studies of radionuclide activities in aerosol particles provide a mean for evaluating the integrated effects of transport and meteorology on the atmospheric loadings of substances with different sources. The aim of the present study is to explain the behaviour of aerosols associated with 7Be (T1/2=53.3 days) in the surface atmosphere using exploratory data analysis to obtain information on their possible mechanisms of transport and deposition. This naturally occurring radionuclide is an important isotope in studying atmospheric processes because of its convenient half-life and sufficiently detectable -radiation (E = 0.477 MeV), which has served for studying precipitation scavenging, vertical and horizontal removal of air masses, aerosol transit and residence times in the troposphere [1]

Variations of PM10 and its relationship with 7Be and 210Pb measurements at Malaga (Southeastern coast of Spain)

INTRODUCTION Levels of particulate matter fraction PM10 were monitored between 2009 and 2011 in Malaga (Spain) in one of the Atmospheric Pollution Monitoring network managed by the Environmental Health Service of the Andalusian Government. Long-term measurements of cosmogenic radionuclides such as 7Be provide important data in studying global atmospheric processes and comparing environmental impact of radioactivity from man-made sources to natural ones. 7Be is a natural radionuclide tracer of aerosols originated over a range of high altitudes in the atmosphere. On the other hand, 210Pb is produced by radioactive decay from its progenitor, 222Rn, which emanates primarily from land surface. Therefore, 210Pb in the air is an effective tracer of the continental surface air mass. The variation of the data with time was studied by time series analyses and seasonal patterns were identified. The study of air back-trajectories were computed by means of the Hybrid Single-Particle Lagrangian Integrated Trajectories (HYSPLIT) trajectory model (Draxler, 1994) using meteorological data supplied by the US National Climatic Data Centr

Atmospheric fluxes of radionuclides on monthly time-scale in Málaga (Spain)

ABSTRACT.- Bulk atmospheric deposition of gamma radionuclides ( 7Be, 210Pb and 40K ) has been measured at Málaga (4º 28´80′′ W; 36º 43′ 40′N) at a coastal Mediterranean station in the south of Spain, from January 2005 through December 2012 for monthly period

Long-term atmospheric fluxes of radionuclides at a coastal Mediterranean station

7Be is one of the radionuclide produced by spallation reactions of cosmic rays with light atmospheric nuclei. 7Be rapidly associates primarily with submicron-sized aerosol particles. Gravitational settling and precipitation processes largely accomplish transfer to the earth’s surface. 210Pb which is one of the natural radionuclide of the 238U series is widely used as a tracer. 210Pb depositional pattern gave us information on continental aerosols in lower troposphere. These two radionuclides with their different sources and therefore are useful to understand the mechanisms of aerosol removal from the atmosphere. These radionuclides have measured routinely in many places in order to study the description of environmental processes such as aerosol transit and residence times in the troposphere , aerosol deposition velocities and aerosol trapping by ground vegetation.40K has been associated with the arrival of coarse re-suspended material from the Africa continent. The bulk atmospheric deposition of 7Be , 210Pb and 40K has been measured at Málaga , south-eastern Spain, from January 2005 to December 2012 for monthly periods.CS

The 40k used as tracer of saharan dust contributions

The present study is carried out in Málaga, frequently affected by intrusions of air masses with high concentrations of atmospheric particulate matter. 40K is a natural radionuclide and has been associated with the arrival of coarse re-suspended material from the Africa continent. A systematic 13-year analysis (January 2005-December 2017) of the concentration of radionuclides in bulk (wet + dry) deposition and PM10 air concentrations has been performed to test the possible utility of 40K as tracer of African mineral dust inputs in Málaga (4° 28ʹ 8ʺ W ;36° 43ʹ 40ʺ N). Also the atmospheric aerosols are collected using a high volume sampler during 9-year (January 2009-December 2017). It is a prerequisite to know the environmental long-term behaviour of radionuclides an a relatively large number of values are required for statistically meaningful conclusions . The identification of African dust events was carried by 96-hour back-trajectory analysis arriving at thee different heights (500 m, 1500m, 3000m a.g.l.) calculate with the HYSPLIT model , and by the information obtained from the output of the dust regional Atmospheric model (DREAM 8b).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Surface activity levels of 7Be, 210Pb, 40K and other atmospheric species and teh influence of African air mass intrusions

The high frequency of mineral dust plumes blown across from Africa to the Iberian Peninsula significantly affects dust levels in the atmosphere. Therefore, it is of great interest to analyse and quantify the African dust loading over the region due to the impact it has on air quality. This work presents results from a 2-year sampling campaign carried out to provide information on the frequency and impact of these African dust episodes on the concentrations of radioactive matter and non radioactive matter in the lower atmosphere at this Mediterranean coastal site. Aerosol samples for radiometric measurements were collected at the University of Málaga (36° 43′ 40″ N; 4° 28′ 8″ W) over 3-day periods using a high-volume sampler fitted with square polypropylene filters. All the radiometric measurements were performed by low-level gamma spectrometry with a coaxial-type germanium detector. The identification of African events was confirmed by means of 4-day backward trajectories (at 500, 1500, 3000 m.a.g.l.) computed using the HYSPLIT model and BSC-Dream8b dust images. Higher average concentration values were found for the three radionuclides in the set of samples collected under the influence of African dust events. The correlation patterns of the three radionuclides with meteorological variables and with the concentrations of the other atmospheric species were examined, both on the total set as well as on dusty and non-dusty basis.Universidad de Málaga. Campus de Excelencia Internacional de Andalucía Tec

Deposition patterns of atmospheric 7Be, 210Pb, 40K in cost of west Mediterranean sea, Málaga (Spain)

The deposition of radionuclides on the ground is an essential process to understand atmospheric transportation, sedimentation and geological process, being the major removal pathway for airborne particulates. To predict the long-term radiological consequences of an accidental deposition of the radionuclides to the ground, it is a prerequisite to know the environmental long-term behaviour of these radionuclides and a relatively large number of values are required for statistically meaningful conclusions. Nuclides of the natural decay chains, especially for 238U decay chain, are widely applied into atmospheric research, oceanography and marine geology. Atmospheric depositional fluxes of 7Be, 210Pb and 40K were simultaneously measured in monthly interval for eleven years (from January 2005 to December 2015 at Málaga (4 º28´ 8W; 36º 43´40N). Samples were collected monthly in an area of 1 m2 using a collector that is a slightly tilted stainless steel tray and filling 25 or 50 L polyethylene vessels with bulk deposition. The radionuclides present in all samples are 7Be, 210Pb and 40K appears approximately in 50% of the samples. The temporal variations of radionuclides in bulk deposition exhibit similar seasonal behaviour with low values in winter-autumn months and maximum values in spring-summer months. The time variations of the different radionuclides have been discussed in relation to various meteorological factors and the mean values have been compared to those published in recent literature for other sites located at different latitudes. Bulk depositional fluxes of 7Be, 210Pb and 40K have been evaluated for period of measurements. Bulk depositional fluxes of 7Be , 210Pb and 40K varied between 3 and 1779 Bq m-2 month-1 (annual mean = 1247 Bq m-2 year-1 ), and 1 to 102 Bq m-2 year-1 (annual mean = 140 Bq m-2 year-1) and 0,5 to 81 Bq m-2 year-1 ( annual mean = 65 Bq m-2 year-1). Data on the atmospheric depositions of radionuclides in Málaga show clear seasonal variations which can be attributed to the meteorological conditions affecting the transport and deposition processes. The amount of rainfall controls mainly the depositional fluxes. .There is a statistically relationship between 7Be and 210Pb fluxes indicating that removal behaviour from the atmosphere is relatively similar.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Events affecting levels of gross alpha and gross beta activities and heavy metals composition of airborne particulate samples

Particulate matter (PM) pollution is a serious environmental issue mainly due to the presence of toxic substances and trace metals in the atmosphere. The association of PM with adverse health effects has been recognized for a long time. Monitoring of both PM mass and chemical composition is important for identification of the emission source, determination of compliance with the set air quality standards and establishment of effective pollution control programs. In addition, the Saharan dust events have been recognized to have a non negligible impact on the particulate matter surface concentrations recorded in Europe. The objective of this study was to analyse temporal variation in mass concentrations, gross-alpha and gross-beta activities and heavy metal components for evaluating the integrated effects of transport and meteorology on the atmospheric loadings of substances with different sources and to further examine the relationship between the occurrence of African dust outbreaks and radionuclide activity concentrations. Gross-alpha and gross-beta radioactivity measurements are of particular interest for routine monitoring purposes and allow establishing trends in radionuclide concentrations. X-ray fluorescence analysis was successfully applied for the determination of metallic elements on the aerosol filters collected.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech Acknowledgments: This study was financed by the Spanish Ministry of Economy and Competitiveness, (Project CTM12-37598-C02, co -funded by FEDER-EU)

Levels of heavy metals composition in atmospheric aerosol samples and the influence of african episodes

Particulate matter pollution is a serious environmental issue mainly due to the presence of toxic substances and trace metals in the atmosphere from a variety of pollution emission sources. Information about aerosol composition and their sources especially during pollution events can be further used to establish strategies for the reduction of particulate matter concentration. The objective in the present study was to analyse variations in total suspended particle (TSP) mass concentration and heavy metal components for evaluating the atmospheric loadings of substances with different sources as well as to further examine the relationship between the occurrence of African dust intrusions and metallic species concentrations at our coastal station located in South Spain. Non-destructive Wavelength-Dispersive X-Ray Fluorescence (WDXRF) analysis has been applied for the determination of multi-element contents of atmospheric particulate matter.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Temporal analysis of natural radionuclides deposition at Málaga(2005-2016)

Atmospheric deposition of radionuclides has been investigated in many studies from the aspects of both radiation protection and geochemistry. The present study, carried out in the city of Málaga, in the southeast of Spain, focuses on the assessment of the bulk depositional fluxes of three natural radionuclides: 7Be (cosmogenic origin), and 210Pb and 40K (crustal origin). These three radionuclides are useful markers of particles arising from their respective sources. To obtain fundamental information of atmospheric transportation, sedimentation and geological process of particulate matter, a long-term monitoring of atmospheric deposition has been carried out in Málaga from January 2005-December 2016. Samples of bulk deposition were collected on a monthly basis on a stainless steel tray from January 2005 to December 2016. Afterwards, a volume of 6 L of the bulk deposition was reduced via evaporation to 1 L approximately and transferred to a Marinelli geometry container for gamma counting. Additionally, aerosols samples were collected weekly in cellulose membrane filters of 0.8μm pore size and 47mm diameter with an air sampler lodged in an all-weather sampling station, situated on the roof near the bulk rain collector. Gamma counting of the aerosols and bulk deposition samples was performed using an intrinsic germanium coaxial detector, Re-Ge-type (CANBERRA). This study describes the results and then discusses characteristics of atmospheric deposition of mentioned radionuclides with respect to seasonal variations and dependency on controlling factors. The depositional fluxes of all radionuclides showed a clear seasonal trend with summer minimum and high values in wintertime