MARTÍNEZ AGUIRRE , Aránzazu

El trabajo se ha centrado en el estudio de radionúclidos naturales, emisores alfa, en diversos compartimentos de Andalucía y puede dividirse en tres partes fundamentales. Una primera ha consistido en la puesta a punto de métodos radioquímicos para la extracción de U, Ra, Th y Po en muestras ambientales. También se han calibrado los diferentes...

Soils and two wild plant species (Spartina densiflora and Spartina maritima) have been collected from the Odiel river marsh and analysed for 210Po and 238U. The radioactivity concentrations in plants and soils reflect the impact of the operation of two phosphoric acid production factories located close to the marsh. Concentrations ratios (CR)...

A numerical model to simulate the dispersion of non-conservative radionuclides in an estuarine system that surrounds a marsh area has been developed. The model includes six phases: water, two types of suspended particles (natural particles in the estuary and contaminated particles released from the source of contamination), bottom sediments,...

A study of the distribution of U and Th-isotopes in different fractions of intertidal sediments collected in a marsh area has been carried out. This marsh area is affected by the releases of natural radionuclides from fertilizer industries carried out into the Odiel river. The study has shown that uranium is mainly located in non-residual...

¹he Odiel river forms an estuarine system which surrounds a large marsh area. A phosphate fertilizer processing complex releases its wastes into the estuary. ¹he presence of 226Ra in soils and plants (Spartina Densiflora) from the marsh has been investigated. Concentrations up to 700 and 15 mBq g~ 1 have been detected in soil and plant samples,...

In this paper an extensive study of the presence of natural radionuclides in a marshland area located in the vicinity of a phosphoric acid production complex in southwestern Spain is presented. This marsh is a natural reservation where significant biological activity takes place. The marsh is highly affected by the inflow of water from the...

two fertilizer factories operate at the estuary formed by the Odiel and Tinto rivers in Southwestern Spain. In previous work the authors have shown that such operation enhances the natural radionuclide background of the sea. Thus, fairly high levels of U, Th and Ra-isotopes were found in water and sediment samples taken from the estuary. In...

A study of the distribution of U in different fractions of intertidal sediments collected in a marsh area enhanced by the radioactive wastes discharged from a fertilizer complex has been carried out. The study has shown that U isotopes are mainly located in non-residual fractions of the sediments. Coprecipitation with amorphous ferromanganese...

The activity levels of 210Pb in solution and bottom sediments were measured in the estuary formed by the Odiel and Tinto rivers in southwest Spain. The levels in both water and sediment samples indicate that the discharges from two fertilizer factories in the area enhance the radioactivity of such samples.

The Odiel river, in southwest Spain, forms an estuarine system which is affected by waste disposal from a fertilizer complex. Uranium and thorium concentrations in waters and suspended matter, activity ratios and distribution coefficients, kd, have been measured along the river during two different tidal states. The results have shown that a...

The Chafarinas Islands are a group of volcanic outcrops off the north coast of the African continent. Quaternary deposits and calcrete formations cover most of the islands' planed surface, mainly on Rey Francisco I Island. Uranium-series ages are presented for a geological section with 18 m of detrital deposits and calcrete layers. Calcretes...

A study ofthe concentration ofthe U isotopes, 226Ra and 230Th in a groundwater system has been carried out. This aquifer, located in the provinces of Sevilla and Huelva, is the most important in the south of Spain having a surface area of2500 km2 . The proximity of a fertilizer factory complex to this aquifer system is of particular concern...

Experiments were designed to evaluate the behaviour of detritus during the leaching of impure carbonates by applying the U-Th isochron technique. We used one natural detritus and a pure, well-dated CaCO3 , alone and in artificial mixtures. One set of experiments was designed to study the effects of sample pre-treatment on the detritus and a...

A study is presented on the distribution of U and Th isotopes in the solid and liquid fractions of waters collected along the Odiel and Tinto rivers (southwest Spain). Such rivers are affected by the operation of phosphate fertilizer factories. The analysis of activity concentrations and activity ratios in both fractions provides interesting...

A study of the distribution of natural radionuclides in different fractions of river bottom sediments has been carried out. The study has shown that the majority of the total U in the sediment is located in the non-residual fraction of the sediment, while Th is more suitable to be present in the residual fraction of the sediments. Also, it has...

A study of the distribution of some natural radionuclides in different chemical fractions of river bottom sediments has been carried out. The study has shown that the majority of the total U in sediments is located in the non-residual fractions, while Th is more likely to be present in the residual ones. This difference between U and Th...

This paper reports an extensive study of the presence of natural radioactivity around a phosphate fertilizer factory complex situated in an estuarine area of southwest Spain. The study has concluded that the wastes from such industries are the cause of the enhancement of natural radioactivity in the immediate environment. Thus, significantly...

A study of the presence of U and Th isotopes in soil samples from a saline wet Marshland located close to a phosphoric acid production factory is presented. The samples were collected during low tide in areas washed by water during high tide. The incoming Odiel riverwaters, which directly receive the wastes from this factory, provokes the...

In this paper preliminary levels of natural and man-made radionuclides in the South Spanish marine environment are presented. Local man-made sources are found to be the main contributors to the natural environmental radioactivity in such areas while fallout is mainly responsible for the occurrence of artificial radioactivity in our zone.

The presence of U- and Th-isotopes in suspended matter from an estuarine system which surrounds a phosphate fertilizer processing complex has been investigated. A clear radioactive impact from the complex has been confirmed since up to 86 and 116 μg/g of U and Th respectively have been detected. The effect of tides and seasonal conditions,...

Two sampling campaigns were performed in 1993 at the marsh area (Odiel marsh) located in southwestern Spain, in the city of Huelva. Spartina densiflora and substrate soil (5 cm deep) samples were collected in several locations across the area in each campaign. Activity concentrations of 210Po, U-and Th-isotopes were determined in the plant and...

U-Series dating method is applied to speleo thems from Los Covachos Cave in the south of Spain. A combination of solvent extraction method with ion exchange resins is used for uranium and thorium isotopes. Uranium concentrations are low and for younger samples correction by detrital contamination is necessary. Ages obtained range from 30 to 135...

The uranium-series method is applied to date relic flowstone from karstic mountains in the south of Spain. Geomorphological mapping shows three staircased erosion surfaces with a typical karst landform. Exhumed flowstones fill the surficial palaeosinkholes and open fractures. Some of the samples analysed were impure carbonates consequently the...

An extensive study on the distribution of natural radionuclides in an estuarine ecosystem located in Southwestern Spain is presented. This environment is highly affected by the wastes released by a phosphoric acid industry which uses phosphate rocks as raw material for fertilizer production. This rock has generally high concentrations of U and...