Search

Following the occurrence of a fire at a tire landfill in the surrounding area of Madrid City (Spain), polycyclic aromatic hydrocarbons (PAHs) and trace elements present in soils were analyzed to assess the impact of the fire. The capacity of the soils' clay mineral fraction to reflect this air pollution incident was studied. Fourteen soil samples were collected at different distances under the smoke plume, and they were subjected to high-performance liquid chromatography-photodiode array detection, inductively coupled plasma mass spectrometry and X-ray diffraction analyses. Clay minerals content showed a strong correlation with the pollutants potentially released in the tire fire, acenaphthene, pyrene, benzo(a)pyrene and benzo(a)fluoranthene. Trace metals Zn and Se were related to the proximity of the tire fire without any relationship with clay minerals content. This work suggests the use of natural clay minerals as potential PAHs geo-indicators in response to air pollution, complementary to current air and biological analyses.

Castilla-La Mancha (central Spain) is a region characterized by significant agricultural production aimed at high-quality food products such as wine and olive oil. The quality of agricultural products depends directly on the soil quality. Soil geochemistry, including dispersion maps and the recognition of baselines and anomalies of various origins, is the most important tool to assess soil quality. With this objective, 200 soil samples were taken from agricultural areas distributed among the different geological domains present in the region. Analysis of these samples included evaluation of edaphological parameters (reactivity, electrical conductivity, organic matter content) and the geochemistry of major and trace elements by X-ray fluorescence. The dataset obtained was statistically analyzed for major elements and, in the case of trace elements, was normalized with respect to Al and analyzed using the relative cumulative frequency (RCF) distribution method. Furthermore, the geographic distribution of analytical data was characterized and analyzed using the kriging technique, with a correspondence found between major and trace elements in the different geologic domains of the region as well as with the most important mining areas. The results show an influence of the clay fraction present in the soil, which acts as a repository for trace elements. On the basis of the results, of the possible elements related with clay that could be used for normalization, Al was selected as the most suitable, followed by Fe, Mn, and Ti. Reference values estimated using this methodology were lower than those estimated in previous studies.

In healthy buildings, it is considered essential to quantify air quality. One of the most fashionable indicators is radon gas. To determine the presence of this element, which is harmful to health, in the environment, the composition of the soil is studied. The presence of radon gas within a building depends both on the terrain in which it is located and on the composition of the materials of which it is composed, and not as was previously believed, only by the composition of the soil (whether granitic or not). Many countries are currently studying this phenomenon, including Spain where the building regulations regarding the accumulation of radon gas, do not list in their technical codes, the maximum dose that can a building can hold so that it is not harmful to people and the measures to correct excessive accumulation. Therefore, once the possible existence of radon in any underground building has been verified, regardless of the characteristics of the soil, the importance of defining and unifying the regulations on different levels of radon in all architectural constructions is evident. Medical and health science agencies, including the World Health Organization, consider that radon gas is a very harmful element for people. This element, in its gaseous state, is radioactive and it is present in almost soils in which buildings are implanted. Granitic type soils present higher levels of radon gas. Non-granitic soils have traditionally been considered to have very low radon levels. However, this paper demonstrates the relevant presence of radon in non-granitic soils, specifically in clayey soils, by providing the results of research carried out in the underground air raid shelter at Balmis Square in Alicante (Spain). The results of the measurements of radon accumulation in the Plaza Balmis shelter are five times higher than those obtained in a similar ungrounded building. This research addresses the constructive typology of an under-ground building and the radon presence in its interior obtained using rigorous measurement techniques.