Inmaculada Menéndez

Soil solution composition in forest soils of sierra de gata mountains, Central‐Western Spain: Relationship with soil water content

Nutrient ion concentrations in soil water were assessed in three deciduous forests in the Sierra de Cata Mountains, central‐western Spain, with annual precipitation ranging between 720 and 1,580 mm. Soil solutions were obtained at incremental depths from 15 to 110 cm with tension lysimeters and analyzed for pH, electrolytic conductivity (EC), dissolved organic carbon, soluble Si and Al components, Fe3+, Cu2+, Mn2+, Zn2+, Na+, K+, Ca2+, Mg2+, Cl−, SO4 2‐, and NO‐3. In general, ion concentrations and pH decreased with depth (from pH 6.5 to 5.5) and EC from 50 to 25 μS cm−1. At the driest forest site (Fuenteguinaldo), the highest EC values were at the profile surface, probably due to a lower degree of leaching and increased capillary action, as compared with profiles from forests with a higher annual precipitation. Soil water content was correlated with soil solution composition, showing a strong interdependence. The ionic composition of soil water in the three Cambisols, however, did not reflect the differe...

Functional and chemical calibrates of ceramic cup water samplers in forest soils

A study was conducted to assess the properties of a tension porous-ceramic cup soil-solution sampler and its usefulness in extracting soil solutions in selected forest soils (haplic Umbrisols) at “Sierra De Gata” Mountains, CW-Spain. The main characteristics of the sampler evaluated were hydraulic conductivity, the time required to obtain the soil-water sample, and the volume of water uptake for optimum calibration prior to analysis of the chemical composition of the soil water solution. Hydraulic conductivity values were not substantially modified during the sampling (two hydrologic cycles). The time required to obtain the samples was relatively short (mean value 2 h) and the sphere of sampling influence was small (radii ranging from 6 to 15 cm), both depending on the size of the sampler. The chemical analyses obtained after calibrating the ceramic cup sampler pointed to: a) an effect of light adsorption by the ceramic cup, involving DOC, major and minor cations (Na+, K+, Ca2+, Mg2+, Fe3+, Al3+, Mn2+, and Zn2+), and and anions; b) a release of H4SiO4; and c) no clear trend for Cl−. The Cu2+ values obtained between a blank soil solution and those obtained after passage through the ceramic cup were not correlated. Relatively low pH values (the pH of these acid forest soils is 5.1–6.2) favor the adsorption of anions and DOC, the latter also increasing the exchange capacity and cation adsorption of the cup. The results point to a generalized tendency of the ceramic cup to adsorb DOC, cations and anions (with the exception of chlorides), H4SiO4, by contrast, being released.

Saharan dust and the impact on adult and elderly allergic patients: the effect of threshold values in the northern sector of Gran Canaria, Spain

Abstract Gran Canaria Island is frequently impacted by Saharan dust, a health hazard of particular concern to the island population and health agencies. Airborne mineral dust has the severest impact on the higher age groups of the population, and those with respiratory conditions; despite that, on average, the ambient particulate matter (PM) concentrations fall within international PM guidelines. During 2010 and 2011, an epidemiological survey, in parallel with an air quality study, was conducted at the Dr Negrín hospital in Gran Canaria. This included the quarterly monitoring of outpatients and recording of emergency patients with respiratory diseases, together with the measurement of aerosol, meteorological, and PM-related air quality levels. The finer more toxic particles were collected with PM2.5 (particulate matter with aerodynamic diameter less than 2.5 μm) aerosol samplers. The filter samples were gravimetrically and chemically analyzed for their elemental, water-soluble ions, carbon, and mineralogical contents. Individual particle morphology was measured by Scanning Electron Microscopy. Statistical analysis of the chemical and clinical data included the analysis of variance and calculation of Spearman correlation coefficients. No statistically significant relations were found between the allergic control group, the emergency room admissions, pulmonary conditions, medication, and elevated Saharan dust levels. However, changing environmental conditions, such as an increase in humidity or a reduction in ambient air temperature made a significant difference to the outcomes recorded on the health statements of the allergic and respiratory illness groups of the Gran Canary population.