In order to determine the mechanisms of the retention of 60Co, 85Sr and 134Cs in natural silica sand columns, desorption experiments were performed by changes of pH and ionic strength and by injection of natural organic matter (NOM). Injection of KCl (0.1 M) resulted in a high release of 60Co (60-100%) and 85Sr (72-100%) but a smaller release of 134Cs (31-66%). Only limited release of 60Co (66%) and 85Sr (71%) and no release of 134Cs were observed by injection of NOM. The different percentages of desorption were related to the chemical characteristics of the organic colloids previously retained in columns before the desorption step. The results evidenced different sorption processes on energetically heterogeneous surface sites. According to the initial conditions, the binding of the radionuclides to the solid phase resulted from weak and easily reversible sorption processes to strong association probably by inner sphere complexes. The rather weak release of 134Cs by KCl was attributed to the strong retention of 134Cs by clay coatings on the natural silica sand surfaces. © 2005 Elsevier Ltd. All rights reserved.

Transfer parameters are key inputs for modeling radionuclide transfer in the environment and estimating risk to humans and wildlife. However, there are no data for many radionuclide-foodstuff/wildlife species combinations. The use of parameters derived from stable element data when data for radionuclides are lacking is increasingly common. But, do radionuclides and stable elements behave in a sufficiently similar way in the environment? To answer this question, at least for soil to plant transfer, sampling was conducted in four different countries (England, Kazakhstan, Spain and Ukraine) affected by different anthropogenic radionuclide source terms (in chronological order: global fallout, Semipalatinsk Test Site, the 1957 Windscale accident and the 1986 Chernobyl accident) together with a bibliographical review. Soil to grass transfer parameters (ratio between dry matter concentrations in plant and soil), Fᵥ, for ¹³⁷Cs and ⁹⁰Sr were significantly higher than those for stable elements, suggesting that the use of the latter could lead to underestimating radionuclide concentrations in plant samples Transfer parameters for ¹³⁷Cs and stable Cs were linearly correlated, with a slope of 1.54. No such correlation was observed for ⁹⁰Sr and stable Sr, the mean value of the ⁹⁰Sr:Sr ratio was 35 ranging (0.33–126); few data were available for the Sr comparison. The use of radionuclide transfer parameters, whenever possible, is recommended over derivation from stable element concentrations. However, we acknowledge that for many radionuclides there will be few or no radionuclide data from environmental studies. From analyses of the data collated there is evidence of a decreasing trend in the Fᵥ(¹³⁷Cs)/Fᵥ(Cs) ratio with time from the Chernobyl accident.

This study employs the grain size distributions and the concentrations and isotopic compositions of Sr, Nd, and Pb in the precipitation samples collected from the Laohugou Glacier (LHG) in northeastern Tibetan Plateau (TP) during August 2014–2015 to investigate seasonal variability in the insoluble precipitation particle sources. Fine dust particle (0.57–27 μm) depositions dominated in autumn and winter, whereas both fine and coarse dust particle (27–100 μm) depositions were found in spring and summer. Furthermore, the concentrations of Sr, Nd, and Pb also varied seasonally—the highest and lowest Sr and Nd concentrations were recorded in spring and autumn, respectively, whereas the highest and lowest Pb concentrations were recorded in winter and summer, respectively. The Sr and Nd isotopes revealed that the dust in the winter precipitation originated predominately from the Taklimakan Desert and that in spring originated from the Badain Jaran and Qaidam deserts. The precipitation residues in summer were derived from a complex mixture of dust sources from the Gobi and other large deserts in northwest China. Autumn residues were predominately sourced from local soil near the LHG as well as from the Qaidam Basin and the northern TP surface soil. The Taklimakan, long suspected as a major source of long-range transported dust, was an insignificant contributor to the precipitation over LHG during spring, summer, and autumn. Further, the Pb isotopic ratios indicated a primary impact of anthropogenic pollutants for most part of the year (except spring). Meteorological data and the MODIS AOD model are in good agreement with the results from the analyses of the Sr, Nd, and Pb isotopes for the LHG particle source, and further clarify the source regions. Thus, this study thus provides new evidence on the seasonal variability of the sources of the residual particles in remote glaciers in Central Asia.

Human activities lead to increasing concentration of the stable elements cesium (Cs) and strontium (Sr) and their radioactive isotopes in the food chain, where plants play an important part. Here we investigated Plantago major under the influence of long-term exposure to stable Cs and Sr.The plants were cultivated hydroponically in different concentrations of cesium sulfate (between 0.002 and 20 mM) and strontium nitrate (between 0.001 and 100 mM).Uptake of Cs and Sr into leaves was analyzed from extracts by inductively coupled plasma mass spectrometry (ICP-MS). It was increased with increasing external Cs and Sr concentrations. However, the efficiency of Cs and Sr transfer from solution to plants was higher for low external concentrations. Highest transfer factors were 6.78 for Cs and 71.13 for Sr. Accumulation of Sr was accompanied by a slight decrease of potassium (K) and calcium (Ca) in leaves, whereas the presence of Cs in the medium affected only uptake of K.The toxic effects of Cs and Sr were estimated from photosynthetic reactions and plant growth.In leaves, Cs and Sr affected the chlorophyll fluorescence even at their low concentrations. Low and high concentrations of both ions reduced dry weight and length of roots and leaves.The distribution of the elements between the different tissues of leaves and roots was investigated using Energy Dispersive X-Ray microanalysis (EDX) with scanning electron microscope (SEM). Overall, observations suggested differential patterns in accumulating Cs and Sr within the roots and leaves.When present in higher concentrations the amount of Cs and Sr transferred from environment to plants was sufficient to affect some physiological processes. The experimental model showed a potential for P. major to study the influence of radioactive contaminants and their removal from hotspots.

Huelva is a highly industrialized city in SW Spain hosting, among others, a Cu smelter, a phosphate fertilizer plant, a power plant, and oil refineries. This study aims to evaluate metal concentrations in lichens as bioindicators of atmospheric pollution in the impacted urban areas. Xanthoria parietina species from Huelva and nearby villages, as well as reference samples from remote, non-contaminated urban areas, were analyzed for trace elements (V, Cr, Mn, Co, Ni, Cu, Zn, Sr, As, Cd, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Er, Tm, Yb, Lu, Pb, Th, U) using Inductively Coupled Plasma-Mass Spectrometry; and for major elements (Ca, K, Mg, P, and S) by Inductively Coupled Plasma-Optical Emission Spectrometry after acid digestion.The metal composition of X. parietina exhibits spatial distribution patterns with extremely elevated concentrations (Co, Ni, Cu, Zn, As, Cd, Sb, Ba, Pb, U, and S) in the surroundings of the industrial estates to <1 km distance. Mean concentrations were significantly lower in the urban areas >1 km from the pollution sources. However, air pollution persists in the urban areas up to 4 km away, as the mean concentrations of Cu, Zn, As, Cd, Sb and S remained considerably elevated in comparison to the reference samples. Though rigorous source apportionment analysis was not the aim of this study, a good positive correlation of our results with metal abundances in ambient particulate matter and in pollution sources points to the Cu smelter as the main source of pollution. Hence, the severe air pollution affecting Huelva and nearby urban areas may be considered a serious health risk to local residents.

In this paper, the equilibrium and mass transfer kinetics of Sr2+ sorption onto 3 types of microplastics, including polyethylene terephthalate (PET), polyethylene (PE), and polyvinyl chloride (PVC) were investigated. A novel film-pore mass transfer (FPMT) model was developed and used to study the sorption kinetics and mechanisms. This model can be used to describe the external mass transfer (EMT) and the internal mass transfer (IMT) processes and to calculate the diffusion rate. The FPMT model could successfully predict the kinetics data of Sr2+ sorption onto microplastics. The maximum value of the EMT rate achieved at the beginning of sorption was 103 μg g−1·h−1 for PET, 247 μg g−1·h−1for PE, and 854 μg g−1·h−1 for PVC, and then it decreased dramatically with time. The IMT rate was far less than the EMT rate, and decreased slowly with time. The overall sorption rate of Sr2+ onto microplastics was controlled by the external mass transfer step.

This study aims to summarize results on potential phytomanagement of two metal(loid)-polluted military soils using Miscanthus x giganteus. Such an option was tested during 2-year pot experiments with soils taken from former military sites in Sliač, Slovakia and Kamenetz-Podilsky, Ukraine. The following elements were considered: As, Cu, Fe, Mn, Pb, Sr, Ti, Zn and Zr. M. x giganteus showed good growth at both military soils with slightly higher maximum shoot lengths in the second year of vegetation. Based on Principal Component Analysis similarities of metal(loid) uptake by roots, stems and leaves were summarized. Major part of the elements remained in M. x giganteus roots and rather limited amounts moved to the aerial parts. Levels taken up decreased in the second vegetation year. Dynamics of foliar metal(loid) concentrations divided the elements in two groups: essential elements required for metabolism (Fe, Mn, Cu, and Zn) and non-essential elements without any known metabolic need (As, Sr, Ti, and Zr). Fe, Mn, Ti and Sr showed similar S-shaped uptake curve in terms of foliar concentrations (likely due to dilution in growing biomass), while Cu exhibited a clear peak mid-season. Behavior of Zn was in between. Foliar Zr and As concentrations were below detection limit. The results illustrated a good potential of M. x giganteus for safely growing on metal-polluted soils taken from both military localities.

Bogota registers frequent episodes of poor air quality from high PM₁₀ concentrations. It is one of the main Latin American megacities, located at 2600 m in the tropical Andes, but there is insufficient data on PM₁₀ source contribution. A characterization of the chemical composition and the source apportionment of PM₁₀ at an urban background site in Bogota was carried out in this study. Daily samples were collected from June 2015 to May 2016 (a total of 311 samples). Organic carbon (OC), elemental carbon (EC), water soluble compounds (SO₄²⁻, Cl⁻, NO₃⁻, NH₄⁺), major elements (Al, Fe, Mg, Ca, Na, K, P) and trace metals (V, Cd, Pb, Sr, Ba, among others) were analyzed. The results were interpreted in terms of their variability during the rainy season (RS) and the dry season (DS). The data obtained revealed that the carbonaceous fraction (∼51%) and mineral dust (23%) were the main PM₁₀ components, followed by others (15%), Secondary Inorganic Compounds (SIC) (11%) and sea salt (0.4%). The average concentrations of soil, SIC and OC were higher during RS than DS. However, peak values were observed during the DS due to photochemical activity and forest fires. Although trace metals represented <1% of PM₁₀, high concentrations of toxic elements such as Pb and Sb on RS, and Cu on DS, were obtained. By using a PMF model, six factors were identified (∼96% PM₁₀) including fugitive dust, road dust, metal processing, secondary PM, vehicles exhaust and industrial emissions. Traffic (exhaust emissions + road dust) was the major PM₁₀ source, accounting for ∼50% of the PM₁₀. The results provided novel data about PM₁₀ chemical composition, its sources and its seasonal variability during the year, which can help the local government to define control strategies for the main emission sources during the most critical periods.

This study examines size-resolved heavy metal data for particles sampled near an urban site affected by non-ferrous metal smelting in China with a focus on how particle sizes impact regional respiratory deposition behavior. Particles with aerodynamic diameters between 0.43 and 9 μm were collected during winter haze episodes from December 2011 to January 2012. The results showed that concentrations of individual trace elements ranged from ∼10⁻²–∼10⁴ ng/m³. Mass size distributions exhibit that Cu, Zn, As, Se, Ag, Cd, TI, and Pb have unimodal peak in fine particles range (<2.1 μm); Al, Ti, Fe, Sr, Cr, Co, Ni, Mo, and U have unimodal peak in coarse range (>2.1 μm), and Be, Na, Mg, Ca, Ba, Th, V, Mn, Sn, Sb, and K have bimodal profiles with a dominant peak in the fine range and a smaller peak in the coarse range. The total deposition fluxes of trace elements were estimated at 2.1 × 10⁻² – 4.1 × 10³ ng/h by the MPPD model, and the region with the highest contribution was the head region (42% ± 13%), followed by the tracheobronchial region (11% ± 3%) and pulmonary region (6% ± 1%). The daily intake of individual element for humans occurs via three main exposure pathways: ingestion (2.3 × 10⁻⁴ mg/kg/day), dermal contact (2.3 × 10⁻⁵ mg/kg/day), and inhalation (9.0 × 10⁻⁶ mg/kg/day). A further health risk assessment revealed that the risk values for humans were all above the guidelines of the hazard quotient (1) and cancer risk (10⁻⁶), indicating that there are potential non-cancer effects and cancer risks in this area.

Concentrations of halogenated pesticides in freshwater fish can be affected by age, size, trophic position, and exposure history. Exposure history may vary for individual fish caught at a single location due to different life histories, e.g. they may have hatched in different tributaries before migrating to a specific lake. We evaluated correlations of pesticide concentrations in freshwater brown trout (Salmo trutta) from the Clutha River, New Zealand, with potential predictors including capture site, age, length, trophic level, and life history. Life history was determined from otolith (fish ear bone) strontium isotope signatures, which vary among tributaries in the region of our study. Variability in pesticide concentrations between individual fish was not well explained by capture site, age, length, or trophic level. However, hexachlorobenzene (HCB) and chlorpyrifos concentrations were distinct in lake-based trout with different life histories. Additionally, one of the riverine life histories was associated with relatively high concentrations of total endosulfans. Linear models that included all potential predictor variables were evaluated and the resulting best models for HCB, chlorpyrifos, and total endosulfans included life history. These findings show that in cases where otolith isotope signatures vary geographically, they can be used to help explain contaminant concentration variations in fish caught from a single location.