Assessment Of Soil Pollution Research Articles

Genomics technology for assessing soil pollution

Transcription and metabolite analysis is a powerful way to reveal physiological shifts in response to environmental pollution. Recent studies on earthworms, including one in BMC Biology, show that the type of pollution and its availability for uptake by organisms can differentially affect transcription and metabolism.

A novel dynamic approach for automatic microsampling and continuous monitoring of metal ion release from soils exploiting a dedicated flow-through microdialyser

In this paper, a novel concept is presented for automatic microsampling and continuous monitoring of metal ions in soils with minimum disturbance of the sampling site. It involves a hollow-fiber microdialyser that is implanted in the soil body as a miniaturized sensing device. The idea behind microdialysis in this application is to mimic the function of a passive sampler to predict the actual, rather than potential, mobility and bioavailability of metal traces. Although almost quantitative dialysis recoveries were obtained for lead (> or = 98%) from aqueous model solutions with sufficiently long capillaries (l > or = 30 mm, 200 microm i.d.) at perfusion rates of 2.0 microL min(-1), the resistance of an inert soil matrix was found to reduce metal uptake by 30%. Preliminary investigation of the potential of the microdialysis analyser for risk assessment of soil pollution, and for metal partitioning studies, were performed by implanting the dedicated probe in a laboratory-made soil column and hyphenating it with electrothermal atomic absorption spectrometry (ETAAS), so that minute, well-defined volumes of clean microdialysates were injected on-line into the graphite furnace. A noteworthy feature of the implanted microdialysis-based device is the capability to follow the kinetics of metal release under simulated natural scenarios or anthropogenic actions. An ancillary flow set-up was arranged in such a way that a continuous flow of leaching solution--mild extractant (10(-2) mol L(-1) CaCl2), acidic solution (10(-3) mol L(-1) HNO3), or chelating agent (10(-4) or 10(-2) mol L(-1) EDTA)--was maintained through the soil body, while the concentration trends of inorganic (un-bound) metal species at the soil-liquid interface could be monitored at near real-time. Hence, relevant qualitative and quantitative information about the various mobile fractions is obtained, and metal-soil phase associations can also be elucidated. Finally, stimulus-response schemes adapted from neurochemical applications and pharmacokinetic studies are to be extended to soil research as an alternative means of local monitoring of extraction processes after induction of a chemical change in the outer boundary of the permselective dialysis membrane.

Multivariate statistical assessment of polluted soils

AbstractThis study deals with the application of several multivariate statistical methods (cluster analysis, principal components analysis, multiple regression on absolute principal components scores) for assessment of soil pollution by heavy metals. The sampling was performed in a heavily polluted region and the chemometric analysis revealed four latent factors, which describe 84.5 % of the total variance of the system, responsible for the data structure. These factors, whose identity was proved also by cluster analysis, were conditionally named “ore specific”, “metal industrial”, “cement industrial”, and “steel production” factors. Further, the contribution of each identified factor to the total pollution of the soil by each metal pollutant in consideration was determined.

Crop-specific human exposure assessment for polycyclic aromatic hydrocarbons in Czech soils

Polycyclic aromatic hydrocarbons (PAH) are pollutants frequently found in soils, particularly in urban areas. From polluted soils, the PAH can be taken up into crops and the consumption of these crops can result in a human health risk. We estimated the bioconcentration factors (BCF) in the edible plant tissues for PAH using crop-specific models for leafy vegetables, root vegetables, potatoes and tree fruits. The estimates were compared with results from the empirical regression of Travis and Arms (T&A) for above-ground vegetation. The comparison shows that the use of crop-specific models resulted in lower BCF values of pollutant concentrations in fruits, potatoes and leafy vegetables, particularly for the heavier PAH (M>220 g mol −1). However, the crop-specific models yielded higher BCF values for root vegetables (carrot) and leafy vegetables if the attached soil particles (1%) were considered. Consequently, the average daily intake of benzo( a)pyrene (BaP) by an adult Czech through fruits and vegetables was estimated with the crop-specific models to be 190 ng BaP per person, and 460 ng BaP per person with the T&A regression, for a soil concentration of 1 mg BaP kg −1 soil (wet wt.). A virtually safe oral dose of BaP, as a marker of the carcinogenic PAH, was suggested by a European expert commission to be below 4.2 to 35 ng per person and day. Using these figures, an acceptable soil concentration of BaP was estimated for the purpose of crop production to be below 0.02 or 0.18 mg kg −1 (wet wt.) with the crop-specific models, and below 0.01 or 0.08 mg kg −1 (wet wt.) with T&A. The results demonstrate clearly the advantage of the crop-specific exposure assessment: it can be adapted to different food baskets and allows more effective risk assessment and management of soil pollution.

Some major developments in soil science since the mid-1960s

Although the science of soil was established about 150 years ago with the modern soil science taking off after the Second World War, the new Millennium has brought other challenges and new opportunities. Rapidly increasing population in countries that can least afford it have made them food-insecure. With inadequate inputs in agriculture, developing countries are degrading their lands rapidly and destroying ecosystems. Affluence in the richer countries has precipitated other problems hampering ecosystem functions and quality of land resources. These changing conditions have placed new demands on both the society and the soil science community. The latter has resulted in new areas of soil sub-disciplines such as land and soil quality, land degradation and desertification, cycling of bio-geochemicals, soil pollution assessment and monitoring etc. Advances in information technology have also enabled the science to meet the new demands of the enviro-centric world. In the last decade, noticeable changes are evident in methods and research priorities in the discipline. Soil resource assessment and monitoring is entering a new era, in terms of quality of information produced by new information technologies through the innovative use of Geographic Information Systems and remote sensing and significantly improving the acceptance and use of soil survey information. Electronic technology has dramatically increased the demand for and ability to process more data. Other innovations have resulted in quantitative approaches in soil genetic studies and demonstrated the integral role of soils in ecosystems. For global and regional resource assessment, concepts and procedures were refined. The World Reference Base for soil classification and the Global Soil and Terrain Database are the first steps towards standardisation and a more detailed assessment of global soils. The global assessment of human-induced land degradation and vulnerability to desertification are benchmark products of the databases. Environmental pollution and its effects on human and ecosystem health have become public concerns and soil science has contributed to localising, quantifying, and developing mitigation technologies to address the problems. The challenges of climate change and the charge to maintain ecological integrity have been met with technologies such as conservation tillage, agroforestry, precision agriculture etc. New concepts such as multi-functionality of land, soil quality, sustainability of agriculture and carbon sequestration, have emerged leading to new management strategies and an enhanced quality of life.

Critical examination of trace element enrichments and depletions in soils: As, Cr, Cu, Ni, Pb, and Zn in Swiss forest soils

The aim of this study was to obtain an overview of trace element concentrations in Swiss forest soils and to critically assess the measured values with respect to anthropogenic input vs. lithogenic background. Twenty-three sites were selected which represent a broad range of natural forest sites, bedrock material and soil types of Switzerland. At each site, samples were collected from all genetic soil horizons down to a C or B/C horizon. Total concentrations of As, Cr, Cu, Ni, Pb, and Zn in all samples were determined by X-ray fluorescence spectrometry. There were distinct differences in the geological background values estimated from the concentrations measured in the samples from the lowest soil horizon. Background concentrations for Cr and Ni were lowest in granite and gneiss, whereas Pb and Zn were highest in limestone and marl. Enrichment or depletion of the trace elements was assessed using Zr as reference element. Within the same profile, the six trace elements showed completely different enrichment/depletion patterns with depth. The various natural processes and anthropogenic inputs that can lead to these patterns are critically discussed. Based on this critical assessment, pollution of the investigated forest soils was found to be most severe for Pb and Zn and to a somewhat lesser extent for As and Cu, whereas anthropogenic input of Cr and Ni seems to be less important. The data suggest that a critical evaluation of enrichment factors is a better tool to assess soil pollution with trace elements than the use of maximum allowable concentrations (MAC) for topsoil samples. The enrichment factors calculated as described here consider the effects of geological variation on metal abundances whereas the MAC does not. In order to obtain an estimate of soil solution concentrations, water extracts of the samples collected from a subset of 10 soil profiles were analyzed for the same trace elements. Solubility of all elements generally decreased with soil depth. An exception was Cr, Cu, and Ni solubility in the humus layer, which was lower than in the underlying mineral horizon. For all elements, solubility was higher for the collective of soil samples depleted in this element when compared to the samples, in which the element was enriched.

Tissue-Level Biomarkers in Sentinel Slugs as Cost-Effective Tools to Assess Metal Pollution in Soils

In previous laboratory experiments, slugs were shown to be sensitive to metal pollution. Therefore, they might be invaluable instruments for biological assessment of soil pollution. The present investigation was carried out to validate previous laboratory results in a field study. Slugs were collected from an abandoned copper mine (Parys mountain top, PMT), from a site 7 km away from the mine (Parys mountain bottom, PMB), and from a clean site (Snowdonia Cwm Idwal, SCI) in Wales in early July 1994. Whole soft body and digestive gland Cd, Cu, and Zn concentrations were measured by means of atomic absorption spectrophotometry (AAS). The digestive gland was the main tissue for metal accumulation, with significant differences in tissue metal levels between samples from different sites. PMB presented the highest Cd and Zn levels and the highest Cu levels were found at PMT. In addition, metals were demonstrated in situ by autometallography as black silver deposits (BSD) on histological sections of digestive gland tissue. The extent of BSD within lysosomes of digestive cells was closely related to metal levels determined by AAS. Histochemistry revealed that Ca metabolism and structural and reserve connective tissues might be altered in slugs living in metal-polluted soils. Finally, tissue-level biomarkers of biological effect [mean epithelial thickness (MET), mean diverticular radius (MDR), mean luminal radius (MLR), MET/MDR and MLR/MET] were quantified by image analysis of digestive gland histological sections stained with hematoxylin-eosin. MET and MDR values of slugs collected from SCI were high, while slugs from PMB presented low MLR/MET associated with environmental stress induced by metal exposure. We conclude that exposure and effect biomarkers recorded in sentinel slugs could be sensitive, quick, and cheap indices of metal pollution in soils. A Slug Watch monitoring program could be developed similar to the Mussel Watch program, which is currently applied to assess environmental quality in coastal and estuarine areas.

Proposed assessment of the vulnerability of European soils to pollution using a soter shell approach

AbstractAfter recent unanticipated occurrences of environmental pollution caused by the time‐delayed and sudden release of contaminants previously believed to be held firmly in soils, awareness has increased that the vulnerability of soils to chemical degradation needs to be assessed and mapped. Although some soils appear to be capable of receiving and holding chemical compounds while at the same time retaining their ecological functions, others are readily damaged. Procedures for identifying areas where vulnerable soils occur are presented, with special reference to the minimum soil data sets that would be required in a small scale study at the European level using geographical information systems. These data can readily be compiled, stored and processed with the relational database management system developed for SOTER, The 1:1 million world soil and terrain digital database project of the International Society of Soil Science, which is co‐ordinated by the International Soil Reference and Information Centre. the proposed initial soil vulnerability programme would essentially serve to increase awareness about areas prone to chemical soil degradation, and will form the basis for implementing soil pollution assessment programmes at larger scales (1:1 M to 1:250 000). the latter national or regional programmes would include the identification of the major sources of soil pollution, and measurement of the accumulated load and the rate of loading according to uniform and standardized procedures, providing the conceptual basis for developing process based models to assess where particular types of soil degradation are likely to occur.

Bioavailability of pollutants to soil organisms via the soil solution

The hypothesis that the availability of pesticides to organisms in soil is determined solely by their concentration in the pore water was tested. The potato cyst nematode Globodera rostochiensis was exposed to the pesticides chlorpyrifos and pentachlorophenol mixed into two arable soils and one artificial soil. The nematode was also exposed to the pesticides in saline solution and in pore water isolated from these soils. Mixed in soil, chlorpyrifos was a 1000 times, and pentachlorophenol more than 100 times less toxic than if dissolved in solution. Sorption of these pesticides to dissolved organic matter in pore water decreased their toxicity only slightly. The concentrations in the soil solution, in equilibrium with soil at the soil LC 50 content, were similar to the LC 50 values determined in saline or soil solution. The use of non-adsorbing aqueous media is proposed for the toxicity testing of chemicals in the hazard assessment of soil pollution.

Qualitativer Bodenschutz in der Schweiz - eine Standortbestimmung

The present paper deals with the efforts made in Switzerland to treat the qualitative soil protection (monitoring and assessment of soil pollution mainly by heavy metals) on a scientific and legislative basis. In addition to a critical appreciation of guide levels for pollutants in soil, indications on important gaps in research are given (e.g. risk assessment in soils with exceeded guide levels or organic micropollutants).