Singular Spectrum Analysis of Hydroecological Parameter Dynamics of Lake Naroch’ in the Years 1978–2015

Singular Spectrum Analysis (SSA) has been used to decompose continuous series of data on certain characteristics of Lake Naroch’ ecosystem during the vegetative seasons of years 1978–2015 into a long-time trend, a periodic component, and a residue not amenable to decomposition. The contribution of each component to changes in this variable has been assessed. The trends accounted for 78–97% of parameter variability, and the periodic components accounted for 2.5–15%. The fluctuations of phytoplankton and zooplankton biomass dynamics were the most diverse, and the contribution of these components was the greatest (15 and 8%, respectively). The periodic components in the changes of all parameters could be divided into four groups according to period duration (17–22, 7–15, 4–7, and less than 4 years). Multidimensional factor analysis of seven biotic parameters was performed in order to identify fluctuations in the ecosystem. Five major factors accounting for 93.6% of ecosystem changes together were identified, and each factor variable was subjected to SSA analysis. The period durations were similar for the oscillatory components identified. The first factor was interpreted as a trophic status of the water body, the second was taken to be the geographical location that defines the amount of solar radiation energy available, the third was taken to be the availability of biogenic elements (phosphorus in particular), and the fourth was interpreted as specific developmental cycles of live components of the ecosystem.     

Radionuclide transfer to fruits: a critical review. Introduction

This paper provides a brief introduction to fruit, their definition, classification and geographical distribution. In the following review, the term "fruit" refers not to a well-defined botanical plant part but, in the horticultural sense, to a component of the human diet generally consumed as a dessert item. Plants that bear fruits cover a vast range of morphological and physiological traits. A generic classification of fruit-bearing plants is proposed for use in studies on radionuclide transfer to fruit.     

Short rotation coppice for revaluation of contaminated land.

When dealing with large-scale environmental contamination, as following the Chernobyl accident, changed land use such that the products of the land are radiologically acceptable and sustain an economic return from the land is a potentially sustainable remediation option. In this paper, willow short rotation coppice (SRC) is evaluated on radiological, technical and economic grounds for W. European and Belarus site conditions. Radiocaesium uptake was studied in a newly established and existing SRC. Only for light-texture soils with low soil potassium should cultivation be restricted to soils with contamination levels below 100-370 kBq m-2 given the TFs on these soils (5 x 10(-4) and 2 x 10(-3) m2 kg-1) and considering the Belarus exemption limit for firewood (740 Bq kg-1). In the case of high wood contamination levels (> 1000 Bq kg-1), power plant personnel working in the vicinity of ash conveyers should be subjected to radiation protection measures. For appropriate soil conditions, potential SRC yields are high. In Belarus, most soils are sandy with a low water retention, for which yield estimates are too low to make production profitable without irrigation. The economic viability should be thoroughly calculated for the prevailing conditions. In W. Europe, SRC production or conversion is not profitable without price incentives. For Belarus, the profitability of SRC on the production side largely depends on crop yield and price of the delivered bio-fuel. Large-scale heat conversion systems seem the most profitable and revenue may be considerable. Electricity routes are usually unprofitable. It could be concluded that energy production from SRC is potentially a radiologically and economically sustainable land use option for contaminated agricultural land.     

Atmospheric xenon radioactive isotope monitoring

The Comprehensive Nuclear Test Ban Treaty (CTBT) organisation is implementing a world-wide monitoring network in order to check that the State Signatories comply with the treaty. One of the monitoring facilities consists of an atmospheric noble gas monitoring equipment. According to the requirements annexed in the treaty, the French Atomic Energy Commission (CEA) developed a device, called SPALAX, which automatically extracts xenon from ambient air and makes in situ measurements of the activities of four xenon radioisotopes (131mXe, 133mXe, 133Xe, 135Xe). The originality of this device is noticeable essentially in the gas sample processing method: thanks to the coupling of a gas permeator and of a noble gas specific adsorbent, it can selectively extract and concentrate xenon to more than 3 x 10 E6. This process is carried out continuously without cryogenic cooling, without any regeneration time. The detection of the xenon radioactive isotopes is done automatically by high spectral resolution gamma spectrometry, a robust technology well-suited for on-field instrumentation. In the year 2000, a prototype was involved in an international evaluation exercise directed by the CTBT organisation (CTBTO). This exercise demonstrated that the SPALAX equipment perfectly met the requirements of the CTBTO for such systems. On the basis of the continuous 24-h resolution record of the atmospheric xenon radioactive isotopes concentrations, the SPALAX system also demonstrated that ambient levels of 133Xe can fluctuate quickly from less than the detection limit to over 40 x 10(-3) Bq m(-3). In order to build an industrial version of this equipment, the CEA entered into a partnership with a French engineering company (S.F.I., Marseille, France), which is now able to produce an industrial version of SPALAX, i.e. more compact and more efficient than the prototypes. The 133Xe minimum detectable concentration is 0.15 x 10(-3) Bq m(-3) air per 24 h sampling cycle.     

The protection of wildlife from mortality: hypothesis and results for risk assessment

Wildlife deaths associated with cyanide-bearing tailings dams are a significant environmental issue that has affected the gold mining industries for many years and still characterized by little knowledge about how to measure, monitoring, reduce or eliminate those deaths. The purpose of this paper is statistically to determine: the potential for establishing causal relations between exposure to cyanide (in its most common species relevant to tailings) and response (measured by death counts), to develop a protocol of data analysis, the understanding of the significance of data gaps, and the effect of likely risk management interventions to achieve the goals of the International Cyanide Management Code (ICMC); [ICMC The International Cyanide Management Institute. International cyanide management code, the international cyanide management institute 2005, www.cyanidecode.org.]. However, operator's certification under the ICMC is difficult because of the limited data and potentially serious under-estimation of the death counts. This is due to observational skill and monitoring frequency, the small size of the carcasses, large extent of tailings facilities, carcasses loss by; entombment in tailings, sink, or taken by scavenging wildlife. This (1st order or bounding) assessment results focus on bird-deaths, which appear to be most frequent at sites where elevated cyanide concentrations are found. Those results indicate that the empirical causal associations we generate support the hypotheses that: This paper also develops the basis for a complete risk assessment study to be based on additional data gathering activities and detailed statistical analyses. These two activities, combined with a risk management plan also being developed, will provide a tool for compliance with the ICMC.     

Determination of the sources of toxic elements in environmental particles using microscopic and statistical analysis techniques

Samples of urban dust were physically fractionated into subsamples having unique size, density, ferromagnetism, and elemental compositional characteristics. The high density fractions containing the majority of each of the potentially toxic metals (Pb, Cd, Zn, Cr, Co, Mn) were subjected to X-ray microanalysis and to bulk analysis using instrumental neutron activation. Microanalysis was used to classify individual particles with respect to primary sources. The bulk analytical results were subjected to factor analysis to delineate the underlying factors (particle sources) responsible for the compositional variation in the subsamples. The advantages of the combined use of microanalytical and statistical techniques for source definition are described. X-ray microanalysis is used to substantiate the attribution of a given factor to a suspected particle source, to aid in the determination of the number of factors (sources) present, and to assess the extent to which a given factor represents a unique source of particles. Bulk analysis/factor analysis promotes the most effective use of X-ray microanalysis to characterize major particle types, and provides data on some toxic trace metals (e.g., Cd) that are not detectable using X-ray microanalysis. Target transformation factor analysis also is more useful in the quantitative determination of the relative mass contributions of major sources to the total dust sample.     

Analysis of microcystins in cyanobacteria blooms and surface water samples from Meiliang Bay,Taihu Lake,China

Taihu Lake is the third largest freshwater lake in China. In recent years, the water pollution of cyanobacteria blooms has become a severe problem in this area. Microcystins (MCs) are an important group of toxic compounds mainly produced by some cyanobacteria species and have both acute and chronic hepatotoxic effects on animals and humans. This paper presents the first data on the identification and detection of MCs in both natural occurring cyanobacteria blooms and surface water samples (0-0.5 m), collected from Meiliang Bay, Taihu Lake, China. A conventional method for extraction and isolation of MCs from cyanobacteria blooms was applied. High-performance liquid chromatography (HPLC) analysis showed that the main toxic component in the cyanobacteria materials was MC-LR. The monoclonal antibody (mAb) against MC-LR produced by hybridoma technique was employed for direct competitive ELISA to detect the concentrations of MCs in bloom and water samples collected in 2001. The results not only revealed the presence of MCs but also temporal variations of MCs levels of three sampling stations in Meiliang Bay in 1 year. It is obvious that the MC contents were relatively higher during warm months and related with the status of eutrophication. Our study indicates the threat associated with MCs in water body of Taihu Lake. To prevent the MCs potential hazard on public health in this area, some necessary measures of monitoring and control of growth of cyanobacteria are urgently needed.