Catálogo de publicaciones - libros

This study was designed to demonstrate the biological effects of BPA, one of the well-known endocrine disruptors, by means of the micronucleus assay. The biological effect of gamma rays on the same cell system was also evaluated for comparison with that of BPA to estimate the equidosimetric effectiveness of BPA. Fresh cuttings of BNL 4430 were treated with BPA solutions of 0 to 4 mM for 6 hours for the absorption of the solution through the stem of the plant cuttings. Other groups of the cuttings were irradiated with 0 to 1.0 Gy of gamma rays. The frequencies of micronucleus showed a positive dose-response relationship in the range of 0 to 0.5 Gy, and a clear concentration-response relationship in the experimental range of BPA concentrations. By comparing the two experimental results, it is possible to estimate the BPA concentration and its equivalent radiation dose for a fixed value of MCN frequency. BPA of 11.8 mM can give rise to 53.3 MCN/100 tetrads, the same frequency that is induced by 25 cGy of gamma rays. It is of biological importance that clinical symptoms start to develop after a whole body exposure to radiation higher than 25 cGy. The results indicated that the pollen mother cells were an excellent biological end-point for measuring toxicity of endocrine disrupting chemical bisphenol A. In addition, Trad-MCN assay can be easily applied to measure the biological effects of suspected endocrine disruptors such as octylphenol and nonylphenol.

Stable and radioactive isotopes are extensively used as tracers of numerous processes in the planetary and terrestrial environment. The relative abundances of isotopic species measured by their ratios provide indications of the origin of various materials and differences in the abundance ratios that develop in different processes make it possible to identify the mechanisms behind a variety of phenomena in extraterrestrial space, within the solid Earth, on its surface, and in the biosphere. The improvements in the sensitivity and precision of mass spectrometers used for the determination of isotope abundances are continually expanding the number of isotopes that can be identified in natural materials aswell as the understanding of the mechanisms that drivemany parts of the Earth’s system. The involvement of carbon dioxide in many geochemical inorganic as well as biogeochemical processes focused long ago attention on the behavior of the different isotopic species of CO and made possible many new interpretations of processes in the atmosphere, on land, in the oceanic and continental waters, and within the biosphere. The goal of this Chapter is to review the essentials of the isotope geochemistry of carbon dioxide and the mechanisms of its isotopic fractionation, and to discuss the broader aspects of the global carbon cycle that are based on the carbonisotope geochemistry.

The history of the Chernobyl accidents knows many examples, where the behaviour radionuclides in ecosystems in an obvious way reflected the course and laws of ecological phenomena, this is for example this phenomenon of active washout of nuclides from the surface of the Dnieper reservoir, in particular, from territories of Chernobyl zone of 30 km, into the territory of Ukraine and Byelorussia. Rate and parameters of such drain (0,01–2 % in year for Cs-137 and 0,1% – 4 % in year for Sr-90), define themselves as fundamental drains characteristic for big ecosystems like the Dnieper reservoir areas. The dramatic example of those phenomena of sorbptioning and desorbption of radionuclides (especially for Cs-137) in the closure of a reservoir cooler, the Kiev water basin and other superficial reservoirs, reflects the fundamental hydrological properties of water ecosystems.

The following conclusion can be drawn. At any severe hydrological, biological and technological process in ecosystems polluted by radionuclides, an appreciable redistribution of radionuclides - tracers in biotic and a-biotic components ecosystems is observed. Also the inverse conclusion is possible therefrom. Therefore it is countable count that research of distribution and redistribution radionuclides on biotic and abiotic components of ecosystems may serve as an important tool to research of dynamics and to forecasting the condition of an ecosystems and its biota.

The theory of radiocapacity of ecosystems developed hereby has permitted to assess the integrated characteristics of radionuclides distribution in ecosystems, to establish laws of radioecological processes and to determine the location of increases of radionuclides in ecosystems. The theory and models of radiocapacity of ecosystems have allowed to define approaches to a substantiation of ecological specifications on permissible levels of pollution in an ecosystem and their elements, and to permissible dumps and radionuclides emissions in ecosystems [1–3].

Our researches on reliability of ecosystems have shown a line of parameters, such as a variety of type of ecosystems; of biota; of number of species in ecosystems and rate of duplication of species. They form eventually the necessary “integrated parameter”, suitable for an estimation of the general stability and reliability of ecosystems [2, 3, 4, 5].

The definition however of such parameter demands a huge amount of initial data on contributing parameters at different stages of the life of ecosystems. Already on noticeable changes of the status of the ecosystem an estimation of their well -being and reliability can be made. Clearly, when in ecosystem as a whole, the variety of species decreases, the biota, number and speed of duplication of dominant kinds is reduced, then it is not difficult to observe a damage and/or an oppression of ecosystems. Such affirmative research is useful, but it is not enough, as it does not allow the making of an outstripping forecast of the condition of ecosystems nor to offer counter-measures. Radiocapacity - a sensory characteristic for the plant ecosystem’s well-being is preferable. It is a non-dimensional quantity that characterises the part of radionuclides, which can be retained by the ecosystem without having deteriorated neither the whole system nor its parts. The only considerable effect on the ecosystem to be considered would the effect on the of radiocapacity rate factor. Separately, we based oneself on the theory, according to which the negative influence on the ecosystem would give rise to deterioration of its well-being; and, accordingly, - would be observe a reduction of the radiocapacity of the system. On the other hand, - the improvement of the ecosystems well-being would induce an increase of its of radiocapacity rate factor.

Stable and radioactive isotopes are extensively used as tracers of numerous processes in the planetary and terrestrial environment. The relative abundances of isotopic species measured by their ratios provide indications of the origin of various materials and differences in the abundance ratios that develop in different processes make it possible to identify the mechanisms behind a variety of phenomena in extraterrestrial space, within the solid Earth, on its surface, and in the biosphere. The improvements in the sensitivity and precision of mass spectrometers used for the determination of isotope abundances are continually expanding the number of isotopes that can be identified in natural materials aswell as the understanding of the mechanisms that drivemany parts of the Earth’s system. The involvement of carbon dioxide in many geochemical inorganic as well as biogeochemical processes focused long ago attention on the behavior of the different isotopic species of CO and made possible many new interpretations of processes in the atmosphere, on land, in the oceanic and continental waters, and within the biosphere. The goal of this Chapter is to review the essentials of the isotope geochemistry of carbon dioxide and the mechanisms of its isotopic fractionation, and to discuss the broader aspects of the global carbon cycle that are based on the carbonisotope geochemistry.

Approaches to the identification and the equi-dosimetric assessment of radiation, chemical and combined effects on natural populations of the aquatic organisms are proposed. These approaches are based on generalization of our previous experimental data concerning separate and combined effects of ionising radiation and chemical mutagens (heavy metals and chlororganic compounds) on crustacean and fish embryos, as well as on the results of field studies carried out before and after the ChNPP accident. For the identification and the equi-dosimetric assessment of the damaged factors it is proposed to use the following criteria: the comparison of cytogenetic effects in , the distribution of chromosome aberrations in cells and the number of aberrations per aberrant cell.

The landscape based GIS is an effective tool for the structuration and classification of the ecosystems, for the field experimental data collection, analysis and extrapolation, as well as the ecotoxicological parameterisation of the ecosystems and solution the regional and local ecotoxicological problems.

Stable and radioactive isotopes are extensively used as tracers of numerous processes in the planetary and terrestrial environment. The relative abundances of isotopic species measured by their ratios provide indications of the origin of various materials and differences in the abundance ratios that develop in different processes make it possible to identify the mechanisms behind a variety of phenomena in extraterrestrial space, within the solid Earth, on its surface, and in the biosphere. The improvements in the sensitivity and precision of mass spectrometers used for the determination of isotope abundances are continually expanding the number of isotopes that can be identified in natural materials aswell as the understanding of the mechanisms that drivemany parts of the Earth’s system. The involvement of carbon dioxide in many geochemical inorganic as well as biogeochemical processes focused long ago attention on the behavior of the different isotopic species of CO and made possible many new interpretations of processes in the atmosphere, on land, in the oceanic and continental waters, and within the biosphere. The goal of this Chapter is to review the essentials of the isotope geochemistry of carbon dioxide and the mechanisms of its isotopic fractionation, and to discuss the broader aspects of the global carbon cycle that are based on the carbonisotope geochemistry.

Fallout-derived Cs and naturally occurring radionuclides, such as K and Be in soils and grass were measured in Thessaloniki area, Northern Greece, at temperate zone (40°), in order to examine their behaviour in natural ecosystems. For long-term measurements over a 15-y period, Cs concentrations ranged from 3.73 to 1307 Bq kg (avg. 210.5 Bq kg) in soils and from 0.4 to 334.9 Bq kg (avg. 14.5 Bq kg) for grass. Potassium-40 concentrations ranged from 141.4 to 580.2 Bq (avg. 224.4 Bq kg) in soils and from 66.3 to 1480 Bq kg (avg. 399.8 Bq kg) for grass. Beryllium-7 concentrations ranged from 0.53 to 39.6 Bq kg (avg. 14.4 Bq kg) in the soils and from 2.1 to 348.0 Bq kg (avg. 54.4 Bq kg) for grass. Cesium-137 transfer coefficients, TF from soil to plants (grass) ranged from 0.002 to 7.42 (avg. 0.20). Potassium-40 TF values from soil to plants (grass) ranged from 0.16 to 2.42 (avg. 0.73). Beryllium-7 TF values from soil to plants (grass) ranged from 0.027 to 2.37 (avg. 0.42) 137 An ecological half-life, T for Cs in grassland 3 1/3 y could be derived, when TF values varied between 0.1 and 0.01 in an 11-y elapsed time since contamination (May 1986). An almost similar T value (3 2/3 y) was derived for K in grassland.

Analysis of data of magnitudes of ecological Grey-equivalent for chemical toxicants and their “dose-effect” dependencies allow to conclude that in case the efficiency of toxic effect of chemical agents is less than efficiency of damaging effect of gamma-irradiation these toxicants lead to an equidosimetric evaluation represented at ecological Grey-equivalent of less than 1 (as in case with phenol). Toxic chemical agents with a toxic effect efficiency higher than the damaging effect of gammairradiation have accordingly an ecological Grey-equivalent higher than 1 (as in the case of copper).

In this article the equidosimetric evaluation of effect nuclear and chemical factors (in ecological Grey-equivalent) on cells of red algae was given. This evaluation allows to make prognosis of the comparative ecological danger of the studied toxic agents for red Black Sea algae.

The landscape based GIS is an effective tool for the structuration and classification of the ecosystems, for the field experimental data collection, analysis and extrapolation, as well as the ecotoxicological parameterisation of the ecosystems and solution the regional and local ecotoxicological problems.