Catálogo de publicaciones - libros

refers to responses, usually negative and detrimental responses, in living organisms exposed to radionuclides in ecosystems contaminated with artificially produced radionuclides or enriched with naturally occurring radionuclides. The key focus is put on the link between radionuclide exposures and the subsequent biological effects in flora and fauna. Radioecotoxicology is therefore an essential ingredient in impact and risk assessments associated with radioactive contaminated ecosystems.

It is generally accepted that pollutants, such as hydrocarbons, enter the aquatic environment by accident or deliberately, and may lead to large-scale and sudden kills of animal life, especially when the compounds are in high quantities. However, more subtle changes to the host may ensue when lesser quantities of pollutants are involved. Here, the resulting damage may include immunosuppression, physical damage to gills and epithelia, and adverse affects on metabolism. Also, there may well be increased susceptibility to various infectious diseases, including lymphocystis and ulceration. Much of the work to date has centered on laboratory studies and also surveys of polluted and clean marine sites, but it is not always possible to make firm conclusions from the data. Keywords: fish disease; ulceration; fi n rot; tail rot; pollutants; pesticides; hydrocarbons; heavy metals

Exposure of organisms in the environment to ionizing radiation is generally considered to be harmful, regardless of the dose. This assumption derives directly from the basic assumption used for human radiation protection, that harm is directly proportional to dose, without a threshold. The consequence of combined exposures is generally unknown, but is assumed to be either additive or multiplicative. We have examined the in vivo and in vitro responses of a variety of cells and organisms. We show that exposure to one stressor can influence the outcome of a subsequent exposure to the same or another stressor. In many cases, pre-exposure to one stressor appeared to induce an adaptive response that mitigated the harm from a second stressor. These observations challenge the basic assumptions used in environmental protection strategies, suggesting that new approaches are needed. Keywords: combined stressors; radiation; heat; chlorine; non-human biota

Ecotoxicology assesses the fate of contaminants in the environment and contaminant effects on constituents of the biosphere. With respect to effects assessment, current ecotoxicology uses mainly reductionistic approaches. For concluding from the reductionistic approach to the effects of toxicant exposure in a multifactorial world, ecotoxicology relies on extrapolations: (i) from suborganism and organism effect levels, as determined in laboratory tests, to ecological levels, (ii) from few laboratory test species to the broad range of species and their interactions in the ecosystem and (iii) from the analysis of the effects of single toxicants under standardized laboratory settings to the toxicant response under real world conditions, where biota are exposed to combinations of chemical, biological and physical stressors. The challenge to ecotoxicology is to identify strategies and approaches for reducing uncertainty and ignorance being inherent to such extrapolations. This chapter discusses possibilities to improve ecotoxicological risk assessment by integrating mechanistic and ecological information, and it highlights the urgent need to develop concepts and models for predicting interactions between multiple stressors. Keywords: ecotoxicology; risk assessment; effect propagation; interspecies extrapolation; multiple stressors

This article introduces the concept of multiple stressors. It has been written for the layperson, in terms that do not require a strong scientific background. It has been written to facilitate scientists’ communication with the public and funding agencies about multiple stressors. This article briefly explains several major classes of contaminants whose global dispersal and long-term persistence in the environment might cause them to contribute to multiple stressors. Highlighted is our lack of understanding about the potential interactions among multiple stressors and the need for much additional research. Interactions are explained through a simple example of various plausible responses that an organism might exhibit when exposed to both cadmium and radiation. Our current approach for determining human and ecological risks from contaminants is explained such that the reader is aware of why multiple stressor research is needed. This article stresses the need for a coordinated, multinational, multidisciplinary research plan for multiple stressors.

Results of laboratory, “green-house” and long-term field experiments carried out on different plant species to study ecotoxical effects of low doses and concentrations of most common environmental pollutants are presented. Special attention is paid to ecotoxic effects of chronic low dose exposures, synergistic and antagonistic effects of multipollutant exposure. Plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic disturbances and genetic diversity. The chronic low dose exposure appears to be an ecological factor creating preconditions for possible changes in the genetic structure of a population. A long-term existence of some factors (either of natural origin or man-made) in the plants environment activates genetic mechanisms, changing a population’s resistance to exposure. However, in different radioecological situations, genetic adaptation of plant populations to extreme edaphic conditions could be achieved at different rates. The findings presented indicate clearly that an adequate environment quality assessment cannot rely only on information about pollutant concentrations. This conclusion emphasizes the need to update some current principles of ecological standardization, which are still in use today.Keywords: radioactive and chemical contamination; multipollutant exposure; bioindication; plant populations; environment quality assessment

Anthropogenic violation of the principles of rational environmental management has resulted in degradation changes in social life and environment. It has caused emergence of abnormal ecosystems and changes in gene pool. For enhancement of socio-ecosystems and improvement of the national gene pool, it is necessary to implement complex systems of socio-ecological monitoring. A methodology of socio-ecological monitoring has been developed. It is based on high-sensitivity indication systems of various levels of organization, and standardized procedures of integral estimation of the state of environmental objects according to toxic and mutagenic background, and level of health of different age groups. All this made it possible to define integral tests, which allow assessing ecological and genetic danger (risks) imposed on biota and human by mutagenic and ecological factors.

due to a defective gene is a factor in a small percentage of people who develop cancer (<5 %), while , which is due to the wide variation in individual responses to exogenous agents, is believed to result from the great diversity in responsiveness to risk factors in the environment. Interindividual variations in DNA repair capacity for specific types of DNA damage are documented.

It was shown that the irradiated mice gave off with urine immunosuppressive components which possessed of high volatility. With their help even the one irradiated individual can induce in intact mice the disturbance of immunity and alteration of number of blood cells. Moreover, the predominant mouse from exposed group of mice also was capable to elicit disturbance of immunity in next group of intact animals. The same effects could be received by transfer of the urine samples from irradiated mice or from intact mice exposed with urine of irradiated animals to the box with intact individuals. It was established that ionizing radiation (4–6 Gy) of male mice increase their scent attractiveness to intact singenic male conspecifics. The carried out experiments have shown existence of the mediated by volatile chemosignals mechanism of multiplication second post-radiated disturbances of immunity in the groups of animals. The immunosuppressive volatile components were induced also by stress and some immunodepressants (dexametasone and cyclophosphamide).

So far, mutation induction in the germline of directly exposed parents has been regarded as the main component of the genetic risk of ionising radiation. However, recent data on the delayed effects of exposure to ionising radiation challenge for the existing paradigm. The results of some publications imply that exposure to ionising radiation results in elevated mutation rates detectable not only in the directly irradiated cells, but also in their non-irradiated progeny. Here I review the data on transgenerational instability showing that radiation-induced instability in the germline of irradiated parents manifests in their offspring, affecting their mutation rates and some other characteristics. This paper summarises the data on increased cancer incidence and elevated mutation rates in the germline and somatic tissues of the offspring of irradiated parents. The possible mechanisms of transgenerational instability are discussed.