Radionuclide Contamination as a Risk Factor in Terrestrial Ecosystems: Occurrence, Biological Risk, and Strategies for Remediation and Detoxification

Radionuclide contamination poses serious hazards for terrestrial ecosystems. Beyond the readily apparent damage to the biota at high doses, low doses of ionizing radiation produce stochastic effects: mutation, carcinogenesis, and genomic instability. The proposed chapter is a review of the biological and ecological effects of radionuclides. The authors discuss, beyond the Chernobyl accident, other contamination events. The review includes the biological and ecological effects of the three principal technogenic contaminants in terrestrial ecosystems: Cs-137, Sr-90, and I-131. Ecological risks to terrestrial small mammals are assessed in detail. In addition, the chapter provides some of the lesser-known methods of remediation and detoxification, including the use of modified natural zeolites as environmental remedies and bio-sorbents. Presented herein is little-known information on environmental protection against radioactive contamination

Ecocide – global consequences (pesticides, radionuclides, petroleum products)

The problem of environmental pollution is becoming increasingly important on a global scale. Man has oversaturated the environment of his habitat with harmful and most often toxic waste. It is difficult to describe all the toxic substances, as a separate book can be written for each group. The term “ecocide” has been introduced, which reflects large-scale destruction of the natural environment. We will focus only on three classes of pollutants that are of particular concern, creating environmental conflicts. These are: • Pesticides are extremely toxic and create large amounts of non-degradable waste. It accumulates in tissues and organs of target organisms, becoming toxic and causing serious pathological changes in the body, mainly at the cellular and subcellular levels, causing various diseases and as a result, serious changes in the structure and functions of the populations and the whole ecosystem are increasingly observed. • Waste from the nuclear industry and radioactive fallout from nuclear explosions. It is especially dangerous that radioactive elements can be concentrated in certain organs. • Petroleum products - often large quantities end up in the seas and oceans, along with industrial waste of various kinds, impossible to compensate for by nature and they pose a serious threat to ecosystems, many of which have already been destroyed. At the submolecular level, chemical and physical effects can lead to genetic rearrangements (mutations); destructive ionization in the tissues of every living being, sometimes with completely unexpected consequences for humans

Nefarious, but in a Different Way: Comparing the Ecotoxicity, Gene Toxicity and Mutagenicity of Lead (Pb) and Cadmium (Cd) in the Context of Small Mammal Ecotoxicology

Lead and cadmium are long established toxic and carcinogenic metals. Still, the mechanisms of their interaction with eukaryotic DNA are not unequivocally understood. New data provide evidence on the influence of both metals on DNA repair, particularly non-homologous end joining (NHEJ) and mismatch repair (MMR). This may help explain the weak direct mutagenicity of both Pb2+ and Cd2+ ions in the Ames test, as opposed to the proven carcinogenicity of both metals; it has long been proposed that lead and cadmium may induce an imbalance in mammalian systems of DNA damage repair and promote genomic instability. While new evidence for mechanistic interactions of metals with DNA repair emerges, some of the old questions involving dose distribution, pathways of exposure and bioaccumulation/detoxification kinetics still remain valid. To help place the current state of the art in the genetic toxicology of lead and cadmium within the context of ecotoxicology, the current authors propose an integrative approach and offer a review of other authors’ work as well as some of their own data on systemic and organ-specific toxicities in laboratory mice. The current chapter is a comparative analysis of the state of the art in the specific toxicity and genotoxicity of Pb and Cd, presenting some new and little-known information

Natural zeolites as detoxifiers and modifiers of the biological effects of lead and cadmium in small rodents: A review

The present investigation analyzes the literature about the toxicity of Cd and Pb in small rodents’ organisms and the role of natural zeolites as modifiers of the biological effects. An array of ecotoxicological, morpho-physiological, hematological, genetic and biochemical methods as most representative are under discussion as a basic point for further exploration of biological effects in laboratory mice. The review of existing results demonstrated that there is abundant data on the sorption of lead and cadmium by modified natural zeolites in water and soils. Nevertheless, there is insufficient data on the ion exchange capacity and biological effects of this sorbent in living organisms, especially regarding Cd detoxification. On the basis of the current review, it is possible to conclude that future investigations in this field will elucidate the potential of the use of zeolites as successful detoxifiers against heavy metals and other toxic elements in living organisms

Phylogeographic Aspects of Bat Lyssaviruses in Europe: A Review

During the last few decades, bat lyssaviruses have become the topic of intensive molecular and epidemiological investigations. Since ancient times, rhabdoviruses have caused fatal encephalitis in humans which has led to research into effective strategies for their eradication. Modelling of potential future cross-species virus transmissions forms a substantial component of the recent infection biology of rabies. In this article, we summarise the available data on the phylogeography of both bats and lyssaviruses in Europe and the adjacent reg ions, especially in the contact zone between the Palearctic and Ethiopian realms. Within these zones, three bat families are present with high potential for cross-species transmission and the spread of lyssaviruses in Phylogroup II to Europe (part of the western Palearctic). The lack of effective therapies for rabies viruses in Phylogroup II and the most divergent lyssaviruses generates impetus for additional phylogenetic and virological research within this geographical region

Senescence-associated oxidative DNA damage promotes the generation of neoplastic cells

Studies on human fibroblasts have led to viewing senescence as a barrier against tumorigenesis. Using keratinocytes, we show here that partially transformed and tumorigenic cells systematically and spontaneously emerge from senescent cultures. We show that these emerging cells are generated from senescent cells, which are still competent for replication, by an unusual budding-mitosis mechanism. We further present data implicating reactive oxygen species that accumulate during senescence as a potential mutagenic motor of this post-senescence emergence. We conclude that senescence and its associated oxidative stress could be a tumor-promoting state for epithelial cells, potentially explaining why the incidence of carcinogenesis dramatically increases with advanced age. ©2009 American Association for Cancer Research.SCOPUS: ar.jinfo:eu-repo/semantics/publishe