[en] Efficient scientific development may promote the solution of all the environmental problems. The way the question is put is new, for science is finally considered to be the source of all environmental disasters and to be blamed for that. Search for the means to solve scientifically induced crisis situation seems to be very interesting. (author)

[en] The author believes contaminants in our external environment play a significant role in causing cancer in humans and the cumulative impact of exposure to chemical carcinogens over a lifetime has also to be considered. An efficient method to prevent cancer is to restrict the presence of chemical carcinogens not only indoor, but also in outdoor, environments. Due to collective efforts to reduce tobacco use, lung cancer rates are falling in the USA. Most chemical carcinogens are derived from coal and petroleum, so finding substitutes for these two substances is the right way to proceed in cancer prevention efforts, the author states.

[en] Fruit is an important component of the total diet that encompasses a wide variety of plant products. Fruit contamination can result from various processes: (i) direct deposition to fruit surfaces, absorption by the fruit skin and transport to the interior; (ii) deposition to the above-ground parts of the plant, absorption to interior and transfer to fruit; and, (iii) deposition to soil, root uptake and transfer to fruit. The relative significance of each pathway after an accidental release depends upon the radionuclide, the kind of crop, the stage of plant development, the season at time of deposition and the timescale for dose assessment. This paper indicates the state of the art on understanding processes concerning the radiocontamination of fruit, provides information on data available in the literature and gives recommendations for future work. (author)

No abstract available

[en] The criticism mainly refers to the statement that the diffusion parameters given in the rule pertaining to section 45 of the Radiation Protection Ordinance do not stand the scientific test, so that it seems unjustified to incorporate such calculation methods and parameters for the atmospheric diffusion of radioactive emissions into legal provisions such as, e.g., an ordinance on radioecological standards. The author states that the calculation principles applied for determining the atmospheric distribution of nuclide emissions lead to an underassessment of the radiation exposure involved. (DG)

No abstract available

[en] The project to established the dietary pattern in designated barangays in Bagac and Morong is being undertaken in order to determine age and site specific usage factors (Aap) in areas, within the plume exposure pathway (PEP) after the Emergency Planning Zone (PEZ) of the PNPP-1. Uap is an important parameter in the computation of dose projections through ingestion within the PEP. (author)

[en] In a previous paper by the same author, emphasis was placed on the role that 'pathways analysis' would play in providing 'beyond reasonable doubt' that a particular method and a particular formation would be suitable for the safe geologic disposal of nuclear wastes. Since that paper was released, pertinent pathways analyses have been published by Bernard Cohen, de Marsily et al., the American Physical Society's Special Study Group on Nuclear Fuel Cycles and Waste Management, and KBS of Sweden. The present paper reviews and analyses the strengths and weaknesses of each of these papers and their implications for the Canadian plan for the geologic disposal of nuclear waste. The conclusion is that the Canadian plan is on the right track and that the disposal of nuclear wastes is not an intractable problem. Indeed the analyses show that several options, each with large safety factors, are likely eventually to be identified. (author)

[en] Radionuclides entering the ocean from runoff, fallout, or deliberate release rapidly become involved in marine biogeochemical cycles. Sources, sinks and transport of radionuclides and analogue elements are discussed with emphasis placed on how these elements interact with marine organisms. Water, food and sediments are the source terms from which marine biota acquire radionuclides. Uptake from water occurs by surface adsorption, absorption across body surfaces, or a combination of both. Radionuclides ingested with food are either assimilated into tissue or excreted. The relative importance of the food and water pathway in uptake varies with the radionuclide and the conditions under which exposure occurs. Evidence suggests that, compared to the water and food pathways, bioavailability of sediment-bound radionuclides is low. Bioaccumulation processes are controlled by many environmental and intrinsic factors including exposure time, physical-chemical form of the radionuclide, salinity, temperature, competitive effects with other elements, organism size, physiology, life cycle and feeding habits. Once accumulated, radionuclides are transported actively by vertical and horizontal movements of organisms and passively by release of biogenic products, e.g., soluble excreta, feces, molts and eggs. Through feeding activities, particles containing radionuclides are ''packaged'' into larger aggregates which are redistributed upon release. Most radionuclides are not irreversibly bound to such particles but are remineralized as they sink and/or decompose. In the pelagic zones, sinking aggregates can further scavenge particle-reactive elements thus removing them from the surface layers and transporting them to depth. Evidence from both radiotracer experiments and in situ sediment trap studies is presented which illustrates the importance of biological scavenging in controlling the distribution of radionuclides in the water column. (author)

[en] We have at hand the tools for development of both a single amino acid substitution and a gene loss type assay for somatic cell mutations in human red cells. We are close to being able to assess the assays as possible means for screening the human population for individuals who may be a risk of acquiring abnormally high frequencies of mutant cells. The cause for such a high frequency of mutant cells could be a prior exposure of the individual to large amount of mutagen, or it could indicate a member of a vulnerable subpopulation that may have poor DNA repair systems. Either of these cases could well be an indication that the particular individual is at high risk that exposure to mutagens could lead to potential pathology. In the near future we expect to determine the reliability of the assays and to perform experiments to confirm the validity of flow cytometry in measuring real somatic mutagenic events that occur in vivo. (orig./AJ)