Tritium in some typical ecosystems

The environmental significance of 3H releases prompted an IAEA-sponsored coordinated research programme on various aspects. Data were collected to help health physicists, radioecologists, radiobiologists and environmentalists to predict the behaviour of 3H in the major terrestrial ecosystems of the world. A common methodology was used to carry out a variety of projects in widely varying biomes, from tropical to arctic regions: in Belgium, on terrestrial food chains, with deposition of tritiated water (HTO) on crops and pasture, and incorporation of 3H into proteins, nucleic acids, etc.; in Finland, plots of pasture and forest were labelled by HTO, and plant uptake were studied; in France, 3H-content in water, in relation to different parts of vines, orange and olive trees in a Mediterranean climate; in the Federal Republic of Germany, contamination due to 3H-releases; in India, mean 3H-residence time in some tropical trees; in Mexico, 3H-persistence as free-water 3H and tissue-bound 3H in crops; in the Netherlands, 3H-metabolism in ruminants; in the Philippines, residence time in soil and in various commonly edible crops, and excretion time; in Thailand, half residence time in soil and local vegetation; in the USA, the effects of HTO vapour and liquid exposure in a wide range of climatic conditions, including organic fixation and concentration factors. An extensive bibliography is attached, and also annexes of laboratories and project titles; plant species, exposure and residence times; comparable lists for animals studied; scientific and common names of the species, and a glossary