An overview of environmental aspects of the tritium method is given. Temporal and local variations of the specific tritium activity of precipitations, particularly the decay of the bomb peak as well as the continential and latitude effects, are used to subdivide the tritium content of precipitations in bomb tritium and technogenic tritium for the example of the measurement series of Freiberg. Technogenic tritium is shown to have prevailed from the beginning of the eighties, whereas the emission of technogenic tritium has strongly decreased in Europe since the middle of the seventies.