Ortwin Renn

Eckard Rehbinder

Christian Streffer

Carl Friedrich Gethmann

Robert Guderian

Josef Bücker

Adrienne Cansier

Dieter Cansier

Gerd Hanekamp

Dietrich Henschler

Gerald Pöch

Marco Slesina

Kerstin Wuttke

The rapid growth of the world population - nearly six-fold over the last hundred years - combined with the rising number of technical installations especially in the industrialized countries has lead to ever tighter and more strained living spaces on our planet. Because ofthe inevitable processes oflife, man was at first an exploiter rather than a careful preserver of the environment. Environmental awareness with the intention to conserve the environment has grown only in the last few decades. Environmental standards have been defined and limit values have been set largely guided, however, by scientific and medical data on single exposures, while public opinion, on the other hand, now increasingly calls for astronger consideration of the more complex situations following combined exposures. Furthermore, it turned out that environmental standards, while necessarily based on scientific data, must also take into account ethical, legal, economic, and sociological aspects. A task of such complexity can only be dealt with appropriately in the framework of an inter disciplinary group.

Combined Exposures and Their Effects on Human Beings and Their Environment

Environmental Standards

Tumour therapy depends essentially on being able to destroy the clonogenic activity of tumour cells while keeping the damage to the normal tissue low. Clinical experience shows that tumour response varies greatly even if tumours with the same localisation, clinical, and histopathological staging are compared. Some tumours appear to be resistant to conventional radiotherapy (X-rays, y-rays or fast electrons) or chemotherapy. In these cases new therapy modalities are necessary. Combined therapy modalities seem to have advan tages for some resistant tumours; one possibility of such a treatment is to combine radiotherapy or chemotherapy with hyperthermia. This means that the local tumour, the tumour region or even the whole body of the patient has to be heated to temperatures between 40° to 45° C (in case of whole body hyperthermia to 42° C maximal) for a certain time (usually 30-60 min are adequate). Hyperthermia has a long tradition in medicine as a treatment modality for various diseases. Inscriptions of the old Egyptians and texts of the Greeks have pointed out its importance. Usually whole body hyperthermia has been used by the induction of fever. Local hyperthermia began around 1900 when Westermark treated unre sectable cervix carcinomas with hot water in a metallic coil. By the beginning of this century an increase of radiation effects was hy pothesised with hypothermia and later observed. However, only in the 1960s and 1970s were systematic investigations started which showed radiosensitisation and chemosensitisation by hyperthermia in cells and tissues including tumours.

Hyperthermia and the Therapy of Malignant Tumors

Klaus-Rüdiger Trott

Eberhard Scherer

The aim of radiation protection standards is to make the radiation workplace as safe as is humanly possible. The gradual evolution over the last 20 years has been towards a more precise definition of the limits for occupational exposure. These have been created not only in terms of short-term effects but also more importantly in terms of long-term risks involving such problems as the potential for carcinogenesis and genetic change. In the United States the National Committee for Radiation Protection has recom mended that 5 rems (50 mSv) should remain as the maximum permissible dose equiva lent for total body exposure. This would represent the sum of internal and external ex posure and should be regarded as the upper limit allowed. The community of radiation users is required to conduct its operations in such a man ner that the absolute value of the individual's dose equivalent in rems does not exceed his age in years. There should be additional limits for tissues and organs based on short term effects. Therefore, individual organs are limited to dose equivalents low enough to ensure that the dose threshold values are not exceeded.

Radiation Exposure and Occupational Risks

Wolfgang Kröger

Georg Kamp

Radioactive waste (above all highly radioactive wastes from nuclear installations) caused by research, medicine and technology must be disposed of safely. However both the strategies disputed for the disposal of radioactive waste as well as concrete proposals for choosing a location for final waste disposal are highly debatable. An appropriate disposal must conform to both complex, technical requirements and fulfill the radio-biological conditions to appropriately protect man and nature. Ethical, legal and social conditions must also be considered. An interdisciplinary team from various, relevant fields compiled the current status-quo and developed criteria and strategies, which on the one hand meet the requirements of optimal warning and prevention of risk for present and future generations, and additionally on the other hand meet the needs of what current society agrees what is expected to be allowed. This study can be understood as an advanced and continuing contribution to the corresponding scientific specialized debates, due to its interdisciplinary treatment. At the same time it serves as a fundamentally informing contribution to public and political debates, offering an easily comprehensible executive summary and precise content recommendations.

Technical and Normative Aspects of its Disposal

Radioactive Waste

Christian Streffer

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