Seventh Coordination Meeting of WHO Collaborating Centers in Radiation Emergency Medical Preparedness and Assistance Network : REMPAN 97 : Proceedings / Sétima Reunión de Coordinación de los Centros Colaboradores de la OMS en Preparativos médicos y Redes de Asistencia en casos de emergencias por irradiación

This meeting brought together many outstanding specialists and scientists from different countries and it is a witness to recognise the large contribution made in the prevention of radiation health hazards by the Institute of Radiation Protection and Dosimetry in Brazil after twenty five years of his creation. One important aspect in the development of REMPAN is further strenghthening coordination and cooperation between different elements of its infrastructure. In this context, WHO/HQ initiated the integration process within its programme activity in the field of radiation protection. This process is aimed, first of all, at combining the efforts of WHO/HQ and all WHO/ROs in the implementation of a comprehensive programme on the prevention of radiation health hazards. There are seven elements within this programme: 1. Scientific assessment; 2. National programme development; 3. Emergency preparedness and assistance; 4. Radiation monitoring; 5. Follow-up exposed population; 6. Research; 7. Networking for information exchange

Henri Jammet Memorial Lecture : The role of dosimetry in radiation accident response

This document explores the techniques of internal dosimetry, as well as radiation cytogenetics. Also it explains aspects about internal and external exposure accidents and some techniques to measure doses of radiation received such as decorporation therapym diuretics or simply increasing fluid intake may be used to increase the excretion rate of incorporated radioactive materials, adding another aspect to patient care. It mentions Prussian Blue used successfully in treating victims of the Goiania accident. In another part of the document explains investigations with biodosimetry: radiation cytogenetics

REMPAN at international level : Current status

The mitigation of the public health consequences of disasters and emergencies is particularly dependent on the speed of an effective response, which in turn depends on preparedness to act, and access to information on the hazards involved. Technological disasters that cause radiation hazards are of special concern. For the promotion of radiation emergency medical and public health preparedness and for practical assistance and advice to countries in a case of overexposure from any source of radiation, WHO has established the network of specialized institutions (REMPAN). The present meeting is held at the 10th anniversary of REMPAN. It describes the current status of REMPAN since its first steps. In the narrow sense of the word, REMPAN means a network consisting of WHO Collaborating Centres located in specialized radiological institutions in Argentina, Armenia, Australia, Brazil, France, Germany, India, Japan, the Russian Federation, United Kingdom and USA. The objectives of REMPAN are: 1. Promote the preparedness for radiation accidents among WHO Member States; 2. Provide advice and assistance in a case of a radiation accident and radiological emergency and 3. Assist in follow-up studies. In addition to the objectives, REMPAN would benefit from sharing the experience and unique expertise in follow-up studies. Describe REMPAN actions for assistance to the accident country and WHO and REMPAN actions in the phases of an accident in compliance with the Convention on Early Notification and Assistance Convention

Radiological accident in Salvador, Bahia : Physical and medical aspects

Between 25 September and 9 November 1997, a radiological accident occurred, involving three workers of a Brazilian mineral processed industry, during the maintenance of an X-ray diffraction equipment. The accident reconstitution was done in four steps: interviews with involved persons; dosimetric evaluation with radiographic films, ionizing chamber and thermoluminescence dosimeters; cytogenetic dosimetry, and taking the X-ray diffraction equipment apart. The results of investigation showed that the radiological accident happened during the calibration of the X-ray diffraction equipment and that the victims had their hands exposed to high level of radiation between 5.6 and 20 Gy. These radiation doses began an erythema process with progressive injuries. It was concluded that the causes of the radiological accidents were due to lack of maintenance of the main part of the equipment, where the X-ray is liberated and, the non observance of maintenance, calibration and radiation protection procedures. Some recommendation about radiation protection and safe use of the X-ray diffraction equipment are also shown in this paper

Radiation effects after low dose chronic long-term exposure

Depending on the place of resident human beings receive during one year on average 2,4 - 20mSv (0,0066 - 0,055 mSv/d) in the form of normal background radiation (Fig.2). Obviously, the organism is able to quantitatively compensate the resulting cell loss by additional cell production. The accepted dose level for occupational radiation exposure is 50 mSv/y (0,14 mSv/d). Unusual long term radiation exposure was found in the Uranium miners and the radiation accident in the South Urals with daily radiation doses of about 100 mSv. In accidents resulting from the loss of radiation sources in Mexico (1962), Algeria (1978) and Estonia (1994), the daily absorbed radiation exposure doses were much higher (Fig 3). Exposure doses between 80 mSv/d and 400 mS/d resulted in a severe strain of hematopoiesis and skin. The overall strain limits of the hematopoiesis are determined by the remaining function of the stem cell compartment and, of course, the overall levels of progenitor and proliferative cell production. To determine the extent of cell system impairment by chronic, repeated or protracted radiation exposure, a professional medical examination is necessary which considers the pathophysiological mechanisms of critical system failure. The available diagnostic methods have developed and considerable improved during the last years. It should be state of the arts to obtain daily data on the peripheral blood count and blood smear until the systems is completely recovered. Cell system alterations should, for example, be analyzed by quantitative progenitor cell assays. The determination of lymphocyte subpopulations, lymphocyte proliferation tests and phagocytosis tests are necessary to review the patients immunology status. All common functional tests helpful in the examination of the organ systems can be helpful to detect primary or secondary reactions of the cardio-vascular-systems, the impairment of the central and peripheral nervous systems, the gastro-intestinal-tract, digestion, hormone-system and the clinical immune status. Cytogenetic studies to assess the frequency of the unstable and stable chromosomal aberrations are helpful to confirm the exposure of the organism to ionizing radiation. To determine the optimal therapy, it is extremely important to know the extent of system impairment and to decide early in the course whether the critical cell systems have the capacity to regenerate spontaneously or not. If the outlook is a irreversible bone marrow failure, stem cell transplantation should be considered as if one is treating a "severe aplastic anemia". Skin lesions should be treated adequately and quickly to prevent patients from secondary wound infections and late effects