Therefore the main topic of this symposium will be the discussion and analysis of benefit and risk of the therapeutic application of 224-Radium in the treatment of ankylosing spondylitis and arthritic diseases.

We all are anxious to learn from the findings and experi­ence of the clinicians and they will certainly also profit from the basic findings of the radiobiologists and experi­mental pathologists. So I believe that the main purpose of this symposium is to bring these two groups together.

We hope that after these two days we will have a more clear picture about the therapeutic effect of 224-Radium in these diseases and also an answer to the question whether this kind of treatment is justified or not.

Lisbon 1977

The International Meeting was attended by 32 scientists.

From the lntroduction and Welcome (Jorge da Silva Horta)

I sincerely hope that this Meeting will prove to be another step forward in the path of research towards a wider understanding of the alterations caused by ionizing actions. I also hope that the present stage of our line of research may in consequence be reinforced and that through the exchange of our ideas, new channels will be pursued. I feel confident that in an ever increasing spirit of solidarity, and with the vast knowledge already acquired on the use of Thorotrast, new information regarding positive or probable lesions, caused by employment of other alpha-emitters, may be discovered.

Nowadays, in a world where such different ideologies prevail, mankind lives in constant alarm. The fear of war looms in front of us, as if the constant so-called "little wars" were the premonition of a larger and devastating one.

But contacts among scientists, especially between those that explore the specialized field of knowledge that studies the consequences of atomic energy, will eventually result in a great and better understanding of all men faced by a common enemy.

I would like to end by quoting Amold Toynbee's words:

"We are living in an age in which, for the first time, the whole human face, over the whole surface of our planet, is growing together in a single-world society. We have, indeed, to become a single-world family. In the atomic age, this is the only way of banishing the present danger that we may commit mass-suicide.

"It is because of the knowledge we have obtained in the field of our research that, better than most, we understand the need for an approach towards a "single-world family."

"However, even if this aim seems no more than a dream, we must always bear in mind the superior meaning of human fraternity. It is in this spirit that we work in our laboratories and that we are here today, and not only for the pleasure of discovering the unknown."

We must bear all this in mind as we now initiate our Meeting.

Lake Geneva, Wisconsin 1981

The International Conference was attended by more than 60 scientists.

From the Foreword (J Rundo, Patricia Failla, Robert A. Schlenker)

This volume contains 60 of the papers presented at the International Conference on the Radiobiology of Radium and the Actinides in Man. These contributions constitute more than 75% of the presentations, making the use of the word "proceedings" a reasonable approximation.

By the time the meeting was held, a total of 81 titles appeared in the program, although some were withdrawn at the last minute. After the conference, manuscripts and promises began to arrive in quantity and our best estimate of the number of printed pages swelled to more than 600. This was far more than could be accommodated in a single issue of Health Physics, the average contents of which extend only to 150 pages. At some point in the discussion as to how to resolve the conflict between the projected size and the commitments to authors, the idea of a special supplement to the Journal was mooted, developed and eventually approved by the Board of Directors of the Health Physics Society, with the understanding that it would be distributed at no extra cost to all recipients of the Journal. At the time of conception of the idea of a supplement the refereeing process was almost complete and it was pursued, resulting in the probable twin precedents.

The usefulness of the proceedings of any conference decreases rather rapidly with time and considerably more than a year will have elapsed between the oral presentations and their appearance in print. Authors, reviewers and editors must all accept their share of responsibility for the delay, but we refrain from apportioning it quantitatively!

There is a happy coincidence in the appearance of this volume in 1983; Dr. Harrison S. Martland, the leading light in the elaboration of radium toxicity, was born on 10 September 1883. Some of Martland's papers would be entirely appropriate in these proceedings (e.g. Ma29); had the meeting been held in 1983 the organizers could have had the pleasure of calling it the Harrison S. Martland Centennial Conference.

REFERENCE

Ma29 Martland H. S. and Humphries R. E., 1929, "Osteogenic Sarcoma in Dial Painters Using Luminous Paint", Arch. Path. 7, 406.

Tokyo 1999

This International Workshop was attended by 73 scientists.

From the Preface (R. Machinami, Y. Ishikawa and B. B. Boecker)

This meeting in Japan was the first international conference on radium and Thorotrast staged outside of the USA and Europe. The aim was to draw together leading scientists from various regions of the world and from many disciplines, including epidemiology, cancer research, animal studies, dosimetry, pathology, molecular biology, and risk assessment. Discussion was focussed on the health effects and risks from long-term exposure to alpha particles emitted not only by radium and thorium (Thorotrast) but also by other internally deposited radionuclides. Following the last workshop held in Heidelberg, new epidemiological results from Sweden and Portugal were presented.

A series of papers concerning radon exposure at the Wismut mine should provide important new information on radon toxicology. New and revised approaches to the dosimetry of internally deposited radionuclides were also presented. Particular emphasis was put on molecular biology in this workshop. Progress in the methodology of biological research, including use of archival tissues, has revealed new aspects of genetic changes induced by alpha particles. Evidence for the presence of a threshold in bone tumour induction in radium dial painters also fascinated much attention. Collectively, these results demonstrate the value of continuing these workshops to gain a better understanding of the health effects of alpha-particle emitters.

Japan was one of the countries where thorium dioxide was first used for radiography (M. Oka, Fortschr. Roentgenstr. 40, 497-501, 1929). Thereafter, thorium dioxide colloidal agents imported from Germany, largely Thorotrast, were widely used in Japan. However, only several thousand people are estimated to have lived more than 3 years after Thorotrast injection in Japan because most of the injected persons were soldiers. This, in turn, makes the Japanese cohort especially important due to the absence of underlying disorders except war injuries. Epidemiological studies of Thorotrast in Japan were initiated, promoted and conducted with the tremendous efforts of Dr. Takesaburo Mori.

The first results of the Japanese study were presented in 1965 at the first international conference on biological effects of Thorotrast by Dr. Kenpo Tsukamoto, the Director of the National Institute of Radiological Sciences. This presentation included dosimetric data of Dr. Yoshio Kato. Since then, Dr. Mori has been following this cohort, collecting autopsy cases and collaborating with numerous physicians and scientists in a variety of areas for more than 35 years. Also we are very pleased to include a paper in this volume, prepared by Dr. Hiroshi Tanooka, that summarizes the results of data from both Mori's series and another group of Thorotrast patients known as the Aichi series followed by Dr. Choichiro Kido and his colleagues.

As Prof. Wataru Mori mentioned at the beginning of workshop, the year 1998 was the centennial anniversary of the discovery of radium by Marie Curie, whose pioneering work stimulated physics and medicine being united into radiology. It was particularly appropriate that such an interdisciplinary conference was one of the activities of the Centennial of the Discovery of Radium Project in Japan.

Periodical workshops tend to draw the same people just like alumni meetings. In this workshop in Tokyo, however, many young scientists attending for the first time were involved in active and stimulating discussion. Certainly we hope that these young scientists will continue to be productive and creative participants in these important research areas. We look forward to meeting together in the future.

Neuherberg (GSF) 2004

The Conference was attended by 158 scientists from 21 countries.

From the Introduction

(H.G. Paretzke, P. Roth, U. Oeh)

The ninth international conference on “Health Effects of Incorporated Radionuclides – Emphasis on Radium, Thorium, Uranium and their Daughter Products” HEIR 2004 was held at GSF–National Research Center for Environment and Health, Neuherberg, Germany, from November 29 until December 1, 2004.

The growing popularity of this topic among the scientific community, especially the radiation protection community, was demonstrated by the largest number of participants in comparison to the earlier conferences. In all, there were 157 participants from 20 different countries of the world. In the conference 62 scientific and 12 posters presentations were included in 13 sessions. The scope of the conference covered studies related to the long-term follow-up of thorotrast subjects in Japan, Germany and Portugal, and also of the subjects exposed to Ra-224 for the treatment of bone tuberculosis and ankylosing spondylitis. The studies and discussions on these topics are important in view of the large number of liver cancers observed in the thorotrast patients and the number of bone cancers in the cases treated with Ra-224. A growth stunting was also observed for the subjects who received the Ra-224 injections early in their lives. Besides atom bomb survivors, the data from thorotrast patients could well help towards a better understanding of the health effects of irradiations.

In addition to the scientific presentations on the above topics, there were a number of presentations on the incidence of lung cancer from radon exposure of miners and plutonium exposures causing lung cancer among the Mayak workers in the Russian Federation.

Other stimulating presentations were on the tissue damaging mechanisms of alpha particles, having very high L.E.T., and also the related radiation weighting factor in comparison to beta and gamma radiations. There were also interesting presentations on the topics of uncertainties involved in the internal dose assessment from radiation exposure and the possible solutions to minimize the errors due to uncertainties and make radiation protection more effective.

Also discussed were the main challenges and problems encountered in radiation protection regarding the possible questions posed and the decisions needed to be taken in understanding processes such as the 1) tumour induction from external and internal exposures, 2) prediction of risk for the ingestion from long-lived radionuclides and 3) whether a chronic exposure is equivalent to the sum of acute exposures. There were also a few, but very important presentations on the development and applications of highly sensitive analytical techniques for measuring Th, U and Pu in biological matrices such as body fluids.

A couple of papers were presented on the current challenges of the twenty-first century to assess the exposure of humans to depleted uranium and to understand its mechanism of interaction with humans including any possible harmful effects.

This conference has set the tone for further in-depth studies into the interaction of alpha-emitters with tissues and organisms for realistic dose assessments and to make internal dosimetry for radiation workers and the general public even more effective. It is hoped that there will be another occasion of this nature, e.g. a tenth international conference, to discuss this important topic again.

The Proceedings Editors of HEIR 2004