FOREWORD

The unique properties of selenium and tellurium and their compounds have led to these elements being used in an ever changing number of applications over the years in which they have been commercially available. In recent times the beneficial properties of selenium, as an essential element in the human diet, have been recognized to go along with more conventional uses in metallurgy, electronics, pigments, glass and chemicals. The need to assist the development of Se and Te was recognized long ago, and the origins of the Selenium-Tellurium Development Association Inc. (STDA) date back to 1938. Over the years the STDA has played an active role in the technical development and use of the elements but, also, recently we have responded to environmental concerns about our products by providing information on safe handling, transportation and storage of selenium and tellurium. The Association helps identify new areas of usage for selenium and tellurium and has been a major force in encouraging efforts to improve man's knowledge of the essentiality of selenium. As a result, the STDA has become the primary source for the dissemination of information on selenium and tellurium to organizations and individuals throughout the world. Current topics are discussed in a regularly released Bulletin, and publications and papers on a wide variety of subjects are available on request. The STDA also sponsors international symposia as another means of technology transfer, the last being held May 1998 in the USA. The many uses of selenium and tellurium bring together a wide number of respected speakers and scientists, resulting in a unique interchange of ideas between professionals with a wide variety of backgrounds in fields such as minerals science, materials science, electronics, physics, chemistry, metallurgy, economics, medicine, and agriculture. The proceedings of all symposia are published in full and also are available from the Association. They represent a comprehensive overview of activities in selenium and tellurium. As you read further, you will discover how the STDA operates and what our objectives are.