A Procedure To Include Deposion In The Model For Short And Medium Range Atmospheric Dispersion Of Radionuclides

Air pollution remains a major environmental issue despite many years of study and much legislative control. In rec~nt times, pollution on a global scale has become of particular concern. The gradually changing con centration of trace gases in the global troposphere due to man's activity is becomming a matter of serious concern. No scientist would dare to pre dict in detail the consequences of this gradual change due to its immense complexity involving social and economic factors and near countless chemical and phjsical cycles in our biosphere. In this chain of processes, the transport of pollution is an important factor, but only a factor. Therefore, I would like to emphasize that the mOdelling of atmospheric transport is becoming more and more an activity which fits into larger frameworks and can no longer be exercised as a single step, which bridges the gap between emissions and policy measures. This is also reflected in the topics and papers which were presented at this conference. The topics were: - emission invetories for and source treatment in air pollution dispersion models; - modelling of accidental releases; - regional and global scale dispersion mOdelling; including boundary layer-free troposphere exchange processes and subgrid scale parameter isations; - model verification and policy implications; - new developments in dispersion modelling and theory. 56 papers were presented in these sections. While many posters were dis cussed in a special session.

As an industry, biotechnology may be likened to the Hymn Book, being both ancient and modern. Whereas activities such as baking, brewing, the fermenting of foods date from our earliest attempts to control and utilise the environment, the application of recombinant DNA technology is recognised as being at the forefront of novel industrial development. Perhaps because of its association with processing foodstuffs together with the benefits derived from applications in the early organic chemistry and pharmaceutical industries, biotechnology has been regarded as being inherently safe. Yet unlike other modern industries, such as chemical and nuclear, where regulation has followed from incidents or accidents, modern biotechnology has been subject to close scrutiny and regulation almost from its inception. The process of regulation itself is somewhat unusual in that it was initially self-imposed by the very scientists who developed the fundamental techniques of recombinant DNA technology. They recognised the signific ance of their development but were concerned of the effects on humans and the environment of uncontrolled application of the new, powerful technology. Concern about the possible consequences of genetic manipula tion has undoubtedly been the driving force behind the regulations that are now in place in many parts of the world and which are the subject of this book. Safety issues in the biotechnology industry can be categorised under three headings: worker, environmental and consumer (product) safety.

This work sets out a procedure for taking account of all aspects of the environment in a proposed process right from the start.

Just as an environmental model typically will be composed of a number of linked sub-models, representing physical, chemical or biological processes understood to varying degrees, this volume includes a series of linked chapters exemplifying the fundamental nature of environmental radioactivity models in all compartments of the environment. Why is a book on modelling environmental radioactivity necessary? There are many reasons why such a boook is necessary, perhaps the most important that: - modelling is an often misunderstood and maligned activity and this book can provide, to a broad audience, a greater understanding of modelling power but also some of the limitations. - modellers and experimentalists often do not understand and mistrust each other's work yet they are mutually dependent, in the sense that good experimental science can direct good modelling work and vice-versa; we hope that this book can dispel mistrust and engender improved understanding. - there is an increasing reliance on model results in environmental management, yet there is also often misuse and misrepresentation of these results. This book can help to bridge the gap between unrealistic expectations of model power and the realisation of what is possible, practicable and feasible in modelling of environmental radioactivity; and finally, - modelling tools, capacity and power have increased many-fold in a relatively short period of time. Much of this is due to the much-heralded computer revolution, but much is also due to better science. It is useful to consider what gap if any still remains between what is possible and what is necessary.

The interest in air pollution modelling has shown substantial growth over the last five years. This was particularly evident by the increasing number of participants attending the NATO/CCMS International Technical Meetings on Air Pollution modelling and its Application. At the last meeting 118 papers and posters were selected from an abundance of submitted abstracts divided over five modelling topics: (i) model assessment and verification, including policy applications, (ii) air pollution modelling in coastal areas with emphasis on the mediterranean region, (iii) accidental atmospheric releases, including warning systems and regulations, (iv) modelling of global and long-range transport and (v) new developments in turbulent diffusion. A round-table discussion chaired by John Irwin (USA) and Jan Kretzschmar (Belgium) on the harmonization of air pollution models was attended by more than 50 scientists and is reported in these proceedings. The opening paper addressed the main issue of this conference: modelling over complex terrain. Of particular interest were coastal areas where the surface inhomogeneities introduce small-scale circulation and varying atmospheric stability, often combined with a complex topography. As the conference was located on the beautiful island of Crete, problems faced by the host nation, particularly Athens and its environs were obvious examples for consideration. These together with other regions with similar geographical features were addressed. Heavily populated and industrialized as they often are, air quality is generally poor there and emission regulations are desired. Obviously, a major task of air pollution dispersion modelling is to assist policy makers in formulating sensible regulations.