Living with Radiation 2025

Introduction
Life on Earth has evolved and survived for two billion years while constantly exposed to radiation of various kinds. Indeed, light and heat from the sun are natural sources of radiation essential to life and our continued existence. In the modern age, humans have harnessed radiation for use in industry, electricity generation, communications, medicine and even within the home. Without radiation in its various forms, life as we know it would be very different. We use radiowaves for mobile phones, X-rays in medicine and microwaves for cooking, among the very many other uses. These radiations are generated by electrical devices and can be controlled or turned off, limiting or stopping the production of radiation. However, radiations emanating from naturally occurring minerals led to the discovery of radioactivity. In this case unstable atoms spontaneously emit various radiations to become more stable. The dawn of the nuclear age in the 1940s brought us novel radioactive materials that led to dramatic advances in medical diagnostics and treatment therapies. Such materials are also used in a wide range of processes and procedures, for example, in industry, oil exploration, and life science research. These different types of radiation can be classified according to the effects they have on matter, including living cells. The two categories of radiation are ionising and non-ionising. lonising radiation includes cosmic rays, X-rays, and the radiation from radioactive materials while non-ionising radiation includes ultraviolet radiation, light, heat, radio waves, and microwaves. Radiations may also be classified in terms of their origin as naturally occurring or artificial (human-made sources of) radiation.

Benefits and risks
The benefits from some forms of natural non-ionising radiation, notably heat and light from the sun, are enormous to all life on Earth, indeed such radiation is essential to life. However, there are no specific benefits from exposure to natural ionising radiation, and although a radiation may be of natural origin, this does not mean it is somehow less harmful than radiation of artificial origin. Indeed, excessive exposure to ultraviolet light is causally linked to skin cancers and likewise excessive exposure to the naturally occurring radioactive gas radon is linked to lung cancer. While we make considerable use of both ionising and non-ionising radiations for the benefit of society, they can also be harmful, therefore, people must be protected from unnecessary or excessive exposures wherever possible. The greatest health concern about ionising radiation is that it can cause cancers in exposed people and subsequent inherited defects in later generations. The likelihood of such effects depends on the amount of radiation that a person receives and is equally true whether the radiation is of natural or artificial origin. So, in circumstances that can be controlled, a careful consideration of the balance of the risks posed and the benefits gained from procedures that expose people to radiation is required.

Public anxiety
When the terms 'radiation' or 'nuclear' are used, people are reminded of the atomic bombs dropped on the Japanese cities of Hiroshima and Nagasaki towards the end of World War II or the nuclear accidents in Fukushima in 2011 and Chornobyl in 1986, understandably leading to concerns and anxiety. However, there are many uses of radiation that are of great benefit to individuals (e.g. in medical diagnostics and treatment) and society more widely (e.g. electrical power generation, communications). The effects of ionising and non-ionising radiations have become better understood during recent decades. This has led to the development of internationally agreed systems of radiological protection to protect people from sources of ionising and non-ionising radiations and where exposure cannot be eliminated, to better manage the residual risk and ensure it is as low as possible. The subject of radiation safety receives much public attention, partly because radiation is one of the many causes of cancer. Unlike other risk factors encountered during a lifetime that may pose a more tangible risk, ionising radiation cannot be seen, smelled, or tasted and only detected using specialised devices. This undoubtedly adds to public anxiety. The lack of reliable, authoritative, and publicly accessible information written in plain English about radiation, and with ever increasing concerns about the potential sources of misinformation in modern society on the subject, adds to this anxiety. The aim of this book is to help fill this gap by providing information in a straightforward manner for those who are not experts. In the following chapters, we describe the sources and effects of radiation of all types and explain the principles and practices of radiological protection.

Alternatives To Caesium Irradiators for Biological Sciences and Blood Transfusion Services

Abstract

Global concerns on the potential for malevolent use of high activity sealed sources of ionising radiation have prompted moves to identify options for their replacement with alternative technologies. Sealed sources of caesium-137 are in common use in biological sciences research and in the production of blood products in blood transfusion services. This report considers the current uses of caesium-137 sources in biological sciences and blood transfusion services in the United Kingdom and potential alternatives. The characteristics of caesium-137 radiation fields are considered as well as those of X-ray alternatives. It is identified that suitable alternatives, including X-irradiators and non-radioactive methods, are available for all current applications but in some cases individual users and researchers may be required to test and develop the alternatives before they can be routinely adopted. A decision tree is provided to aid current users of caesium-137 sources to identify suitable alternative technologies