TU DELFT OPEN ACCESS JOURNAL NOVEMBER 2018 SUPERHERO SCIENCE + TECHNOLOGY DOI: 10.24413/SST.2018.1.2928 REAL-LIFE RADIOACTIVE MEN: THE ADVANTAGES AND DISADVANTAGES OF RADIATION EXPOSURE JIM O’DOHERTY1,2, * BRUNO ROJAS-FISHER3 AND SOPHIE O’DOHERTY4 1 Department of Molecular Imaging, Sidra Medicine, Doha, Qatar 2 Weill Cornell Medical College Qatar, Education City, Doha, Qatar 3 Joint Departments of Physics, Royal Marsden Hospital & Institute of Cancer Research, Sutton, United Kingdom 4 Imaging Facility, EVMC, Qatar Foundation, Doha, Qatar Received: 9th October 2018 // Revised: 19th October 2018 // Published online: 23rd November 2018 * Corresponding author: [email protected] ABSTRACT A common perception in modern society is that exposure to any amount of radiation is a bad thing and should be avoided at all costs. In the fictional superhero genre, exposure to radiation has been used as a vehicle to enable superpowers in what were previously ordinary humans. For instance, Dr Chen Lu, a Nuclear Physicist otherwise known as Radioactive Man, exposed himself to increasing amounts of radiation until he could endure a massive barrage, and in the process turned himself into Radioactive Man. In a similar fashion, Bruce Banner was exposed to a large amount of gamma radiation, giving him the superpowers of the Incredible Hulk. Although there is an element of truth in that the body can withstand low levels of radiation without any observable effects, there are many harmful side effects of being exposed to high levels of radiation. These harmful side effects form the underlying fear of the general publics’ understanding of radiation exposure. This article will explore in detail the reasoning behind the principles of radiation safety, and how different types of damage are caused to the human body when exposed to radiation. Furthermore, we discuss how cellular mutations are caused, as well as the potential of organisms to develop resistance to the harmful effects of radiation and the beneficial uses of radiation in the medical field for diagnosis and cancer treatment. J. O’DOHERTY, B. ROJAS-FISHER AND S. O’DOHERTY REAL-LIFE RADIOACTIVE MEN: THE ADVANTAGES AND 1 / 16 DISADVANTAGES OF RADIATION EXPOSURE TU DELFT OPEN ACCESS JOURNAL NOVEMBER 2018 SUPERHERO SCIENCE + TECHNOLOGY DOI: 10.24413/SST.2018.1.2928 PROLOGUE Chen Lu paused as he placed his hand on the door handle. His radiation Geiger metre frantically responded as the clicking ticks blend into a single continuous noise, an indication of the danger of the contents of the laboratory, what he was about to do, and what he was about to become. He took a deep breath, opened the door and sealed his destiny… INTRODUCTION genetic mutations. He intends to use any powers that he develops in the treatment to The application of radiation as a mysterious defeat Thor, who is responsible for stopping the catalyst for the development of superpowers Chinese army’s invasion of India. After has captured the imagination of sci-fi prolonged exposure, Lu gains a number of enthusiasts for many generations [1]. After all, superpowers including the ability to manipulate radiation is essentially invisible “rays” we can’t radiation across the electromagnetic (EM) see, hear, smell or feel, but with unusual spectrum, to emit thermal radiation or heat, to properties that tend to not be very well emit high-energy radiation causing symptoms understood by non-scientists. Therefore in the of radiation sickness, to absorb radiation and world of science fiction, these properties can be convert it to energy for his own use, and held responsible for the development of any accelerated healing. He wears a customized superpower that the human imagination can radiation suit to shield his allies so that he only conjure. Although radiation is not overly exposes enemies to radiation. However for dangerous in itself, the issue with radiation for short periods of time, he can also lower the us as human beings is whether it has a radioactivity in his body to levels that make him detrimental effect on the human body if we are appear normal and thus not require the suit. exposed to it in damaging doses. A second character with powers that Appearing in the Marvel comic series stem from exposure to radiation is better known “Journey into Mystery #93” in 1963, Dr Chen Lu in the superhero universe than Chen Lu. For the is a Chinese nuclear physicist known for his various iterations of the Hulk (Bruce Banner) in research on how radioactivity could be used to the 1962 Marvel comic [3], 1977-1982 TV trigger superpowers in humans [2]. With the series, and the Hollywood films [4, 5], the origin support of his government, he exposes himself story is slightly different. Nonetheless, the to low-dose radiation (over an unknown period overall premise is that Banner is exposed to a of time) to make himself immune to the effects direct blast of high-energy gamma radiation of radiation. Although we do not know what (see Figure 1). Following the exposure, when specific type or amount, we can speculate that Banner gets angry he turns into the Hulk, a it was low enough to not kill him large green being with superhuman strength, instantaneously but ionizing enough to cause speed, agility, powers of regeneration amongst J. O’DOHERTY, B. ROJAS-FISHER AND S. O’DOHERTY REAL-LIFE RADIOACTIVE MEN: THE ADVANTAGES AND 2 / 16 DISADVANTAGES OF RADIATION EXPOSURE TU DELFT OPEN ACCESS JOURNAL NOVEMBER 2018 SUPERHERO SCIENCE + TECHNOLOGY DOI: 10.24413/SST.2018.1.2928 a host of other abilities. Insights could be made and ionising radiation. Ionisation is the process into the trigger for his transformation due to by which an atom gains or loses electrons so anger, which could for example be linked to a that it can become a positively charged (by threshold in his blood chemistry, such as up- losing electrons) or negatively charged (by regulation of the hormones testosterone or gaining electrons) particle. After the process the adrenaline or a down-regulation of the stress atom is referred to as an ion. Therefore, non- hormone cortisol. ionising radiation does not change the number In this paper, motivated by the stories of of electrons in an atom while ionising radiation Dr. Chen Lu and Dr. Bruce Banner, we will typically removes electrons from atoms. address a number of important questions in In the human body, ionisation can directly relation to radiation such as “What makes cause damage to atoms in DNA, or indirectly by radiation dangerous?” “Can exposure to X-ray creating “free radicals” that can then damage or gamma radiation, no matter how small, be DNA. Free radicals are highly reactive diffusible damaging to our health?”, “Can we make ions or molecules with unpaired electrons that ourselves “immune” to the effects of damaging interact with cellular components, and over radiation?”, “Can exposure to a huge dose of 70% of cellular damage is caused by free gamma radiation really give a person radicals [6]. Ionisation results in the superhuman strength?”, and “Do mutations development of biological and physiological really occur when you are exposed to high alterations in the molecular structures within a levels of radiation?” We also consider a number cell such as inability of the cell to divide of the plausible themes that have been used to correctly that may manifest themselves allow ordinary humans to acquire superpowers seconds or decades later. Consider UV following exposure to a given radiation. In radiation. It is well known to cause sunburn not addition, we explore why these narratives are long after exposure to the sun, and prolonged interesting concepts in the field of radiation exposure increases the lifetime risks of science. developing melanoma (skin cancer) many years after the exposure [7]. High-energy radiation WARNING – RADIATION such as ultraviolet radiation, X-rays, and HAZARD! gamma rays are ionising radiation since they can cause ionisation of atoms in the human To begin answering the aforementioned body (Figure 1). Low-energy radiation such as questions, it is important to know why some visible light and radio waves do not cause types of radiation on the electromagnetic (EM) ionisation of atoms and are forms of non- spectrum can be considered dangerous to ionising radiation. Furthermore, there is also human health. The broadest definition of radiation emitted as particles (rather than rays), radiation is that there are 2 types, non-ionising which results from the interaction of ionising J. O’DOHERTY, B. ROJAS-FISHER AND S. O’DOHERTY REAL-LIFE RADIOACTIVE MEN: THE ADVANTAGES AND 3 / 16 DISADVANTAGES OF RADIATION EXPOSURE TU DELFT OPEN ACCESS JOURNAL NOVEMBER 2018 SUPERHERO SCIENCE + TECHNOLOGY DOI: 10.24413/SST.2018.1.2928 rays radiation with matter. Examples of these even more highly biologically reactive than rays. are protons, neutrons and electrons, which are Figure 1: The electromagnetic (EM) spectrum, and applications in modern medicine. Ionising radiation is a term used to describe radiation with enough energy to cause damage to the cells of the human body while non-ionising radiation does not have enough energy to damage cells. dose”, which is the absorbed dose multiplied by MEASUREMENT OF RADIATION a radiation weighting constant (i.e. the constant EXPOSURE for X-rays = 1, the constant for neutrons = 20) and a tissue-weighting constant (i.e. skin = It is useful to know when considering radiation 0.01, bone marrow = 0.12). The effective dose exposure how it is physically measured and parameter has the unit of Sieverts (Sv), and is a how it is quantified. “Radiation exposure” is a crude (although internationally accepted) term that accounts for the potential damage by attempt to quantify the biological effects of certain types of radiation, as well as the exposure to radiation.