Lessons to Be Learned From Hiroshima and Nagasaki 1945 - Coursework Example

Health Effects of Radiation Exposure: Lessons from Hiroshima and Nagasaki 1945 Introduction More than half a century after the atomic bombs were dropped on Hiroshima and Nagasaki in a successful effort by the United States to end World War II, there still remains much controversy over the decision to employ nuclear weapons. Recently released documents of previously censored information about the initial effects of the bombings have permitted historians to obtain a more realistic view of the effects of the atomic radiation released in the early days after the nuclear weapons were detonated. In 2005, several articles written by journalist George Weller, the first reporter to enter the city of Nagasaki after the bomb was dropped on August 9, 1945, were released for the first time (Little, 2009). His eyewitness reports of the scenes he encountered in hospitals dramatically portray the horrors of nuclear war. The acute radiation sickness that was prevalent was referred to “Disease X”. Some of the patients showed obvious signs of radiation poisoning: their mouths were black, the skin was covered with red patches and their hair was falling out. In other cases, patients were dying with no obvious symptoms. No one knew why so many people were dying - no one understood how radiation affects the human body. This graphic information on the horrific effects of the atomic radiation was suppressed for many years. It was not published until journalist Weller’s son, Anthony Weller, discovered copies of his father’s documents long after his father’s death. In addition to these written reports, photographic images of the aftermath of the bombings were also suppressed from publication until the 1980s (Marston, 1986). Shortly after the bombings, the American military, under the direction of General George MacArthur, directed the filming of the cities after the bombing. The film reveals the vaporized images of human bodies as shadows obliterated in the wake of the initial effects of the bombs. Images of the dying in area hospitals were also recorded on film. The filmmakers wanted to record for history the horrific images that serve as a testament to the devastation of nuclear war, so that people would remember more than the mushroom cloud in the skies, more than the military victory symbolized by the powerful weaponry. The film was called “#342 USAF” and hidden from view until their release almost 50 years after they were recorded. Additional Japanese footage was seized by the US government and finally returned to Japan in the 1960s, whereupon filmmaker Erik Barnouw prepared a short edited version of the footage, called “Hiroshima-Nagasaki 1945”. The film was released in 1982 under the name of “Dark Circle” at the New York Film Festival (Marston, 1986). Medical Consequences of Radiation Exposure: Short term and Long term Effects What was the source of these mysterious effects of atomic radiation on the human body? The damaging effects from a nuclear explosion are determined by the amount of exposure, or dosage of radiation, measured in units called rems (radiation equivalent in man). Rems are released by the explosion itself, which represents an instantaneous exposure, and also from the radiation released from the contaminated areas impacted by the explosion and from “fallout”, a term that refers to the radioactive particles that are absorbed into the atmosphere and eventually deposited as radioactive particles on the surface of the earth (Leibow, 1970). Acute radiation sickness occurs following doses of radiation over 100 rems. The primary symptoms of acute radiation sickness are nausea and vomiting, headache, and a drop in white cell count (Pierce et al, 1996). At 300 rems exposure, additional symptoms are observed, including temporary hair loss, nerve damage and damage to the gastrointestinal tract. Loss of platelets may result in hemorrhaging. AT 450 rems of radiation exposure, the mortality rate due to acute radiation poisoning is 50%. Higher doses (800 rems or greater) are invariably fatal. Fever and diarrhea are also experienced at these high level doses; death usually occurs between two days and two weeks (Pierce et al, 1996). Longer term survivors who show no signs of acute radiation sickness may also experience more subtle health consequences resulting from low dose radiation exposure (Little, 2009). Included among these health risks are an increased incidence of leukemia, lung cancer, thyroid cancer breast cancer and others. Leukemia was the first human cancer to be associated with long term radiation effects, appearing at significantly elevated rates in atomic bomb survivors and their children. As time passed, elevated levels of other types of cancer were seen in this survivor population. Many children born to survivors also suffered from congenital birth defects (Little, 2009). To appreciate the powerfully destructive effects of radiation, it is necessary to understand how this energy is produced. In 1934, Enrico Fermi demonstrated that it was possible to split the atomic nucleus by bombarding it with neutrons. This process is called fission, and the splitting of the atomic nucleus results in the conversion of small amounts of matter to extraordinary amounts of energy, in accord with Einstein’s famous equation of relativity: E=mc^2. The energy released by atomic fission in the bombs dropped over Hiroshima and Nagasaki was highly destructive to all life forms: plants, animals and humans. The first atomic bomb was detonated over the city of Hiroshima on August 6, 1945, which resulted in 140,000 deaths. The second atomic bomb was dropped over the city Nagasaki three days later and was responsible for an additional 75, 000 deaths (Leibow, 1970). In the minutes following the 15 kiloton blast of uranium fission, 90% of all people within a one-half mile radius of the bomb were dead (Pierce et al, 1996). This was followed by a raging firestorm that engulfed a 4.4 mile radius from the explosion site. Within two weeks, thousands of individuals were dying from acute radiation sickness, which began to slow after another six weeks (Pierce et al, 1996). The plutonium bomb dropped over Nagasaki three days later produced 40% more energy than the first bomb. The biological effect of high energy radiation is the result of energy transfer processes that destroy the structures of molecules of which cells and tissues are comprised. This type of radiation is called “ionizing” radiation because its energy strips the electrons off atoms to convert them to high energy destructive ions that destroy proteins and the genetic material of cells. The tissue damage is associated with the formation of free radicals that can damage the structure of DNA and cause mutations that affect gene structure and function. The damaging effects of radiation alter chemical bonds and produces damage in many of the biomolecules essential to cell function. Although DNA repair mechanisms exist to correct the damaging effects of radiation, high level exposure can override the capacity of the cell to repair itself and cell death occurs (Leibow, 1970). The effect of high energy ionizing radiation on cells in the body is dependent upon the mitotic rate; more rapidly dividing cells experience greater damage from radiation exposure than non-dividing cells of the body. For this reason, the blood forming and reproductive cells are generally more sensitive to the effects of radiation than other tissues in the body. Thus, among the primary consequences of sub-lethal doses of radiation are diseases of the blood, such as leukemia, and effects on reproduction associated with infertility, miscarriage and congenital effects in the developing fetus (Pierce et al, 1996). The effect of radiation exposure on leukemia incidence among the atomic bomb survivors has been far more dramatic. Even today, 60 years after the bombs were detonated, the incidence of leukemia in the surviving population exceeds population averages (Little, 2009). A correlation was also noted for the age of the individual at the time of the bombings and relative risk for the development of leukemia, such that the younger the age, the greater the lifetime risk for developing some form of this disease. Although the incidence of leukemia worldwide is about 4%, in survivors the incidence continues to occur at 20% frequency. The data obtained from these epidemiological research studies supports the theory of linear dose response effects to radiation exposure, such that relative risk is directly proportional to the amount of radiation exposure (Neel, 1991). Delayed effects of radiation exposure are generally experienced when sub-lethal exposure has occurred, such that the cellular damage is not great enough o cause death, but nevertheless produces genetic damage that may lead to the development of cancer over a time frame of 2-30 years post radiation exposure (Little, 2009). For most cancers, long-term epidemiological studies have shown that survivors of the atomic bombs do not display an earlier age onset of disease than other populations. Rather, an increased incidence overall of all cancers combined have been observed in these survivors. Since the early 1970s, however, the overall cancer incidence in atomic bomb survivors has not exceeded population controls (Little, 2009). At 10 rems of exposure or greater, the effects of ionizing radiation on the fetus include microcephaly, cognitive impairment. In 1948 the Atomic Bomb Casualty Commission initiated a study on the effects of radiation exposure in atomic bomb survivors on pregnancy and childbirth (Neel, 1991). 90% of the pregnancies occurring in the years following the atomic bomb explosions were assessed for evidence of radiation exposure effects. Despite these efforts, the study results were inconclusive as they were only initiated several years after the bombings and did not uncover any discernible effect on this group of women. Numerous studies conducted since that time have documented a significant effect only on children conceived immediately before the bombings with regard to increased congenital defects associated with radiation-induced DNA damage (Neel, 1991). These studies indicated that pregnant women exposed to radiation at 3-4 months pregnancy have a significantly greater risk of having a child with cognitive impairment associated with brain damage or other congenital malformations. A total of 21/800 babies born at that time suffered profound cognitive impairment. IQ tests conducted on children born within 5 years of the atomic bomb explosions have recorded a significant decrease in scores in this group compared the norm (Little, 2009). Conclusion At the time the atomic bombs were detonated at Hiroshima and Nagasaki, the long term effects of nuclear radiation on human life and the environment were unknown. Today, more than six decades later, researchers are continuing to asses the ramifications of the deadliest assault against human life ever implemented in history. References Liebow, Averill.  Encounter with Disaster, A Medical Diary.  New York: W.W. Norton and Company, Inc., 1970. Little, M.P. Cancer and Non-Cancer Effects in Japanese Atomic Bomb Survivors. J. Radiol. Prot., 2009, A43-59. Marston, Robert Q. M.D., and Fredric Solomon M.D., eds.  The Medical Implications of Nuclear War.  Washington, D.C.: National Academy Press, 1986. Neel, James V. M.D., and William J. Schull M.D., eds.  The Children of Atomic Bomb Survivors, A Genetic Study.  Washington, D.C.: National Academy Press, 1991. Pierce D.A., Shimizu, Y., Preston, D.L,. Vaeth. M., and Mabuchi. K. Studies of the mortality of atomic bomb survivors. Report 12, Part I. Cancer: 1950-1990.Radiat Res. 1996 Jul;146(1):1-27.     Read More