International Baccalaureate Diploma Programme Extended EssayBiology Higher LevelResearch title:A comparison between the biological effects of radiation during the Chernobyl and Fukushima Nuclear disastersResearch question: What were the actual health consequences caused by the radiation released during Chernobyl and Fukushima nuclear accidents and how comparable are they?Subject: BiologySupervisor: Ms. SheaName: Gabriel Rodrigo Salinas TorrezTable of contents Acknowledgements……………………………………………………… i Hypothesis……………………………………………………………….ii????????INTRODUCTIONOver the years people have grown a certain fear of radiation as there have been several Nuclear disasters resulting in some health concerns. Two of the the most known Nuclear accidents are the Chernobyl disaster which occured in 1986 and the Fukushima one in the year of 2011 which I will go into detail about during this essay. First of all Radiation can be defined as energy that travels through space there are types of radiation which can cause damage to matter, particularly living tissue. At high levels it is therefore dangerous, so it is necessary to control our exposure. This were very serious cases and therefore people worried a lot about it which lead to a big fear of radiation regarding the health concerns. There are two types of radiation one being ionizing and the other one being non-ionizing radiation. Both of this radiation types can be harmful to organisms and also result in changes to the natural environment. There are many dangerous effects of our health and body in terms of the biological effects of radiation. Due to the fact that there are high (acute) and low (chronic) doses of radiation both of them have different effects in our body. Low doses can change cells which is one of the reasons why radiation is used as medicinal tool in many cases such as radiation therapy for cancer. However on the other hand high doses can be harmful to the body as it kills cells, resulting in tissue and organ damage. This is turn may cause a rapid whole body response often called the acute radiation syndromeNuclear weapons explosions is what we usually think of when we hear about high doses of radiation, but there have been documented cases of individuals dying from exposures to high doses of radiation resulting from tragic events. A large amount of radiation is required (more than 75 rad) in a short amount of time in order to lead to effects of radiation sickness Some serious effects of radiation include skin burns, hair loss, sterility, cataracts.The side effects with skin (reddening like sunburn), dry (peeling), and moist (blistering). Skin effects are more likely to occur with exposure to low energy gamma, x-ray, or beta radiation. Most of the energy of the radiation deposit in the skin surface. The dose required for erythematous to occur is relatively high, in excess of 300 radiations. Blistering requires a dose in excess of 1,200 radiations. Hair loss, also called epilation, is similar to skin effects and can occur after acute doses of about 500 radiations.Some groups of people that are relatively sensitive to exposure of radiation are pregnant women and children and this is because the cells in children and fetuses divide rapidly which gives radiation more opportunity to disrupt the process and cause cell damageThroughout this essay I will analyse and explain in detail based on research the exact impacts of both Nuclear accidents which I mentioned earlier and talk about the circumstances they were in and how they affected things including the health of individuals.Chernobyl Nuclear Accident The Chernobyl disaster which occured in April 26th 1986 is known as one of the most frightening environmental disasters in the world.The event was the worst accident in the history of nuclear power. There was no containment building to trap the radiation and therefore radioactive fallout drifted over parts of the western Soviet Union, Eastern Europe, Scandinavia, the UK, and the eastern United States. Large areas of Ukraine, Belarus, and Russia were badly contaminated. About 60% of the radioactive fallout landed in Belarus. About 350,000 had to be evacuated from the areas affected and moved to other places where they could live after the accident.The accident happened due to the fact that the fourth reactor suffered a huge power increase. Because of this the core of the reactor proceeded to explode. After that happened large amounts of radioactive materials and fuel were released into the atmosphere. Then this caused other things in the reactor, made of graphite, to start to burn. The fire caused more radioactive fallout to be released, which was carried by the smoke of the fire, into the environment and atmosphere.Safety was a huge concern for the Soviet nuclear power industry. The Soviet Union slowed down the process of making its nuclear industry bigger for some time.The food in the areas affected contained radioactive iodine and because of this some individuals received high internal doses of radiation, particularly in the thyroid gland. Cows were also affected when eating the contaminated grass, this led to children being particularly affected because they drank the cow milk and developed thyroid cancer. According to several epidemiological studies, including atomic bomb survivors, patients who are treated with radiotherapy and occupationally exposed populations in medicine and the nuclear industry, have shown that ionizing radiation can cause solid cancers and leukaemia. Some findings also indicate an increased risk of cardiovascular diseases in populations exposed at higher doses (e.g. atomic bombing survivors, radiotherapy patients).Most of the people who were affected have by the accident have actually not died yet. It will be extremely hard to say if those who were affected and die of cancer or related diseases would be because of the accident. A report that was made by IAEA in 2005 says that out of 56 direct deaths, 47 were accident workers and 9 were children who died of thyroid cancer which is something that I will talk about with depth later in the essay.. Also, according to the report approximately 4,000 people may die from long term diseases related to the accident. However Greenpeace, along with others, thinks that the study’s conclusions may not be true.Fukushima Nuclear AccidentOn March 2011 one of the most severe earthquakes occured in Japan with a magnitude 0f 9.0. This of coursed huge damages in the region and once a large tsunami was made much more followed after that. Before all the damage was caused eleven reactors at four nuclear plants were working in the region but once the earthquake hit, they were instantly shut down automatically. The reactors however were somehow vulnerable to the tsunami. Many people tend to think that there were numerous deaths following the nuclear incident, however there were no direct deaths from it. Three Tepco employees at the Daiichi and Daini plants were killed directly by the earthquake and tsunami but not from the nuclear accident. Due to the tsunami in Chile on 1960 and assessments they had done, the original design basis tsunami height was 3.1 m for Daiichi so the plant had been built about 10 metres above sea level with the seawater pumps 4 m above sea level. The Daini plant was built 13 metres above sea level. We can see here how from past catastrophic events such as Chile they decided to take different approaches in terms of how to built the plant which is one of the reason why the Fukushima accident was not as severe. It appeared that no serious damage was caused by the earthquake but once the first and second wave of tsunami hit the plant the seawater pumps for both the main condenser circuits and the auxiliary cooling circuits were submerged and damaged. The tsunamis also damaged and obstructed roads, which made it difficult to access the place from the outside. After all this happened they decided to declare a Nuclear Emergency, meaning that the Fukushima Prefecture issued an evacuation order for people within 2 km of the plant. then the Prime Minister extended this to 3 km, and on 12th of March he extended it to 10 km. He visited the plant soon after which made him make the final decision of extending it to 20km in order to ensure complete safety for the people in the surrounding areas.Despite the fact that the people in Japan were not exposed to high doses of radiation like in Chernobyl there was still some exposure to radioactive iodine during the early phase of the emergency. WHO (World health of Organization) carefully assessed the risk of thyroid cancer. The greatest risk was found among girls exposed as infants (i.e. < 1 year old) in the most affected area in the Fukushima. Even if those levels of risk might not be clinically detectable, WHO anticipated that the thyroid ultrasound screening programme being conducted in Fukushima prefecture was likely to lead to an increase in the incidence of thyroid diseases due to earlier detection of non-symptomatic cases.There have also been some reports about thyroid cancer cases being diagnosed in children exposed to low doses of radioactive iodine during the fukushima accident. However these reports should be interpreted with caution because there is the probability that someone who was exposed to this radiation is diagnosed with cancer now the radiation exposure itself could not be the direct cause of it. A large excess of thyroid cancer due to radiation exposure, such as occurred after the Chernobyl accident, can be discounted because the estimated thyroid doses due to the Fukushima accident were substantially lower than in Chernobyl. Nevertheless, the highly-sensitive thyroid screening of those under 18 years old at the time of the accident is expected to detect a large number of thyroid cysts and solid nodules, including a number of thyroid cancers that would not have been detected without such intensive screening. Similar or even slightly higher rates of cysts and nodules were found in prefectures not affected by the nuclear accident. The substantial number of cases that have already been observed in the Fukushima Health Management Survey have been considered likely due to the sensitivity of the screening rather than to radiation exposureAfter years of the accident the Fukushima population is suffering from psycho-social and mental health impact due to their relocation, ruptured social links of people who lost homes and employment, disconnected family ties and stigmatization. Also including higher occurrence of post-traumatic stress disorder among the evacuees was assessed as compared to the general population of Japan. Psychological problems, such as hyperactivity, emotional symptoms, and conduct disorders have been also reported among evacuated Fukushima children.The results and consequences of the two nuclear accidents were very different as both of them were dealt with in different ways and each of them were also under different circumstances. Therefore the biological impacts in the population were drastically different which is something that I will go into next.