Friday, September 20, 2019

Long-term Effects of Chernobyl

Long-term Effects of Chernobyl Abstract Chernobyl was a city in Ukraine that housed one of the most tragic nuclear power plant accidents in history. It happened 30 years ago, however, the effects are still felt by many. This paper will explore the long term effects that Chernobyl left behind. Today, the city is still sectioned off from the rest of the country in an effort to help protect people from the ongoing radiation exposure. Clean up workers and anyone living nearby are at risk for life-long chronic diseases, some of which are not curable at the present time. These diseases or illnesses include cataracts, cardiovascular disease, psychological effects, birth defects, papillary thyroid cancer and chronic lymphocytic leukemia. Other effects include a contaminated agricultural and water system. The Effects that Chernobyl Left Behind The Chernobyl Nuclear Power Plant was one of the most important forms of power in Ukraine and the surrounding areas. It housed 4 nuclear reactors, each of which have been shut down over the years. One particular reactor, number 4, had undergone a test that went awry. On April 26, 1986 one of the worst nuclear power plant accidents occurred at Chernobyl. The personnel controlling these reactors were not following correct operating protocol, which led to the disaster. The reactors were highly unstable and not designed to operate at low power. If the reactors lost water for cooling, nuclear chain reactions occurred more frequently and the power output increased causing a power surge, in turn heating the reactor. The lid to the reactor had reached an excessive temperature and finally blew apart sending nuclear fuel and fragmented material into the surrounding area. A dangerous amount of radioactive material was released into the environment and sent the staff at the plant and the public into a panic (Chernobyl Accident and Its Consequences-Fact Sheet. March, 2015). Reactor number 4 contained about 190 metric tons of uranium dioxide and fuel products that exploded into the environment. It is estimated that about 13-30 percent of this product made it into the atmosphere (Chernobyl Accident and Its Consequences-Fact Sheet. March, 2015). This massive amount of uranium dioxide is the leading component in the radiation exposure to so many people. Uranium is one of the biggest contributors to natural terrestrial radiation. Terrestrial radiation is found in the ground and the major isotopes of concern for terrestrial radiation are uranium and the decay products of uranium. This is the material that was used in the Chernobyl Nuclear Power Plant. This explosion affected 18 miles around the city of Chernobyl. In order to contain the ongoing radiation exposure, officials have built a concrete building around reactor number 4 in order to help filter the radiation exposure from entering the atmosphere. Â  It has been 30 years since the Chernobyl Nuclear Power Plant accident, but the effects still live on. Today Chernobyl is a ghost town since it was evacuated directly after the accident. It has since been deemed to be a toxic and unlivable place due to the radiation exposure that may be received. There have been regulations and emergency preparedness precautions that have been put into effect in order to ensure that this kind of crisis will never happen again. According to the United States Nuclear Regulatory Commission, the government of Ukraine evacuated about 115,000 people from the most heavily contaminated areas in 1986. Even though the vast majority of the area was evacuated, long-term effects still linger. Health effects and diseases have developed in the years after the accident upon individuals who worked at the Chernobyl Nuclear Power Plant, or were in the surrounding area. Some diseases that are more prevalent as a result of the radiation exposure from the accident incl ude, cataracts to the eyes, cardiovascular disease, psychological effects, birth defects such as hydrocephalus, as well as increased risk for cancers such as papillary thyroid cancer and chronic lymphocytic leukemia. Other effects include unusable land for farming or unstable livestock from the accident. As a result of this catastrophic event, more than 200,000 km2 were subjected to levels of radioactive deposits exceeding 37 kBq/m2 of 137 Cs, the cut-off level to classify an area as contaminated. The average dose that was received from the Chernobyl Nuclear Power Plant accident ranges from less than 10 milisievert (mSv) to over 1 sievert (Sv). (Moiseenko, Khvostunov, Hattangadi-Gluth, Muren, & Lloyd, 2016). 1 Sv is equivalent to 100 Rem. Radiation equivalent man (Rem), is the traditional unit of measure for humans. All of the units will be converted into this value. This is a substantial amount of radiation considering the allowable dose for a non-occupational person to receive is 0.5 Rem per year. The dose that was received by some people in the accident is two hundred times that of the normal limit for the entire year. The occurrence and severity of cataracts is proportional to the dose of radiation received. The Ukrainian-American Chernobyl Ocular study reported a dose-related increase in the rate of cataracts in cleanup workers from Ukraine. This study also caused for reevaluation of the dose limits to the eyes by the International Commission on Radiologic Protection. It has since then been changed from 1 Gy (gray) or 100 Rem down to 0.7 Gy or 70 Rem for non-occupationally exposed people, and down to 0.5 Gy or 50 Rem for those occupationally exposed. The Chernobyl Nuclear Power Plant accident caused the universal exposure limit to the eyes to be lowered due to the increase in cataracts among those people who were exposed. (Zablotska, 2016). Cardiovascular disease reports are only increased in the Chernobyl clean up worker cohort. It may not be a significant cause of cardiovascular disease in people elsewhere, however clean up workers had an increased amount of cases because they were exposed to so much radiation in such a short period of time (Zablotska, 2016). Prolonged exposure to radiation may cause chronic kidney disorders, which induce hypertension and thus might contribute to the increased risk of cardiovascular diseases (Kamiya, et al., 2015). Psychological effects pertain to the mind, emotions, or reactions to certain events. According to Zablotska (2016), a catastrophic event such as the Chernobyl Nuclear Power Plant accident warranted many psychological effects on workers as well as ordinary people of the surrounding areas. These effects may never disappear, as many people still have symptoms decades after the accident. The lack of information given to the general public about what had happened caused a panic among many. The mystery of radiation exposure also caused anxiety among those affected by the exposure. Some people have developed severe anxiety due to the fact that they are nervous about being exposed to that much radiation, and the diseases that follow a high dose. Many people including young children and teens during the accident have post-traumatic stress disorder. This is mostly due to being forced to leave their roots in such an abrupt way. People were mistrusting towards their government for not keeping th e reactors under tighter regulations. Many were also frustrated by the lack of emergency preparedness plans that could have prevented so much widespread damage. Young children and teens may also be more susceptible to certain diseases and cancers because their cells are more radiosensitive towards exposures, which makes parents very anxious and depressed fearing something may happen to their babies. Another long lasting effect of the accident is the prevalence of thyroid cancer. This disease is by far the most frightening and notorious of the Chernobyl Nuclear Power Plant accident. This is the disease that everyone worries about because it can affect teens, children and adults in the same way. According to Handkiewicz-Junak et al., (2016) there have been approximately 5,000 thyroid cancer cases since the accident in the surrounding area. Two parallel studies have been performed. One study involved subjects in Ukraine and the other involved subjects in Belarus, one of the neighboring countries of Ukraine. Each study comprised about 12,000 children or adolescents from the accident. All of the subjects had been exposed to Iodine-131, which is a radioisotope. Periodic standardized screenings revealed that thyroid cancer and non-malignant diseases of the thyroid were far more prevalent in these studies than normal. Furthermore, evidence from other smaller population-based case-contro l studies confirms a causal relationship between the observed increase in thyroid cancer risk and exposure to Iodine-131 from the Chernobyl fall out (Zablotska, 2016). Another study was conducted on 65 children who had been exposed to Chernobyl radiation and sporadic papillary thyroid cancer. All participants were residents of the same region so that factors related to genetics or environment were reduced. Using DNA microarray, which measures the gene expression of many different samples, ten genes were confirmed as being associated with radiation exposure samples. This concludes that there is a significant difference in gene expression that causes papillary thyroid cancer to become active in post-Chernobyl subjects who were exposed (Handkiewicz-Junak et al., 2016). Chronic lymphocytic leukemia was found in workers who helped clean up after the Chernobyl accident. A study was conducted on the clean up workers registered in the Chernobyl state registry who resided in six regions of Ukraine (five oblasts and Kiev city). This particular cohort represented about 47% of the total number of clean up workers who helped at the Chernobyl accident. The study was later updated to include another nearby area, which bumped up the cohort to representing about 60% of the clean up workers. The findings showed an excess occurrence of chronic lymphocytic leukemia cases compared with national levels during the study period of about 26 years. The most drastic increase in cases occurred within the first decade after the accident and continues during subsequent decades. The potential risk from a different cohort, measured between 1986-2006, demonstrated the same risk of chronic lymphocytic leukemia, and it still remains active over 20 years after the exposure (Bazyka , et al., 2015). We know that radiation is cumulative and that any amount can cause genetic effects on future generations. Many of the clean up workers at the time of the accident were young adults who were at the start of their fertility and birthing years. The clean up workers could have been exposed to high amounts of radiation without any form of protection to the gonads. Certain mutations in DNA can form due to exceedingly high doses, which are then passed on to subsequent generations. For this reason, birth defects are put in the spot light for those affected. According to the Medical Birth Registry of Norway, a positive correlation has been associated with external and food based exposure, with hydrocephaly (Lie, Irgens, Skjaerven, Reitan, P. Strand, T. Strand, April 1992). According to Webster’s dictionary, hydrocephalus is an increase in the amount of cerebrospinal fluid within the cranial cavity. This causes expansion of the cerebral ventricles in the brain, and increased intracrania l pressure, skull enlargement, and cognitive decline (Hydrocephalus: Merriam-Webster). This is one of the very serious birth defects related to those individuals of reproductive age during the exposure. Lastly, effects of the Chernobyl accident extend further than just diseases or cancers directly affecting humans. The accident has a large impact on the soil and water system. The soil around Chernobyl cannot be used for farming since radioactive fuel and isotopes were scattered across a large area. In the first few weeks after the accident, private farm owners were not educated on the risks associated with the radioactive isotopes and fuel particles in the air and now onto their farms. Their farm animals, such as cows, consumed the radioactive material that was sprinkled over their hay, or other feed, and then produced milk that the farm owners then drank. The milk contained very high amounts of Iodine-131, which as previously discussed, contributed to increased rates of thyroid cancer. The water system was also contaminated with Iodine-131 and had the same effect on people as contaminated milk does. Contaminated water and milk are one of the leading causes of thyroid cancers among young children and teens (Beresford, et al., 2016). In conclusion, the Chernobyl Nuclear Power Plant accident was one of the most catastrophic nuclear accidents in history. The wide range of people that were affected is astonishing. The radiation exposure blanketed some 200,000 km2, including Ukraine and the surrounding areas with thousands of people sickened by disease and turmoil, living with the consequences and long-term effects for the rest of their lives. People had to abruptly evacuate their homes and hometown roots due to this nuclear crisis. The after effects caused psychological problems and stressors, while also leaving many with no place to live. Anyone who may have helped clean up after the accident are at risk for cataracts, cardiovascular disease, and cancers such as thyroid or leukemia. Those individuals who were of reproductive age may have passed along mutated DNA causing birth defects. The effects that Chernobyl left behind are countless, however, regulations and safety precautions have been put into place in order to prevent such a catastrophic event from happening again. References Backgrounder on Chernobyl Nuclear Power Plant Accident. (2014, December 12). http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html Bazyka, D., Gudzenko, N., Dyagil, I., Goroh, E., Polyschuk, O., Trotsuk, N., . . . Romanenko, A. (2015, September 24). Chronic Lymphocytic Leukemia in Chornobyl Cleanup Workers. Health Physics, 111(2), 186-191. doi:10.1097/HP.0000000000000440 Beresford, N., Fesenko, S., Konoplev, A., Skuterud, L., Smith, J., & Voigt, G. (2016, June). Thirty years after the Chernobyl accident: What lessons have we learnt? Journal of Environmental Radioactivity, 157, 77-89. doi:10.1016/j.jenvrad.2016.02.003 Chernobyl Accident and Its Consequences-Fact Sheet. (2015, March). http://www.nei.org/master-document-folder/backgrounders/fact-sheets/chernobyl-accident-and-its-consequences Handkiewicz-Junak, D., Swierniak, M., Rusinek, D., Oczko-Wojciechowska, M., Dom, G., Maenhaut, C., . . . Jarzab, B. (2016, January 26). Gene signature of the post-Chernobyl papillary thyroid cancer. European Journal of Nuclear Medicine and Molecular Imaging Eur J Nucl Med Mol Imaging, 43(7), 1267-1277. doi:10.1007/s00259-015-3303-3 Hydrocephalus. (n.d.) . In Merriam-Webster online dictionary. http://www.merriam-webster.com/dictionary/hydrocephalus Kamiya, K., Ozasa, K., Akiba, S., Niwa, O., Kodama, K., Takamura, N., . . . Wakeford, R. (2015, August 01). Long-term effects of radiation exposure on health. The Lancet, 386(9992), 469-478. https://wwwclinicalkeycom.sladenlibrary.hfhs.org/#!/content/playContent/1-s2.0-S0140673615611679. Lie, R., Irgens, L., Skjaerven, R., Reitan, J., Strand, P., & Strand, T. (1992, April 2). Birth Defects in Norway by Levels of External and Food-based Exposure to Radiation from Chernobyl. American Journal of Epidemiology, 136(4), 377-388. http://aje.oxfordjournals.org/content/136/4/377.short Moiseenko, V., Khvostunov, I. K., Hattangadi-Gluth, J. A., Muren, L. P., & Lloyd, D. C. (2016, April 1). Biological dosimetry to assess risks of health effects in victims of radiation accidents: Thirty years after Chernobyl. Radiotherapy and Oncology, 119(1), 1-4. doi:10.1016/j.radonc.2016.02.033 Zablotska, L. B. (2016, April 29). 30Â  years After the Chernobyl Nuclear Accident: Time for Reflection and Re-evaluation of Current Disaster Preparedness Plans. Journal of Urban Health J Urban Health, 93(3), 407-413. doi:10.1007/s11524-016-0053-x

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.