Radiation Effects on the Human Body
Radiation can enter the body through internal or external pathways; penetrating the body like X-rays, inhaled from the air, absorbed by the skin, and even consumed through foods and drinks. Once in contact with the body’s cells, these radioactive substances can damage or alter DNA directly by attacking DNA and damaging cells or even indirectly by creating radicals which can cause the same damage. Nonetheless, there are two types of effects caused by radiation, generally divided into deterministic effects and stochastic effects. Deterministic effects occur when individuals receive a high dose of exposure, producing health problems such as skin burns, eye cataracts, and fetus damage on pregnant women. To the contrary, stochastic effects occur when individuals receive a low dose of exposure and usually yield long term health effects, as the magnitude of the effects are dependent on the dose consumed.
Radioactive Contamination of Fukushima
Within days following the Daiichi nuclear power plant blast on March 2011, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), reported workers inside the power plant were subject to the highest exposure of radiation as nearly 167 workers each received a radiation dose of over 100 millisieverts, the level known by experts to significantly increase risks for cancer. Fortunately, human inhabitants were immediately evacuated out of exclusion areas heavy with radiation as nearly 20,000 Tokyo Electric Power Co. workers and the 150,000 Japanese citizens living nearby were exposed to much lower levels of cesium, ranging from 2 to 10 millisieverts as reported by the World Health Organization. Other residents in nearby communities where evacuation had been delayed, Namie town and Litate village, received 10 to 50 millisieverts of exposure to radiation. A few extreme cases were reported in the town of Namie, where Japanese officials believe 1-3 year old babies may have been exposed to 100 to 200 millisieverts of radioactive iodine-131. This radioisotope is of great concern as it was the largest health impact of Chernobyl nuclear disaster, summing up to about 6,000 cases by 2005 as reported by UNSCEAR. Nevertheless, the radioactive iodine has a half-life of about 8 days but can gather in the thyroid glands and with enough potency can cause thyroid cancer, especially in children. Overall, Cesium-137 has been the primary radioactive substance present in the exclusion zones, contaminating land, animals, and water. Even recently in 2013, researchers have detected radioactive cesium throughout a large variety of Japanese edibles, including spinach, milk, beef, and freshwater fish up to 200 miles from the shores of Fukushima. Cesium-137 is extremely difficult to detect and remove as it will take residence of exclusion zones for centuries to come since it has a half-life of 30 years but it takes approximately 10 half-lives for any radionuclide to disappear. Overtime, the radioactive cesium will continue to bioaccumulate, bioconcentrate, and biomagnify up the food chain which is troubling since routine ingestion of contaminated foods could yield “low levels” of radioactive cesium, known to concentrate in the heart and endocrine tissues overtime, including kidneys, spleen, pancreas, and liver.
How Evacuees were Affected
The moment the Fukushima Daiichi Nuclear Power Plant exploded, was the same exact moment the lives of thousands of people would never be the same ever again. On the 11th of March, in the year 2011, approximately 300,000 people had to be evacuated from their homes due to the nuclear radiation that was being released from the power plant. In the midst of confusion and fear, what was not expected was that radiation was not going to be the only factor to change these individuals’ lives. From an on-the-surface perspective, the radiation was of course dangerous to any person living near the vicinity of the explosion. Females exposed as infants had a 70% higher chance of developing thyroid cancer, and any other individual had an increased risk for developing leukemia, breast cancer, and several other life threatening diseases. Asides from physical health risks, the evacuation caused by the explosion had a mental toll on the evacuees. Relocating caused a lot of stress for everyone; the litate local government obtained survey responses from 1,743 evacuees, and it can be seen from the survey that there was frustration, instability (financially), and despair growing amongst the large population that survived the crisis. 60% of the respondents reported that they were in poor health, and 39.9% of the individuals reported that they were already feeling extremely irritable towards everyone, including the government. Eventually, people started developing sleep insomnia leading to sleep deprivation, irregular eating habits which led to starvation, and they even faced mental challenges. Articles have reported some evacuees developing symptoms similar to PTSD because of all the stress that they endured during the crisis. One particular girl named Keiko Okamoto went into a state of depression after having lost her best friend during the time of the crisis (cause of death not mentioned in the article). Children could not live their happy lives anymore. Their playtimes outside were limited because of the amount of nuclear radiation exposure allowed for a person. Everyone had to wear masks and even had equipment to check for the amount of radioactive activity in their area to help them determine how safe it was to be outside or how long they should be outside for. Families had to be wary of what they ate or drank because TEPCO reported that 37,000 becquerels of cesium-134 and 93,000 becquerels of cesium-137 was detected in each liter of groundwater they sampled. Since the water was contaminated, this also meant the fish was contaminated which further limited the food and water resources that were available to the people of Japan. To make matters even worse, workers were limited to their amount of exposure time on the clean-up site. This is important to note because the best-fit individuals were sent in first, so once their time was up, it would be anyone else who had not been exposed yet to be sent in, and since the more experienced individuals could not get in there, they could guide these less experienced individuals only through word of mouth. What is to be taken from this, is that all these individuals’ lives were affected from the radiation not only physically, but mentally also.
Radiation effect on the Pacific
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The Fukushima disaster is often noted for being the largest discharge of radioactive material into the ocean in history. Fortunately, over 80 percent of the radiation released by the Daiichi power plant reactor blast was carried into the ocean by the strong prevalent winds during the time of the accident. Within 15 months of the accident, Ken Buesseler, a senior scientists at the Woods Hole Oceanographic Institution (WHOI), developed a research team of 17 people from 8 institutions to test the waters near the power plant. The research identified the presence of radioactive cesium in 56 percent of all fish catches in Japan although below the safe threshold for direct human exposure. The reason for such diminished presence of cesium can be attributed to the cesium’s solubility in seawater as it becomes diluted overtime by the Pacific Ocean currents. However, cesium levels found in 40 percent of bottom dwelling fish at levels greater than the Japanese regulatory limits for seafood set the fisheries off Fukushima to an end as they continue to be banned today. |
Low-Dose Radiation Concern
James Seward, medical director at Lawrence Livermore National Laboratory in California, has determined stochastic effects to be of more concern for Fukushima, as radiation is often found at low levels as he states, “The challenge is that in a population where radiation exposures are very low, it may be difficult to detect a significant change in cancer rates and attribute that with certainty to the Fukushima releases.” Furthermore, Dale Preston, a specialist in radiation health effects at Hirosoft International in Eureka, CA, supports Seward’s belief about the effects of low dose radiation on cancer by stating, “We also know that the effects, if any, of low to moderate doses appear to be small but sifting out those effects requires accounting for how they will vary—not just with dose rate but with factors such as time since exposure, age at exposure, sex, and ethnicity, not to mention interactions with other risk factors like smoking.” Preston and Seward both agree on the importance of maintaining an efficient intervention to measure the long term effects of the radiation in Fukushima. Currently, the Fukushima Medical University has launched a survey to determine individual radiation exposures, asking residents of their locations during the time of the crisis, the amount of time they spend outdoors, and everything they consumed. In addition the study will provide constant thyroid exams for all Fukushima’s pregnant women and children, estimated to continue for the next 30 years. With such ongoing long term interventions, Preston and Seward believe, “the stress of living with uncertainty about the effects caused by low dose radiation will be the largest and longest-lived health effect of all.”
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