(This is part VII of this series on energy. We hope it helps the reader better understand the issues facing our country and our state as we endeavor to tackle the problem of providing our citizens and our businesses with their energy needs.)
* A commonly utilized measure of radiation dosage is millisieverts (mSv). On average, each person receives 2.4 mSv per year of natural background radiation, typically varying from 1-13 mSv per year. Per the United Nations Scientific Committee on the Effects of Atomic Radiation, “sizeable population groups receive 10-20 mSv annually” of natural radiation. This does not include any radiation from human activities. 
* Over the course of a lifetime, most people receive about 70-700 mSv of radiation from natural sources.
* After tobacco smoke, the second leading cause of lung cancer in the U.S. is radon, a gas that arises from the decay of natural uranium, which is common in rocks and soils. The EPA estimates that 14.4 percent of lung cancer deaths in the U.S. are related to radon.
* Due to hot springs that leach a radioactive element from underground, 2,000 residents in the city of Ramsar, Iran, receive up to 260 mSv of natural background radiation per year. Per a 2002 paper in journal Health Physics, preliminary studies indicate an “apparent lack of ill effects among observed populations of these high dose rate areas….”
* Regarding manmade sources of radiation, on average: a person underdoing a CT scan receives a dose of 10 mSv. a nuclear power plant worker receives a dose of 1 mSv per year. the general population receives a dose of 0.0002 mSv per year as a result of the nuclear power industry. 
* Concentrated (i.e., high-level, high-rate) radiation doses generally cause more harm than the same doses spread out over longer periods of time. Concentrated radiation doses of:more than 10,000 mSv are always fatal.1,000-10,000 mSv can cause radiation sickness (which may result in death) and can increase the risk of certain cancers.
10-1,000 mSv have no immediate effects but may increase the long-term risk of certain cancers.
* Two major studies of survivors of the 1945 atomic bombings in Hiroshima and Nagasaki have found increased rates of certain cancers among populations who received concentrated radiation doses below 100 mSv, but none of the results were statistically significant below this level.
* The largest nuclear power accident in the world occurred in the city of Chernobyl in the Soviet Union in 1986. A picture of the reactor after the accident is shown here:
* Per the official summary of a 2006 three-volume report by the International Atomic Energy Agency, World Health Organization, U.N. Development Programme, Food and Agriculture Organization, U.N. Environment Programme, U.N. Office for the Coordination of Humanitarian Affairs, U.N. Scientific Committee on the Effects of Atomic Radiation, World Bank, and the governments of Belarus, the Russian Federation, and Ukraine:
“Approximately 1,000 on-site reactor staff and emergency workers were heavily exposed to high-level radiation on the first day of the accident….”
“More than 350,000 people have been relocated away from the most severely contaminated areas, 116,000 of them immediately after the accident.”
“An estimated five million people currently live in areas of Belarus, Russia and Ukraine that are contaminated with radionuclides due to the accident….”
“[M]ost recovery operation workers and those living in contaminated territories received relatively low whole body radiation doses, comparable to background radiation levels and lower than the average doses received by residents in some parts of the world having high natural background radiation levels.”
“As of mid-2005 … fewer than 50 deaths had been directly attributed to radiation from the disaster, almost all being highly exposed rescue workers, many who died within months of the accident but others who died as late as 2004.”
“About 4,000 cases of thyroid cancer, mainly in children and adolescents at the time of the accident, have resulted from the accident’s contamination and at least nine children died of thyroid cancer; however the survival rate among such cancer victims … has been almost 99%.”
“A total of up to 4,000 people could eventually die of radiation exposure from the Chernobyl nuclear power plant accident…. The estimated 4,000 casualties may occur during the lifetime of about 600,000 people under consideration. As about a quarter of them will eventually die from spontaneous cancer not caused by Chernobyl radiation, the radiation-induced increase of about 3% will be difficult to observe.”
“Because of the relatively low doses to residents of contaminated territories, no evidence or likelihood of decreased fertility has been seen among males or females. Also, because the doses were so low, there was no evidence of any effect on the number of stillbirths, adverse pregnancy outcomes, delivery complications or overall health of children.”
“Persistent myths and misperceptions about the threat of radiation have resulted in ‘paralyzing fatalism’ among residents of affected areas.”
“Poverty, ‘lifestyle’ diseases now rampant in the former Soviet Union and mental health problems pose a far greater threat to local communities than does radiation exposure.”
* Per the “environment” volume of the above-cited 2006 report:
“Radiation from radionuclides released by the Chernobyl accident caused numerous acute adverse effects in the biota [plants and animals] located in the areas of highest exposure (i.e. up to a distance of a few tens of kilometers from the release point).”
Such effects included: “(a) Increased mortality of coniferous plants, soil invertebrates and mammals; (b) Reproductive losses in plants and animals; (c) Chronic radiation syndrome in animals (mammals, birds, etc.).”
“Beyond the CEZ [Chernobyl exclusion zone, which is 30 km or 19 miles around the site of the accident], no acute radiation induced effects on biota have been reported.”
“Following the natural reduction of exposure levels due to radionuclide decay and migration, populations have been recovering from the acute radiation effects.”
“By the next growing season after the accident, the population viability of plants and animals substantially recovered as a result of the combined effects of reproduction and immigration. A few years were needed for recovery from the major radiation induced adverse effects in plants and animals.”
“Both in the CEZ and beyond, different cytogenetic [cellular/genetic] anomalies attributable to radiation continue to be reported from experimental studies performed on plants and animals. Whether the observed cytogenetic anomalies have any detrimental biological significance is not known.”
“At present, traces of adverse radiation effects on biota can hardly be found in the near vicinity of the radiation source (a few kilometers from the damaged reactor), and on the rest of the territory, both wild plants and animals are flourishing because of the removal of the major natural stressor: humans.”
* The second-largest nuclear power accident occurred in March of 2011 at the Fukushima Daiichi nuclear power facility in Japan. A 9.0-magnitude earthquake and resulting tsunami killed roughly 18,500 people, caused $220 billion in damage, and caused explosions and radiation leaks in multiple reactors at the nuclear power facility. 
* A 2014 report about the Fukushima nuclear accident by the United Nations Scientific Committee on the Effects of Atomic Radiation found that:
“no radiation-related deaths or acute diseases have been observed among the workers and general public exposed to radiation from the accident.”
“no discernible increased incidence of radiation-related health effects are expected among exposed members of the public or their descendants.”
“a total of 24,832 workers were reported to have been involved in mitigation and other activities on the site and were occupationally exposed to radiation.”
among the workers, 16,162 received radiation doses of 10 mSv or less, 173 received doses of 100 mSv or more, and 6 received doses of 250 mSv or more (the highest dosage was 679 mSv).” 
* The largest nuclear power plant accident in the U.S. occurred near Middletown, Pennsylvania, at the Three Mile Island nuclear facility in March of 1979.
* As a result of the Three Mile Island accident, the maximum radiation dosage to local residents was less than 1 mSv.   Per the U.S. Nuclear Regulatory Commission:
In the months following the accident, although questions were raised about possible adverse effects from radiation on human, animal, and plant life in the TMI [Three Mile Island] area, none could be directly correlated to the accident. Thousands of environmental samples of air, water, milk, vegetation, soil, and foodstuffs were collected by various government agencies monitoring the area. Very low levels of radionuclides could be attributed to releases from the accident. However, comprehensive investigations and assessments by several well respected organizations, such as Columbia University and the University of Pittsburgh, have concluded that in spite of serious damage to the reactor, the actual release had negligible effects on the physical health of individuals or the environment. 
* As of 2014, the U.S. nuclear power industry had accumulated 3,500 reactor-years of operation without any known deaths or injuries to the public.
To be continued …