Radiation

Every person on Earth is exposed to radiation dose. At the beginning of the XX century, natural sources caused the dose, such as minerals, coal, soil, radon gas in the air, and cosmic rays. Today, except for the natural radiation, everyone is exposed to artificial radiation. It appeared as a result of the nuclear weapon testing and the major nuclear accidents at nuclear power facilities (Sellafield, Three Mile Island, Chernobyl, and Fukushima). After the accident, people around the area were exposed to high doses from short-lived nuclides.

However, these nuclides decayed within few weeks. Then, the main concern is the influence of long-lived nuclides that cause low, but constant dose. The effect of the low doses is an issue under various research programs. After the Fukushima accident, low doses are on the agenda again. Thus, the article presents the state-of-the-art research in the sphere of social sciences, epidemiology, radiobiology and biostatistics that relate to low doses radiation effects. The strong focus of the article is a linear non-threshold theory (LNT), presented by National Research Council (2006).

It concludes that the risk continues at lower doses without a threshold and states that even the smallest dose increases a risk for the human. Since risk issues are the communities’ concern, several social scientists participate in the risk exposure studies. The policy analyst Gordon Thompson deals with the risk perception and public suspicion, raised by application of LNT for estimation of Fukushima and Chernobyl consequences. The social scientist Paul Slovic presents the updated prospective of his work at perception of radiation risk. The work of Roger Kasperson describes the dissemination of information, needed for democracy versus the social amplification of the risk.

The research in the biology field is essential in understanding the low-level radiation risks. The epidemiologist David Richardson studied the one-time exposures of Japanese atomic bomb. Now he presents the achievements in the strengths and limitations of the studied populations, as well as the magnitude of the dose response. The studies of Collin Hill include the genomic stability and bystander effects. The radiobiologist also introduces the research that enables understanding of the adaptive responses at small doses. It allows estimating the deviations from the LNT.

The biostatistician Sander Greenland maintains the importance of the correct interpretation of the low-dose epidemiologic data, as it leads to understanding the health iimpacts. He claims that in many cases epidemiologic data have been misinterpreted. US Nuclear Regulatory Commission representatives Terry Blocks and Sami Sherbini assess the impact of quantitative health risk studies on the nuclear power rules and regulations in the USA.Jan Beyea has been investigating low doses risk for forty years. In his paper, he contributes to epidemiologic studies by large-scale research. The results can be used for long-term exposure from continuous decay of isotopes, released from the nuclear accidents or nuclear weapon testing.

Another aspect of the study is the an analysis of the dose responses. The LNT predicts the level of response, while Beyea states it may be higher or lower. These are supralinear and quasi-threshold responses, both supported by recent epidemiologic data. The hormesis theory stands that at some point the low dose can reduce the cancer risk. It is supported by correlation of radon measurements and lung-cancer rates.

However, the standard epidemiologic studies show the expected response. The objective of the article is to inform the reader about the epidemiologic evidence, their interpretation, perspectives, and the social aspects of the low-level radiation research.