Article Review (1): Radiation exposure and the LNT model

Summary prepared by Lauren Griffin for discussion on 10/03/17:

Article 1: Is a Little Dose of Radiation So Bad?
The linear no-threshold model (LNT) holds that any amount of radiation increases cancer risk, with the danger rising with the dosage. The tolerance dose model claims that radiation below a certain level is not harmful. The disputed range involves annual radiation exposures below 10,000 millirems. Each side of the argument has its own data but occasionally point to the same information to support the different arguments.

Article 2: A Radiation Reality Check
Radiation comes from everything: food, the earth, living creatures and man-made objects. The average American gets 620 millirems of radiation each year with half due to background radiation. That number needs to reach 100,000 to be a threat. During the Cold War, nuclear testing on American soil caused more harm to Americans than Soviet weapons. Remember harm comes from dosage, not the particular atom. For example, Chernobyl spread a cloud 400 times the size of Hiroshima killed only 75 people. In a study of Hiroshima and Nagasaki survivors, only 1% had cancer due to radiation and there was not increase in inherited mutations. The same 1% was seen in the Fukushima disaster.

 

One thought on “Article Review (1): Radiation exposure and the LNT model

  1. Wrap-up summary of the in-class discussion (prepared by Lauren Griffin):

    We first discussed average radiation from a variety of sources. For example, a medical chest x-ray only gives 2/3 millirems of radiation while a CT scan gives 1,000 millirems. We then talked about the cutoff for dispute in radiation level vs cancer risk. Generally, the disputed range involves exposure below
    10,000 millirems.

    We then established the difference between radiation and radioactivity. The application of isotopes came up. The radioactive isotope of iodine, for example, will accumulate and continue to give off radiation. On the other hand, radiation can be turned on and off in an x-ray source. Essentially, accumulated isotopes are a much greater hazard than diagnostic x-rays.

    Also, we discussed pros and cons of the LNT and threshold model. In the LNT model, the following point was mentioned: there is a high concern for safety so precautions are followed carefully. Concerning the threshold model, the following two points were mentioned: it can greatly reduce the cost of cleaning up contaminated sites and if accepted by the public there would be less cause for concern with lower levels of radiation exposure. The LNT vs threshold model comes to an economical and ethical issue.

    Finally, we discussed the hormesis theory. Hormesis theory is defined as a beneficial effect resulting from exposure to low doses of an agent that is otherwise toxic or lethal when given at higher doses. The hormesis theory is applicable in vaccines but has not been thoroughly tested for radiation.

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