How risky is low-dose radiation?
Life on Earth has always been exposed to ionizing radiation from natural sources. This kind of radiation has enough energy to ionize atoms or molecules by striping electrons from them, as it passes through matter.
Exposure to ionizing radiation is more so in the last 120 years as the human population uses radiation in developing military, medical and industrial advancements.
Large doses of radiation are detrimental to health. However the effects of low doses from different sources are unclear.
Researchers from the Oxford Martin School at the University of Oxford compiled data on low dose radiation and its risks.
The low dose of radiation from a CT scan for the whole spine is 10 mSv while the average dose from natural background radiation (in U.K) is 2.3 mSv each year
They constructed a preliminary review of literature on health risks associated with low dose radiation. A second draft was then made where each piece of evidence was assigned a descriptor based on a set of categories which ranked the strength and consistency of each supporting evidence.
The health risks associated with radiation exposure is well known due to exceptionally careful studies of groups of people exposed to different levels from nuclear bombs or accidents, workers in the nuclear industry or in medicine, medical exposure in patients and from naturally occurring sources such as radon.
The various studies show us that moderate and high doses of radiation increase the risk of developing some types of cancer.
The research team used the following scenarios to describe this risk – If 100 people are briefly exposed to 100 mSv (millisievert is the measure of radiation dose), then on an average over a lifetime one of them would be expected to develop radiation-induced cancer while 42 of them would be expected to develop cancer from other causes.
Low dose of radiation from a CT scan for the whole spine is 10 mSv while the average dose from natural background radiation (in U.K) is 2.3 mSv each year. This explains the difference between high dose radiation and everyday ( low dose) radiation in context and how it can affect us.
The main ill-health caused by low to moderate doses of ionizing radiation is cancer. However, scientists are increasingly concerned of the possibility of non-cancer effects particularly cardiovascular disease. Doses of 1- 10 mSv are routinely encountered through natural background radiation and medical diagnostic exposure.
The researchers believe that further research is necessary to build on the insights from this study so as to better understand the implication of radiation exposure on DNA and cells and the biological basis of such damage.
The study concludes that the overall risk to human health from low-level radiation exposure is small compared to the general risks that humans face in modern society such as obesity, smoking and air pollution.
Its important to protect ourselves from radiation even if its not as risky as other modern lifestyle factors, and several herbal medicines and food such as prunes help protect us and detoxify our bodies of radioactive waste.
Source: Proceedings of the Royal Society B: Biological Sciences
