Ionizing radiation has to do with the strength, volume, and force of the energy, being sufficient to ionize an atom. The ionization of an atom is the process of knocking an electron off the atom, generally resulting in a charged or reactive atom or molecule with unpaired electron(s). Low levels (often termed background) of radiation are inevitable, and all humans on the planet are susceptible. Let's explore how the body handles radiation exposure and what this means for your health.
How Our Bodies Process Radiation
Our bodies are designed to repair the damage quite easily. At higher levels, the damage, like that to DNA, is both vast and more difficult for the body to address. The body tries to eliminate potential genetic damage by initiating a process called apoptosis (programmed cell death). This basically kills off the abnormal cells before they spread. If this process is dysfunctional or too slow to handle the amount of damage to cells, mutations will continue in all subsequent cell divisions. This can contribute to the formation of mutated cells.
When radioactive iodine is present in the body, the thyroid gland will begin to rapidly absorb/take it up. Accumulation of radioactive iodine has been directly linked to increased incidence of mutated cells in the thyroid, especially in younger populations. Potassium iodide competes with radioactive iodine at receptor sites. It fills these sites and prevents the thyroid from taking up any of the radioactive substance. Its action at these receptor sites lasts 24 hours, meaning the thyroid is unable to take up any more iodine, “stable or radioactive“ during that time. It is important to understand that potassium iodide does not protect the body as a whole from radioactive iodine, nor does it prevent any other body part from taking it up. Its actions are very specific to the thyroid. It has no effect on other radioactive elements, like cesium, nor the effects these elements may have on the body.
Environments With Radiation Exposure
Examples of use of ionizing radiation include X-ray machines, power stations and nuclear reactors. Radiologic and nuclear events can release radioactive iodine, strontium, plutonium, and cesium isotopes. Substances in rocks and soil naturally give off a small amount of ionizing radiation, as does the environment outside our solar system, otherwise known as cosmic radiation. Cosmic radiation far exceeds what we have the capacity to create ourselves. Airline flight crews typically receive higher annual radiation exposure from cosmic radiation than most workers. Radon 222, a major contributor to "background radiation", is a colourless, odourless gas found in soil, water and air. It seeps from uranium-containing soils, present in all areas of the world. High radon exposure increases the risk of lung cancer.
A standard chest X-ray exposes patients to a small amount of ionizing radiation. The exact dose varies by imaging procedure. In terms of sieverts (a measure that quantifies the amount of radiation absorbed by human tissues), an X-ray gives off 400-600 microsieverts, while a whole body CT scan is equal to 15-20 millisieverts, significantly more. That's roughly the same amount that nuclear industry employees and uranium miners are advised to limit their exposure to in the course of one year! Flying creates 3-9 microsieverts per hour. Over a one-year period, natural sources of radiation, including radon from soil and radiation from the sun, total approximately 1-5 millisieverts, depending on location.
What Are The Symptoms of Radiation Toxicity?
Radiation sickness, a life-threatening illness characterized by:
- Nausea
- Fatigue
- Diarrhea
- Hair loss
- Destruction of white blood cells
These symptoms can occur at levels of 1-2 sieverts in a one-time dose. There is very little information or research dedicated to the overall health effects of long-term, low dose (or background levels) of radiation and its potential to accumulate in the body. 100 millisieverts/year is said to be the lowest at which increased incidence of cancer is clearly evident.
Understanding Non-Ionizing Radiation
Non-ionizing radiation involves changing the position of atoms within a molecule, but not altering the structure, composition, and properties of the atom. Because the atoms are not altered, non-ionizing radiation is thought to be less dangerous. TV and radio waves, ultraviolet and infrared waves, cell phone, microwaves, electric blankets and visible light are all examples of non-ionizing radiation. Ultraviolet and visible light from the sun does cause physical damage to both the skin and eyes. Some argue that the well-researched and damaging effects of the sun, being a form of non-ionizing radiation, bring to light questions about the damaging effects of other "safe" forms of radiation, like those given off during microwave and cell phone use. Governments regulate radiation emissions from household devices such as microwaves and cell phones. Researchers continue to study the potential health effects of long-term exposure. MRI devices, radar and satellite stations, as well as cell phone towers, produce exponentially more than our in-home devices and may be doing more long-term damage than we realize.
Food has been shown to have significantly decreased, if any, nutritional value when heated in a microwave. Some studies have shown food to possess carcinogenic properties from radiation through microwave cooking methods. Some studies have examined possible links between heavy cell phone use and certain brain tumours. Researchers have also investigated acoustic neuroma and tumours occurring on the phone-use side. However, current evidence remains inconclusive. Researchers continue to study these potential associations. You can take simple steps to reduce exposure to both ionizing and non-ionizing radiation. Using a convection oven as an alternative to microwaving, wearing a headset or hands-free device when talking on a cell phone, driving instead of flying, when possible, and avoiding excess imaging, such as X-rays, CT and MRI, may all help to significantly lower exposure.
