Radiation In Humans
Everything has some form of radiation, and humans are no exception. We are in fact all naturally radioactive to some degree. This is due to the fact that people are always exposed to radioactive substances and forms of radiation, sometimes through what we eat, drink, or breathe. Humans also are exposed to man made radiation from X-rays and radiation used to diagnose diseases for cancer therapy, as well as fallout from nuclear explosive testing, and radioactive materials released from coal and nuclear power plants. We are constantly surrounded by naturally radioactive elements in the soil and stones, and we even receive cosmic radiation entering the atmosphere from outer space. All of the radiation humans encounter is then just absorbed into our tissues, organs, and bones, and is once again replaced because of the constant exposure.
Radiation That Humans Emit
We all contain a small amount of radionuclides in our bodies. Potassium-40, an isotope of potassium that is present in nature in a very small amount, produces penetrating gamma radiation and is the main source of radiation in the human body. This is because potassium is present in many of the foods we eat and can be found in almost all of the tissues in the body.
The amount of Potassium-40 in a person weighing around 70kg is about 5,000Bq. Bq is the abbreviation for becquerel, which is the unit for the measure of radioactivity a nucleus has per second. This means that 5,000 atoms are undergoing radioactive decay per second. Potassium-40 then emits about 500 gamma rays per second.
Radiation can be measured using sensitive detectors in a whole body counter and can measure the gamma rays emitted by radioactive materials that are in or on the body. Since different radioactive materials give off gamma rays that have different energies, the material in the body can be identified. Many people report having small to moderate levels of uranium in their hair after getting an analysis, and that is due to the uranium being consumed and a fraction of the metal being excreted through the hair.
Harmful Radiation Exposure
Not all radiation that humans are exposed to is harmless, a lot of radiation can cause serious health problems. Radiation damages the DNA and chromosomes in cells and causes them to stop dividing. For example, being exposed to too much UV radiation (a type of cosmic radiation) can damage human tissues and cause skin cancer (UV radiation being the cause of approximately 99% of non-melanoma skin cancers and 95% of melanoma skin cancers). Scientists have now learned more about the effects of being exposed to too much radiation by doing research on the health records of the survivors of the bombing of Hiroshima and Nagasaki. This research is currently being used to understand how radiation causes health problems and ultimately help find ways to reverse or prevent its effects.
A video about this research can be found here:
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Wow! I had no idea we are exposed to different kinds of radiation as often as we are. I find it interesting how some kinds of radiation can be harmful and other kinds are not. One kind of radiation I didn't know is so powerful is UV radiation. My mom always pesters me about wearing sunscreen to softball practice but I never did because I thought of it as a chore that would only keep me pale. Now that I know exposure to UV radiation from sunlight causes skin cancer I will be sure to put on sunscreen and maybe even find a foundation with more SPF.
ReplyDeleteAs a follow up question to my comment, could you explain how SPF works? How does SPF prevent UV radiation from harming the cells in your skin?
DeleteAmazing article! I found the section on nutrition relating to Potassium-40, commonly found in bananas, especially captivating. This unit along side the negative effects of U.V radiation make it easier to relate to and actually apply the information in our daily lives. The combination of these two create a transition into the world of biochemistry I'm quite interested in the effects of radiation on one's health. It makes me wonder about the daily quantity one should consume to avoid the harmful effects that radiation has on the human body. Whether that be through food or through cosmic rays. Researching the positive effects of radiation (if there are any) would also be quite thought provoking as well as practical for the general population. I know that Potassium has a positive effect on one’s health but I do not know how it does.
ReplyDeleteAs a follow up comment relating to the nature of radiation in a useful way in the health field I personally experienced such a thing today after school. Yesterday I had the pleasure of dislocating my ring finger of my right hand. This afternoon after much plea from my mother, I went in for x rays. If you did not know, x rays have the ability to pass through most tissues. When the radiation intersects with a material like, commonly found in the bones of most species, it cats a shadow that can then be registered on a film of digitally through a digital sensor. After having my x rays done, I now know that I had broken several ligaments and bones throughout my finger.
DeleteIt's really interesting how we all just have a negative connotation of radiation without really all that much about it and it's really weird to think that we're actually all exposed to radiation all the time.
ReplyDelete