The Different Effects of Radiation on Human Beings

Feb 17, 2020

Exposure to radiation is always harmful. In fact, in some cases, it turns out to be pretty lethal. So let’s look at the different effects of radiation on human beings without further ado.


Quick hair loss occurs with exposure to radiation at 200 rems or higher.


Brain cells don’t reproduce. Since they don’t reproduce, brain cells won’t be damaged directly unless the exposure to radiation is 5000rems and above. If it’s above, radiation can kill nerve cells as well as tiny blood vessels causing seizures and in some cases, immediate death.


Certain body parts are more susceptible to radioactive damage than others. The thyroid gland is more susceptible to radioactive (I) iodine. Radioactive iodine has the capability of destroying almost the entire part of thyroid if it’s exposed to the thyroid in specific amounts.

The effects of the exposure can be reduced by taking potassium iodide.

Blood system

Blood system is the most susceptible of all to radiation. When a person’s exposed to more than 100 rems, the lymphocyte cell count of blood will get reduced. When the lymphocyte count of the blood gets reduced, the victim becomes more susceptible to illness. The initial stage of this sickness is known as mild radiation sickness. The early symptoms of radiation sickness are very similar to that of flu. This resemblance is the main reason due to which it gets unnoticed until a blood count test is done.

Effect of radiation on blood system is most dangerous because of its long-term risk. According to data obtained from Hiroshima and Nagasaki, the symptoms have the tendency to persist for up to 10 yrs, and the victims might also have an increased risk of lymphoma and leukemia.


Intense exposure to radiation at around 1,000 to 5,000 rems would do instant damage to tiny blood vessels and can also cause heart failure and direct death. Therefore, radiation is considerably more lethal especially when the part in question is the heart.

Gastrointestinal Tract

Exposure to radiation to the gastrointestinal tract lining will cause diarrhea, vomit (containing blood) and nausea. Such symptoms usually occur when exposure to radiation is more than 200 rems. The radiation will destroy cells that divide rapidly. This include:

  • Blood,
  • Reproductive system,
  • Hair cells,
  • GI tract.

The DNA and the RNA of surviving cells are also affected.

Reproductive Tract

Reproductive tract cells usually divide rapidly. Therefore, these areas are more susceptible to damage and can get affected at rem levels as low as 200.

Long-term exposure might also make the victims sterile.

 The final verdict should be that radiation is harmful to humans unless it’s done on a controllable leash. Some people might say that small amount of radiation won’t harm anyone but why would you take the risk? We don’t know how susceptible you are. Therefore, it’s always necessary to handle radioactive substances with care. Safety precautions need to be implemented for proper handling of radioactive substances. With that, we’ll be signing off for now. Hope you had a good read.

Title image: tico_24

Article Posted in: Academics
Tags: Physics

Sudipto Das

Sudipto writes educational content periodically for MyPrivateTutor Singapore and backs it up with extensive research and relevant examples. He's an avid reader and a tech enthusiast at the same time with a little bit of “Arsenal Football Club” thrown in as well. He's got more than 5 years of experience in digital marketing, SEO and graphic designing.

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