Radiation Effects on the Body

Natural radiation is everywhere. It comes from the sun, outer space, rocks, and even food. Human activities also produce radiation, such as nuclear power and X-rays. This can have detrimental effects on the body, depending on the dose received. No one can avoid exposure, because radiation bounces and scatters in all directions. Being close to an atomic blast can cause acute biological effects of radiation such as skin burns and radiation sickness. Exposure to low levels of radiation contributes to our overall cancer risk. Barrier Technologies develops innovative products to protect people from the harmful effects of scatter radiation.

Brief Overview of Radiation

Radiation is energy or particles emitted from a source that travel at the speed of light. Some forms generate electric and magnetic fields, hence the name “electromagnetic radiation”. The electromagnetic spectrum ranges from low energy waves, such as radio waves and to high energy waves, such as gamma rays. Visible light falls in the middle of the spectrum.

There is also radiation caused by radioactive particles. They are highly energetic ions, or pieces of atoms such as electrons, protons, and neutrons. Many are known as “cosmic rays”.

Non-Ionizing Radiation

Most of the radiation we are exposed to has low energy. It may produce heat which can cause burns.

Ionizing Radiation

Ionizing radiation can break chemical bonds and strip electrons from atoms or molecules. The resulting reactive particles are called free radicals. High energy ionizing radiation’s effects on humans include the breakdown of biomolecules, damage to genetic material (DNA,) and malfunctions in critical cellular processes.

Cellular Damage Mechanisms

Cells have an amazing ability to fix DNA damaged by the effects of radiation, estimated at 50,000 incidents per day! However, repair mechanisms are imperfect and damage accumulates. The consequences are cell death, or the development of cancer. Also, the damage is passed on to subsequent generations of daughter cells. There are two mechanisms of cellular damage:

  • Direct radiation damage: Bombardment with radiation causes mutations or errors in the genetic code, or breaks the DNA strands. The damaged DNA cannot be transcribed (read) at these points, which leads to the malformation or absence of vital proteins.
  • Indirect radiation damage: Radiation hits water or organic molecules in the cells. The biological effect is the generation of dangerous free radicals that damage DNA.

Biological Effects of Exposure to Radiation

Exposure to radiation harms cells in three distinct ways – non-ionizing radiation causes heating, whereas ionizing radiation can break chemical bonds in molecules, or strip electrons off atoms and molecules. The damage caused by ionizing radiation has the most serious and dangerous consequences. Radiation’s effects on humans are damage to normal body cells (somatic damage) or eggs and sperm (genetic damage). The most serious harm occurs in rapidly dividing cells, for example, in the stomach lining, hair follicles, bone marrow, and embryos.

Different Types of Radiation

There are four types of dangerous radiation:

  1. Alpha particles: These are heavy, positively charged particles each consisting of 2 protons plus 2 neutrons. They are emitted by substances such as uranium, thorium, and radon. They cannot penetrate the skin but have serious radiation effects if inhaled or ingested.
  2. Beta particles: Are negatively charged free electrons with infinitesimal mass, emitted by substances such as tritium and carbon-14. They can penetrate the body, but not deeply.
  3. Neutrons: are uncharged particles that travel deep into the body
  4. Gamma rays and X-rays: These are electromagnetic waves without mass or charge, which can pass right through the body.

Related Article: ALARA Principles: Standard Safety Protocol of Radiation

Cellular Sensitivity to Radiation

The cells most sensitive to radiation effects are those that are unspecialized or actively dividing, such as stem cells and lymphocytes. The least sensitive cells are the most highly specialized or not actively dividing, such as neurons.


Radiation’s Effects on Human Systems:
Most sensitive
Blood-forming cells: Bone marrow and lymphatic tissues
Reproductive system: Testes and ovaries
Gastrointestinal system: Mucous membranes, villi in small intestine
Moderately sensitive
Skin and eyes: Hair follicles, sweat glands, skin, lenses
Other major organs: Lungs, kidneys, liver and thyroid gland
Support system: Blood vessels, muscles, and bones
Least sensitive
Nervous system: Nerves and brain

Effects of Long-Term Radiation Exposure on the Human Body

Short-term acute exposure to a large dose of radiation causes noticeable illness, with death occurring within weeks. However, the cumulative effects of long-term exposure can be similarly pernicious – it depends on the type, energy, and location of the radiation.

Humans are sensitive to background radiation, such as radon from the ground and cosmic rays, as well as low-dose radiation from medical procedures, including X-rays and CT scans. Devices like cell phones emit non-ionizing electromagnetic radiation. Tiny amounts of particle radiation enter the body through skin contact, inhaled air, and ingested food.

The effects of particle radiation depend on where they occur and how long they persist. For example:

  • Radioiodine collects in the thyroid gland, but is eliminated fairly quickly.
  • Radium and strontium collect in the bones and persist for years.
  • Inhaled particles settle in the alveoli of the lungs.
  • Ingested particles accumulate in the liver, spleen, and bone marrow.

Limiting Cancer Risk from Radiation in the Environment

Here are some tips for limiting your exposure to the harmful biological effects of radiation:

  • Limit the number of diagnostic procedures, such as X-rays, CT scans, and dental tomography.
  • Quit smoking! Tobacco products contain radioactive polonium.
  • Avoid airport scanners where possible – opt for a pat-down.
  • Test your home for radon and radon-proof it.
  • Eat green leafy foods containing chlorophyll to detoxify the blood.
  • Eat foods rich in natural iodine, like dairy products, to displace radioiodine.
  • Check the seal on your microwave oven.
  • Use a headset with your cell phone and sit a distance away from your tv or monitor.


If you work in a profession where you risk any radiation exposure, it is absolutely essential that you protect yourself from radiation’s effects on the body. Barrier Technologies is an industry leader in radiation protection product manufacturing. We emphasize quality, innovation, shorter lead times, and world-class customer service. Our high-quality USA-manufactured radiation shielding products include our lightweight lead-free aprons, thyroid shield collars, leaded eyewear, lead glasses, radiation-reducing gloves, x-ray accessories, and mobile barriers. If you are searching for radiation safety products with style and durability, contact us today for expert advice. We look forward to your call or email.