9 Common Sources of Radiation in the Home and Workplace

By Kurina Baksh
Last updated: November 26, 2019
Key Takeaways

With a few simple upgrades and changes in habits, you can reduce your exposure to harmful radiation.

Most people may not realize it, but we are constantly exposed to radiation.


The United States Nuclear Regulatory Commission (NRC) estimates that every year on average Americans receive a radiation dose of about 0.62 rem (roentgen equivalent man), or 620 millirems. Natural background radiation from radon, cosmic rays, and the Earth itself makes up about half of this dose. The remaining half originates from human-made sources like industrial activities and medical procedures such as X-rays, mammograms, and CT scans.

While much of this radiation is benign and can even have beneficial applications, excessive amounts of radiation can be harmful to human health. As such, it's important to be aware of the sources of radiation that surround us and the steps we can take to limit our exposure to it.


What Is Radiation?

The Department of Labor defines radiation as energy traveling through space. As you can probably infer from that definition, this is a broad definition that includes various types of energy, some more harmful than others.

There are two main types of radiation:

  1. Non-ionizing radiation, including optical radiation (ultraviolet, visible, infrared) and electromagnetic fields (power frequencies, microwaves, radio frequencies)
  2. Ionizing radiation, which occurs as either electromagnetic rays (x-rays and gamma rays) or particles (alpha and beta particles)

Measurement and Exposure Limits

Radiation is measured in rem, with millirem (mrem) being the unit used to measure the effect of radiation on the body. The mrem also takes into account the differences in the various types of radiation.

According to the Environmental Protection Agency (EPA), human-made sources of radiation should not exceed 4 mrem per year. The radiation limit for adult male workers is 5 rem per year, while pregnant women should not be exposed to more than 500 mrem per year.

Effects of Radiation Exposure on Human Health

The nature and extent of the effects of radiation on the human body depend on the level and frequency of exposure, as well as the penetrating power of the radiation.


Radiation has two types of effects on human health:

  • Deterministic effects, which occur at the organ level. If a sufficient number of cells become affected, the organ becomes impaired and is no longer able to function. This can result in skin-level burns, blood count effects, hair loss, and cataracts. These effects are not noticeable until the absorbed dose of radiation is greater than the threshold level.
  • Stochastic effects, which occur at the cellular level. They are caused by more subtle radiation-induced cellular changes, such as DNA mutations. For these effects to occur, the radiation exposure must be random in nature with no threshold dose. Cancer is the only observed clinical manifestation of radiation-induced stochastic effects.

(Find out How to Reduce the Risk of Occupational Cancer)

9 Common Sources of Radiation in the Home and Workplace

1. Older Television Sets

If you own a television set that's at least a decade old, it might contain cathode ray tubes (CRTs), which generate low-level X-rays. Watching 4.5 hours of television per day on a CRT TV set results in approximately one mrem of radiation.

CRT televisions are now largely obsolete and have been replaced with flat-screen televisions with either LCD or plasma screens. Since they don't contain CRTs, they don't generate X-ray radiation.

2. Vintage Computer Monitors

Bulky, vintage computer monitors also contain cathode ray tubes that generate low-level X-rays. Thankfully, these have also been phased out in favor of flat-screen style monitors that display images without the use of CRTs and, therefore, pose absolutely no radiation risk.

3. Drinking Water

Water can pick up radiation from natural sources, such as rocks and soil. In urban areas, radiation found in the water comes from rivers and lakes, while in rural areas it comes from wells. The average person can acquire up to 5 mrem of radiation from drinking water per year.

4. Natural Gas

Cooking or heating your home with natural gas can increase your radiation exposure by 9 mrem per year.

5. Cellphones

Cellphones give off radio frequency waves, exposing the average user to 11 mrem of radiation per year. Fortunately, these radio frequency waves are at low enough levels not to cause damage to cells or tissues.

6. Microwave Ovens

Microwave ovens emit radio frequency electromagnetic energy. These appliances are able to contain the radiation, preventing it from any negative health consequences. However, if the seal or hinges of the door are damaged or worn and can no longer form a proper seal, the microwave oven may leak radiation and pose a bigger risk.

7. Soils

Radioactive particles are present in soil due to cosmic radiation in the Earth's crust, as well as human-made releases such as nuclear power plant disasters. These particles are then released in the form of gases which can be inhaled or consumed through water or plants. The average person acquires 35 mrem of radiation per year from soils.

8. Radon Gas

Radon is the second-leading cause of lung cancer in the United States. It is emitted from the radioactive decay of natural uranium in the ground. It is also found in some construction materials. The average person may be exposed to up to 200 mrem of radiation per year from building materials containing radon.

9. Cigarette Smoke

Smoking not only increases the risk of lung cancer and heart disease, it also increases exposure to radiation. In addition to toxins like tar, arsenic, and nicotine, cigarettes contain two radioactive materials: polonium 210 and lead 210. It is estimated that the average smoker is exposed to 1,300 mrem of radiation per year.

General Safety Tips to Avoid or Reduce Radiation Exposure

  • If you are still using a CRT television or computer monitor, consider upgrading to one that does not contain cathode ray tubes. Whether plasma or LCD, any flat-screen will eliminate the radiation exposure from sitting in front of the screen.
  • Opt for bottled water over tap water. While both may contain radiation, the levels of radiation in bottled water are far lower.
  • Although radiation levels from cellphones are extremely low, taking calls with a hands-free headset or using speaker phone will further reduce the levels of exposure.
  • If your microwave oven door does not seal properly even after being cleaned, replacing it will reduce the amount of radiation you are exposed to while using it.
  • Radon is odorless and colorless, but you can easily detect it with a low-cost DIY testing kit.
  • Quitting smoking will eliminate the radiation exposure you get from cigarettes, not to mention the other toxins inhaled while smoking.

The Importance of Radiation Safety

Since radiation is invisible and odorless, it is easy to become complacent about the risks associated with it. Many people are not even aware of the sources of harmful radiation in their daily lives and, as such, cannot take steps to reduce their exposure.

The simplest solution is to identify the sources of radiation you encounter and build routines and habits that reduce your exposure levels.

Harnessing the power of radiation has given us a number of beneficial medical procedures, advanced our scientific knowledge, and has provided us with day-to-day conveniences. While it generally has a positive impact on our lives, there is nevertheless a measure of risk with every activity involving radiation. By taking the proper precautions, you will be able to enjoy the technological benefits of radiation without harming your health in the process.

Share This Article

  • Facebook
  • LinkedIn
  • X

Written by Kurina Baksh

Kurina Baksh

Kurina Baksh is a Health, Safety and Environment Professional from Trinidad and Tobago. As a recent graduate in the field, she is trained to analyze and advise on a wide range of issues related to her area of expertise. Currently, she is an independent consultant who develops public outreach and education programmes for an international clientele. She strongly believes that increasing public outreach and education can promote hazard awareness and ultimately save lives.

Related Articles

Go back to top