Everyday Sources of Radiation

Radiation is a type of energy source with both electric and magnetic fields. You've likely heard about radiation and its part in X-rays for medical treatment or cell phones. Here's more about that and other everyday sources of radiation.

What Is Radiation?

Radiation is energy that exists in several forms. It travels through space at the speed of light. Its sources can be natural (like sunlight) or human-made (like nuclear reactors). Either can be harmful in large quantities by damaging the DNA in our cells, which can lead to cancer or organ failure.

How Are You Exposed to Radiation?

Most people are typically exposed to about 620 millirems (mrem) of radiation per year. Nearly half of that comes from natural (known as "background") sources, mostly radon in the air outdoors. The other half comes from human-made sources, with the most significant amount usually coming from medical procedures like X-rays.

Trace amounts can also come from consumer products like televisions and cell phones. Disasters like nuclear power plant accidents and nuclear weapons testing can result in dangerous levels of exposure to the public in a short time frame.

Radiation Exposure Regulations

To protect the public's health and safety, the U.S. Nuclear Regulatory Commission (NRC) has developed standards for radiation exposure. These standards allow people who work with radioactive materials to be exposed to 5,000 mrem each year and members of the public to be exposed to 100 mrem each year beyond the typical average.

For most people, small amounts of radiation are common and unavoidable. But there are some things you can do to avoid being exposed to large amounts of radiation over time. Below are some common radiation sources for people living in the United States.

Everyday Sources of Radiation

Knowing how much different sources are responsible for can help you realistically navigate your risk and learn to avoid exposure to more radiation than necessary. The amounts listed are based on the EPA's Calculate Your Radiation Dose online calculator.

Tobacco Smoke

Dose: 1,300 mrem per year for smokers

Most people have probably heard that tobacco contains toxins like tar, arsenic, and nicotine. It also contains two radioactive materials—polonium-210 and lead-210.

These materials build up in smokers' lungs and can lead to cell and tissue damage. Many years of exposure to polonium-210 and lead-210 can eventually result in lung cancer.

If you smoke, quitting will help you reduce your risk. The Centers for Disease Control and Prevention (CDC) offers a guide for the quitting process that includes what to do:

• Before you quit (e.g., knowing why you want to quit and building a quit plan)
• During the quitting process (e.g., managing stress)
• After you quit (e.g., preparing never to smoke again)

It's also worth avoiding secondhand smoke, which can also damage your lungs.

Radon

Dose: 200 mrem per year (typical outdoor exposure)

Radon is a radioactive gas released from soil, rocks, and water. It is naturally present in our outdoor air at levels so low that it's not considered harmful.

But radon can get into homes and buildings through small cracks or holes and build up to dangerous levels. Indoor exposure can lead to lung cancer. It is odorless and invisible, so testing is the only way you would know that it's present.

The Environmental Protection Agency (EPA) has resources and information about when and how to test for radon in your home. After testing your home, you can do the following to reduce further risk of radon exposure in your home:

• Get a radon reduction system installed if the radon level is high (over four picocuries per liter of air)
• Increase airflow and ventilation
• Seal any cracks or holes with plaster or similarly appropriate materials

Medical Imaging

Dose: 1 to 1,000 mrem per screening

Medical imaging is the most significant source of human-made radiation for most people. Doses vary widely, so your annual dose depends on your circumstances. For example, here are some x-ray exposure amounts for different procedures:

• Dental x-rays: 1.5 mrem
• Chest x-rays: 10 mrem
• Full body x-rays: 1,000 mrem

The benefits of imaging usually outweigh the risks. However, the U.S. Food and Drug Administration (FDA) recommends taking special care to avoid over-exposure to pediatric patients due to their small size and pregnant people due to potential risks to the developing fetus.

The FDA adds that medical imaging should not be used if it is unnecessary for helping a healthcare provider give care to a patient. Instead, to reduce exposure for other patients, x-rays should be completed for:

• Answering medical questions
• Treating conditions
• Guiding medical procedures
  

Food and Drinking Water

Dose: 40 mrem per year

All organic matter, including plants and animals, contains trace amounts of radiation, as does all Earth's water. You take in tiny amounts of radiation when you eat or drink. The amounts are so small that dietary intake is not considered a radiation risk.

If a radiation emergency occurs, food and drinks in sealed packages and containers (e.g., cans, bottles) that are not close to anything radioactive will generally be safe to eat. Foods from gardens would not be okay to eat unless officials say so.

You should follow public officials' directions about what you can or cannot eat or drink during those emergencies.

Consumer Products

Dose: 13 mrem per year

A lot of everyday products can emit traces of radiation but in amounts low enough that they don't pose a significant risk to the public. They can include:

• Smoke detectors
• Watches
• Televisions
• Computers
• Fluorescent lights
• Ceramics
• Glass

Cell phones give off radio frequency (RF) waves. These are non-ionizing and have a lower frequency than ionizing forms like X-rays. However, there is no evidence linking cell phones to health problems.

But if you're concerned, you can minimize your exposure by using a headset or earbuds when listening and talking. Also, using landline phones when possible can also reduce your risk of being exposed to radiation.

Older TV sets and computer monitors containing cathode ray tubes can create low-level X-rays, but the FDA requires all TV sets sold in the U.S. to be tested to ensure they do not exceed a safe level of X-ray emission. Most modern televisions and monitors are LCD, plasma, or LED screens, so they don't produce X-rays.

Plane Travel

Dose: 2–5 mrem for a transcontinental flight

Cosmic radiation comes from outer space and accounts for about 11% of background radiation exposure in the U.S. The atmosphere protects us from this radiation, so it makes sense that our exposure increases when we fly on a commercial airplane.

However, when on a flight, the dose of radiation you can get depends on:

• How long your flight is
• How high in the air you are
• How far north or south you are going
  

For most people, plane travel is not a significant source of radiation. However, those who spend more time in the air (e.g., pilots, flight attendants) absorb more than average. Individuals who spend a lot of time in air travel can reduce exposure by decreasing time spent working on longer, higher flights or flights over the North and South Poles.

Also, the new full-body X-ray scanners in airports are another radiation source, but the exposure is negligible.

Sunlight

Sunlight is a source of ultraviolet radiation, another non-ionizing type. Of course, it's unavoidable and beneficial to people at the right levels. But avoiding overexposure to the sun reduces the risk of skin cancer.

To avoid too much exposure to UV radiation, you can do things such as:

• Cover your head with a hat and skin with long clothing (e.g., long-sleeved shirts) when possible
• Wear sunglasses that can block UVA and UVB rays
• Use sunscreen with an SPF of 15 or higher when out in the sun
• Stay in the shade as much as possible

A Quick Review

Radiation is an energy source that comes in different forms and amounts of exposure. It can be found in sources like products we use daily (e.g., computers), tobacco smoke, and during plane travel.

However, there are ways to reduce exposure to everyday radiation sources, like protecting yourself from sunlight and having x-rays done only when required.