Radiation is a flow of energy in the form of waves or rays. We're exposed to it every day in many ways. Through cosmic rays... Underground radioactive substances... Microwaves... And even some of the foods we eat.

That's non-ionizing radiation. It could be harmful, depending on level of exposure, your diet, and other factors. But the body is usually able to heal itself.

Ionizing radiation is a different story. That's the type you're exposed to in a nuclear explosion... or every time you get an X-ray or CT scan. And that's what you should be concerned about.

Radiologists use ionizing radiation for diagnosis. It allows them to view the inside of your body.

But it's a double-edged sword. Ionizing radiation is also a potent carcinogen. It can remove electrons from atoms and molecules. That creates cell-damaging free radicals. And that's why the technician who gives you an X-ray covers you with a big lead vest... and steps out the room.

The medical industry is aware of the risks. They know it can kill you... or cause serious problems. Ovaries and testicles exposed to radiation can result in gene mutation. So X-rays could lead to deformities in children. Studies conducted as early as 1927 linked X-rays to cell damage. The evidence continues to mount.

The National Academy of Sciences released a study in 2005. It shows that radiation from X-rays and scans carries a risk for cancer. Even in low amounts. And it's not getting better. That's according to a study in the New England Journal of Medicine. It says current cancers in the US due to CT scans may increase as much as four to five times what they are now.

The Radiological Society of North America and American College of Radiology offer some surprising insight. They say an abdominal or chest CT scan is equivalent to two to three years of background radiation. It instantly increases your cancer risk.

The FDA said radiation emitted from X-rays and CT is just slightly lower than what the Japanese faced in Nagasaki and Hiroshima. So why aren't they doing anything?

The use of CT scans and X-rays is also being used for patients at younger and younger ages.

Researchers at the Children's Hospital of Cincinnati studied the issue. They looked at data from 1995 to 2008. They found a five-fold increase in the percentage of CT scans given to children in emergency rooms. In other words, doctors are giving our children more and more radiation... knowing it could kill them.

Women are also at high risk. Paul Yaswen is a cell biologist and breast cancer research specialist. He works at the Department of Energy's Lawrence Berkeley National Laboratory. He did a study on the impact of radiation on breast cells. It ran in the online journal Breast Cancer Research.

Yaswen found that radiation changed the cells' microenvironment. Made it easier for cancerous cells to grow. The dosage used in the study was what a woman would receive in a routine mammogram.

"Many in the cancer research community, especially radiobiologists, have been slow to acknowledge and incorporate in their work the idea that cells in human tissues are not independent entities, but are highly communicative with each other and with their microenvironment," Yaswen said. "We provide new evidence that potential cancer agents and their effects must be evaluated at a systems level."

Physicians do have other diagnostic imaging devices at their disposal that don't use ionizing radiation. Magnetic Resonance Imaging doesn't have any known negative effects. And it can be used for a wider variety of medical conditions. Thermography also doesn't contain ionizing radiation. For women, it could be used as an alternative to a mammography.

You should be aware of your exposure levels. Here are the typical exposure amounts for each scan:

• X-ray Security Scan – 0.00025 mSv

• Chest X-ray – 0.1 mSv

• Head CT – 1.5 mSv

• Mammography – 3.0 mSv

• Abdomen CT – 5.3 mSv

• Chest CT – 5.8 mSv

• CT Colonography – 3.6-8.8 mSv

• Cardiac CT Angiogram – 6.7-13 mSv

• Neonatal Abdominal CT – 20 mSv

The good news is there are a lot of natural ways to protect yourself. And they're backed by solid research.

One study was conducted by the University of Toronto and the University Health Network. Researchers looked at a unique blend of antioxidants. (Antioxidants help protect your cells from damage caused by free radicals.) They found that the blend helped prevent cell damage when taken orally before X-rays.

Dr. Kieran J. Murphy led the team. He said the formula reduced DNA injury by 50 percent.

"Pre-administering this formula before a medical imaging exam may be one of the most important tools to provide radioprotection and especially important for patients getting CT scans," he said.

The British Journal of Radiology published an article in 2004. It listed vitamins E, C, and beta-carotene as great defense against iodizing radiation.

Aside from supplementing with these nutrients, there's one other simple thing you can do. Discuss ionizing radiation procedures with your doctor. Ask if you really need them. Or if there are other options. Don't do anything you aren't comfortable with.

Symptoms of acute radiation (dose received within one day):

• 0 – 0.25 Sv (0 – 250 mSv): None
• 0.25 – 1 Sv (250 – 1000 mSv): Some people feel nausea and loss of appetite; bone marrow, lymph nodes, spleen damaged.
• 1 – 3 Sv (1000 – 3000 mSv): Mild to severe nausea, loss of appetite, infection; more severe bone marrow, lymph node, spleen damage; recovery probable, not assured.
• 3 – 6 Sv (3000 – 6000 mSv): Severe nausea, loss of appetite; hemorrhaging, infection, diarrhea, peeling of skin, sterility; death if untreated.
• 6 – 10 Sv (6000 – 10000 mSv): Above symptoms plus central nervous system impairment; death expected.
• Above 10 Sv (10000 mSv): Incapacitation and death.

Single dose examples

• Dental radiography: 0.005 mSv
• Average dose to people living within 16 km of Three Mile Island accident: 0.08 mSv during the accident
• Mammogram — Single Exposure, Equipment Mean: 2 mSv
• Mammogram — Procedural Mean, Equipment Variation: 4 mSv - 5 mSv
• Brain CT scan: 0.8–5 mSv
• Chest CT scan: 6–18 mSv
• Gastrointestinal series X-ray investigation: 14 mSv
• International Commission on Radiological Protection recommended limit for volunteers averting major nuclear escalation: 500 mSv[10]
• International Commission on Radiological Protection recommended limit for volunteers rescuing lives or preventing serious injuries: 1000 mSv[

Hourly dose examples

• Average individual background radiation dose: 0.23μSv/h (0.00023mSv/h); 0.17μSv/h for Australians, 0.34μSv/h for Americans
• Highest reported level during Fukushima accident: 1000 mSv/h reported as the level at a pool of water in the turbine room of reactor two.

Yearly dose examples

• Maximum acceptable dose for the public from any man made facility: 1 mSv/year
• Dose from living near a nuclear power station: 0.0001–0.01 mSv/year
• Dose from living near a coal-fired power station: 0.0003 mSv/year
• Dose from sleeping next to a human for 8 hours every night: 0.02 mSv/yr
• Dose from cosmic radiation (from sky) at sea level: 0.24 mSv/year
• Dose from terrestrial radiation (from ground): 0.28 mSv/year
• Dose from natural radiation in the human body: 0.40 mSv/year
• Dose from standing in front of the granite of the United States Capitol building: 0.85 mSv/year
• Average individual background radiation dose: 2 mSv/year; 1.5 mSv/year for Australians, 3.0 mSv/year for Americans
• Dose from atmospheric sources (mostly radon): 2 mSv/year
• Total average radiation dose for Americans: 6.2 mSv/year
• New York-Tokyo flights for airline crew: 9 mSv/year
• Dose from smoking 30 cigarettes a day: 13-60 mSv/year
• Current average dose limit for nuclear workers: 20 mSv/year
• Dose from background radiation in parts of Iran, India and Europe: 50 mSv/year[
• Dose limit applied to workers during Fukushima emergency: 250 mSv/year[

Dose limit examples

• Criterion for relocation after Chernobyl disaster: 350 mSv/lifetime
• In most countries the current maximum permissible dose to radiation workers is 20 mSv per year averaged over five years, with a maximum of 50 mSv in any one year. This is over and above background exposure, and excludes medical exposure. The value originates from the International Commission on Radiological Protection (ICRP), and is coupled with the requirement to keep exposure as low as reasonably achievable (ALARA) – taking into account social and economic factors.
• Public dose limits for exposure from uranium mining or nuclear plants are usually set at 1 mSv/yr above background.