Ionizing radiation is a generic term used to designate the corpuscular or electromagnetic readiations which, when interacting with matter, produce ions in a direct or indirect manner. It can present health problems when surpassing certain doses, and for this reason some people are reluctant regarding certain radiation-emitting objects, devices or activities. This is an unfounded fear, since the doses are well below the risk level.
Ionizing radiation is measured in sieverts, and radiation levels are measured in milisievert (mSv).
A Sievert (mSv) is a unit of ionizing radiation dose received by ionizing radiation to the irradiated material. It is the quotient of one joule per one kilogram.
It is generally recommended not to receive over 50 milisieverts in one year.
Should we take this into account when carrying out activities that imply a certain degree of exposure to radioactivity, such as traveling on a plane or having an X-ray?
Not really. The doses are not high at all and never exceed the recommendations, according to experts.
Flying in an airplane
When you fly in an airplane, you spend some time at the highest layer of the atmosphere, and thus are more exposed to cosmic rays, a source of natural radiation.
But in an airplane flight, this dose is very small. For instance, in a flight from thee East Coast to the West Coast ofthe United States (approximately 6 hours long) you would absorb approximately 0.035 mSv.
What if you are part of an airplane crew?
The National Coucil on Radiation Protection and Measurement (NCRP) calculates that the highest annual dose received by crew members (pilots and flight attendants) is 0.2 to 0.5 mSv.
Getting an X-ray
The exact amount of radiation exposure in a radiographic tests varies depending on the part of the body being exposed. Generally it is:
Chest X-ray: 0.02 mSv
Dental X-ray: 0.004 mSv
Arms and legs: 0.06 mSv
Abdomen: 0.7 mSv
Mammograph (4 images): 0.13 mSv
Working in a nuclear power plant or living near one
A nuclear power plant produces very small quantities of direct radiation. If you live within an 80 km radius of a plant you would receive an average of 0.01 mSv per year, the same amount you would get from a mammograph or two airplane flights.
The employees in a nuclear power plant are subject to strict safety measures that include the maximum dose they can receive. This dose is usually around 20 mSv per year, but in practice it is a lot lower.
Working in a mine
According to a study from the Journal of Radiological Protection, a research carried out in 27 subterraneous mines in Western Australia showed that the concentration of radon gas in the soil (another source of natural ionizing radiation) produced an average yearly dose of 1.4 mSv for their workers, and none received more than 5 mSv.
What about an uranium mine?
In this case the exposure is slightly higher, although it remains below risk levels. According to studies made by the World Information Service on Energy Uranium Project, the average annual dose is 4.45 mSv for workers in subterranean mines, and 1 to 5 mSv for workers in open mines. The total annual average for all workers in 4.4 mSv. Mine workers are also protected by prevention and protection measures for a maximum reduction of the received dose.
Watching television, using internet or talking on the phone
Signals from mobile phones, Bluetooth, wifi and smart TVs produce non-ionizing radiation (radiofrequency) and do not pose health risks. The frequency and energy range of non-ionizing radiation is too low to cause any harm to your ADN.
Exposure to natural radiation
Cosmic rays and terrestrial radiation (radon gas) are sources of natural radiation that we are all exposed to.
The average dose per person is around 2.4 mSv a year. In Spain, we receive a dose of 2.4 to 3.0 mSv a year from natural ionizing radiations.
Under normal circumstances, all these sources of radiation, both natural and artificial, almost never amount to the 50 mSv recommended as the maximum dose to avoid health risks.
Journal of Radiological Protection
Centers for Disease Control and Prevention