Ultrasound, Wi-Fi, microwave ovens, magnetic resonance imaging: what kind of radiation is harmful, what you need to do so as not to harm yourself, and what you should not be afraid of.
What kind of radiation happens
Radiation is, in a narrow sense, ionizing radiation, that is, a type of energy that is capable of knocking electrons out of atoms and making them ions. These rays can directly or indirectly damage DNA and cell membranes.
Often, radiation and ionizing radiation are not separated, but it is ionizing radiation that damages living cells and causes DNA breakdowns. Therefore, in a broad sense, radiation is any radiation.
If the radiation is not ionizing, it can still be harmful: for example, solar radiation can cause burns.
Types of ionizing radiation:
• Alpha radiation. Cannot penetrate clothing or skin. But if radionuclides with alpha radiation enter through the respiratory tract, mouth or open wounds, they can be very harmful.
• Beta radiation. It cannot penetrate wood or brick, and under the skin it can, but does not damage the main organs.
• Gamma radiation. Penetrates organs through many obstacles. It can be stopped by a concrete wall and a few centimeters of heavy metal.
Who emits radiation
Sources of radiation:
• The process of decay of atomic nuclei.
• Reactions of fusion of atoms.
The second process takes place in the interiors of stars, including the Sun. Outside of Earth’s atmosphere and magnetic field, solar radiation includes not only light and heat, but also X-rays, hard ultraviolet light and protons accelerated to impressive speeds.
Protons are the most dangerous for those in deep space. In a year of increased solar activity, exposure to a beam of protons will give a lethal dose of radiation in a matter of minutes. This roughly corresponds to the background near the destroyed reactor of the Chernobyl nuclear power plant.
However, closer to our understanding, other sources of radiation, such as rocks, including granite and coal, contain uranium, thorium and emit radon gas. So if the house is built on rocks and is poorly ventilated, then due to radon, residents have an increased risk of lung cancer. Smoking is also harmful in this regard: polonium-210 in tobacco smoke is an active and dangerous isotope.
All these are components of the natural background radiation: the human body has adapted to live in such conditions.
Household and medical devices with radiation
• Microwave
The energy of microwaves is not enough to rip electrons from the nuclei of atoms. Physicians and biologists argue about how microwave radiation in small doses can affect the human body, but so far the results are rather encouraging: a comparison of a number of different large-scale studies indicates that there is no connection between telephones and malignant tumors.
• ultrasound
There are many methods that allow you to literally look inside a person and they are all considered dangerous, although in essence they are very different. For example, in ultrasound, non-ionizing radiation is used – these are waves with low energy, they cannot damage DNA, but can, for example, heat tissues.
Ultrasound does not apply to ionizing radiation that damages DNA; it has also been proven that it does not have any negative effect on a woman or fetus.
Despite this, it is better to do an ultrasound scan only when a doctor has prescribed it for you.
• MRI
MRI works on the same principle as ultrasound. Both MRI and ultrasound use non-ionizing radiation.
• CT and X-ray
During computed tomography (CT) and X-rays, a person is actually irradiated. This method is based on ionizing radiation, that is, one that can take off electrons in atoms, thus creating ions, and provoke mutations in DNA. High doses of ionizing radiation can increase the risk of developing cancer.
In order to understand how much CT is really dangerous or not, the harm of ionizing radiation was assessed mainly from the consequences of major disasters, for example, the explosion of the atomic bomb in Hiroshima and the Chernobyl accident. Therefore, one cannot speak with confidence about the dangers of CT and X-ray: after all, the radiation doses in these cases are quite small. Perhaps even such methods do not harm health in any way – or harm, but not as much as is commonly thought.
However, there are a number of separate indications during pregnancy. If the procedure is necessary, you can reduce the amount of radiation, for example, if you take a picture from the back. X-rays of the head, neck, chest, and extremities are not particularly harmful to the fetus, especially if a lead apron is used.
Computed tomography of different parts of the body is also relatively harmless when you cover your belly. In addition, a slightly lower quality CT scan can be done to reduce radiation exposure.
Most studies do not go beyond the absorbed radiation dose of 0.05 Gy (5 rad). If the dose is 0.1 Gy (10 rad), then soon up to 14 days this does not affect the fetus in any way, but for a longer period there is a risk that the fetus will develop with a delay. Irradiation after 20-25 weeks is relatively safe.
• Wi-Fi
The harm from wifa has also not been proven. This is RF energy and is much weaker from a router than from a mobile phone.
• Mobile phone
And it is also not dangerous: a comparison of a number of different large-scale studies indicates that there is no connection between phones and malignant tumors.
Phones emit non-ionizing radio frequency radiation, the effect of which on humans has not been 100 percent studied. But for now, according to the US Centers for Disease Control and Prevention, there is no reason to ditch mobile phones.
Radiation and other technology
Radiation can be devastating with prolonged and methodical exposure. Microcircuits on spacecraft in interplanetary space, where there are many cosmic rays, have to be specially adapted to work in conditions of an increased background radiation.
It is because of this that the performance of the processor, say, on the Mars rover or the Jupiterian probe Juno, is very modest by earthly standards: designers pay for the resistance to radiation with the size and speed of work.
Who is most exposed to radiation
Children are more susceptible to the negative effects of radiation. Irradiation of an embryo or fetus can lead to a variety of serious consequences: from death to deterioration of cognitive abilities in the future. But much depends on the dose, and in the case when the dose of absorbed radiation is less than 0.1 Gy, no consequences are known.
