Radiation in medicine and life: why you shouldn't be afraid of ultrasound, X-ray and microwave

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.

Viewsionizing 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 it can penetrate the skin, but it does not damage major 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.
  • Fusion reactions.

The second process takes place in the bowels of the stars, includingThe 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 the distantouter 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, other sources are closer to our understandingradiation, such as rocks including granite and coal contain uranium, thorium and emit radon gas. So if a house is built on rock and is poorly ventilated, then due to radon, residents have an increased risk of developing 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

Microwave energy is not enough toto tear 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 lookliterally inside a person and they are all considered dangerous, although in essence they are very different. For example, ultrasound uses non-ionizing radiation - these are waves with low energy, they cannot damage DNA, but can, for example, heat tissue.

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 radiography

During computed tomography (CT) andX-rays actually expose people to radiation. This method is based on ionizing radiation, that is, radiation that can strip electrons from atoms, thus creating ions, and provoke mutations in DNA. Ionizing radiation in high doses can increase the risk of developing cancer.

In order to understand how many CTreally 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, during pregnancy there are a number of separateindications. 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 do not particularly harm the fetus, especially if a lead apron is used.

Computed tomography of different parts of the body toorelatively harmless when covered with belly. In addition, a slightly lower quality CT scan can be done to reduce radiation exposure.

Most research does not go beyond doseof absorbed radiation in 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 Wi-Fi has also not been proven. This is radio frequency radiation, and from a router it is much weaker than from a mobile phone.

  • Mobile phone

And it’s not dangerous either: a comparison of a number of different large-scale studies indicates that there is no connection between phones and malignant tumors.

Phones provide non-ionizing radio frequencyradiation, the effect of which on humans has not been studied 100 percent. 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 have devastating effectswith long and methodical exposure. Microcircuits on devices in interplanetary space, where there are a lot of cosmic rays, have to be specially adapted to work in conditions of increased background radiation.

It is because of this that the performance of the processor,for example, on a Mars rover or a Jupiterian probe, Juno is very modest by earthly standards: designers pay for their resistance to radiation in terms of size and speed of work.

Who is most exposed to radiation

Children are more susceptible to negativethe 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.

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