Statement 1. Iodine protects against radiation contamination.
Not really. As such, iodine or its compounds absolutely cannot withstand the negative effects of radiation. Why do doctors recommend taking iodine after man-made disasters with the release of radionuclides into the environment? The fact is that if radioactive iodine-131 enters the atmosphere or water, it very quickly enters the human body and accumulates in the thyroid gland, sharply increasing the risk of developing cancer and other diseases of this organ. In advance, "filling up to capacity" the iodine depot of the thyroid gland, it is possible to reduce the capture of radioactive iodine and thus "protect" its tissue from the accumulation of a radiation source. Lead walls are the best protection against radiation.
Statement 2. Lead walls are the best protection against radiation.
Only partially true. At the same thickness, a layer of lead will be slightly more effective than an equal layer of, say, concrete or compressed soil. But lead is not some magic material or a panacea. An important parameter is density, and for lead it is simply quite high. It is because of its density that lead was indeed often used for protective purposes in the middle of the 20th century, at the beginning of the nuclear age. But lead has a certain toxicity, so today they prefer to simply use thicker layers of concrete for the same purposes.
Statement 3. Radioactive substances glow.
Sometimes, but not always. The radiation associated with radioactivity is called "radioluminescence", and it cannot be said that this is a very common phenomenon. Moreover, it is usually caused not by the glow of the radioactive material itself, but by the interaction of the emitted radiation with the surrounding material.
It is quite obvious where this idea came from. In the 1920s – 1930s, when there was a peak of public interest in radioactive materials in various household appliances, medicines, and other things, the paint, which included radium, was used for the clock hands and the coloring of numbers. Most often, this paint was based on zinc sulfide mixed with copper. The impurities of radium, which emitted radioactive radiation, interacted with the paint, so that it began to glow green.
Statement 4. Radiation exposure leads to mutations.
True. In fact, radioactive radiation can lead to various damage to the DNA helix, while if both of its strands are damaged at the same time, the genetic information can be completely lost. To restore the integrity of genes, the DNA repair system can fill the damaged area with random nucleotides. This is one of the ways for a new mutation to appear. If the DNA damage is large-scale, then the cell may “decide” that it cannot survive with so many mutations, so it decides to take “suicide” - to enter the path of apoptosis. This, by the way, is partly based on the effect of radiation therapy for malignant neoplasms: even cancer cells can be "persuaded" to start apoptosis when a large amount of damage is introduced into their DNA.
