Radioactivity is considered to be a cause of tumor diseases, among other things: Radiation from radioactive materials and X-rays can trigger malignant tumors. The energy of this radiation is so great that it can trigger “ionizations” on atoms and molecules, i.e., change their charge and thus, for example, break the bonds that hold molecules together.
What is radioactivity?
There are chemical elements or isotopes (nuclides that have the same number of protons (the same atomic number) in their atomic nuclei but contain different numbers of neutrons; the isotopes of one and the same element thus have different mass numbers) that are so unstable that they decay spontaneously, that is, without external influences. They are called radioactive. The ionizing radiation they emit in the process can either be particles or it can be electromagnetic waves (gamma rays; gamma rays; γ rays; e.g., from cesium-137). Particle radiation is alpha radiation (α-radiation) – in the form of helium nuclei – or beta radiation (β-radiation) – in the form of electrons. Alpha and beta emitters, because of the short range of their effect, are mostly dangerous only if they enter the body. The relevant dose for humans, i.e. the “effective dose” of ionizing radiation, is given in Sievert* (Sv). Ionizing radiation can cause tumors by damaging DNA. Up to about 5 Sievert, the probability of tumor initiation increases with increasing dose. * For X-rays, gamma and beta radiation, one sievert (Sv) is identical to one gray (= 1 joule per kg; unit symbol Gy) 1 Sv = 1,000 mSv; 1 mSv = 0.001 Sv; 1 μSv = 0.000001 Sv; natural radiation exposure in Germany: 2 mSv per year or 0.002 Sv per year The harmful effect of isotopes depends on its physical half-life, i.e. the period of time during which the amount of a certain radioactive substance has decreased to half. The other half has not disappeared, but has been transformed into another nuclide, which in turn may also be radioactive. The biological half-life, on the other hand, refers to the period of time required by the body to halve the number of radioactive nucleotides through excretion processes. This depends on gender, age, body weight and dietary habits. Below is a brief description of the important isotopes and their site of action in the human organism (e.g., after radioactive fallout):
Iodine (Iodine)
- Isotopes: Iodine-131 (131I; beta radiation; physical half-life: circa 8 days; biological half-life: circa 80 days Volatile iodine isotopes (iodine isotopes) accumulate in the spaces between the fuel rods during regular operation of a reactor. In the event of an accident, radioactive iodine escapes into the open air as one of the first isotopes.
- Contaminated food: leafy vegetables; milk and dairy products.
- Transport pathways in the body: absorption in the gastrointestinal tract (gastrointestinal tract); absorption due to similarity to iodine (iodine analog).
- Storage depot: thyroid gland
- Prophylaxis: iodide tablets
Cesium
- Isotopes:cesium-134 (134Cs), cesium-137 (137Cs); beta radiation; physical half-life: circa 30.17 years; biological half-life: 110 days.
- Contaminated foods: milk and dairy products; wild mushrooms; wild boar and deer;
- Transport pathways in the body: absorption in the gastrointestinal tract (gastrointestinal tract); absorption due to similarity to potassium (potassium analogue).
- Storage depot: muscle tissue
Strontium-90
- Isotopes:Strontium-90; beta radiation; physical half-life: circa 28.78 years; biological half-life: 17.5 years.
- Contaminated foods: milk and dairy products; wild mushrooms; wild boar and deer;
- Transport routes in the body: absorption in the gastrointestinal tract (gastrointestinal tract); absorption due to similarity to calcium (calcium analogue) and via aerosols.
- Storage depot: skeleton, bone marrow cells.
Xenon
- Isotopes: xenon-133 (133Xe), xenon-135 (135Xe); 135Xe decays to radioactive cesium nuclei (solids) within hours; physical half-life: xenon-133: 5.253 days; xenon-135: 9.14 hours;
- Contaminated food: —
- Transport routes in the body: lungs
- Storage depot: respiratory organs
Plutonium
- Isotopes:plutonium (Pu); 240Pu; alpha emitter; physical half-life: 240Pu; 6,564 years.
- Contaminated food: —
- Transport routes in the body: via the lungs!
- Storage depot: liver; bones; lymph nodes.
Examples of tumor diseases that can be triggered by radioactivity:
- Bronchial carcinoma (lung cancer) – after smoking, involuntary inhalation of radioactive radon – an odorless, radioactive noble gas – in the home is the most common trigger of bronchial carcinoma. When it decays in the lungs, it emits alpha radiation.
- Mammary carcinoma (breast cancer) – due toionizing radiation.
- Neoplasms of the hematopoietic system (leukemia / blood cancer), bone tumors [strontium 90] (atomic bombs dropped at Hiroshima and Nagasaki).
- Thyroid carcinoma (thyroid cancer) – due to radioactive iodine isotopes (e.g. Chernobyl reactor accident).
Ionizing radiation can cause abortions (miscarriages) via damage to DNA (deoxyribonucleic acid; short DNA, English DNA) (lat.-fr.-gr. artificial word); carrier of hereditary information).
Cancer risk in nuclear power plants, nuclear weapons production, or the nuclear waste industry
- U.S. researchers at the University of South Carolina Medical Center have examined data from 136 nuclear power plants in relation to the incidence of childhood and adolescent leukemia (blood cancer). They conclude that the risk of leukemia increases near nuclear power plants. The probability of contracting the disease was increased by 7-10%, and the mortality rate (mortality) was increased by 2-18%.
- A Swiss study of children growing up near Switzerland’s five nuclear power plants found no increase in the incidence of leukemia.
- The following are the results of the International Nuclear Workers Study (INWORKS), in which 15 countries participated: of 66,600 of the nuclear workers, 19,750 have cancer (29.7%). Of these, in turn, about 18,000 died of solid tumors, and the rest died of leukemia and lymphoma. This compares with a lifetime risk of cancer death in industrialized countries of about 25%.A 5% increased mortality risk (risk of death) was found for non-solid tumors, and the risk appears to be dose-dependent: per 1 Gy, the risk of dying from a solid tumor was increased by 48%.