Lungs, radiation damage

Protective against lung radiation damage (rabbit) 397... 

Radon, the heaviest of the noble gases, has been much publicized in recent years because of a fear that low-level exposures increase the risk of cancer. Like astatine and francium, its neighbors in the periodic table, radon is a radioactive element with only a minute natural abundance. It is produced by radioactive decay of the radium present in small amounts in many granitic rocks, and it can slowly seep into basements, where it remains unless vented. If breathed into the lungs, it can cause radiation damage. 

When radioactive substances pass into the body by inhalation of radioactive vapors, gases (e.g., radon) or dusts, or by ingestion, such substances may accumulate and deposit in the bone. They incorporate in the bone matter the ionizing radiations damage cells and cause cancer. Cancer in lungs, bones, and lymphatic systems are known to occur in humans as a result of radiation exposures. 

The frequency of abnormalities in sputum cytology has been utilized as a possible early indicator of radiation damage to lung tissue (Band et al. 1980 Brandom et al. 1978 Saccomanno et al. 1974). The accuracy and precision of this measurement is not known. 

Radiation exposure has been associated with most forms of cancer in many organs, such as the lung, breast, and thyroid gland. If the cell is only modified by the radiation damage, the damage is usually repaired. In some conditions, the repair mechanism may not be perfect, and the modification will be transmitted to daughter cells. This may eventually lead to cancer in the tissue of the exposed individual. Radiation-induced cancer may manifest itself decades after the etqiosure and does not differ from cancers that arise spontaneously or are attributable to other factors. 

Radon constitutes a serious problem because, being a heavy gas, it collects in such places as basements and mine shafts. When inhaled, radon decays in areas where little penetration is require to cause tissue damage. Radiation from a and (3 decay is not of a highly penetrating type, but inside the lungs it does not have to be in order to still cause damage. Table 15.10 shows several properties of the noble gases. 

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