Thursday, 14 July 2011
Cancer and Radiation !!!
From natural source of radiation, the most common type of cancers are skin cancers and lung cancers. As it have been discussed early in the article, it will be in discussed details in here.
Huge number of scientific publications indicate UV ray as major causative agents for skin cancers. More precisely UV-B an UV-C, the two forms of UV radiation at precise frequency. Although UV ray plays important role in human physiology such as Vitamin D formation, it can also be malicious. The mechanism for causing cancer is based on damaging DNA. Summary on how DNA might be damaged can be found from the article under title Damage to DNA and progression to cancer. Skin being the largest and the outermost organ of the human body it faces humongous amount of pressures from the environment. It absorbs the harmful UV-B and UV-C rays. These radiation causes damage to the DNA, which leads to the formation of skin cancer. Skin cancers are generally of three types:
1) Basal cell carcinoma:
The most common type of skin cancer. Consist of uncontrollable growth of cells at stratum basale
2) Squamous cell carcinoma:
At the stratum spinosum, arises from keratinocytes
Among the above illustrated skin cancers, the first two can be treated successfully if detected earlier, but there is a huge number of death every year from malignant melanoma.
Adverse effect of radiation from the natural source is not limited to the skin, human lungs can also be affected. Lung cancers due to radon gas inhalation ranks just after smoking. Radon is an element, a noble gas, which results due to the radioactive decay of uranium. Earth crust contain uranium in huge proportion and from there radon sources out. Not all for radon isotopes are radioactive, only the radon-222 is carcinogenic. Radon-222 decays by emitting alpha particle which a strong ionizing radiation. This form radiation gave rise to mutant genetic material, which when uncheked progress to cancer. Below is the graphical representation of alpha partile decay:
And the image below is graphical model of how radon might seeps into domestic environtment: