Thursday, 14 July 2011


This is a vlog based on the article " On human health on exposure to radiation". It deals with the issue of harmful effect of radiation on human body. Radiation is not always harmful, if the use is regulated by expert. Certain radiation are at most necessary for human physiology such as Vitamin D production. But a lot of the time , radiations turned out to be lethal for human health. As an assignment project, we tried to deal with the adverse effect of radiation on human health, their sources and the mechanism of damages

MAN made radiation

Man made radiation pose no less threat then the natural form of radiation. No body can ever forget the memories of Hiroshima and Nagasaki. Recently there was another nuclear accident, an major earthquake jolted the plant and causes Higher amount of radiation to be present in the environment. This is just one example of  man made radiation hazard. There are lot other and more severe one. Even from the faulty apparatus of X-ray, diagnostician health can be in danger. These form of man made radiation are dangerous in nature as they emit highly ionizing ions as radiation which causes damages at cellular level to cause severe condition such as cancer. As the blog scrolls down more information can be retrieved about such hazard.

 Deformed baby as depicted above are still born in hiroshima, which is just showing the degree of adverse effect of radiation on human health. Mutation due to radiation from 50 years ago are still passed on to geneartion reasultin in major upset in cellular processes.

There are other sources of radiation: which include cosmic radiation and radiation from the crust of earth. Details on the source of radiaton can be found from the article.

Does cell phone radiation poses threat to the human body?

Cell phone, microwave oven or any electronic devices  which are capable of radiation, do they harm human body? In order to answer that question, it is important to understand the nature of radiation. The radiation which are not ionizing do not harm human body. Radio wave, microwave or electromagnetic radiation which are not x-ray or gamma ray do not pose threat to human health. As the energy level of this waves are not good enough to cause harm. Although rumors were around that cell phone causes cancer, till  now there had been no scientific papers suggesting so but a lot there to prove on the contrary. Same goes for microwave or any non-ionizing radiation. They can be harmful to human body if subjected to prolonged exposure and main causative agent would be heat.

Below is excerpt from the article about the nature of radiation:

Based on nature of radiation, it can be classified into two types. The criteria are Ionizing radiation and non-ionizing radiation.

 Ionizing radiation: In the simplest word radiation which consist of particles which are energized enough to knock electron from atom or in other words capable of forming ions by changing the electronic configuration of a stable atom is known as ionizing radiation. These are the type of radiation which is capable of damage at cellular level, with other adverse effect. There are main four types of ionizing radiation: Alpha particles, Beta particles, Gamma rays and X-rays. Both Gamma rays and X-rays belong to the electromagnetic spectrum. Where else ultra violet (UV) radiation can be considered both ionizing and non-ionizing, depending on the energy content of the wave. Compared to the non-ionizing radiation ionizing radiation pose much more severe health risk for human.
  Non-ionizing radiation: The particles or the wave for radiation is not energized enough to alter the electronic configuration of the atoms involved. As it is not highly energized, it pose none or whatsoever threat to human health. Types of non-ionizing radiation include radio waves, microwaves and radiation within the visible spectrum of the electromagnetic spectrum. Ultra Violet radiation is also considered non-ionizing radiation.


DNA mutation.

Just by mere chance it misses.........

Ionizations due to radiation may act indirectly on the water molecules forming water-derived radicals or directly on the molecules that makes up the cellular component. This formed radical reacts with adjacent molecules, resulting n breaking bonds. DNA breakage is the most adverse effect. DNA breakages are of two major criteria, single strand or double strand breaks. Most single-strand breaks can be repaired normally as the DNA molecule is double stranded in structure(the two strands complement each other, so that an intact strand can serve as a template for repair of its damaged, opposite strand). In the case of double-strand breaks, however, repair is more difficult and erroneous rejoining of broken ends may occur. These faulty repair result in induction of mutations, chromosome aberrations, or cell death.
Deletion of DNA segments is the predominant form of radiation damage in cells that survive adverse effect due to exposure to radiation. It may be caused by:
(i) Faulty repair of two separate double-strand breaks in a DNA molecule with joining of the two outer ends and loss of the fragment between the breaks or
(ii) (ii) The process of enzyme digestion of nucleotides, the component molecules of DNA, of the broken ends before rejoining to repair one double-strand break.

The video below shows sophsticated DNA repair system, but by mere chance certain mutation passes on without check and lead to the development of cancer. This certain individual with such mutation are so unlucky that even check point at cell division can't detect them. The image below shows such sophticated cellular mechanism:

How faulty repair mechanism of DNA, lead to cancer???

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

 3) Maligant melanomas: The most dangerous of all type.

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: