Mar 14, 2011

Radioactive Effects on Human


Radioactive pollution can be defined as the emission of high energy particles or radioactive substance into air, water or land due to human activities in the form of radioactive waste. Radioactive waste is usually the product of a nuclear process such as nuclear fission, which is extensively used in nuclear reactors, nuclear weapons and other nuclear fuel-cycles.

The radioactivity of nuclear waste diminishes with time. That means the waste needs to be isolated from the reach of living beings until it no longer pose a threat to living beings. This time period may take from days to months and to years depending upon the radioactive nature of the waste.

Radioactive pollution that is spread through the earth’s atmosphere is called “Fallout”. The atmospheric nuclear pollution become prominent during the World War 2 period when United States, Britain and Soviet Union started conducting nuclear tests in the atmosphere. The best example of fallout is the nuclear bomb attack on Hiroshima and Nagasaki, Japan in 1945 by United States of America during World War 2.

As a result of nuclear bomb attack, nearly 2,250,000 people had died as a result of long-term exposure to radiation from the bomb blast within 5 years of attack due to radiation effect and cancer.

In land and water, the major source of radioactive pollution remains with the nuclear fuel cycle. The nuclear fuel cycle is used in nuclear power plants, extraction and refinement of materials from nuclear substance to be used in nuclear reactors and nuclear weapons, where the contaminants are left behind after the useful material (Nuclear Isotope) is extracted.

The effects of radioactive pollution or exposure to nuclear radiations were first reported in early 20th century when people working in uranium mines suffered from skin burn and cancer. The effects vary from organism to organism and from level of radioactivity of nuclear isotopes. The radiations destroy the cells in human body and causes cancer.

Radioactive particles forms ions when it reacts with biological molecules. These ions then form free radicals which slowly and steadily start destroying proteins, membranes, and nucleic acids. A longer exposure to radioactive radiations can damage the DNA cells that results in cancer, genetic defects for the generations to come and even death.

Long Term Effects on Humans
Long after the acute effects of radiation have subsided, radiation damage continues to produce a wide range of physical problems. These effects- including leukemia, cancer, and many others- appear two, three, even ten years later.

Blood Disorders
According to Japanese data, there was an increase in anaemia among persons exposed to the bomb. In some cases, the decrease in white and red blood cells lasted for up to ten years after the bombing.

Cataracts
There was an increase in cataract rate of the survivors at Hiroshima and Nagasaki, who were partly shielded and suffered partial hair loss.

Malignant Tumors
All ionising radiation is carcinogenic, but some tumour types are more readily generated than others. A prevalent type is leukaemia. The cancer incidence among survivors of Hiroshima and Nagasaki is significantly larger than that of the general population, and a significant correlation between exposure level and degree of incidence has been reported for thyroid cancer, breast cancer, lung cancer, and cancer of the salivary gland. Often a decade or more passes before radiation-caused malignancies appear.

Keloids

Beginning in early 1946, scar tissue covering apparently healed burns began to swell and grow abnormally. Mounds of raised and twisted flesh, called keloids, were found in 50 to 60 percent of those burned by direct exposure to the heat rays within 1.2 miles of the hypocenter. Keloids are believed to be related to the effects of radiation.

1 comments:

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