EFFECTS
OF RADIOACTIVE POLLUTION
Nripesh Awasthi
Radioactive pollution
is hazardous to most form of life and environment. Radioactive pollution is one
of the pollution that causes the physical disturbance in air, water, soil and other
elements of environment by radioactive materials through radioactivity. Radioactivity
is the ability of materials to emit energy in the form of streams of particles
such as proton (alpha particle), electron (beta particle) and gamma rays by
their nuclei, owing to the decaying of its unstable atoms. This energy can be
dangerous or fatal to plants or animals exposed to it, measured in term of unit
Becquerel, curie and Rutherford. Radioactive pollution is waste products of nuclear
process (fission and fusion) which is widely used in atomic reactor, nuclear
weapons and other nuclear fuel system.
Production and decommissioning
of nuclear weapons, nuclear power plants and fuel, mining and refining of
radioactive ore, medical wastes, industrial wastes, disposal of nuclear wastes,
naturally occurring radon gas emitted from
beneath the earth, spillage or accidents in radio-labs etc are main
source of radioactive pollution in the form of radiation.
Radioactive pollution
is not curable, hence it must be checked. It can be spreaded by wind
through earth’s atmosphere and fall on the ground along with rain called
“fall out”. An example of it can be taken as the situation after nuclear attack
in Hiroshima (little boy-U235) and Nagasaki (fat man-Pu239)
of Japan in 1945 by US during world war-II.As a result 2,25,000 people had died
of long term exposure of radiation form. Similarly, Chernobyl disaster occurred
in Ukraine/Russia on 1986 where out of 2 billion people exposed to radioactive
fallout, 250,000 cases of cancer and nearly half of them were found fatal
according to Green peace world 2006. It was due to melting of nuclear reactor
that released radioactive substances all over the Europe. Latest disaster,
Fukushima nuclear disaster (Japan) is series of equipment failure, nuclear
meltdown and release of radioactive materials, after Tsunami and earthquake on
11 March 2011, affected air, water, plants and animals with radiation.
Radiation released from
radioactive pollution can be divided based on their action on the living cells.
i.e. Ionising and Non-ionising radiation. Non-ionising radiation includes U-V
rays (wavelength=10-4000A0) that causes sunburn, snow-blindness, formation
of thymine-dimer in DNA ,skin cancer, inactivation of organic bio-molecules (proteins
& pigments) and Xeroderma pigmentosa. Ionising radiation includes X-ray (wavelength=1A0-100A0),
cosmic rays (wavelength=10-16m) and other atomic radiation that
damage the living cell by ionization (shifting of electron from one to another
bio-molecules). Actively dividing or growing cells like stratum germinatum, intestinal
lining, bone marrow, gonads, and embryo are more susceptible to ionising
radiation. Strontium (Sr90)
replaces Calcium in bones causing decalcification and osteitis fibrosa cystic; reaches
cow milk through leaves & grasses and again come to soil through faeces of
cow and human. Thyroid tumors/cancer, defective eyesight, sterility etc may
arise due to radioactive Iodine (I131). Radioactive Cesium (Cs137)
accumulates in muscles, change concentration of Na+ & K+
in the nerve excitation potential, and causes genetic change. Similarly,
Uranium and plutonium causes skin cancer and tumors in miners.
Again, the effect of radioactive
radiation can be studied on its exposure to long and short ranges. Short range
exposure of radiation also called immediate effect, includes loss of hair,
brain tumor, subcutaneous bleeding, skin burn, defective body organs, change in
number of cells and metabolism in the body whereas long range exposure of
radiation also known as delayed effect, may acts as mutagens, teratogens,
carcinogens and causes even death to organism . The radioactive materials like
Zn65, Fe55, Sr90 etc accumulated in some
animals and transferred through food chain, causing imbalance in ecosystem. Nuclear
night and nuclear winter results due to explosion of nuclear power plant and
atomic reactor. As there is no still effective medical treatment for fatal
radiation doses and continual production of nuclear power is risk for nature
& civilization. Therefore, we should be conscious towards the control and
management of radioactive wastes as well as production of nuclear energy.
Reference:
Trueman’s Biology- M
.P. Tyagi and J. P. Goyal,
Trueman’s Physics- B.L.
Taneja and Various Modern Physics books,
Photo of Radiation
damage to DNA-4341-3 gif: radiation-scott.org,
Radioactive pollution
and its effect on human health - By Keshav Saini in Environmental pollution.
Green world peace 2006,
Fukushima Nuclear power plant- Wikipedia.
