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Slide 4:

Unstable atoms emits alpha, beta, gamma as radiation and get stable state – radioactivity Radioactive atom / radionuclide/radioisotope – atom which emit radiation

Slide 5:

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 product of a nuclear process

Sources of radioactive contaminants: :

Sources of radioactive contaminants: Production of nuclear fuel Nuclear power reactors Nuclear tests carried out by Defense Personnel Disposal of nuclear waste Uranium Mining




SOURCES OF RADIOACTIVE POLLUTION Uranium mining : mining of radioactive ores involve the crushing and processing of radioactive ores and generate radioactive byproducts. Mining of other ores may also generates radioactive wastes

Sources of radioactive pollution:

Sources of radioactive pollution

Frequency and Duration of Radioactive Pollution: :

Frequency and Duration of Radioactive Pollution: Continuous pollution : This type of condition exists in uranium mines, nuclear reactors, test labs etc. where the humans are under continuous exposure to radioactive contaminants and protective clothing is required to avoid radiation exposure. Accidental Pollution : This type of condition exists during accidental exposure to radiations by virtue of equipment failure, radiation leak, faulty protective equipment etc. Occasional Pollution: This condition exists during isolated experiment or test of nuclear substance.

Natural radiation:

Natural radiation Natural - from the beginning of earth-we are always exposed to it Cosmic rays will create +vely charged particles and high energy photons -it interact with normal atoms produce radio nuclides It enter to earth Uranium 235,238,thorium232,radium 226,potassium 40 etc

Slide 13:

Alpha = helium nuclei 4he2 , it can stop by even paper sheet Beta = electrons and positrons, stopped by glass wood etc Gama rays = high energy photons, lead or concrete shielding to stop

Measurement SI unit Becquerel:

Measurement SI unit Becquerel 1 Bq = 1 disintegration per second Half life – time period required to radioisotope fall in to its half Absorbed dose ,D - energy absorbed by unit mass of materiel , unit – gray Dose equivalent ,H – product of absorbed dose and quality factor(relative biological effectiveness) sievert is unit linear energy transfer = energy deposited unit length of the track with respect to x – rays (normalised to 1) – help to know damage

Slide 15:

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 2,25,000 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.

Hiroshima -atom bomb:

Hiroshima -atom bomb

Man made hazards:

Man made hazards X - ray diagnosis -90% radiation Nuclear technology – nuclear weapon manufacture, nuclear fuel cycle Each process from mining to management leads to hazards Nuclear reactor –electricity production

Biological effects:

Biological effects Ionization of H2O –H2O2 PRODUCTION Cell damage , cell death ,DNA damage, mutations Genes controlling cell division – disturbed – cancer Skin ,gastro intestinal track lining – speed damage and repair

Slide 22:

Deterministic – high amount and high damage ,e.g. eye lens cataract , organ damage Stochastic (random) – minor damage and repaired

hiroshima before little boy:

hiroshima before little boy

Hiroshima after little boy :

Hiroshima after little boy

Fukushima and chernobyl nuclear disasters:

Fukushima and chernobyl nuclear disasters


Strontium Radioactive Sr-90, like many other radio nuclides, was discovered in the 1940s in nuclear experiments connected to the development of the atomic bomb. Strontium-90 is a by-product of the fission of uranium and plutonium in nuclear reactors, and in nuclear weapons Strontium-90 emits a beta particle with, no gamma radiation, as it decays to yttrium-90 (also a beta-emitter). Strontium-90 has a half-life of 29.1 years. It behaves chemically much like calcium, and therefore tends to concentrate in the bones and teeth.

Slide 29:

The accident at the Chernobyl nuclear power plant also introduced a large amount of Sr-90 into the environment People may inhale trace amounts of strontium-90 as a contaminant in dust. But, swallowing Sr-90 with food or water is the primary pathway of intake.

Health Effects of Strontium-90:

Health Effects of Strontium-90 Strontium-90 is chemically similar to calcium, and tends to deposit in bone and blood-forming tissue (bone marrow). Thus, strontium-90 is referred to as a "bone seeker." Internal exposure to Sr-90 is linked to bone cancer, cancer of the soft tissue near the bone, and leukemia . Risk of cancer increases with increased exposure to Sr-90. The risk depends on the concentration of Sr-90 in the environment, and on the exposure conditions.


cesium . Radioactive cesium-137 is produced when uranium and plutonium absorb neutrons and undergo fission The half-life of cesium-137 is 30 years. It decays by emission of a beta particle and gamma rays to barium-137m. Whether people's health is at risk is not clear, however. Epidemiologists still argue over how many cancers were caused by caesium released by Chernobyl


uses Cesium-137 is one of the most common radioisotopes used in industry. Thousands of devices use cesium-137: moisture-density gauges, widely used in the construction industry leveling gauges, used in industries to detect liquid flow in pipes and tanks thickness gauges, for measuring thickness of sheet metal, paper, film and many other products well-logging devices in the drilling industry to help characterize rock strata Cesium-137 is also used in medical therapy to treat cancer

Waste disposal:

10,50,100 m depth earth In boxes &Containers Closure &post closure Waste disposal