This document discusses radioactivity in drinking water. It notes that minute traces of radioactivity are normally found in all drinking water, with concentrations varying by location. Many natural and artificial radioactive elements and their decay products contribute to this radioactivity. Specifically, potassium-40 is a significant natural contributor. Uranium-238, thorium-232, and their decay products including polonium, radon, and radium isotopes are also widespread natural sources. Radium-226, radium-228, and their daughters pose the greatest health risks. Artificial radioactivity can also come from fallout from nuclear weapons testing. Radioactivity in water can damage tissues, DNA, and increase cancer and birth defect risks. It also

1. Radioactive elements
in Water
By Laiba Sarwar

2. Radioactivity in Water (drinking
Water)
• Minute traces of radioactivity are normally
found in all drinking water whose
concentration vary from place to place.
• Many natural and artificial radio nuclides have
been found in water, but most of the
radioactivity is due to a relatively small
number of nuclides and their decay products.

3. Natural Radio nuclides
• Some of the radio nuclides that are responsible
for the natural radioactivity in drinking water
come from radioactive elements, and their decay
products, and others are produced continuously
by cosmic ray bombardment.
• Of all the natural radio nuclides that occur in
water and emit low-LET radiation, potassium-40
is likely to be the most significant. This primordial
radionuclide occurs as a constant percentage
(0.0118%) of total potassium.

4. Sources of High-Let Radiation
• Radio nuclides that are produced by the decay of
uranium-238 and thorium-232 are widely
distributed throughout the earth's crust. The
majorities of them are alpha-emitters and include
isotopes of polonium, radon, and radium.
• The natural alpha-emitters that occur in drinking
water appear to be bone seekers. Of these,
radium-226 and its daughters and the daughters
of radium-228 probably have the greatest
potential for producing radiation doses of some
consequence to man.

5. Sources of High-Let Radiation
• The major additional contribution to the alpha-
emissions in drinking water is due to the decay of
radium-228; although other alpha-emitting
natural radionuclides have been found in drinking
water, they occur in exceedingly small
concentrations.
• The abundance of the radioactive gas radon-222,
which is formed by the decay of radium-226, is
not highly correlated with the radium
concentration in fresh water.

6. Artificial Radio nuclides
• To some extent, all drinking water obtained from surface
sources will reflect contamination from atmospheric testing
of nuclear weapons. The sharp decrease in radioactive
fallout since that date has been followed by a
corresponding decrease in the radioactivity of surface
water.
• It is likely that potassium-40 in soil suspensions also
account for such water contamination. Because they
account for a major part of the potential dose from nuclear
fission and activation products, and because of their
biological significance, considerable attention has been
devoted to strontium-90, cesium-137, iodine-131, tritium,
and carbon-14 as potential water contaminants.

7. Effects of radioactivity on water

8. Effects of radioactivity on water
• Grays (Gy)
• Everything on
Earth is exposed
to radiation.

9. Risks
• Damage to tissues
• Cells
• DNA and other vital
molecules
• Cancer
• birth defects
• Abnormalities
• Death

10. Effects of radioactivity on fish
• The effects on
reproductive success in
fish that have been
demonstrated include
sterility, reduction in
counts of primordial
germ cells and reduced
testicular weight.
• fertility of aquatic
invertebrates
• germ cells
• mutations in gametes.

11. Effects on marine organisms
• Reproductive stages and growing
tissues are the most sensitive to
radioactivity, notably the eggs of
marine fish.
• Radioactive isotopes can be bio
accumulated, both within primary
producers and by uptake through the
food chain.
• Bacteria, fungi and some lichens tend
to be relatively tolerant to
radioactivity.
• Deleterious effects in the growth
patterns of plants and animals.

12. WHAT IS THERMAL HEATING OF
WATER:
• A thermodynamic process increase in
temperature of water above its normal
existing temperature.
• Contains 42 different minerals.
• High in concentrations are sulphate, calcium
& chloride

13. THERMAL POLLUTION IN WATER:
• Thermal pollution is the degradation of water
quality by any process that changes ambient
water temperature.
• A common cause of thermal pollution is the use
of water as a coolant by power plants and
industrial manufacturers

15. SOURCES OF THERMAL POLLUTION
• Nuclear power plants
• Coal fired power plants
• Industrial affluent
• Domestic sewage
• Hydroelectric power

16. CONTROL MEASURES FOR THERMAL
POLLUTION
• Cooling towers :Use of water from water systems for cooling purposes, with
subsequent return to the water way after passage through a condenser, is called
cooling process.
• Cooling ponds :Heated effluents on the surface of water in cooling ponds
maximize dissipation of heat to the atmosphere and minimize the water area and
volume.
• Spray ponds :The water coming out from condensers is allowed to pass into the
ponds through sprayers. Heat from the fine droplets gets dissipated to the
atmosphere.
• Artificial lakes :Artificial lakes are man made water bodies that offer once-
through cooling. The heated effluents can be discharged into the lake at one end
and water for cooling purposes may be withdrawn from the other end. The heat
is eventually dissipated through evaporation.