Radioactive Pollution in Water

Context: Radioactive pollution of water is newly emerging but is of grave concern for water pollution and human health.
About Radioactivity

• Radioactivity is the phenomenon of spontaneous emission of particles or waves from the unstable nuclei of some elements.
• There are three types of radioactive emissions: Alpha, Beta and Gamma.
• Alpha particles are positively charged He atoms, beta particles are negatively charged electrons and gamma rays are neutral electromagnetic radiations.
• Radioactive elements are naturally found in the earth’s crust.

Radioactive contamination of Water

• Natural: Percolation of naturally occurring radioactive materials (NORM) from the soil sediments to the aquifer causes groundwater contamination.
• Man-made: Anthropogenic sources of such pollution include- nuclear weapon investigation, nuclear calamities, nuclear powerhouses and dumping of radioactive waste.

Various contaminant elements

• Uranium, thorium and actinium are three NORM series that contaminate water resources.
• A number of radionuclides are found in surface and subsurface waters, among which 3H, 14C, 40K, 210Pb, 210Po, 222Rn, 226Ra, 228Ra, 232Th and 234,235,238U are common.
• Strontium-90, Caesium-137, etc are also formed by nuclear reactors, along with numerous unnecessary radioisotopes wastes.
• 40K and 7Be are the most commonly found radioactive elements in the sludge generated in sewage treatment plants.
• Nuclear reactors produce radioisotopes (Cobalt-60, Iridium-192, etc) that hand out as sources of gamma radiation in radiotherapy and numerous industrial appliances.

Oceanic sources

• Oceans and seas are the natural repositories of naturally occurring uranium. It is found in the form of uranyl carbonate ion.
• A significant concentration of uranium is supposed to be found in the greater salinity of the marine water.
• 40K (Radioactive Potassium) is also found in considerable concentration in the marine environment.

Measuring radioactive pollution

• Radioactivity is measured in Becquerel (SI unit) or in Curie.
• Energy absorbed per unit mass is measured by Gray, while the unit Sievert measures the quantity of radiation absorbed by human tissues.
• A small amount of radiation is found in all types of water but the extended amount of radiation is harmful to human health.
• Radioactivity in drinking water can be determined by a gross alpha test.

Hazards of such pollution

• Radioactive elements have an effect on the environment and can cause a risk to human healthiness if inhaled, injected or exposed.
• Human tissues absorb radiation through polluted water and foodstuff, which can cause serious health risks.
• High doses of radiation can cause acute radiation syndrome or cutaneous radiation injury.
• Exposure to radiation causes various disorders in human physiology, including cancer, leukaemia, genetic mutations, osteonecrosis, cataracts and chromosomal disruption.