Radioactive pollution in water

Context

Radioactive pollution of water is newly emerging but is of grave concern for water pollution and human health.

Understanding 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
  • 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 communication

• Radioactive contamination is more prevalent in groundwater as compared to surface water since it is much exposed to radioactive elements found in the rocks.
• Sometimes, magma also releases radioactive gases into the environment.
• The deposition of these radioactive gases in waterbodies also cause radioactive contamination.
• Atmospheric deposition (both dry and wet) of cosmogenic radionuclides also add radioactive nuclei in the surface water.
• 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. Uranium, thorium and actinium are three NORM series that contaminate water resources. 
• Radium, a descendant of the NORM series, is one of the decidedly radiotoxic elements found in aquatic systems and can be penetrated into groundwater via (i) aquifer rock dissolution (ii) decaying of 238U and 232Th, or (iii) desorption processes.

Source of radionuclides discharge

• Nuclear reactors and nuclear warhead experiments are the key sources of human-induced radionuclides discharge.
• Nuclear reactors produce radioisotopes (Cobalt-60, Iridium-192, etc) that hand out as sources of gamma radiation in radiotherapy and numerous industrial appliances.