Radiation pollution – a continuum

In previous posts, I have touched on issues ranging from: the management of radioactive substances, mobilisation mechanisms and transportation of radioactive substances, along with several case studies. Hence in this post I will consolidate some of this information with relevance to the pollutant transfer continuum!

Potential pollutant source

Natural sources (that also happen to be non-point)

  • Radon-222: a gas formed by the breakdown of uranium in soil, rock and water
  • Uranium-238: a radioactive metal found in the earth’s crust
  • Carbon-14: formed when the sun’s radiation hits nitrogen atoms in the Earth’s atmosphere

Artificial sources:

  • Underground repository sites for radioactive wastes (point source)
  • Hospitals: medical applications of radioactive nuclides (X-Rays), contaminated sharps (syringes), contaminated waste (gloves)

Mobilisation mechanisms

  • Water (high humidity, liquid flow) can dissolve and release radionuclides into groundwater sources. This may occur when corrosion of waste packages in repository sites occur, adversely affecting waste isolation that is crucial to maintain the safety of the external environment
  • Natural decay of uranium in soils to produce radon gas. In recent years, residential developments triggers and accelerates radon gas accumulation e.g. increasing popularity of underground residences, highly insulated and sealed structures

Transportation

Radioactive substances can be transported by winds to result in transboundary pollution.

Example: Explosion at Chernobyl’s nuclear power plant created a radioactive cloud that was transported by wind – West Germany, Austria, Finland and Sweden were affected.

Radioactive substances e.g. radon gas can be transported by air flows from beneath the ground -> soil surface -> above the ground into the basement/grounds of homes

Radioactive substances can be transported by water, which can also have far reaching effects where groundwater or surface water flows are often transboundary.

Conversely, these radioactive substances in the atmosphere can be deposited into water bodies.

Radioactive substances can be transported through the food chain, through the absorption of radioactive substances by plants or ingestion by aquatic animals. These eventually become food for people.

Pollution & wider impacts

Health impacts:

Immediate health effects: Hair loss, nails bleeding, changing in proportion of blood cells

Delayed effects: Genetic changes such as mutations, shortening of life span, tumour formation, cancer

Substances of concern:
  • Isotopes in low-level waste:  Cesium-131 that attacks the ovaries and heart (half-life: 30y)
  • Isotopes in intermediate-level waste:  Carbon-14 (half-life: 5000y) and Nickel-58 (half-life: 76,000 years) – both are potential mutagens and carcinogens
  • Radon gas – potential to cause lung-related cancers

Impacts to public health:

  • Leaching of radionuclides into groundwater may contaminate water source. For example, Toronto-based Ontario Power Generation’s aim to construct an underground repository for radioactive waste within the Great Lakes Basin is met with contestations from citizens and officials over concerns of the contamination of drinking water. The Great Lakes are a source of drinking water of over 7 million residents in the region.
  • Biomagnification of radioactive substances up the food chain; contaminated seafood become potential sources of contamination of human bodies

Hope this helped everyone learn more about radiation pollution!

 

Thanks for reading!

YJ.

 

 

 

 

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