Radioecology

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De Molen (windmill) and the nuclear power plant cooling tower in Doel, Belgium (DSCF3859)

Radioecology is the branch of ecology concerning the presence of radioactivity in Earth’s ecosystems. Investigations in radioecology include field sampling, experimental field and laboratory procedures, and the development of environmentally predictive simulation models in an attempt to understand the migration methods of radioactive material throughout the environment.

The practice consists of techniques from the general sciences of physics, chemistry, mathematics, biology, and ecology, coupled with applications in radiation protection. Radioecological studies provide the necessary data for dose estimation and risk assessment regarding radioactive pollution and its effects on human and environmental health.[1]

Radioecologists detect and evaluate the effects of ionizing radiation and radionuclides on ecosystems, and then assess their risks and dangers. The study is European by origin,[2] intended to ascertain and manage the risks involved as a result of the Chernobyl disaster. Radioecology arose as a response to increasing nuclear energy production in order to preserve the natural environment.

History[edit]

Artificial radioactive affliction to Earth’s environment began with nuclear weapon testing during World War II, but did not become a prominent topic of public discussion until the 1980s. The Journal of Environmental Radioactivity (JER) was the first collection of literature on the subject, and its inception was not until 1984.[3] As demand for construction of nuclear power plants increased, it became necessary for humankind to understand how radioactive material interacts with various ecosystems in order to prevent or minimize potential damage. The aftermath of Chernobyl was the first major employment of radioecological techniques to combat radioactive pollution from a nuclear power plant.[4][5]

Chernobyl radiation map 1996

Collection of radioecological data from the Chernobyl disaster was performed on a private basis. Independent researchers collected data regarding the various dosage levels and geographical differences among the afflicted areas, allowing them to draw conclusions about the nature and intensity of the damage caused to ecosystems by the disaster.[6]

These local studies were the best available resources in containing the effects of Chernobyl, yet the researchers themselves recommended a more cohesive effort between the neighboring countries to better anticipate and control future radioecological issues, especially considering the ongoing terrorism threats of the time and the potential use of a "dirty bomb."[7] Japan faced similar issues when the Fukushima Daiichi nuclear disaster occurred, as its government also experienced difficulty organizing collective research efforts.

An international radioecology conference was held for the first time in 2007 in Bergen, Norway.[8] European scientists from various countries had been pushing for joint efforts to combat radioactivity in the environment for three decades, but governments were hesitant to attempt this feat because of the secrecy involved in nuclear research, as technological and military developments remained competitive.[9]

Objective[edit]

The aims of radioecology are to determine the concentrations of radionuclides in the environment, to understand their methods of introduction, and to outline their mechanisms of transfer within and between ecosystems. Radioecologists evaluate the effects of both natural and artificial radioactivity on the environment itself as well as dosimetrically on the human body. Radionuclides transfer between all of Earth’s various biomes, so radioecological studies are organized within three major subdivisions of the biosphere: land environments, oceanic aquatic environments, and non-oceanic aquatic environments.[10]

Scientific Background[edit]

Nuclear radiation is harmful to the environment over immediate (seconds or fractions thereof) as well as long-term (years or centuries) timescales, and it affects the environment on both microscopic (DNA) and macroscopic (population) levels. Degrees of these effects are dependent on external factors, especially in the case of humans. Radioecology encompasses all radiological interactions affecting biological and geological material as well as those between different phases of matter, as each is capable of carrying radionuclides.

Occasionally, the origin of radionuclides in the environment is actually nature itself, as some geological sites are rich in radioactive uranium or produce radon emissions. The largest source, however, is artificial pollution via nuclear meltdowns or expulsion of radioactive waste from industrial plants. The ecosystems at risk may also be fully or partially natural. An example of a fully natural ecosystem might be a meadow or old-growth forest affected by fallout from a nuclear accident such as Chernobyl or Fukushima, while a semi-natural ecosystem might be a secondary forest, farm, reservoir, or fishery that is at risk of infection from some source of radionuclides.[11]

Basic herbaceous or bivalve species such as mosses, lichens, clams, and mussels are often the first organisms affected by fallout in an ecosystem,[12] as they are in closest proximity to the abiotic sources of radionuclides (atmospheric, geological, or aquatic transfer). These organisms often possess the highest measurable concentrations of radionuclides, making them ideal bioindicators for sampling radioactivity in ecosystems. In the absence of sufficient data, radioecologists must often rely on analogs of a radionuclide to attempt to evaluate or hypothesize about certain ecotoxicological or metabolic effects of rarer radionuclides.

In general, techniques in radioecology focus on the study of environmental bioelectromagnetism, bioelectrochemistry, electromagnetic pollution, and isotope analysis.

Radioecological Threats[edit]

Earth in the 21st century is at risk of the accumulation of nuclear waste as well as the potentiality of nuclear terrorism, which could both lead to leaks.

Concentrations of artificial radionuclides throughout the biosphere are on the rise. Radioactivity originating from the Northern Hemisphere[13] is observable dating back to the mid-20th century. Some highly toxic radionuclides have particularly long radioactive half-lives (up to as many as millions of years in some cases[3]), meaning they will virtually never disappear on their own. The impact of these radionuclides on biological material (correlated with their radioactivity and toxicity) is similar to that of other environmental toxins, making them difficult to trace within plants and animals.[3]

Fort-greely-low-level-waste

Some aging nuclear facilities were not originally intended to operate as long as they have, and the consequences of their waste procedures were not well understood when they were built. One example of this is how the radionuclide tritium is sometimes released into the surrounding environment as a result of nuclear reprocessing, as this was not a foreseen complication in the original waste management orders of operations. It is difficult to diverge from these procedures once a reactor has already been put to use, since any change either risks releasing even more radioactive material or jeopardizes the safety of the individuals working on the disposal. Protection of human well-being has been, and remains to this day, paramount in the aims of radioecological research and risk assessment.

Radioecology often calls into question the ethics of protecting human health versus the preservation of the environment in the interest of fighting extinction of other species,[14] but public opinion on this matter is shifting.[15]

See also[edit]

References[edit]

  1. ^ IFE - Radioecology
  2. ^ J. Van Den Hoek (1988)European research on the transfer of radionuclides to animals — A historical perspective ; Pages 17-27 (abstract)
  3. ^ a b c S.C. Sheppard, An index of radioecology, what has been important ? ; Journal of Environmental Radioactivity, Volume 68, Issue 1, 2003, Pages 1-10.
  4. ^ J. Hilton, Aquatic radioecology post Chernobyl—a review of the past and a look to the future ; Studies in Environmental Science, Volume 68, 1997, Pages 47-73
  5. ^ Sir Frederick Warner (Editor), Roy M. Harrison (Editor), Radioecology After Chernobyl: Biogeochemical Pathways of Artificial Radionuclides (SCOPE Series)
  6. ^ 3.1.5. Deposition of radionuclides on soil surfaces (PDF). Environmental Consequences of the Chernobyl Accident and their Remediation: Twenty Years of Experience, Report of the Chernobyl Forum Expert Group ‘Environment’. Vienna: International Atomic Energy Agency (IAEA). 2006. pp. 23–25. ISBN 92-0-114705-8. Retrieved 12 September 2013.
  7. ^ MØLLER Anders et MOUSSEAU Timothy A. (2006), Biological consequences of Chernobyl : 20 years on ; Revue : Trends in ecology & evolution, vol. 21, n°4, pp. 200-207 ; 8 pp et 70 ref. ; ISSN 0169-5347 ([abstract Inist/CNRS])
  8. ^ 1st International Conference on Radioecology and Environmental Radioactivity 15–20 June 2008, Bergen, Norway ; Journal of Environmental Radioactivity, Volume 97, Issue 1, September 2007, Pages 83-84
  9. ^ Commission of the european communities international symposium on radioecology applied to the protection of man and his environment : Rome, 7–10 September 1971 Conference Hall of FAO, Viale delle Terme di Caracalla Water Research, Volume 5, Issue 6, June 1971, Pages 367-368
  10. ^ Radioecology: To understand the evolution of radioactivity in the environment, IRSN Corporate Publications: IRSN's thematic booklets, 2001, Page 2
  11. ^ R.W. Mayes (1989), The quantification of dietary intake, digestion and metabolism in farm livestock and its relevance to the study of radionuclide uptake  ; in Transfer of Radionuclides to Livestock (Oxford, 5–8 September 1988) ; Science of the Total Environment ; Vol 85, September 1989 ; (abstract)
  12. ^ D. Jackson, A.D. Smith (1989) Uptake and retention of strontium, iodine and caesium in lowland pasture following continuous or short-term deposition ; Pages 63-72, in Transfer of Radionuclides to Livestock (Oxford, 5–8 September 1988) ; Science of the Total Environment ; Vol 85, September 1989 (abstract)
  13. ^ Bennett, A. Bouville, Radiation doses in countries of the northern hemisphere from the chernobyl nuclear reactor accident ; Environment International, Volume 14, Issue 2, 1988, Pages 75-82 B.G.
  14. ^ R.J. Pentreath, Radioecology, radiobiology, and radiological protection: frameworks and fractures ; Journal of Environmental Radioactivity, Volume 100, Issue 12, December 2009, Pages 1019-1026
  15. ^ Antoine Debauche, Continuous radioactivity monitoring systems. From the pre-history of radioprotection to the future of radioecology ; Journal of Environmental Radioactivity, Volume 72, Issues 1-2, 2004, Pages 103-108

Further reading[edit]

  • Eric Hall (2006), Radiobiology for the Radiobiologist, Lippincott.
  • Whicker and Schultz (1982), Radioecology.

External links[edit]