As mentioned in my previous post, Chernobyl is now home to many animals species. This also ties back to my point made in a post early on that we should not only be concerned about the impacts of radiation pollution on humans, but also to the larger environment around us. Hence this post is dedicated to all those creatures who now inhabit a contaminated zone that little people reside in.
Here is a video I found online from the New York Times that touches briefly on how biologist, Timothy Mousseau, conducts studies on animals/insects to study the effects of radiation:
Some points mentioned:
- Abundance of many species of birds are depressed, leading to an overall decrease of biodiversity
- Higher frequency of tumours and physical abnormalities e.g. deformed beaks of birds
- Decline in population of insect and spiders
One interesting point noted at 4:15: “The frequency of colour patterns on the back sides of the bugs is directly proportional to how radioactive the area is.” In the video, those bugs are red fire bugs that have a distinctive pattern of black spots and shapes on their bright red back. Yet some had abnormal markings. It turns out that the frequency of abnormal colour patterns was highest in the more radioactive areas, while most bugs in uncontaminated areas had normal colour patterns. Because the pattern of spots is controlled by the fire bugs’ DNA, the abnormalities suggested genetic mutations had occurred. As such, biota can serve as indicators to environmental changes, in this case, an indication of radiation levels.
In another article that can be found here, Mousseau also utilises what he calls “standard ecological techniques” – plotting “line transects” through selected areas and counting the numbers of insects and spiders webs they found along that line. At the same time, the researchers held dosimeters (a device used to measure an absorbed dose of ionising radiation) to monitor radiation levels. The result? The numbers of organisms declined with increasing contamination.
Thriving or dying wildlife?
If you have read my previous post on the thriving wildlife in Chernobyl, you may think that my post here today is rather contradictory. However, this is reflects the multiple results from studies done on wildlife and organisms in Chernobyl today. Some researchers claim that the lack of human activity in the exclusion zone of Chernobyl has been beneficial for wildlife. But perhaps, such privilege is only accorded to certain species with tolerance high enough to maintain biodiversity.
Adaptability of wildlife is one point that researchers have tried to put across. In 2005, researchers from Texas Tech University and West Texas A&M University conducted a study on mice in the exclusion zone. They found out that the mice displayed adaptation to the radiation exposure, producing more amounts of proteins and enzymes that repaired DNA that were broken by the radiation. These also countered the ill effects of radiation-created oxygen radicals which can cause cell damage and disease.
Hence, there are two schools of thought that exist on what radiation exposure does to living things:
- Upon long-term radiation exposure, a living thing e.g. plant or animal will ultimately die from the exposure
- Regular exposure to radiation may help plant or animal cells respond to a radioactive environment in a positive way
The second response is also known as radiation hormesis.
An article by Luckey (2006) talks of hormesis as the stimulation of any system by low doses of any agent. Radiation hormesis is thereby the stimulation, often considered to be beneficial, from low doses of ionising radiation. Examples of which include the use of ionising radiation in physiology, medical diagnosis and therapy. But Luckey also acknowledges that many research papers show that low dose radiation of exposure to radiation is stimulatory and/or beneficial in a wide variety of microbes, plants, invertebrates and vertebrates.
Some thoughts of mine:
This is certainly enlightening, to know that some wildlife thrive in Chernobyl because of the radiation levels still present. While I understand that some doses of radiation may be beneficial to the human body, as of therapy in chemotherapy and all, I have never thought of how this may affect the bodies of animal species! I guess this thereby goes to show how there is a tendency for humans (or rather just me) to look at pollution from an anthropocentric perspective. But we are surrounded by so much wild life around us and we should also look to them for clues to better understand the environment around us!
Thanks for reading!
Davis, J. (2011, April 26). 25 YEARS LATER: AMAZING ADAPTATION IN CHERNOBYL. Retrieved March 11, 2015, from Texas Tech Today: http://today.ttu.edu/posts/2011/04/25-years-later-amazing-adaptation-in-chernobyl
Fountain, H. (2014, May 5). At Chernobyl, Hints of Nature’s Adaptation. Retrieved March 11, 2015, from The New York Times: http://www.nytimes.com/2014/05/06/science/nature-adapts-to-chernobyl.html?_r=0
Gill, V. (2009, March 18). Chernobyl ‘shows insect decline’. Retrieved March 11, 2015, from BBC News: http://news.bbc.co.uk/2/hi/science/nature/7949314.stm
Luckey, T. (2006, September 27). Radiation Hormesis: The Good, The Bad, and the Ugly. Dose Response, 4(3), 169-190.