Humans, plants, and all living species are parts of the environment. All of them need either plain lands, highlands/mountains, woods or a water body to live with and to flourish with their own characteristics and specialties. At the same time, to maintain good health, all of them need pure air, water, soil, and sufficient light. However, when the environment is polluted, it becomes very difficult to maintain life.
The Industrial Revolution, technological development towards modernization, environmental pollution activities like the use of fossil fuels, uncontrolled use of plastics and heavy metals, noise and light pollution, use of deadly arms & weapons etc., are creating an environmental crisis imposing severe and irreversible damage to the world and also posing extinction problems for many species.
But we know human activity is overwhelmingly the primary driver of environmental degradation. Without there being any humans, how much safe nature is, can be proved by focusing on the most devastating nuclear accident in history at Chernobyl. The Chernobyl Nuclear Power Complex, lying about 130 km north of Kyiv, Ukraine, and about 20 km south of the border of Belarus, was built during the 1970s and 1980s and consisted of four nuclear reactors. But on 2nd August 1986, one of the reactors accidentally caught fire and at once a vigorous explosion took place as there were some serious faults in the design and construction of the reactors. Immediately after the explosion, radioactive debris of fuel and reactor components rained over the area, toxic fumes and dust were carried by the blowing wind, bringing fission products and other gases with them and fire spread over a vast area. The cloud of radiation spread first across the local area, and eventually over large parts of Europe.
The explosions killed two plant workers at once. 31 more people died within one month, from radiation exposure or other direct effects of the disaster. Also, within next few years, about 4000 more people died of radiation-related hazards and toxicity. Open areas, water bodies, green fields, forests, and farmland become contaminated with very high doses of radiation. About 144,000 hectares of agricultural land and 492,000 forest area were contaminated. Over 100,000 people were forced to evacuate from the area around the plant, with many others relocated later. Dozens of towns and villages were left crumbling and abandoned.
The then authority of the Soviet Union marked a 2800 square kilometer area around the accident site as being most affected, is not suitable for human inhabitants, and declared it as the `Exclusion Zone’.But scientists keep that area under constant surveillance and continue to do research on the devastating effects of radiation on the environment.
Besides human beings, thousands of domestic and wild animals died of the immediate effects of radiation.Those that escaped death were either culled off due to fear of being contaminated or removed to safer areas. Wildlife in the nearby forest areas showed deterioration in health condition for about six months. Water being contaminated, the aquatic life of freshwater and forest areas was also badly affected.
Large trees, plants, flora, and fauna of a vast area also became highly contaminated by the direct deposition of radiation on the plants or absorbed from the air. If the soil and water become contaminated, that radiation may also contaminate plants in the long term, primarily through uptake via the roots, which eventually spreads out to their fruits, adding threats to human and other animals’ health. After the devastating accident of Chernobyl, a lot of plants, trees, birds, and animals became contaminated by this process. Chernobyl was a land of pine trees. After the accident, radiation caused the leaves of thousands of trees, including the pine trees, to turn a rust color, giving a new name to the surrounding woods: the ‘Red Forest’. All the burnt or contaminated trees were cut down and buried to reduce radiation hazards.
Radiation through mutation increases the probability of distorting or altering hereditary trends and characteristics. After the Chernobyl accident, the contaminated animals were seen to give birth to an increased number of deformed offspring. Some of them were so badly affected that they succumbed at once or after a few days. Later on, the animals with birth defects were seen to have fertility problems. Still around the accident area, some animals born with birth defects.
Oncespread out into the environment radiation level comes down quickly due to some environmental effects and also by self-decaying process. Radiation emitted by Short half-life radioactive substances reduces very quickly, while for long half-life substances the process is very slow and continues for a long time, keeping the place contaminated.
In the Chernobyl accident, at once a huge amount of radiation was emitted but radiation levels from soil, water, and wind of the affected area started to reduce very fast. Within a month, the radiation level had reduced by only a few percent, and within a year, it came down to less than 1%. But substances with a higher half-life will continue to harm the nature for years to come.
Nature has a fantastic ability to bounce back after a catastrophe, and the natural surroundings of Chernobyl were no different. If human inhabitants and their activities that pose big burdens on nature could be controlled or reduced, the nature would flourish using its own power and generosity. After the initial trauma of the accident, Chernobyl started the healing process slowly, and within a couple of years, the undisturbed, calm, and haunted area was soon covered with thick forest. Animals from less affected areas started to come back to this area, a new generation came out, small and large mammals, amphibians, fish of different species, a huge variety of worms and insects made their safe home there, and soon the area became a wonderland of biodiversity.
Scientists from Russia and England found that the land surrounding the plant, which has been largely off limits to humans for three decades, has become a haven for wildlife, with boar, elk, and roe deer populations exploding between 1987 and 1996, wolves were so plentiful that the numbers were seven times higher. Within the disaster region, grizzly bears, wolves, lynx, buffalo, deer, elk, beavers, foxes, bison, wild boar, raccoons, dogs, and over 200 species of birds have developed their own ecosystem. It became home to a variety of frogs, fish, worms, and germs, in addition to the larger species. Within a couple of years, mammal populations reached the same level comparable to those in the other natural reserves in the region. Research on 400 different species revealed that some of them were healthy, breeding successfully, also there was evidence that the animals had long lives. It seems that mutations have affected the populations, but not enough to stunt large-scale growth. Researchers also recorded hundreds of plant and animal species in the zone, including more than 60 rare species.
From these observations, scientists started to think that animals and plants may be more resilient and adaptable to radiation, that is why, with some changes in body structure and functional characteristics, they had made the way to survive in the harsh conditions of radiation (more research is needed in this regard). According to them, wildlife is flourishing in the affected area, not because radiation is good for the ecosystem, but because of the virtual absence of human activities that threaten the lives from being surviving and flourishing.
The disaster area of Chernobyl, which was once declared as Exclusion Zone (CEZ), now represents the third-largest nature reserve in mainland Europe. Forests full of diversity and beauty, an abundance of wildlife, and biodiversity have made the area very attractive to tourists. For the last few years, on average, 0.1 million tourists per year from different parts of the world have come to Chernobyl to visit the world’s largest nuclear disaster site together with its biodiversity.SergiyZibtsev, a forestry expert at the National University of Life and Environmental Sciences of Ukraine, says “it’s ironic that it’s taken a devastating nuclear accident to create a richer forest ecosystem and biodiversity”.
But it is a matter of regret that the recent war between Russia and Ukraine has posed a threat on this natural wealthsqueezing the research opportunities. However we should not forget if we want to sustain human life in this world and like to live a life with peace and happiness, we must constrain ourselves from battle and war and should take measures to protect the environment, take protection against all sorts of pollution and maintain ecological balance.
Prof. Dr. Zakia Begum, Nuclear Physicist and Professor, Eastern University,Savar, Dhaka, Bangladesh.
