A ray of hope emerges if one sees the response of wildlife to radiation exposure in the exclusive zone of 30 km radius around the 1986 Chernobyl nuclear reactor explosion in Ukraine. But the jury is still out on the final word on the full impact on animals found to be flourishing in the exclusive zone. More than a hundred radioactive elements were released into the atmosphere that contaminated the surrounding areas. While most of these elements decayed quickly because of their short half-life, a few like Caesium-137 and Strontium-90 with ~30 years half-life still linger around. Short duration exposure to these radiations are tolerable but for longer time it is known to cause leukaemia and can affect the entire body especially liver and spleen.
From time-to-time scientists capture animals to study the effects of radiation on their bodies. Numerous camera trapping operations have shown that Chernobyl Exclusion Zone has grown a healthy population of large mammals like, grey wolfs, European badgers, wild boars, Roe deer and even moose. The smaller mammals include, Eurasian beavers, least weasels and voles and some flashy bird’s species like the black storks and enormous white-tailed sea eagle. In addition to this native wildlife, several of the other Eurasian mammals like the European bison and wild Przewalski’s horses that were involuntary released into this zone are happily thriving and animals not seen over a century in this region are returning like Eurasian lynx and brown bears. DNA of several hundreds of feral dogs reveal that they are the descendants of dogs that were either present at the time of accident or that settled in the area shortly afterwards.
Certain bird species show development of higher levels of antioxidants that protect them from the radiation-induced environment. Several insects and spiders have shown much more resilience with no significant declines in their populations. One common deviation that is observed is albinism, a congenital recessively inherited lack of melanin pigment in animals, manifested by the absence of the inherent colour of the skin, hair, wool, iris and pigment membranes of the eyes. However, long term radiation exposure are still being studied.
But Bikini Atoll incidence always gives us hope. This Pacific Island was the test ground where USA conducted 23 nuclear tests sixty years ago evacuating the entire atoll population as soils were too contaminated by radiation. But slowly, atoll’s ecosystem has clearly recovered, even though the wounds are still far from fully healed. Corals repopulate coastal areas now and the development of these reefs attracts many animal species – invertebrates, fish and even sharks; sharks being apex predators, their presence is a sign of a healthy ecosystem. This is great news and shows that even when an environment is devastated, it can regenerate commanding great admiration for our resilient nature.
While admiring our mother Nature’s resilience that is at work in Chernobyl, it compels me to ponder, “was the sheer presence of humans worse for the environment than even a catastrophic nuclear disaster” A food for thought.
Dr. R K Chadha
