By Katherine Raines
Many imagine Chernobyl to be a nuclear wasteland, where wildlife is struggling to survive or is severely mutated. But this is not the case. Much of the exclusion zone is relatively uncontaminated (with radiation levels close to that of unexposed places) and wildlife is thriving in the absence of humans – with some species having reappeared.
However, some parts of the CEZ have radiation levels high enough to affect wildlife. These areas are predominantly along what is called the North and West Trace, where the wind blew the contamination after the accident. Located on the West Trace, the Red Forest is a 10km² area surrounding Chernobyl and remains the most contaminated area in the CEZ.
Scientists are divided as to whether there are effects on wildlife living in these contaminated areas, with some studies reporting Chernobyl as a refuge for wildlife or, conversely, with serious consequences for the wildlife living there.
Such effects on wildlife following acute radiation exposure are reasonably well understood. But the effects of long-term exposure of lower levels of radiation, as seen currently within the CEZ are still being debated.
When it comes to insects, our research provides insight into the effects of Chernobyl-level radiation dose rates on bumblebees by estimating the impact and determining the shape of the dose-response relationship.
We chose bumblebees for several reasons: first, these insects are essential pollinators so any effects may have consequences for the ecosystem; second, there are studies on the impact of pesticides showing how bumblebees respond to stress; and third, bumblebees are used within the International System for Radiological Protection (ICRP) which sets guidelines for every country to adhere to. However, at the moment there is little data on how bees respond to chronic radiation exposure.
This new data shows effects on bumblebees are happening at dose rates previously thought safe for insects, and the current international recommendations will need to be re-evaluated. It should be noted that the dose rates at which we exposed bumblebees are well above those seen in the environment from practices such as nuclear energy generation and radionuclide therapy used in medical treatment for cancer.
See also Moller & Mousseau, “Reduced abundance of insects and spiders linked to radiation at Chernobyl 20 years after the accident” (2009)
and Moller, Mousseau, and Barnier, “Ecosystems effects 25 years after Chernobyl: Pollinators, fruit set, and recruitment” (2012)