The destruction of a large Ukrainian dam across the Dnipro River in 2023 did more than flood Ukrainian villages. It also triggered a “toxic time bomb” of environmental harm, according to a new  study. Host Carolyn Beeler speaks with river scientist Oleksandra Shumilova of the Leibniz Institute in Berlin, co-lead author of the study about the threat to the environment posed by thousands of tons of heavy metals exposed when the Kakhovka dam was blown up by Russian forces.