Ali Hewson and Adi Roche are marking the 21st anniversary of the Chernobyl disaster with 21 children in Dublin this afternoon.
Ms Roche, executive director of Chernobyl Children's Project International (CCPI), and Ms Hewson will be at the Shelbourne Hotel, where the world's worst environmental disaster will be remembered.
One of the children, who are all pupils at St Mary's School in Trim, is Raisa Carolan, who was affected by the Chernobyl explosions with damaged legs and a cleft in her palate.
On this day in 1986 at 1.23am, operations at a power plant in Chernobyl went wrong, resulting in a nuclear power surge that was 100 times the reactor's maximum.
The disaster resulted in multiple nuclear explosions that released fatal quantities of radiation into the atmosphere.
Some 70 per cent of the radiation fell onto the population of Belarus, and the fallout has affected western Russia and northern Ukraine, afflicting around seven million people, most of whom were children.
Chernobyl Children's Project International said that the consequences of the fallout will not be fully seen "for another 50 years".
The UN estimated that the area contaminated by radiation covers an area the size of England, Wales and Ireland.