THERE is something baffling about how radiation kills cells. Much of the damage to DNA is caused by low-energy electrons, but no one could work out exactly how, as they are simply too feeble to tear off an atom, or even knock out another electron. Now the puzzle has been solved, and the result should aid the design of more effective radiotherapy.
Electromagnetic radiation or high-energy particles do their damage by breaking the helical backbone of a cell’s DNA, knocking out electrons in the process. Less energetic electrons, especially those with energies of less than 20 electronvolts, were once thought…
