Greater risk from radiation?

Radiation can harm cells even if they don't take a direct hit, according to a new study. Injured cells apparently pass on damage to neighboring cells through gap junctions. The report has raised a ruckus because it suggests that current safety standards may underestimate the hazards from low-level radiation exposure

Although some scientists suspected that radiation damage might spread from cell to cell—the so-called bystander effect—only the development of a technique for targeting individual cells allowed them to confirm the idea. The researchers were able to fire a single α particle at individual cells, so they knew exactly how many cells had absorbed hits. They used the absence of the CD59 antigen on the cell surface as an indicator of mutation. Zapping only 10% of the cells in a solution caused the same number of mutations as hitting...