In the wake of last fall's E. coli outbreaks, some scientists and businesses are encouraging the Food and Drug Administration to approve the use of bacteria-killing radiation to treat produce such as spinach and lettuce.

Spinach has returned to store shelves after September's deadly E. coli outbreak. NewsHour correspondent Spencer Michels reports from California on what caused the problem and what growers are doing to prevent another one.

Over one-hundred people in at least twenty-one states have become sick by eating spinach contaminated with E. coli bacteria according to the Food and Drug Administration, which advised consumers not to eat any fresh spinach until further notice.