Southern California residents can take it easy. State health officials have decided to more than triple the number of potassium iodide (ki) pills distributed among communities around the state's two nuclear plants. The decision comes after health experts and residents near the San Onofre and Diablo Canyon nuclear power stations expressed concern over a shortage of the medicines. At least 400,000 pills will be given within a 16-kilometre radius of the plants in San Luis Obispo county and the border of southern Orange and northern San Diego counties.

Although no specific threats have been issued against any of the 103 nuclear plants in the us, federal officials apprehend the risk of an attack or an accident spreading radioactive contamination over wide areas.

ki is added to table salt to make it iodised. It contains about 76.5 per cent iodine.The medicine is sold over the counter and considered safe and effective in shielding the thyroid from the effects of radioactive iodine after an accidental radiation release or act of terrorism.