If you have warnings from the news that release of radioactive materials has occurred upwind from where you are, you probably have time to take some of the following actions:

• At home, close windows and doors and put you ventilation fan on recycled air. Raise the temperature in your home; expanding air provides positive pressure, pushing air through cracks to the outside. Tape around windows to prevent outside air from entering. Stuff towels under doors, etc. If you have a below ground basement, go to a spot in the corner below ground and remain there unless local police or emergency personnel provide instructions either in person or on the radio to evacuate to a given area. One foot of concrete (solid block) will cut most radiation to one-hundredth so you will very likely not be harmed from radioactive fallout dispersed from either a conventional explosive of the type of nuclear bomb that might be obtained by terrorists. Inviting neighbors to bring supplies and join you will improve, not decrease, your protection.
• Do not evacuate unless instructed to do so by authoritative personnel. You can be more exposed outdoors or in a traffic jam if you are in an area where harmful agents are dispersed into the air.
• If you are in or near a high-rise building, go to a middle floor to use the concrete floors to shield you from radiation coming from the roof or ground or to get away from agents that are probably concentrated near ground level. Within hours, these agents will probably be dispersed by the wind, and you will probably be advised it is safe to venture our for food or to evacuate to a safe location.
• If you are in a department store or place with many people and know that radiation has been dispersed, go to the basement or ground level and get everyone to form a group where individuals take turns standing in the center and the outside. People are mostly made of water, and four to five inches of water will reduce any gamma radiation by a factor of one-half.