1.   The spacecraft is fitted with a shield to block cosmic radiation.

2.   Beta radiation can be blocked by wood or aluminum.

3.   By blocking ultraviolet radiation produced by the sun, ozone protects human beings from damage to the immune system and increased risk of cataracts and skin cancer.

4.   The use of potassium iodide to block radiation is not new.

5.   The water once cooled the rods but now serves primarily to block radiation from reaching the outside.

6.   Typical defenses against EMP are voltage shields and electromagnetic filters, similar to the wire mesh that blocks radiation inside a microwave oven.

7.   Unless it is in the form of microscopic particles that can be inhaled, she said, its radiation can be blocked by clothing, skin or even paper.

8.   Two years ago, the U.S. Food and Drug Administration approved the first product marketed specifically to block UVA radiation.