Use proper barriers to block or reduce ionizing radiation.

Chemically incorporated into a polymer, gold is less poisonous than other heavy metals that also block radiation.

This may be done to prevent electromagnetic interference with other equipment, or even to block radiation re-entering from elsewhere on the same circuit.

Greenhouse gases block outbound radiation at all times of day.

"Near minimum levels for habitable environment, blocking EM and nuclear radiation."

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

The ozone layer blocks ultraviolet radiation from the sun that can cause skin cancer and harm ecosystems.

Average daily maximum temperatures have fallen by 0.014 degrees each year, as air pollution is blocking solar radiation.

Will the use of nanoparticles in sun lotions, whose purpose is to block ultraviolet radiation, cause side effects on health?

The ozone layer is vital to life because it blocks dangerous radiation coming from the sun.