radioactivity

Long enough for most of the radioactivity to be gone, it seemed.

The air was clean of radioactivity now, to be sure.

When radioactivity turned up on the surface, they had to figure out why.

The official said the level of radioactivity was low and would not be a health risk.

This is to avoid the take up of radioactivity by the people.

She says radioactivity is the most dangerous thing on earth.

All the more reason to make the increase in radioactivity very slow.

In most radioactivity, the entire mass of something does not get changed to energy.

Certainly enough time had passed for the building to be free of any dangerous radioactivity.

Because of its radioactivity, it is a very poor planet.

She said plans were to remove 95 percent of the radioactivity.

By tonight, federal officials had still not determined the cause of the radioactivity.

Another wanted to bring in soil with low levels of radioactivity.

"You mean, radioactivity will kill us if we try to land on it?"

In practice there is no such thing as zero radioactivity.

This is so long, that its radioactivity can be ignored.

At a nuclear plant, nearly all the radioactivity is created in the process of making power.

It also made other important discoveries possible, such as that of radioactivity.

In that time, radioactivity was thought to have healing effects.

The wind would carry the radioactivity in the other direction.

And how safe is nuclear power - testing for radioactivity.

Then he found himself in an area of high radioactivity (he'd taken along counters).

Radioactivity must have disappeared in a few centuries at most.

So far, all we have are vague stories about radioactivity, and that is not enough.

Some hospitals say they will have to cut back on the use of radioactivity for cancer treatment and in research studies.