We don't know what the present level of radiation is.

There must still be a very high level of radiation.

Once the radiation level becomes too high, we turn back.

We learned later how high the radiation levels were there at the time.

Because a very low level of radiation is involved it may take weeks or even months to produce an image on the film.

The level of radiation from outside was climbing by the hour.

This was probably the cause of the high radiation levels measured.

The radiation levels 70 years ago would have been lethal.

The radiation levels here were high enough to kill him with a few hours' exposure.

It all depends upon the radiation levels, but I wouldn't think we'd land.