Improve the grammaticality of this text: Research had shown that the radioactivity that is produced by the nuclear waste under the ground is equivalent to the radioactivity emitted by the cosmic rays.
The radioactive decay of the radioactive elements in the waste is not the same as the decay of the radioactive elements in the atmosphere. The radioactive decay of the radioactive elements in the waste is not the same as the radioactive decay of the radioactive elements in the atmosphere.
The radioactive decay of the radioactive elements in the waste is not the same as the radioactive decay of the radioactive elements in the atmosphere.
The radioactive decay of the radioactive elements in the waste is not the same as the radioactive decay of the radioactive
The radioactive decay of the radioactive elements in the waste is not the same as the decay of the radioactive elements in the atmosphere. The radioactive decay of the radioactive elements in the waste is not the same as the radioactive decay of the radioactive elements in the atmosphere.
The radioactive decay of the radioactive elements in the waste is not the same as the radioactive decay of the radioactive elements in the atmosphere.
The radioactive decay of the radioactive elements in the waste is not the same as the radioactive decay of the radioactive