Answer:
Worries over radiation from bomb research and bomb dropping on Planet Earth was the concern that the Venusian expressed in the UFO incident with George Adamski.
Specifically, the incident occurred on November 20, 1952 in the Colorado Desert near the California town of Desert Center. Adamski (April 17, 1891 - April 23, 1965) was picnicking with friends when a submarine-shaped spacecraft appeared in the sky. A smaller scout ship exited from the craft to drop a silver disk and a messenger. It was the messenger who conveyed to Adamski the anxieties of the inhabitants of the planet Venus.