Our radios utilise a Gallium Arsenide Metal Semiconductor Field Effect Transistor (GaAs MES-FET). Gallium is a byproduct of smelting metals, chiefly aluminium and zinc, and is actually rarer than gold. Gallium Arsenide is a superior alternative to Silicon for producing solid state chips.
This transistor is better at handling multiple strong signals than integrated circuits or bipolar transistors (used in most other radios). The Model One was the first radio to use this technology in an FM tuner.
Please note that almost all electronic devices, including cellular telephones, emit some degree of electromagnetic radiation (EMR), but there have been no scientific-based studies proving this poses a health hazard.