Electron screening of the Coulomb barrier between reacting nuclei leads to an exponential-like enhancement of nuclear cross sections for lowering projectile energies. Recently, this effect has been demonstrated by many groups for the H-2(d,p)H-3 and H-2(d, n)He-3 reactions taking place in metallic environments. The experimental results show a much stronger effect for metals than for gaseous or insulator targets. Similar effects are also expected for radioactive alpha decays. Based on experimental and theoretical results achieved for nuclear reactions and a dynamic approach to the electron screening in the electron gas, an increase of alpha-decay constants of order of a few per cent is anticipated for metallic environments.