We have observed three radiation-induced lines (A, B, and C) in the collision-induced fundamental infrared spectra of solid hydrogens containing tritium. These hydrogens are T2, DT, D2, HD, and HT at 7 to 9 K. The A line is about 100 cm−1 below the Q1(0, 1) of the corresponding hydrogens. The B line lies at 10 to 20 cm−1 below the Q1(0, 1). The weak C line occurs only in T2 and D2 at a position between the A and B lines. These lines are interpreted as being due to the effect of ions on the molecules of the host lattice (T2, DT, D2, HD, and HT). These ions are formed following the radioactive decay of tritium. The positions of the A and B lines are due to the Stark shift in the host molecules caused by the electric field of the ions. The intensity of the lines yields an ion concentration in pure tritium of the order of parts per million.