We present a study on the 1,3Se, 1,3P° and 1,3 De He resonant states below the He+ (N = 2) threshold under the influence of a plasma environment, when the Debye screening length is varied. The interaction between all charged particles is modeled with Yukawa-like screened Coulomb potentials. We make use of the Feshbach projector method to characterize resonant states, implemented by using explicitly correlated CI-wave functions.