A weakly relativistic treatment of absorption and emission at the electron cyclotron frequency and its harmonics is presented in a toroidal geometry characterized by general magnetic-equilibrium surfaces. Dia/paramagnetic effects are included in the toroidal component of the magnetic field. Along the ray trajectory the possible overlapping between different harmonics is taken into account and the wave polarization is computed at the plasma edge. Thermal and non-thermal plasmas are described by an electron distribution function given as a suitable superposition of drifting Maxwellians.