Observations of lithospheric Q for shear waves in the range 1--30 Hz reported in the literature are examined using a scattering model consisting of randomly distributed spheres. For the single scattering approximation I have assumed 1/Q = 1/Qi+gv/&ohgr;, where Qi is the intrinsic Q due to anelasticity, v is the velocity of shear waves, &ohgr; is angular frequency and g is the turbidity. g is taken as a constant in this paper, since g = F n(a)&sgr;da, where n(a)da is the number of scattering spheres of radius a/unit volume and &sgr; is the scattering cross-section for a sphere, this suggests that geometrical scattering dominates. This will be true for ka>1, where k is wavenumber. Based on this criterion and the observation that Q is large (i.e. g small) at a frequency of 0.05 Hz, a is of the order of magnitude 1--10 km. Fits of observations of shear wave Q from Japan and Central Asia indicate that Qi = 2000¿500 for the lithosphere of both regions; g = 0.01 km for the Japan observations and g = 0.005 km-1 for Central Asia.