Cool cement blocks are used for pavement construction to mitigate the heat island effect. Cement block pavements in contact with water will produce leachates, which may affect soil, surface water and groundwater quality. Therefore, the objective of this work was to determine and compare the leaching behavior of heavy metals (Cd, Co, Cr, Fe, Mn, Ni, Pb, Zn) from conventional and reflective cool cement blocks using the mass transfer tank leaching test, according to USEPA method 1315 and the batch leaching test as a function of pH, according to method CEN/TS 14429. Comparison of the results of the two tests indicates that equilibrium was not reached during the mass transfer test. In all cases, the Leachability Index values are higher than 8, indicating limited mobility. Observed diffusivity values differ by several orders of magnitude (10−11 – 10−20 m2/s) and are very small, indicating very slow diffusion. Leaching curves as a function of pH were very consistent and close to each other, indicating that the leaching mechanisms were the same for all cement blocks. Α two-domain one-dimensional mathematical model describing heavy metal diffusion from the pavements to the underlying soil was developed and tested. Simulations with this model showed that emissions from reflective cool cement pavements to the underlying soil are not different from the conventional ones in the long run.