It is for the first time demonstrated by means of the three-dimensional electrostatic particle-in-cell simulation that the impurity ion transport caused by blob and hole propagations might not be negligible as compared with other types of transport. The simulations have shown that the impurity ion density profile in the blob/hole structure becomes a dipolar profile and the dipolar profile of the impurity ion density propagates with the blob/hole. Furthermore, the simulations in which the initial impurity ion density has a radial gradient have revealed that the estimated effective radial diffusion coefficient for impurity ions by a single blob/hole is comparable to the Bohm diffusion coefficient.