The deleterious effect of environmental pollution on interacting biological populations depends upon the toxicity and the level of pollutant, the sort of damage it causes to the physiological and biochemical systems of the populations and their environment. To study this situation, in this paper, a mathematical model is presented by considering that the growth rate of species and the carrying capacity of its environment are directly affected by pollution and decrease as the concentration of the pollutant increases. After that a solution of this mathematical equation will also obtained with the help of I- function of two variables.