On the basis of three-dimensional spectral fluctuation functions of the number density gradient of a passive conservative admixture in the turbulent atmosphere, refraction phenomena are investigated and a model is constructed. Spectra of the refractive index gradient and fluctuation of the refractive angle for the entire range of inhomogeneity scales are obtained. Variances of the incident angle of radio waves for various levels of air pollution are determined. The horizontal and vertical gradients of the number density of a chemical admixture in the troposphere are found from experimental data. Model calculations were carried out for the following substances: NH3, NO2, H2S, and SO2. The influence of water vapor is analyzed. This has made it possible to bring the model more closely in line with real conditions. Comparison with a number of experimental works reveals a high degree of correspondence with actual conditions.