There is question like this, but the answer is wrong. So pleasee please solve by use the dispersion coefficients from the table shown below

19. On overcast day a stack with an effective height of 50m is releasing nitrogen oxides at a rate of 80g/s. The wind speed is 6m/s, Determine: a) The mean concentration of SO2, on the ground 500m downwind. b) The mean concentration on the ground 600m downwind and 60m cross wind. c) What are the social and environmental impacts of this release? Table 5-1 Atmospheric Stability Classes for Use with the Pasquill-Gifford Dispersion Model M,2 1,2 TABLE 5-3 EQUATIONS AND DATA FOR PASQUILL-GIFFORD DISPERSION COEFFICIENTS