During a summertime inversion, the maximum O3 (ozone) concentration measured in a downtown area of the city is 0.15 mg/m3. The wind speed is 2 m/sec, and the mixing height, H, is 700 meters. The background concentration is 0.05 mg/m3. This downtown area measures 2.5 km x 2.5 km. Estimate the emission rate for the downtown area. Express the answer in units of g/(sec-m2)