"Smoke pouring into the air from a Pittsburgh steel mill, 1906. Each month the steam boilers and furnaces of its industries, railroads, and homes dumped 100 tons of pollutants on its streets." Steel was the main component in the Model-T. One of the largest industries for steel was the automotive industry. Once a middle class friendly automobile was made, more and more vehicles were being designed using more resources and polluting the air further.