Question

tall smokestacks were built due to the theory \dilution is the solution to pollution.\ it caused local air quality to improve, but what problems did it cause? decreased air quality downwind improved global air quality

Explanation:

When tall smokestacks are built based on the "dilution is the solution to pollution" theory, while local air quality may improve as pollutants are carried away from the immediate local area, the pollutants are still in the atmosphere. They can be carried by wind (downwind) to other regions. This leads to decreased air quality in those downwind areas as the pollutants accumulate there. It does not improve global air quality because the total amount of pollutants in the global atmosphere remains the same (or may even increase if more pollutants are emitted due to the false sense of'solving' pollution locally by dilution).

Answer:

Decreased air quality downwind.