The air quality in Phoenix, Arizona
From the moment people arrived here in The Salt River area, they started polluting the air. Just walking around in the desert kicks up a lot of dust. Add horses, and cattle, and you are sending a lot of pollutants into the air! And then when the automobile arrived in 1902, the city proceeded to burn gasoline with no thought of "pollution control". Of course businesses were free to dump as much filthy black smoke into the air as they wanted to.
By the 1970s, the Phoenix, Arizona area had some of the most polluted air in the country, and it fought back. New laws were enacted restricting how much pollution could be dumped into the air. Emission controls were required on new cars, and a system was set up to insure that those controls stayed in place, and were working properly. Construction sites had to watch the amount of dust that they were sending into the air. The list goes on and on.
In the last forty years, attitudes have changed about air quality. Mostly people have started thinking about it.
Posted by Brad Hall