Respuesta :
The fact that the left column has less significant change than the one on the right might be because of several factors. As the years pass by, the regulation of air pollutants has improved drastically. Air quality has shown great progress during years thanks to things such as 1-less use of toxic raw material or fuels, 2- less use of polluting industrial processes, 3- controlling transport-related emissions, 4-improvement of clean air technology center gadgets like mechanical collectors and fabric filters, 5- development of control and monitoring strategies.
These shows evidence that it has been a lot of change in the air quality results but the charts show less reducing regulations because there are fewer pollutants in the air. The levels of carbon monoxide, lead and nitrogen dioxide had dropped because there is less of it in the air so the "change" is less because there is less to be changed thanks to the improvement on air polluting regulations.
Answer:
1.Less of a time period, the easy/cheap/fast solutions to pollution might have been used early on in the history of the EPA.
2. Air quality has improved quite a bit since the founding of the EPA. Strict regulations are not as needed now.
Explanation: