Final answer:
The Clean Air Act of 1970 permitted U.S. citizens to sue polluters for violations, which represented a significant empowerment for environmental protection and citizen involvement.
Step-by-step explanation:
The Clean Air Act of 1970 was a milestone in environmental regulation in the United States. Among its many provisions, the Act for the first time allowed U.S. citizens to sue polluters for violations of the law. This empowerment was part of a broader movement toward giving citizens a more active role in environmental protection and enforcing the newly established pollution standards set by the Environmental Protection Agency (EPA), which was also created in 1970.
The Act also included provisions for significantly reducing air pollution from industries and vehicles. Automakers, for instance, were required to reduce vehicle emissions by 90 percent, leading to the introduction of catalytic converters and the requirement of lead-free gasoline. These changes brought about a noticeable improvement in air quality and marked the beginning of command-and-control regulations in environmental law.
The creation of the EPA, along with the enactment of the Clean Air and Clean Water Acts, represented a paradigm shift towards proactive and preventative environmental protection strategies. These strategies have had a lasting impact on America's air and water quality, leading to measurable improvements over subsequent decades.