Sun breaks through a line of clouds to a clear blue sky below.

Clean Air

Congress first passed the Clean Air Act in 1963 to ensure that all Americans breathe clean, healthy air and are shielded from airborne pollutants that pose a serious threat to public health. Over the past 40 years, significant progress has been made in addressing air pollution, but major challenges remain. A number of communities around our nation – often populated by disadvantaged residents – continue to be exposed to poor air quality and suffer from unacceptably high rates of cancer, respiratory diseases and asthma. In addition, EPA is only beginning to apply Clean Air Act obligations to sources of greenhouse gases that are causing the scourge of climate change.


The Trump administration undertook a number of initiatives that threatened to undercut decades of progress under the Clean Air Act, to the detriment of public health and the environment. State attorneys general opposed efforts by the Trump administration to undercut smog-forming ozone and toxics air quality standards, to ignore public health harms caused by exposure to pollution from upwind states, and to weaken “new source review” standards that apply when companies invest in major expansions of existing facilities.

State attorneys general also stepped in to stop EPA’s attempts to roll back legally-required reductions on climate change-causing greenhouse gas emissions for the electricity sector (the Clean Power Plan), the automobile industry (the Clean Car Standards) and the oil and gas industry (restrictions on methane emissions). Beyond their impact on efforts to combat climate change, these fights also carry significant public health implications, including their effects on cancer rates and rates of respiratory, neurological and developmental illnesses. More information on these issues can be found within the Climate Action section.