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Clean Air Act Overview

50th Anniversary of the Clean Air Act

For 50 years, the EPA's Office of Air and Radiation has worked across all levels of government and with private partners to protect our nation's air.  “Today our national air quality is the cleanest since we started recording,” said Anne Austin, Principal Deputy Administratory for the Office of Air and Radiation (OAR). “From 1970 to 2019 emissions of six key pollutants have dropped 77% and the economy has grown 285%, proving that clean air policies and a robust economy can go hand in hand.” 

Reducing power plant pollution and combatting acid rain

Since the 1990 Clean Air Act Amendments, EPA has implemented highly successful clean air market approaches for curbing emissions from power plants to address acid rain and reduce air pollution transported across state lines. From 1990 to 2019, annual emissions of sulfur dioxide from power plants fell by 94%, and emissions of nitrogen dioxides fell by 85%. From the 2000-2002 period to 2016-2018, wet sulfate deposition – a common indicator of acid rain – decreased 86%, and the number of monitored streams and lakes with high levels of sulfur and nitrogen pollution fell by 81%.  

Reducing skin cancer and cataracts by protecting the ozone layer

Through the Montreal Protocol and the Clean Air Act, and in collaboration with many partners, EPA has made great progress in phasing out ozone-depleting substances (ODS) and healing the ozone layer. In 2020 OAR completed the phaseout of all hydrochlorofluorocarbons in new equipment. Full implementation of the Montreal Protocol is expected to prevent 443 million cases of skin cancer and 63 million cases of cataracts in the United States alone. 

Cleaner cars, trucks, and transportation

EPA began setting emissions standards for cars, trucks, and engines in the  1970s. These standards sparked technology innovations that resulted in lower tailpipe emissions and increasingly stringent emissions standards. Today, new passenger vehicles and heavy-duty trucks are 99% cleaner for most tailpipe pollutants compared to the 1970s. Fuels are cleaner – lead has been eliminated, and sulfur levels are more than 90% lower. Average fuel efficiency for passenger cars has gone from 13 miles per gallon in the mid-1970s to an estimated average of 25 miles per gallon in 2019. These achievements have been a major contributor towards the  improved air quality, particularly in U.S. cities that we see today.   

Reducing industrial toxic air pollution

The Clean Air Act requires the EPA to regulate hazardous air pollutants (HAP, also known as toxic air pollutants) from large industrial facilities. Through these efforts, emissions of hazardous air pollutants dropped 74%, from 1990 to 2017.

Promoting energy efficiency, partnering with business, and cutting greenhouse gases

Since 1992 EPA has forged voluntary partnerships with thousands of companies and other enterprises to promote cost-effective ways to increase energy efficiency and reduce air pollution. Through the highly successful ENERGY STAR program and other partnerships, EPA has worked with businesses to remove market barriers, develop tools, offer technical assistance, and serve as a credible voice in defining and conveying best practices. The partnerships are estimated to have cumulatively saved more than $529 billion and avoided over 4.9 billion metric tons of greenhouse gas emissions.

Protecting indoor air and combatting asthma

OAR is a leader in indoor air quality, providing resources to individuals, schools and businesses to help reduce exposure to indoor air pollutants such as mold, smoke and radon.  With federal, state and local partners, we are also building the nation's capacity to control asthma and manage exposure to pollutants linked to asthma. Today, nearly half of all public-school students attend schools that have comprehensive indoor air quality management programs in place, based on EPA’s Indoor Air Quality Tools for Schools program. Since EPA’s Indoor Air and Radon program began 35 year ago, elevated radon levels have been fixed in approximately two million homes, and radon resistant features have been incorporated in over 3 million new homes – estimated to save nearly 2,000 lives each year that would otherwise be lost to lung cancer.

Radiation protection and preparing for emergencies

EPA’s radiation protection programs protect public health and the environment by limiting radiation emissions in air and water through setting environmental regulations, partnering with state, local and tribal authorities, preparing for and responding to emergencies, and promoting adoption of the most current scientific understanding of radiation health effects. With 140 stations in all 50 states, EPA’s RadNet system provides scientists, emergency responders and the public with ambient radiation measurements 24-hours-a-day, seven-days-a-week. EPA sets standards for radioactive emissions from industrial and federal activities and advises federal agencies about radiation matters affecting public health and the environment.

Learn more about the Office of Radiation programs:

Learn about air pollution trends since the implementation of the Clean Air Act: