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EPA Research

Milestones in EPA's Air Quality Research History

EPA's air quality research has informed and enabled the nation’s efforts to improve air quality significantly. Here are some of the most important achievements. 
EPA Science Flashback: Air Quality Impacts on Public Health (Video) EXIT
History of EPA Research

1975 - EPA Research on Lime Scrubbing Leads to Lower Sulfur Dioxide Emissions

smoke rising from smokestacksThe National Research Council notes that EPA research has cast important new light on the chemistry of lime scrubbing, setting the stage for successful commercial development of sulfur dioxide scrubbers for coal-fired power plants. The research leads to lower emissions of the air pollutant.
Report on the Status of Lime/Limestone Wet Scrubbing Systems

1979 - EPA Outlines the Environmental Concerns of Acid Rain 

lake lined with evergreen treesEPA releases a research summary outlining the environmental concerns of acid rain in lakes and rivers, caused by emissions of sulfur dioxide and nitrogen oxides. The research to monitor impacts, study the health effects on aquatic life and understand atmospheric processes were crucial to support the 1990 Acid Rain Program established by Congress to reduce emissions impacting aquatic life and ecosystems.

EPA's Research Summary on Acid Rain
EPA’s Acid Rain resources

1988 - Research on Nitrogen Oxides Leads to Cleaner Emission Standards

Coal fired furnaceEPA research uncovers the mechanisms responsible for formation of nitrogen oxides (NOx) from fuel-bound nitrogen in coal. This discovery allows the development of low-NOx burners that enable more protective emission standards for coal-fired boilers under the Clean Air Act Amendments of 1990.

EPA's Clean Air Markets resources

1988 - EPA Studies Effects of Ozone Exposure on Lungs 

man jogging EPA begins research that demonstrates prolonged exposure during exercise to ozone results in lung function decrements, respiratory cell damage, respiratory tract inflammation, and respiratory symptoms at low levels. The findings formed the basis for revisions of the National Ambient Air Quality Standard (NAAQS) for ozone. Ozone research by EPA and grantees has made significant contributions to the Congressionally mandated reviews of the ozone standard over the years that have protected public health.

Research on Health and Environmental Effects of Air Quality

1992 - EPA Identifies Alternatives for Chlorofluorocarbons and Hydrochlorofluorocarbons 

aerosol can spraying a model of EarthEPA research identifies alternatives for chlorofluorocarbons and hydrochlorofluorocarbons, both classes of stratospheric ozone depleting substances that resulted in the so-called ozone hole. The alternatives are evaluated for their ability to maintain engineering performance while reducing risk to stratospheric ozone and global climate change.

Ozone Layer Protection

1992 - EPA Conducts Health Risk Assessment on Passive Smoke Effects 

hand holding a lit cigarette near a childEPA completes its risk assessment on the respiratory health effects of passive smoking. The report concludes that exposure to environmental, or secondhand, tobacco smoke is responsible for approximately 3,000 lung cancer deaths each year in nonsmoking adults and impairs the respiratory health of hundreds of thousands of children. The risk assessment provides the scientific basis for EPA to declare secondhand smoke as a carcinogen.

The Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders

1994 - EPA Develops Radon Mitigation Technology 

Radon symbol (Rn) surrounded by toy housesRadon is a cancer-causing radioactive gas found naturally in the environment.  It comes from the natural decay of uranium that is found in nearly all soils. It typically moves up through the ground to the air above and into homes and other buildings through cracks and other holes in the foundation. Radon mitigation technology developed by EPA researchers has been installed in over 300,000 homes, preventing an estimated 100 premature lung cancer deaths.

EPA's Radon resources

1997 -EPA Issues New Air Quality Standards for Particulate Matter

smoke rising from smokestacksEPA issues new air quality standards for fine particulate matter (PM), based on scientific findings by EPA, research grantees and others that the air pollutant is harmful to public health. Research on PM by EPA and grantees over the years has found the pollutant has adverse effects on the lungs and cardiovascular system. The science has supported the congressionally mandated review of the PM standards to protect public health.  

EPA's Particulate Matter (PM) Pollution Resources

1998 - EPA Develops Method for Measuring Fine Particulate Matter 

Sun partially hidden by smogEPA develops the Federal Reference Method for measuring fine particulate matter (PM2.5) that assists state regulators in meeting the National Ambient Air Quality Standards (NAAQS). Many Federal Reference Methods have been developed to support the implementation of the NAAQS.

EPA scientists develop and evaluate Federal Reference & Equivalent Methods for measuring key air pollutants

1998 - EPA Releases Community Multiscale Air Quality Modeling System 

CMAQ LogoEPA releases the first version of EPA’s Community Multi-scale Air Quality (CMAQ) modeling system. CMAQ is continually updated and is a premier global-to-local air quality modeling system used worldwide to support air quality management. States in the U.S. use CMAQ to develop and assess implementation actions to attain the National Ambient Air Quality Standards.

CMAQ: The Community Multiscale Air Quality Modeling System


2000 -EPA Research Shows Cardiovascular Effects of Particulate Matter  

PM2.5 Scale GraphicEPA demonstrates particulate matter (PM)-induced changes in lung inflammation and blood clotting components as well as changes in heart rate variability in humans. The data provided biological plausibility of PM-induced health effects observed in epidemiological studies and contributed to the revision of the National Ambient Air Quality Standards. A large body of research by EPA and others has provided confirmation and insight into the effects of PM on the cardiovascular system.

EPA's Healthy Heart Toolkit and Research

2001 - EPA Conducts Air Quality Monitoring Following World Trade Center Attack on 9/11 

blue lights marking location of former World Trade CenterEPA scientists played a key role in the nation’s response to the September 11, 2001 terrorist attacks on the World Trade Center in Lower Manhattan by conducting toxicity studies of settled dust and air quality measurements, and setting up monitors to collect air quality data in and around Ground Zero, protecting the health of emergency workers and citizens.

EPA’s Response to September 11
EPA's Homeland Security Research

2004 - EPA Launches First National Air Quality Forecasting Capability 

AirNow screenshot showing air quality across the US.EPA and the National Oceanic and Atmospheric Administration combine meteorological, emissions, and air quality modeling tools to launch the first national air quality forecasting capability-- initially for ozone, and later for fine particulate matter. The work supported the development of, a multi-agency resource to provides daily air quality conditions and forecasts for over 400 cities using the air quality index.

Air Quality Index

2009 - EPA Publishes Greenhouse Gases Endangerment Finding 

Global Change CoverEPA publishes a report and an accompanying synthesis article that describes the potential effects of climate change on regional air quality in the United States. These products were the culmination of nearly a decade of EPA-led research and a major scientific pillar of the 2009 Endangerment Finding, which states that greenhouse gases pose an endangerment to public health and welfare and are therefore air pollutants that need to be addressed under the Clean Air Act.

Assessment of the Impacts of Global Change on Regional U.S. Air Quality: A Synthesis of Climate Change Impacts on Ground-Level Ozone
A Preliminary Synthesis of Modeled Climate Change Impacts on U.S. Regional Ozone Concentrations
Endangerment and Cause or Contribute Findings for Greenhouse Gases under the Section 202(a) of the Clean Air Act

2010 - EPA Supports Development of Clean Cookstove Technologies 

Cookstove ResearchEPA supports the Clean Cooking Alliance, a public-private alliance that addresses one of the greatest threats facing developing countries and their populations - extraordinarily high exposures to toxic smoke from indoor fires and inefficient cookstoves that lead to nearly two million deaths each year, primarily in young children and women. EPA scientists conducted studies to evaluate cookstoves and provided extensive data on cookstove emissions and energy efficiency to support the development of cleaner sustainable cooking technologies.

Clean Cookstove Research 

2011 - EPA Collaborates in DISCOVER-AQ with NASA and Others

DiscoverAQEPA collaborates in DISCOVER-AQ with NASA and others to better understand how to measure and forecast air quality globally, via satellite data from space. Ongoing studies, with support from EPA, are helping to advance measurement of air pollution using spaced-based instruments, including NASA’s upcoming Tropospheric Emissions: Monitoring Pollution (TEMPO)  mission.

DISCOVER-AQ: Tracking Pollution from the Skies (and Space!)

2012 - EPA Publishes Climate Change Impacts to Watersheds 

Watershed Report CoverEPA publishes a report that summarizes climate change impacts to selected watersheds and recommendations for how to improve the process of conducting watershed assessments in the future.

Climate and Land-Use Change Effects on Ecological Resources in Three Watersheds: A Synthesis Report


2012 - EPA Supports the Development and Evaluation of Emerging Air Sensor Technology 

Air Monitoring SiteEPA scientists begin an initiative that is advancing emerging air sensor technology by conducting performance evaluations of sensors and providing best practices for effectively using sensors. These portable and lower-cost air sensors have increased in popularity with the public as a way to learn about local air quality conditions. One of the first efforts was the Village Green Project. It engaged the public in air quality with a near real-time air monitoring system built into a park bench. In 2014, the online Air Sensor Toolbox for Citizen Scientists was developed to share information with developers and users of air sensor technology. 

EPA's Air Sensor Toolbox

2017 - EPA Develops First Fenceline Monitoring Regulation 

Fenceline MonitorAs part of the Next Generation Emissions Measurements (NGEM) initiative to reduce costs and regulatory burden through technology, EPA’s first fenceline monitoring regulation (Method 325) was developed for chemical facilities emissions. The technology supports implementation of EPA’s refinery fenceline rule. Researchers continue to advance fenceline monitoring technology with the development of prototype air measurement monitors.

Studies Advance Air Monitoring During Wildfires and Improve Forecasting of Smoke


2017 - EPA Launches Smoke Sense Project and Mobile App

Smoke Sense LogoEPA researchers launch a citizen science research project called Smoke Sense, along with a Smoke Sense mobile app, to advance understanding of the health impacts of wildfire smoke and provide individuals with critical information to protect their health during smoke events. The app can be used to explore current and forecast maps of air quality and learn ways to reduce exposure from smoke. It also enables people to participate in science by recording smoke experiences, health systems and actions taken to reduce smoke exposure.  The research project will be used to support the development of effective strategies to communicate health risks from smoke exposure.  

Smoke Sense Study: A Citizen Science Project Using a Mobile App

2019 - EPA Identifies Wildland Fire Research as a High Priority

Balloon Used In Wildfire ResearchFollowing earlier research to understand emissions and health impacts of wildfires and prescribed burns, EPA designates wildland fire research as a high priority and publishes a report to guide additional research on the impacts to air and water quality, health and ecosystems from  larger and more intense wildfires occuring, primarily in western states.

EPA's Wildland Fire Research Framework 2019-2022
EPA's Wildland Fire Research to Protect Health and the Environment

2020 - Five Years of Progress in Household Energy Research

Five Years of Progress in Household Energy and Clean Cookstove Research Research between 2015-2020 advanced the science to characterize emissions, exposures and related health and environmental impacts of the use of solid fuels such as wood and charcoal for cooking, heating and lighting. The research addresses the global public health and environmental impacts from these emissions. 

Household Energy and Clean Cookstove Research

2020 - Studies Published on Air Quality and Cardiovascular Disease

Studies Published on Air Quality and Cardiovascular Disease Four key research articles offer new insights into the health effects of fine particulate matter (PM2.5) on the cardiovascular system, especially for those with heart disease.


2020 - AirNow Sensor Data Pilot Provides Additional Information on Wildfire Smoke

Fire and Smoke Map from AirNow.govEPA researchers developed a U.S.-wide correction equation and quality control checks to make air sensor data on local air quality during wildfire and other high pollution events available on the AirNow Fire and Smoke Map.


2020 - Novel Next Generation Emissions Measurement Method Tested

Rubbertown image for milestonesEPA and the City of Louisville Metro Air Pollution Control District (LMAPCD)  in Kentucky collaborated on a project in an industrial area, known as “Rubbertown,” to evaluate emerging measurement approaches for select hazardous air pollutants and volatile organic chemicals (VOCs) using EPA Method 325B.


2020 - Research Improves Understanding of How Everyday Products Impact Air Quality

Research Improves Understanding of How Everyday Products Impact Air Quality Through modeling, researchers find that the contribution to air pollution from Volatile Chemical Products (VCPs) in personal care products, cleaning agents, paints, adhesives, and pesticides has been underestimated.  VCPs emit volatile organic chemicals that are important precursors for air pollutants such as ozone and fine particles (PM2.5).

Journal article

2020 - Modelers Study Airborne PFAS Emissions

Modelers Study Airborne PFAS Emissions Atmospheric modelers simulated the transport and chemistry of Per- and Polyfluoroalkyl Substances (PFAS) air emission compounds from a North Carolina manufacturing facility, representing the first study of the fate of chemically resolved total PFAS air emissions from a manufacturing source.

Journal article

2020 - Measurement Technique Developed to Measure Greenhouse Gas Emissions from Reservoirs

Measurement Technique Developed to Measure Greenhouse Gas Emissions from Reservoirs EPA researchers adapted a measurement technique that is widely used for monitoring greenhouse gas emissions from terrestrial ecosystems to measure methane emissions from reservoirs. The method is improving estimates of this gas from reservoirs in the U.S. and globally.

Journal article

2020 - Ozone Measurement Methods Studied During Smoky Conditions

Ozone Measurement Methods Studied During Smoky Conditions EPA and other federal partners identified issues associated with the operation of ozone monitoring methods in smoke from wildfires and prescribed burning. Results provide state and local air quality agencies with additional monitoring information to address ozone measurement challenges in areas frequently impacted by smoke.

Journal article

2020 - Two Reports Published on Air Sensor Performance Targets and Testing Protocols

Two Reports Published on Air Sensor Performance Targets and Testing Protocols Two EPA reports outline step-by-step testing protocols for ozone and PM2.5 air sensors to provide a consistent set of performance targets and testing procedures for non-regulatory, supplemental and informational monitoring that can be used by sensor developers, manufacturers and testing organizations.

Air Sensor Performance Reports

2020 - Biomarker Identifies Health Outcomes in Neighborhoods Impacted by Environmental Stressors

City Landscape of DetroitResearch shows a molecular biomarker for mortality risk increases in people living in disadvantaged neighborhoods with abandoned cars, poor streets, and non-art graffiti. The biomarker may be a possible early indicator of other environmental stressors such as air pollution.

Journal article