Indoor & Outdoor Air Quality
Cleaner air protects health at every stage of life.
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The air we breathe has a profound impact on human health. Air quality affects people throughout their lives, influencing respiratory and cardiovascular health, cognitive function, pregnancy outcomes, and overall well-being.
While many people think of air pollution as an outdoor problem, indoor air can also contain pollutants from building materials, cleaning products, cooking, heating systems, tobacco smoke, mold, and other sources. Because Americans spend most of their time indoors, indoor air quality can significantly affect daily exposure to environmental contaminants.
For more than two decades, we have examined how air pollution and environmental exposures affect human health. Through research, education, and policy engagement, we work to advance practical solutions that improve air quality and protect public health.
Why It Matters
Poor air quality is associated with a wide range of health concerns, including asthma, respiratory disease, cardiovascular disease, adverse pregnancy outcomes, and premature death.
Children, older adults, pregnant women, and individuals with underlying health conditions are often particularly vulnerable to the effects of air pollution.
Outdoor air pollution can originate from vehicle emissions, industrial activities, power generation, wildfires, and other sources. Indoor air pollution may result from cooking, heating systems, cleaning products, mold, tobacco smoke, building materials, and inadequate ventilation.
Improving air quality can provide immediate and long-term public health benefits while helping create healthier homes, schools, workplaces, and communities.
What You Should Know
Fine Particulate Matter (PM2.5)
Fine particulate matter, often referred to as PM2.5 (Particulate Matter 2.5, meaning fine particles smaller than 2.5 microns [0.0025 millimeters]), consists of tiny airborne particles that can penetrate deep into the lungs and and the smallest of which can enter the bloodstream. Research has linked PM2.5 exposure to asthma, heart disease, stroke, lung disease, and premature death. Learn more at these websites: EPA, Harvard
Diesel Exhaust and Transportation Emissions
Diesel engines emit fine particles and other pollutants that can contribute to respiratory and cardiovascular health problems. Children who attend schools near heavily traveled roads and individuals who live or work near transportation corridors may experience elevated exposures. Learn more at these websites: California Air Resources Board, NCI
Indoor Air Quality Matters
Indoor air pollution may come from cooking, heating systems, cleaning products, mold, building materials, and inadequate ventilation. Because people spend much of their time indoors, improving indoor air quality can significantly reduce exposure to harmful pollutants. Learn more at these websites: EPA, NLM
Wildfires and Wood Smoke
Wildfires and residential wood burning can produce significant amounts of fine particulate matter and other harmful pollutants. Exposure may be especially concerning for children, older adults, and individuals with asthma or other respiratory conditions. Learn more at these websites: EPA, CDC
Clean Air Improves Health
Reducing exposure to air pollution can help lower the risk of respiratory illness, cardiovascular disease, and other adverse health outcomes. Improving air quality benefits individuals, families, schools, workplaces, and entire communities. Learn more at these websites: WHO, American Lung Association
Our Work
EHHI has examined the relationship between air pollution and human health through research, education, and policy engagement.
Areas of work have included:
- Diesel exhaust and school transportation
- Indoor air quality
- Fine particulate matter (PM2.5)
- Wood smoke
- School environmental health
- Community air quality
- Children's respiratory health
Through reports, educational materials, and policy recommendations, EHHI has worked to increase awareness of air pollution and opportunities to reduce exposure.
Featured Resources
Please download and read these important publications.
Our Recommendations
Improving air quality requires action by individuals, communities, businesses, and policymakers.
National Government
- Strengthen national air quality standards.
- Support air pollution monitoring and research.
- Reduce emissions from transportation and industrial sources.
- Improve public access to air quality information.
State & Provincial Government
- Expand clean transportation initiatives.
- Strengthen air quality protections near schools and residential areas.
- Support programs that reduce emissions from diesel engines and other pollution sources.
- Improve wildfire and smoke preparedness.
Local Government
- Support clean air initiatives in schools and neighborhoods.
- Improve indoor air quality in public buildings.
- Encourage active transportation and public transit.
- Expand community education on air quality and health.
Individuals
You can help reduce exposure to air pollution by:
- Monitoring local air quality forecasts.
- Using high-efficiency air filters (HEPA).
- Improving home ventilation.
Reducing exposure to tobacco smoke and wood smoke. - Supporting clean air policies in your community.
- Participating in local environmental health initiatives.
- Download our Fast Look Checklists for improving indoor and outdoor air quality.
Current Developments
Explore these authoritative websites for the latest developments in emerging research, policy developments, and environmental health issues related to the air we breathe.
- Wildfire Smoke and Respiratory Health: New guidance helps communities reduce exposure during wildfire smoke events. Visit AGU.
- Air Pollution and Respiratory Health: Recent studies continue strengthening evidence linking air pollution with asthma and cardiovascular disease. Visit The Physcological Society.
- Indoor Air Quality Innovations: Schools and public buildings continue adopting improved ventilation and filtration. Visit Harvard.
Frequently Asked Questions
What is PM2.5 and why is it important?
PM2.5 refers to tiny airborne particles that can travel deep into the lungs and bloodstream, contributing to a variety of health problems. Visit EPA, AirNow, and American Lung Association to learn more.
How does air pollution affect children?
Children breathe more air relative to their body weight than adults and have developing lungs, making them more vulnerable to air pollution. Visit EPA and AAP to learn more.
Is indoor air pollution a serious concern?
Yes. Indoor air can contain pollutants from cooking, heating, cleaning products, mold, and building materials, among other sources. Visit EPA and AirNow to learn more.
What can individuals do to improve air quality?
Individuals can improve indoor air quality, reduce exposure to pollutants, and support policies that promote cleaner air. Visit AirNow and American Lung Association (Resources) to learn more.
Download our Fast Look Checklists for improving indoor and outdoor air quality.