On average, Americans spend 90% of their time indoors, whether that be at home, at work, or in school. As such, the air quality inside of buildings can have a profound impact on human health and wellbeing. Indoor levels of pollutants are often two to five times greater than outdoor levels (and up to 100 times in extreme cases). Driven by factors such as inadequate ventilation, building materials, cleaning products, everyday activities that involve fuel-burning (like cooking or heating), and outdoor air quality, exposure to indoor air pollutants can make up a significant portion of total pollutant intake.
Some of the most common indoor air pollutants include particulate matter, mold, nitrogen dioxide, radon, secondhand smoke, carbon monoxide, aerosols, and volatile organic compounds. Individually and in combination, these indoor air pollutants are associated with a broad range of adverse health outcomes, particularly among children, the elderly, and those with preexisting health conditions. Most prominently, poor indoor air quality (IAQ) has been linked to respiratory illnesses—including asthma and lung cancer. In 2020, indoor air pollution was responsible for an estimated 3.2 million deaths.
Indoor pollutants have also been found to exacerbate existing health problems. For example, studies in Baltimore, Maryland, found that children with asthma exposed to greater levels of nitrogen dioxide and particulate matter indoors were more likely to experience greater asthma symptoms and other issues that limited their activity.
Building on decades of work by the Environmental Law Institute (ELI) and other organizations committed to improving IAQ, recent months have brought renewed momentum and collaboration across the IAQ community. The workshop, global pledge, and guidebook detailed below are all important elements of a growing, worldwide network in which IAQ leaders are coalescing and collaborating more than ever to elevate a simple truth: indoor air has a much larger impact on public health than our existing policies and programs reflect—and it is time to act.
ELI’s Indoor Environments Program & Workshop for IAQ Officials
Despite its vital importance to our health and productivity, indoor environmental quality is not regulated by the federal government, meaning state and local governments fill this critical role. For this reason, ELI’s Indoor Environments Program has worked to equip communities, policymakers, and researchers across the country with the resources that they need to advance IAQ, including reports, policy briefs, and policy compilations. Among these tools is ELI’s Database of State IAQ Laws, a long-standing resource that tracks statutes and regulations addressing IAQ across the U.S. The database catalogs policies on issues ranging from mold, radon, and ventilation to indoor air standards in schools and public buildings. In addition, since 1998, ELI has convened a recurring Workshop for Indoor Air Quality Officials to support state, local, and tribal IAQ programs around the country by providing a forum for program officials to share information, ideas, and experiences on a wide array of IAQ topics and issues.
On September 19 and 20, ELI convened the 2025 Workshop for Indoor Air Quality Officials in Washington, D.C. This marked the 18th convening of this workshop, which separates itself from other convenings by covering best practices and practical strategies for addressing IAQ comprehensively, rather than focusing on a specific contaminant or issue. The meeting highlights models for integrated action through state program activities, ranging from developing guidance and conducting outreach, to providing remote and onsite-consultations and healthy homes assessments, as well as participating in policy development and implementation. By promoting an integrated approach that helps break down silos between IAQ issues, the workshop empowers state, tribal, and local governments to deploy their limited resources more efficiently and effectively to protect the health of the public they serve. By participants’ own accounts, this workshop—which is held approximately every 18 months— has become an invaluable opportunity to leverage the information and experience of IAQ programs in other jurisdictions.
This year's workshop was attended by 23 officials representing 16 state agencies, five local governments, and one tribe. This year, ELI also invited representatives from national NGOs like the U.S. Green Building Council, ASHRAE, and the National Center for Healthy Housing to provide information about their current IAQ-related work and, crucially, the variety of technical assistance resources these organizations can provide to state and local programs in a moment where the government is pulling back on investments in public health programs.
The 2025 workshop included presentations and panels on subjects chosen by the attendees including but not limited to IAQ in schools, healthy home environments, and new research in the health and building science areas that underpin evidence-based IAQ management. The workshop also offered several opportunities for participants to discuss their experiences and share resources, whether as part of roundtable conversations or during informal lunchtime discussions and “office hours” with NGOs. At a time when sub-federal partnerships are increasingly essential in the public health field, the workshop served as a platform for forming and sustaining connections in the community of practice and facilitating information and resource exchanges, both immediately and into the future. The next workshop is planned for spring 2027, and we hope that even more states, tribes, and local governments will join us next time.
Elevating Indoor Air on the World Stage
The week following the workshop, ELI Senior Attorney Amy Reed traveled to New York City to attend a historic event at the United Nations Headquarters: the launch of Global Pledge for Healthy Indoor Air. Upon signing the Pledge, the governments of France and Montenegro and over 165 non-governmental organizations and corporations from around the world marked the first international effort to formally recognize clean indoor air as a basic human right essential to health and well-being. ELI’s IAQ team is incredibly proud of our colleagues and partners at Brown University’s Clean Indoor Air Initiative, who originated the concept of the Pledge and have been working tirelessly in recent years to grow and strengthen an interconnected, coordinated community of practice that is made up of IAQ leaders from around the country and the world.
Clean Indoor Air Guide for States
Another recent success of the Clean Indoor Air Collaborative is the release in September of Clean Indoor Air: A Guide for State Leaders to Improve Indoor Air Quality. Developed by Brown University, the International WELL Building Institute, the U.S. Green Building Council, and ELI, the guide provides an evidence-based menu of options for states to improve indoor air quality across public and private buildings. The goal of the guide—which includes case studies illustrating how the ideas can be put into practice—is that state and local leaders will learn from each other and pick up the strategies that make sense for their community, needs, and budget. ELI hopes that the guide will enable stakeholders like parents, local leaders, and community members to push for IAQ improvements in their communities because they better understand what to ask for, of whom, and why.
Sustaining the Momentum
The progress from this past month reflects a growing recognition that clean indoor air is fundamental. By equipping officials with practical tools and fostering coordination among sectors, ELI and its partners are helping lay the groundwork for durable, evidence-based governance of the air we breathe indoors. Sustaining this momentum will require continued investment, collaboration, and leadership, but the foundation for meaningful policy progress is stronger than ever, and ELI will remain a partner in building the necessary infrastructure from the ground up.
If you are a state, tribal, or local IAQ official and are interested in learning more about ELI’s Indoor Environments Program, including our Workshop for State IAQ Officials, please contact Amy Reed at reed@eli.org