We spend roughly 90 percent of our time indoors, yet the air we breathe in our homes, schools, and workplaces remains largely unregulated and often more polluted than outdoor air. Unlike lead and asbestos, which faced regulatory crackdowns after science revealed their dangers, indoor air quality has largely escaped public attention and policy action, even as research demonstrates serious health consequences .

What Does Poor Indoor Air Actually Do to Your Health?

The health effects of indoor air pollution are not theoretical. Research from Dr. Joseph Allen and his team at the Harvard T.H. Chan School of Public Health shows that poor ventilation and elevated levels of carbon dioxide (CO2) and volatile organic compounds (VOCs) can significantly impair cognitive function and increase the risk of long-term respiratory illness . VOCs are chemicals that evaporate from household products, paints, and furnishings, and they accumulate in poorly ventilated spaces.

The cognitive impacts are particularly striking. Poor indoor air can reduce attention, memory, and decision-making, making it harder for students to learn and for workers to perform at their best. Beyond cognition, people in poorly ventilated spaces often experience fatigue, dizziness, and headaches. Young children and older adults are especially vulnerable to these effects, and inadequate ventilation also allows viruses to spread more easily, leading to more sick days in schools and workplaces .

In regions like New Hampshire, where long winters keep people indoors for months, this issue becomes especially urgent. Common indoor pollutants like CO2 and VOCs can silently build up to harmful levels without any visible warning signs.

Why Isn't Indoor Air Quality Regulated Yet?

The regulatory gap is striking. Outdoor air quality is monitored and controlled through Environmental Protection Agency (EPA) standards, yet indoor air remains largely a private matter. This mirrors the historical pattern with asbestos and lead, which were widely used in homes and schools for decades before regulations caught up with the science. The difference now is that we have the research; what's missing is the policy response .

Experts argue that individual action alone cannot solve this problem. While homeowners can take steps to improve their own indoor air, systemic change requires stronger state laws and local ordinances that set minimum standards for ventilation, air quality monitoring, and pollution control in schools, workplaces, and residential buildings.

How to Improve Indoor Air Quality in Your Home and Community

• Immediate Actions: Open windows regularly to increase natural airflow, use fans to circulate air, and reduce sources of indoor pollution by choosing low-VOC paints and furnishings when possible.
• Medium-Term Investments: Upgrade heating, ventilation, and air conditioning (HVAC) systems to improve air circulation, install high-quality air purifiers with HEPA filters to remove particulates, and use indoor air quality monitors to track CO2 and VOC levels in real time.
• Long-Term Policy Support: Advocate for stronger state and local regulations that establish indoor air quality standards for schools, workplaces, and new residential construction, similar to existing outdoor air quality standards.

Indoor air monitors are particularly valuable because they provide immediate feedback. Schools and households can track conditions and take action when pollution levels rise, whether that means opening windows, running air purifiers, or scheduling HVAC maintenance .

The good news is that solutions are both practical and achievable. Schools in the Upper Valley have already begun upgrading their systems. One school received a $202,000 grant to replace heating and ventilation units that were over 50 years old, add six new units, and install a mobile air filtration unit in the school nurse's office capable of removing virus particles from the air . These investments demonstrate that the technology exists; what's needed now is broader adoption and regulatory support.

The science is clear: poor indoor air quality is an invisible danger with measurable health consequences. As communities across New Hampshire and Vermont consider how to protect public health, strengthening indoor air quality standards offers an opportunity to prevent respiratory illness, improve cognitive function in schools, and reduce sick days in workplaces. Like the regulatory responses to lead and asbestos before it, action on indoor air quality is not a matter of if, but when.