Ventilation reduces indoor pollution levels except for NO2, study finds

New research has found that mechanical ventilation systems significantly reduce the levels of particulate matter, carbon dioxide and monoxide, and formaldehyde from indoor air, reducing the risk of respiratory and cardiovascular illness.

The study from the National Center for Healthy Housing (NCHH) and Enterprise Community Partners concludes that mechanical ventilation could save thousands of lives and prevent major health impacts of indoor air pollution.

However, even in homes with ventilation systems, researchers did not observe significant changes in levels of nitrogen dioxide, which primarily comes from gas stoves, suggesting that increasing ventilation is not enough to address the health impacts of these appliances.

Based on these findings, the study recommends that builders and owners install continuous mechanical ventilation systems in all homes, while phasing out gas stoves altogether.

‘Thousands of Americans are dying every year from preventable illnesses exacerbated by poor air quality, and this study shows we have the tools at our disposal to fix this systemic issue. Installing mechanical ventilation and transitioning from gas stoves to electric would have a significant impact on public health, particularly in lower-income communities,’ said Stephany De Scisciolo, Vice President of Impact and Evaluation at Enterprise and a collaborator on the study. ‘We’re grateful to our partners at the National Center for Healthy Housing (NCHH) and The JPB Foundation for making this incredibly important study possible.’

The study found a 20% reduction in particulate matter (PM2.5) when mechanical ventilation was in use. The researchers predicted that if all multifamily housing in the United States had continuous mechanical ventilation, the resulting decrease in indoor PM2.5 alone could lead to:

• 14,800 fewer deaths
• 11,800 fewer emergency department visits due to asthma
• 8,100 fewer hospitalizations due to respiratory or cardiovascular illness

‘Ventilation is much more important than we previously thought,’ said David Jacobs, Chief Scientist at NCHH. ‘This study gives us three clear takeaways: All gas stoves should be replaced, all apartments should have continuous mechanical ventilation, and outdoor air pollution affects indoor air. Ensuring our homes are healthy ones is key to preventing illness and promoting well-being.’

Photo by Brett Jordan