Working Americans spend much as ninety percent of their time inside, making indoor air quality extremely important for worker health, and, according to a new study from the Harvard School of Public Health and SUNY Upstate Medical School, cognition and decision-making abilities.[1]Green buildings have a clear advantage over conventional buildings when it comes indoor air quality, and while previous studies have demonstrated a self-reported improvement in productivity in green buildings, this is the first study to demonstrate improved cognition in green buildings with subjects blind to the study conditions.


The study tracked twenty-four professionals over six workdays from 9 AM to 6 PM in an environmentally controlled office space where they received a standard cognitive assessment each day. On some days the participants were exposed to indoor air quality (IAQ) conditions representative of conventionally constructed buildings, with high volatile organic compound (VOC) levels, and on other days the participants worked in an office with simulated IAQ conditions representative of green buildings (low VOC concentration), both with the same ventilation rate. The study also looked at green buildings with improved ventilation, which they described as “Green +”.

The results are striking. Participants’ cognitive scores were 61% higher on the green building day and roughly double on the two Green + days than on the conventional building days. In other words, green buildings are significantly better and healthier work environments than conventional buildings.

There are many ways that green builders can improve indoor air quality, but the first step is to keep pollutants out by working with materials that do not release pollutants and chemicals at harmful levels. There are also LEED credits that address ventilation, filtration, and the prevention of cross-contamination.[2]

What, exactly, does human health and indoor air quality have to do with green buildings? Beyond reducing the use of chemicals that are good for neither the environment nor human beings, human health is an important piece of the sustainability puzzle. While the link between other green building initiatives such as reduced energy use and reduced waste output and environmental protection are more explicit, improved air quality – indoor and outdoor – is important for a sustainable future.

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