A new study has found that green roofs do a lot more than just provide extra space to grow plants. These eco-friendly roofs can also enhance air quality inside of buildings by reducing the ozone levels that come in from the outdoors.
Scientists at Portland State University conducted the study at a large commercial building in Portland. Researchers installed devices on the roof, which was split between a traditional membrane and a green roof. The devices measured ozone levels of the air surrounding the building. They discovered that plants on the roof helped to trap ozone, preventing it from coming into the building.
The new study adds to the growing list of green roof benefits. According to Phys.org, this includes the ability to filter carbon dioxide, cut down on excess water runoff after big storms and reduce heat in urban environments. Not to mention all of the veggies and plants that can be grown, cultivated and even shared with the local community. But how does the vegetation trap ozone and remove it from the air?
The process of trapping ozone is called dry deposition, where particles in the air accumulate on solid surfaces. The process of dry deposition is completely natural and has been proven to be an effective way of filtering air. Prior to the new research, however, scientists did not know that a green roof could actually improve air quality indoors.
It should be noted that the study, which was published last month in Building and Environment, only took place over a few days. The scientists who led the research effort have admitted that more studies that measure pollutants trapped over a long period should be completed.
They also want to look at other pollutants other than just ozone. Once this happens, we will better understand the broader benefits of green roofs and just how much they can contribute to better indoor air quality.