Healthy air is both low in pollution and rich in airborne bacteria. New research has now shown that this bacteria differs between environments – and can have a wider reaching influence than previously thought.
Airborne bacterial communities differ from one urban park to the next while those in car parks are alike, new research has revealed.
Researchers from the University of Oregon based their findings on the idea that these plant-associated microbes affect human health.
Their pilot study has now unveiled both the differences between microbial communities and how far their influence may extend.
“We’re starting to build larger and more complex cities,” commented Gwynne Mhuireach, who led the study.
She added: “I am interested in ways to help maintain people’s health. Some studies say that as we are building these denser cities we are losing green space. I am looking for mechanisms that explain why vegetation helps people and how we can design for it.”
The researchers simultaneously collected six air samples over an eight-hour period at five parks and five car parks in Eugene in the U.S. state of Oregon. The locations were free from tall trees that block air movement.
The idea, Mhuireach explained, was to discover whether vegetation was a significant source of microbes for nearby areas.
Subsequent DNA analyses revealed that Sphingomonas, commonly found in soil and on plant surfaces, accounted for one fourth of the bacteria collected. Also abundant were Hymenobacter, Pedobacter, Agrobacterium and Rhodococcus – all soil-associated species.
The samples were collected during the harvesting season of the grass-seed industry north of Eugene, when prevailing winds likely blew microbes into the sites, explained the researchers.
Meanwhile, car parks were more similar to each other, with a prevalence of Acetobacteraceae. Parks had unique bacterial fingerprints likely reflecting vegetation types in and near each park.
The researchers suggested that “provisioning urban residents with green space within 400 meters of their homes” would make it more likely for them to be exposed to the “park-like microbiome.”
They added that the study could help guide landscape design in cities where growing populations are driving denser living spaces.
Photo credit: John Lillis/ CC BY-NC-ND 2.0