Emerging research has linked exposure to diverse airborne microbial communities to healthy human immune systems. (1) But few studies have examined how communities of airborne microbes (aerobiomes) vary over time and space (2); none are known to have investigated whether these communities change with height from the ground. A recent proof-of-concept study in Environmental Health Perspectives described how the diversity of airborne bacterial communities decreased from ground level to 2 m in height in an urban park, noting that the makeup of the communities also varied, depending on height. (3)
"Exposure to a diverse set of microbes from our environment trains our immune systems to respond appropriately to pathogens," says Graham Rook, a professor of medical microbiology at University College London who was not involved in the study. Lack of exposure to bacterial diversity has been associated with autoimmune diseases, (4) allergies, (5) Alzheimer's disease, (6) and inflammatory bowel disease. (7)
Airborne microbial communities are important for human health because our skin and mucous membranes are exposed to them every day. (8) Yet the community structure of the aerobiome remains little known, says lead study author Jake Robinson, a doctoral student in microbial ecology at England's University of Sheffield. An earlier study comparing forest and grassland areas found that elements of the local environment likely drive aerobiome structure. (9) "But we wanted to know how the airborne bacterial communities varied over vertical space because, due to height differences, children may be exposed to different microbes than adults," Robinson says.
He and his team chose an urban park in Adelaide, Australia, that consists of about 700 hectares of gardens, woodlands, and playing fields. The researchers set up sampling stations in three randomly selected plots of scrub habitat,...