Study warns of poor health outcomes of unplanned urbanization

 Research from the University of Adelaide and Flinders University, published in the journal Environmental Research, suggests that urbanization may be contributing to poor health outcomes by disrupting beneficial microbes that support our immune systems. 
The study emphasizes the importance of incorporating large green spaces and designing buildings with features such as windows that open and indoor plants to promote health in urban environments.
"Exposure to many bacteria in the environment is actually good for us," says lead author Kate Matthews, a University of Adelaide graduate and Flinders PhD student. "Our bodies are adapted to dealing with a diversity of bacteria, providing the 'training' that teaches our immune system not to overreact to everyday exposures."
The researchers found that as humans become increasingly removed from nature, the diversity of microbes they are exposed to in green spaces decreases. This can lead to overactive immune systems, exacerbating allergies, asthma, and autoimmune diseases.
"Soils provide an incredibly rich and diverse source of microbes, as do the plants that grow in them," Matthews explains. 
"The healthy exposures to nature that we have lost could be regained by designing more green spaces in urban areas. As the percentage of the world's population living in urban environments is expected to increase (68 percent by 2050), it becomes crucial to design our urban environments to promote exposure to diverse microbiota, potentially improving health outcomes."
The World Health Organization (WHO) recommends at least one public green space of at least 0.5 hectares within 300 meters of residences, a key consideration for urban planners aiming to maintain public health.
"Unlike other approaches to alter the human microbiome, such as diet, exercise, and probiotics, making changes to the design of the environments people are exposed to means individuals do not have to alter their behavior to improve their health," says Dr. Jessica Stanhope, leader of the University’s Environmental Allied Health group. 
She suggests, "Landscape designers need to consider how people use these spaces, including those who may experience challenges in access, such as individuals living with disabilities and people in residential care."