Time in nature is valuable for children’s physical and mental health, so a daycare centre in Finland decided to create a playground that replicated the forest floor - with remarkable results.
The daycare replaced their sandy playground surface with lawn and added indigenous forest species like dwarf heather and blueberries. They also added planter boxes and allowed children to tend them. After just one month, children at the daycare had healthier microbiomes and stronger immune systems than their counterparts in other urban daycares.
According to the report published in Science Advances, the children had increased T-cells, increased immune-boosting microbes, and a reduction in interleukin-17A, a contributor to immune-transmitted disease.
Environmental scientist Marja Roslund from Helsinki University said, “We also found that the intestinal microbiota of children who received greenery was similar to the intestinal microbiota of children visiting the forest every day.”
These results demonstrate that loss of biodiversity in urban areas can contribute to poorer health outcomes and that easy environmental manipulation can radically change these health dynamics, especially in young children. Compared to other city kids who play in standard urban daycares with yards of pavement, tile and gravel, 3-, 4-, and 5-year-olds at these greened-up daycare centres in Finland showed increased T-cells and other important immune markers in their blood within 28 days.
Children living in rural areas tend to have fewer cases of allergies and asthma which seems to be directly tied to time outdoors. More studies are needed to definitively draw the correlation between time in nature and childhood health, but this experiment strengthens the argument for this link.
The experiment in Finland is the first to explicitly manipulate a child's urban environment and then test for changes in their micriobiome and, in turn, a child's immune system. The notion that an environment rich in living things impacts on our immunity is known as the 'biodiversity hypothesis'. Based on that hypothesis, a loss of biodiversity in urban areas could be at least partially responsible for the recent rise in immune-related illnesses.
Hopefully, this study will encourage more schools and daycares to incorporate natural spaces into their design. And encourage households living in cities to try and do something similar themselves.