A PhD study suggests that regular exposure to green plants indoors strengthens the human immune defence system.
A recent study shows that indoor plants can contribute to human health.
There are different types of green walls on the market. In the models used in the study, no soil was used as a growing medium to concentrate the effects on the plants. In addition, the green walls had air circulation.
– The plant selection included familiar houseplants, such as traak trees, climbing vines and hive plants, says Laura Soininen.
Exposure occurred through surfaces and indoor air during working hours. The time was not measured, but the exposure was regular.
The effects on the bodies of the subjects were monitored with the help of skin samples and blood level measurements.
– We noticed that the green walls diversified the microbiota of the skin, which protects the workers’ immune system from disturbances, Soininen says.
The results are promising, for example, in terms of the prevention of allergies and autoimmune diseases, but further research is needed. The exposure group under study was small, 30 people, and the changes were subtle.
– However, we were convinced that this is worth investigating further, Soininen says.
Little research has been done on the effects of indoor plants
Indoor plants were studied as part of a larger material in the doctoral research conducted at the Lahti unit of the University of Helsinki. The study investigated whether microbes found in nature could promote human health in urban environments.
Multifaceted microbial exposure is known to stimulate the immune defense, for example, in such a way that it learns to recognize and distinguish between harmless and harmful microbes from outside the body.
– This way unnecessary inflammatory reactions are avoided, Laura Soininen says.
According to Soininen, the green wall study is the first in which the addition of plants to indoor spaces is shown to be connected not only to the human microbiota, but also to the regulation of the immune system.
In the past, the focus has been on outdoor spaces and research has been done, among other things, on nature exposure in kindergarten children
Little is known about the similar effects of indoor plants.
Soininen says that he has come across only one study, but even in that one the subject was plants isolated in closed chambers.