Researcher Tove Fjeld and associates placed 18 plants in 29 single-occupant offices for one year and then moved the plants the next year to 30 offices that had been without plants. Both sets of office workers completed surveys every 2 weeks for 3 months. The surveys included questions on alertness and headache symptoms; eye, nose and throat symptoms and skin symptoms.
Several symptoms were reported as absent or less severe in the presence of plants; including fatigue; hoarse dry throat; cough; and dry or flushed face. Plants seem to influence feelings of comfort, attractiveness to the space and well-being. Additionally plants seem to be able to influence some physical symptoms such as fatigue – evidence that being with plants can be good medicine.
Fjeld, Tove, Bo Veiersted, Levi Sandvik, Geir Riise and Finn Levy. 1998. The effect of indoor foliage plants on health and discomfort symptoms among office workers. Indoor + Built Environments, vol. 7, pp.204-09.