In a recent report published in Trends in Plant Science, Frederico Brilli – a plant physiologist from the National Research Council of Italy – Institute for Sustainable Plant Protection – and his colleagues have concluded that a better understanding of plant physiology, combined with integration of smart-sensor-controlled air-cleaning technologies, could provide an economical and sustainable means to enhance indoor air quality. In modern, energy-saving, airtight constructions, the concentration of air pollutants can build up to dangerous levels, posing a serious threat to human health. Potentially toxic gases and particular matter (PM) can be released by a variety of indoor sources and activities of occupants, including furnishings, paints, varnishes, waxes, carpets, solvents, cleaning supplies, office equipment such as copiers and printers, gas cook tops, and cigarettes. Indoor plants are typically selected on the basis of their aesthetic features rather than physiological requirements reflecting their capacity to remove air pollutants.
“For most of us plants are just a decorative element, something aesthetic, but they are also something else,” noted Brilli.
Plants enhance air quality in a number of ways: they can passively absorb pollutants on the external surfaces of leaves and the plant root-soil system, they ingest carbon dioxide and liberate oxygen through photosynthesis, and they increase humidity by transpiring water vapor through microscopic leaf pores.
Brilli points out that studies could illustrate how to “optimize the use of plants indoors, in terms of how many plants per square meter we need to reduce air pollution to a certain level.” But additional research is required to recognize the characteristics of the highest performing plant species in indoor environments.
Brilli and his team believe that although plants will not replace modern air conditioning, ventilation, and heating systems, plants incorporated with smart sensor networks and other computerized technologies could make air-cleaning more sustainable and cost-effective. Brilli adds, “plant physiologists should work with architects to improve the green indoors.”