Effects of indoor plants on air quality: a systematic review.

No study has comprehensively reviewed the effects of indoor plants on air quality; therefore, this study systematically reviewed quantitative empirical research on these effects in both English and Chinese. The information sources were the Web of Science and WanFang Data Knowledge Service Platform electronic databases. Only journal articles reporting quantitative empirical research were selected. The eligibility criteria included studies with (1) interventions of any indoor plant, excluding biofilters that combine power facilities and vegetation, (2) comparators included within the same experimental treatment or between different experimental treatments, (3) air quality effects objectively measured using any instrument, and (4) any study design. Both authors screened 95 journal articles and compiled information according to (1) intervention (plant species, foliage, or medium), (2) scientific family name of each plant, (3) study design (experiment, field experiment, or survey), (4) air quality (e.g., temperature, humidity, negative ions, radiation, and dust), (5) pollutants, (6) research environment, (7) ventilation (types and rates), (8) climate (lighting, temperature, and humidity), (9) exposure duration, (10) sampling frequency or period, and (11) number of replications. The primary effects of the potential of the indoor plants on air quality were reduced pollutant levels (particularly formaldehyde, benzene, and toluene removal), followed by increase in humidity and decrease in temperature. In addition, including various plant species could improve the effects of indoor vegetation on ameliorating air quality and microclimate conditions.