According to estimation, people spend 80% to 90% of one day indoors in modern society. Recently, reports have shown that if we stay in closed buildings too long, we may have symptoms such as allergy, headache, problems of eyes, nose and throat, catching cold easily, dry and itching skin, sleepy, sickness, losing of concentration, getting tired easily, or being sensitive to odor, scent, and fragrance; which is the so-called ‘Sick Building Syndrome’ (SBS). Many researches show that besides physical and chemical methods, the best way to reduce the occurrence of SBS is to place plants indoors. Therefore, we examined the CO2 reduction ability under different light intensities of 20 interior plants in Taiwan. The tested plants reduced more CO2 under high light level of 120 μmol•m-2•s-1 than 40μmol•m-2•s-1. Twenty CAM plants were collected and tested for reducing CO2 interiors. Plants of Agave have the highest capacity to reduce CO2 under low light level so they could be used in bedroom at night. We determined the ability to absorb formaldhyde of 20 indoor plants. The amount of the dust from different media has also been determined. Three conferences have been held in north, middle, and south of Taiwan for this project.

indoor plants, carbon-dioxide, formaldehyde