ADDITIONAL INDEX WORDS. Fatsia japonica, Ficus benjamina, indoor air quality, potted plant, phytoremediation, volatile organic compounds ABSTRACT. The contribution of aerial plant parts versus the root zone to the removal of volatile formaldehyde by potted Fatsia japonica Decne. & Planch. and Ficus benjamina L. plants was assessed during the day and night. The removal capacity of the entire plant, aerial plant parts, and root zone was determined by exposing the relevant parts to gaseous formaldehyde (2 mLÁL -1 ) in airtight chambers (1.0 m 3 ) constructed of inert materials. The rate of formaldehyde removal was initially rapid but decreased as the internal concentration diminished in the chamber. To compare the removal efficiency between species and plant parts, the time interval required to reach 50% of the initial concentration was determined (96 and 123 min for entire plants of F. japonica and F. benjamina, respectively). In both species, the aerial plant parts reduced the formaldehyde concentration during the day but removed little during the night. However, the root zone eliminated a substantial amount of formaldehyde during the day and night. The ratio of formaldehyde removal by aerial plant parts versus the root zone was similar for both species, at ' '1:1 during the day and 1:11 at night. The effectiveness of the root zone in formaldehyde removal was due primarily to microorganisms and roots (' '90%); only about 10% was due to adsorption by the growing medium. The results indicate that the root zone is a major contributor to the removal of formaldehyde. A better understanding of formaldehyde metabolism by root zone microflora should facilitate maximizing the phytoremediation efficiency of indoor plants.

Twenty-eight ornamental species commonly used for interior plantscapes were screened for their ability to remove five volatile indoor pollutants: aromatic hydrocarbons (benzene and toluene), aliphatic hydrocarbon (octane), halogenated hydrocarbon [trichloroethylene (TCE)], and terpene (α-pinene). Individual plants were placed in 10.5-L gas-tight glass jars and exposed to ≈10 ppm (31.9, 53.7, 37.7, 46.7, and 55.7 mg·m−3) of benzene, TCE, toluene, octane, and α-pinene, respectively. Air samples (1.0 mL) within the glass containers were analyzed by gas chromatography–mass spectroscopy 3 and 6 h after exposure to the test pollutants to determine removal efficiency by monitoring the decline in concentration over 6 h within sealed glass containers. To determine removal by the plant, removal by other means (glass, plant pot, media) was subtracted. The removal efficiency, expressed on a leaf area basis for each volatile organic compound (VOC), varied with plant species. Of the 28 species tested, Hemigraphis alternata, Hedera helix, Hoya carnosa, and Asparagus densiflorus had the highest removal efficiencies for all pollutants; Tradescantia pallida displayed superior removal efficiency for four of the five VOCs (i.e., benzene, toluene, TCE, and α-pinene). The five species ranged in their removal efficiency from 26.08 to 44.04 μg·m−3·m−2·h−1 of the total VOCs. Fittonia argyroneura effectively removed benzene, toluene, and TCE. Ficus benjamina effectively removed octane and α-pinene, whereas Polyscias fruticosa effectively removed octane. The variation in removal efficiency among species indicates that for maximum improvement of indoor air quality, multiple species are needed. The number and type of plants should be tailored to the type of VOCs present and their rates of emanation at each specific indoor location.

The objective of this study was to determine the exercise intensities of 15 gardening tasks in older adults using a portable indirect calorimeter. Twenty older Korean adults (16 females, four males) older than 65 years of age (average 67.3 ± 2.7 years) were recruited from the community of Gwangjin-gu, Seoul, South Korea. The subjects visited a garden created for the study at Konkuk University, Seoul, South Korea, three times and performed a total 15 gardening tasks. Subjects wore a portable calorimetric monitoring system (Cosmed K4b2) with telemetry that allowed measurement of oxygen consumption as they conducted each gardening task over a 5-min period and during a subsequent 5-min rest period while seated on a chair between each task. Their heart rate was also continuously measured using radiotelemetry (Polar T 31) during the test. The gardening tasks performed were of low to moderate intensity physical activities [1.7–4.5 metabolic equivalents (METs)]. Tasks using both upper and lower body (e.g., digging, fertilizing, weeding, raking, tying plants to stakes) required moderate-intensity physical activity (3–4.5 METs); those using the upper body while standing or squatting (e.g., pruning, mixing soil, planting seedlings, sowing, watering using a watering can or hose, harvesting) were low-intensity physical activities (1.7–2.9 METs); and tasks requiring limited use of the upper body while standing (e.g., filling containers with soil, washing harvested produce) were the least demanding physical activities of the gardening tasks tested. The results will allow more precise tailoring of gardening activities of older individuals to achieve appropriate levels of activity for good health.

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Abstract:The objective of this study was to compare physiological and psychological relaxation by assessing heart rate variability (HRV), prefrontal cortex activity, and subjective indexes while subjects performed a task with and without foliage plants. In a crossover experimental design, 24 university students performed a task transferring pots with and without a foliage plant for 3 min. HRV and oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex were continuously measured. Immediately thereafter, subjective evaluation of emotions was performed using a modified semantic differential (SD) method and a profile of mood state questionnaire (POMS). Results showed that the natural logarithmic (ln) ratio of low frequency/high frequency, as an estimate of sympathetic nerve activity, was significantly lower while performing the task with foliage plants for the average 3 min measurement interval. Oxy-Hb concentration in the left prefrontal cortex showed a tendency to decrease in the 2-3 min interval in the task with foliage plants compared to the task without plants. Moreover, significant psychological relaxation according to POMS score and SD was demonstrated when the task involved foliage plants. In conclusion, the task involving foliage plants led to more physiological and psychological relaxation compared with the task without foliage plants.

The present study aimed to assess the physical and psychological health benefits of a 15-session gardening intervention in elderly women and to investigate satisfaction of the gardening intervention. Fifty elderly women (age >70 years) at two senior community centers located in Seoul, South Korea, were selected to participate in this study. Twenty-four elderly women at senior community center “A” participated in a twice-weekly gardening intervention (≈50 minutes per session) during the period Sept. to Nov. 2015; 26 elderly women at senior community center “B” comprised a control group. At the completion of the 15-session gardening intervention, physical health parameters such as body composition, physical functional ability, and hand function ability were assessed in both groups. Additionally, psychological health conditions, such as cognitive ability, depression, and sociality, were assessed. The elderly women also answered a questionnaire to assess the amount of physical activity experienced during daily life. Elderly women in the gardening intervention group exhibited significantly improved muscle mass, aerobic endurance, hand dexterity, cognitive ability, and decreased waist circumference (P < 0.05). In contrast, significantly decreased muscle mass and agility and increased depression were observed in the control group (P < 0.05). Moreover, elderly women in the gardening intervention group reported a significantly higher amount of daily physical activity compared with those in the control group (P < 0.05). Additionally, 95.8% of elderly women in the gardening intervention group reported of being very satisfied with the gardening intervention. In conclusion, the gardening intervention maintained and improved the physical and psychological health of elderly women at a senior community center, whereas elderly women in the control group experienced age-related reduced physical and psychological health conditions. More studies are needed to evaluate the effects of a gardening intervention in a larger population of elderly women; in addition, a longer intervention period would provide a better measure of health in elderly women.

The study’s objective was to investigate the effects of foliage plants on prefrontal cortex activity and subjective assessments of psychological relaxation. In a crossover experimental design, 24 male university students in their 20s observed a container with and without foliage plants for 3 minutes while oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex was continuously measured with a portable near-infrared (NIR) spectroscopy device. Afterward, subjective evaluations of emotions were obtained via two self-report questionnaires: a modified semantic differential (SD) method and the Profile of Mood State questionnaire (POMS). Oxy-Hb concentration in the right prefrontal cortex was significantly lower in subjects who viewed the foliage plants than in those who did not, indicating a physiologically relaxed state. The subjects also reported in the SD method significantly more positive emotions (e.g., comfortable, natural, and relaxed) associated with viewing the foliage plants. In the POMS, a significant positive effect on psychological relaxation when subjects viewed the foliage plants was shown. Thus, we conclude that foliage plants have both physiological and psychological relaxation effects in males even after only short exposure.

The exercise intensity of three different horticulture activities (propagating herbs, transplanting, and making a vegetable garden) in older adults was determined. Seventeen older Korean adults (mean age 66.9 ± 2.7 years, body mass index 26.8 ± 3.4) that met the inclusion criteria (over 65 years in age, no uncontrolled chronic diseases, no heart and lung diseases, no pacemaker, and nonsmoking) participated in the study. The subjects visited the Konkuk University campus, Seoul, South Korea two times to complete the horticulture activities during June 2011. Propagating herbs and transplanting were completed in a glasshouse during the first visit, with each activity taking about 20 min. The third activity involved making a vegetable garden and required an average of 25 min during the second visit. Metabolic and heart rates during each activity were determined using a portable calorimetric instrument with a radiotelemetry monitor. Propagating herbs and transplanting were determined to be low intensity physical activities (2.4 ± 0.5 metabolic equivalents (METs) and 2.7 ± 0.5 METs, respectively) while making a vegetable garden was a moderate intensity physical activity (3.7 ± 0.7 METs) for older adults.