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Mung Hwa Yoo, Youn Jung Kwon, Ki-Cheol Son, and Stanley J. Kays

Foliage plants of Hedera helix L. (english ivy), Spathiphyllum wallisii Regal (peace lily), Syngonium podophyllum Schott. (nephthytis), and Cissus rhombifolia Vahl. (grape ivy) were evaluated for their ability to remove two indoor volatile organic air pollutants, benzene and toluene. Removal was monitored when the aerial portion of plants was exposed singly to 1 μL·L-1 or to 0.5 μL·L-1 of each gas in a closed environment over 6-hour periods during the day and the night. Selected physiological processes were assessed before and immediately after treatment to determine the effect of the gases on the plants. The effectiveness of plants in the removal of air pollutant(s) varied with species, time of day, and whether the gases were present singly or as a mixture. When exposed to a single gas, S. wallisii, S. podophyllum, and H. helix displayed higher removal efficiencies (ng·m-3·h-1·cm-2 leaf area) of either gas than C. rhombifolia during the day. The efficiency of removal changed when both gases were present; H. helix was substantially more effective in the removal of either benzene or toluene than the other species, with the removal of toluene more than double that of benzene. When exposed singly, the removal of both compounds was generally higher during the day than during the night for all species; however, when present simultaneously, H. helix removal efficiency during the night was similar to the day indicating that stomatal diffusion for english ivy was not a major factor. The results indicated an interaction between gases in uptake by the plant, the presence of different avenues for uptake, and the response of a single gas was not necessarily indicative of the response when other gases are present. Changes in the rates of photosynthesis, stomatal conductance, and transpiration before and after exposure indicated that the volatiles adversely affected the plants and the effects were not consistent across species and gases. Deleterious effects of volatile pollutants on indoor plants may be critical in their efficacy in improving indoor air quality and warrant further study.

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Sin-Ae Park, Moon-Kyoung Cho, Mung Hwa Yoo, Soo-Yun Kim, Eun-Ae Im, Jong-Eun Song, Jin-Cheol Lee, and In Gun Jun

The objectives of this study were to examine the effects of a horticultural activity program on the emotional intelligence, prosocial behavior, and scientific investigation abilities and attitudes of kindergarteners. A total of 336 children aged 5 to 7 years in public and private kindergartens and day care centers in Incheon, South Korea, participated in a 24-session horticultural activity program. This program included indoor and outdoor activities such as planting seeds, transplanting plants, making and applying eco-friendly fertilizer, watering, harvesting, using plants to make crafts, and cooking with produce. It was designed to improve the emotional intelligence, prosocial behavior, and scientific investigation abilities and attitudes of kindergarteners. Each session lasted an average of 50 minutes and was held once per week. The results of the study showed that the 24-session horticultural activity program improved the emotional intelligence, prosocial behavior, and scientific investigation abilities and attitudes of the children (P < 0.05). Satisfaction with the program was very high among both the children and their teachers and parents. Future studies should consider exploring the effects of horticultural activity programs on children in different age groups.