Overview of Indoor Plants: Phytoarchitecture as A Building Health Platform

Decorative plants have developed into a strategic position in an effort to healthy indoor buildings, adding to their functions as decorations for the comfort of occupants. This overview of decorative plants aims to describe the determining factors in the relationship between plants, humans, phytoremediation, to produce sustainable healthy indoor quality. The literature searches and selection method used the Mendeley Reference Manager platform. The results were categorized as interactions between plant and human responses, and between plants and indoor environmental quality. In summary, decorative plants are able to make people of all ages and their activities healthy physically and mentally, and it is important to avoid toxic plants even though they look beautiful. The ability of plants has been proven to be able to improve the environmental quality of indoor pollutants, as a function of phytoremediation to make indoor healthy for sustainable use, although should avoid plants with negative effect properties. The status is convincing to make decorative plants an essential living element in indoor. Promotion strategies and implementation tactics are proposed, adapted to local conditions.


INTRODUCTION
The definition of architecture which is closely related to environmental quality is "the art of composing and realizing all public and private buildings. For a building to be appropriate, it must be solid, healthy, and comfortable" (MCH, 2019;Curl, 2006). The definition of architecture puts a high priority on environmental quality for long-term use and with the aim of sustaining its use in a healthy and comfortable manner.  Su & Lin, 2015) in any indoor indoor environment. In special cases, the time to stay indoors is getting longer during the COVID-19 pandemic. Indoor has air quality variability between one building and another due to differences in building materials, indoor volume, air exchange, and others. Hence, people experience exposure to different indoor air qualities for long periods of time throughout the day.
Indoor content generally consists of various physical forms, such as furniture, and various forms of life, such as decorative plants, besides of course people. All indoor building materials and contents can be a source of pollution. Indoor pollution through maintenance of cleanliness may not be sufficient, therefore intervention using the ability of decorative plants is needed. Architectural design for indoor air quality management has involved the role of In response to the advancement of the role of indoor decorative plants, a new definition is proposed as indoor phytoarchitecture, viz. the empowerment of plants for the management and processing of indoor quality of a building.
The existence of plants is not only a decoration, but also a part of the indoor living structure in addition to other living things, which are capable of processing indoor qualities. In this function, a comprehensive and objective understanding framework is needed regarding the effect of indoor decorative plants on residents and their phytoremediation capabilities. The purpose of this study is to describe the important factors that influence each other between the tricomponent of plants, humans, phytoremediation, in an indoor building, which can run in a sustainable manner. Outcomes of this understanding can be a strategy for implementing phytoarchitecture through architectural design of buildings and the application of decorative plants in various places of activity according to local conditions.

MATERIALS AND METHODS
The literature is collected from the Mendeley Reference Manager using keywords: "human response"," indoor air quality", "indoor plant", "indoor phytoremediation". The results show that there are the oldest publications in 2013 and the newest in 2021. The next literature selection used a checklist screening of journal document types and open access types, and the results were 950 articles. Next is a collection of articles published every year with a screening covering English, articles from empirical research, and the word plants or plants indicating living plants, not infrastructure such as electric power, gas, processing, and others. Based on the selection and screening criteria, 350 articles were obtained, but only 104 articles were closely related to the focus of the study of human response and indoor phytoremediation.

Student response
Schools in South Korea are assessed for the potential for sick school syndrome, viz. indoor air quality conditions that have the potential to cause illness for residents. Observations were made using the school treatment without plants and with plants. Indoor air quality uses formaldehyde parameters, which can arise from building materials and furniture inside. At the beginning, both school treatments experienced a decrease in the concentration of formaldehyde, which was due to the time factor. However, after 3 months later, schools without plants had higher concentrations of formaldehyde than schools using plants. School  Also in Italian offices, the placement of decorative plants can reduce stress on employees, be sensitive to the environment, and even reduce energy consumption (Oberti & Plantamura, 2017). Similarly, the results of improved mental health and less fatigue were obtained for work related to electronic use and office workers in Japan (Genjo et al., 2019).
Research on the effects of indoor flowering plants for patients with coronary heart disease, which is usually accompanied by secondary effects of depression and anxiety, shows that symptoms of depression and anxiety can be suppressed, thereby accelerating recovery from the main disease (Koh et al., 2017). Similar results were also provided by other hospitals, which showed a reduction in allergy and allergy symptoms for hospital health workers, and pediatric asthmatic patients alike (Y.

Phytoremediation
Indoor phytoremediation includes the restoration of air quality, which is polluted by substances emitted from buildings and the activities of their users. Physical pollutants include parameters of temperature, humidity, noise. Chemical pollutants include inorganic and organic substances. Microbial contaminants are microscopic living things. Particulates are solid particles, which are separated from physical contaminants, because they contain chemicals and microbes. The level of these pollutants, combined with human response, can produce building environmental conditions that display unhealthy symptoms for occupants, commonly referred to as sick building Physical pollutants come from lighting, kitchen equipment, TV and/or radio entertainment facilities, people's conversations, and various activities in functional spaces. In summary, the progress of indoor phytoremediation research results on physical pollutants is presented in Table 1. , as well as perfumes, cleaning agents, paints and coatings, fabricated goods, and pesticides. In summary, the progress of indoor phytoremediation research results on chemical pollutants is presented in Table 2 and Table 3 for inorganic and organic respectively.   Samudro et al., 2022b), so their existence needs to be an important concern. The progress of microbial-related phytoremediation is summarized in Table 4.

Aromatic VOC elimination
Particulate matter is a small solid and liquid substance that is dispersed in the air. The classification is fine particulate: PM2.5 (diameter size up to 2.5 µm), and coarse particulate: PM10 (diameter size more than 2.5 µm to 10 µm). Fine particulates generally come from burning fossil fuels, so they have a high potential for kitchen activities (Smith et al., 2020). Fine particulates are also produced from cigarettes, building materials, insect repellent, and other household products (Zhang et al., 2019). Particulates become pollutants, when the concentration of PM2.5 in the room is more than 12 µg/m3 (Xing et al., 2016). Meanwhile, coarse particulates generally come from the deterioration of building materials, dust from occupant activities, and combustion residues, generally kitchen activities. In summary, the progress of indoor phytoremediation research results on particulate pollutants is presented in Table 5.

Progress status
The use of decorative plants related to indoor air quality has grown in number and types, and their remediation function has developed in various tropical and non-tropical areas around the world. Although it has not touched all indoor activities, the progress of human response to the presence of indoor decorative plants has reached activities, which have a long stay of more than 3 hours continuously in the room. Schools, offices, health facilities, and residences. In fact, the coverage of humans starts from children to the elderly, with normal physical conditions to people with disabilities. The scope of the place and people are representative enough to state that decorative plants are an essential living structure in indoor spaces. It is undeniable that there is a type of decorative plant that gives a negative response, it is a special concern to avoid its use.
The essence of indoor decorative plants, which are positive for humans, can be judged from two aspects. First, the nature of plant life is the ability to carry out the processes of respiration and photosynthesis, which other living things do not have. The process of plant respiration requires oxygen and produces carbon dioxide all the time. The process of photosynthesis, although limited to light days, is capable of absorbing more carbon dioxide than it produces, and producing more oxygen than it needs. In balance, these processes produce oxygen, which can be utilized by humans and other living things. Second, in line with the absorption of carbon dioxide, and coupled with sufficient water, plants absorb various other substances, including indoor pollutants. In fact, many types of plants have been shown to be able to remediate various pollutants, whether physical, chemical, microbial, and particulate. The existence of types of plants that are toxic to humans, it is a special concern in its implementation.

Implementation strategies and tactics
Within the framework of placing decorative plants on positive human response and indoor phytoremediation capabilities, the authors propose strategies and tactics in Table 6

CONCLUSION
An important understanding has been obtained about decorative plants, which can provide a positive response to their inhabitants, and it is important to avoid the use of plants that have a negative effect. Likewise, it has been widely proven that many plants are capable of improving the quality of the indoor environment, even though there are plants that are counterproductive. The advancement of plant applications as a way of healthy indoor buildings encourages phytoarchitecture as contemporary arts and technology based on nature, and therefore results in sustainable indoor uses. Strategies and tactics to promote phytoarchitecture can be implemented according to local conditions.

Financial supports
This work was entirely self-financed by the authors.

Competing interests
The authors declare no potential conflict of interest affecting this work.

Authors' contributions
HS: conception, design, acquisition of data, analysis and interpretation of data, drafting the manuscript, and revising it, focusing on human response; GS: as did HS' contribution, focusing on indoor phytoremediation; SM: as well as the contributions of HS and GS with the addition of implementation strategies and tactics.