Open Access
Issue
BIO Web Conf.
Volume 11, 2018
IV(VI)th All-Russia Scientific-Practical Conference “Prospects of Development and Challenges of Modern Botany”
Article Number 00014
Number of page(s) 5
DOI https://doi.org/10.1051/bioconf/20181100014
Published online 21 August 2018

© The Authors, published by EDP Sciences, 2018

Licence Creative Commons
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

1 Introduction

In the world practice there is a wide experience of study of the ecological parameters of rooms of various functional purposes. The main ecological factors are temperature, humidity, air movement, qualitative and quantitative air microflora composition. These indices depend on many parameters: locality of a building, quality of used construction and finishing materials [1], as well as stay of people in the building [2]. People often spend 80% – 90% of time indoors [4]. In the indoor air environment there are many microorganisms – bacteria, house fungi and viruses [3]. The person passes through himself by breath on the average 14 m3 of air per day [5]. He absorbs and secrets therewith volatile organic compounds (VOC), both endogenous and exogenous. Air quality indoors affects human performance and health as a whole [2,6,7,8]. Children are especially exposed to the risk of infection caused by poor air quality indoors [9,10]. They are more vulnerable to all types of environmental pollution compared to adults, as they breathe more air relative to body weight, the respiratory tract of children is not sufficiently developed [2,11]. Consequently, careful control of air and prevention of air pollution are essential in the premises of children’s institutions [12]. Poor-quality indoor air of the libraries creates conditions for the appearance at employees and visitors of such diseases as: allergy, rhinitis, asthma and conjunctivitis [13]. Thus, a constant monitoring of the environmental factors promoting growth of air microorganisms and timely elimination of them are needed. There are various ways of cleaning indoor air. Usually recommendations on the improvement of air are reduced to airing of rooms and sanitary processing. The aim of our work is optimization of the air environment of library interiors with the help of ecological phytodesign method developed on the base of Central Siberian Botanical Garden (CSBG SB RAS) [14]. This method is ecologically safe, extremely economical and aesthetic. The essence is to use plants with distinct antimicrobic and gas-absorbing properties to reduce microbic and chemical air pollution.

2 Material and methods

The experiment was conducted in the building of the city library where educational activities with participation of children were carried out regularly. Two rooms similar in volume (195m3), air temperature (+ 25 C0), air humidity (20%) and illumination (500-2000 lx) were chosen. The windows faced the north-west. The experiment was conducted in the first room – hall of children’s literature, the second room – literature issue hall was control. Air samples were taken in triplicate in five points for three days. The total microbic number of CFU, including Staphylococcus and moldy mushrooms in 1 m of air (CFU/m3) was counted. When making experiments, the air samples were taken before classes (20 children at 10-12 years old, duration of a class – 30 min) and after them in both halls – with plants (experiment) and without them (control). Air intake was performed by the aspiration method based on the forced deposition of microorganisms on the surface of a dense nutrient medium. With the help of the sampling device (SD-1B) were pumped 100 l of air which fell on the surface of Petri dishes with meat-peptone agar (MPA). The samples were selected at the height of 1,5-1,8 m from the floor – at the level of human breathing. Cultivation of microorganisms was carried out in the thermostat at +37C0 for 2 days. Microclimatic parameters – temperature, air humidity and illumination were measured by the combined device "TKA-PK" (UF). A phytomodule containing plants grown in the green houses of CSBG SB RAS and adapted to the interior conditions was set in the experimental room. The assortment of plants was selected according to techniques of ecological phytodesign [7]: Begonia «Loospe», B. «Loospe – tu», B. «Nigramarga», B. «November Frost», B. «Major», B. «Nigramarga», B. «Orange County», B. carolinifolia Reg., B. x erytrophylla Neumann, B. heracleifolia Cham. et Schlecht., Nephrolepis exaltata (L.) Schott «Fluffy Ruffles», Rhoeo discolor (L'Her.) Hance), Ruellia caroliniensis (J.F.Gmel.) Steud.), Pelargonium peltatum (L.) L'Her. ex Ait., Spathiphyllum wallisii Reg., Ficus Binnendijkii Miq «Alii», F. retusa L., Chlorophytum amaniense Engl. «Green Orange», Ch. comosum (Thunb.) Jacques «Bonnie», Ch. comosum «Variegatum», Schefflera octophylla (Lour.), Epipremnum aureum (Linden & André) G.S.Bunting, «N'Joy». Calculation of the area of leaf surface of the phytomodule plants was made by the program "Siams photolab", the results were treated by "Microsoft Office Excel".

3 Results

In the course of the experiment air samples were taken in the rooms and the analysis of microorganisms grown on the nutrient medium was performed. The area of the leaf surface of plants required for getting sanitation effect was calculated. The optimal leaf area was 1,5-3 m2 per 100 m of air [7]. The leaf area in plants of the phytomodule amounted to 6,2 m2.

On the first day of the experiment, air composition in the control and experimental rooms was practically the same (Fig.1, sample I). Twenty four hours later CFU/m3 in the room with the phytomodule decreased by three times (Fig.1, sample II). Forty eight hours later the difference in CFU/m3 between the experiment and the control remained unchanged (Fig. 1 sample III). Presence of children for 30 minutes increased significantly the quantity of microorganisms in the room air (Fig. 1, control), however, placement of plants allowed to decrease essentially CFU/m3 in a day.

Figure 2 shows that the ratio of conditional-pathogenic microorganism microflora to constant one changed in the course of the experiment. In the control room Staphylococcus was more on 14% than in the room with plants.

It was revealed that air humidity in the library was lowered. Relative air humidity in the hall of children’s literature before installation of the phytomodule was 21,6%. Forty eight hours after placement of plants air humidity amounted to 30,2% (Fig. 3).

thumbnail Fig. 1.

Effect of plants on quantitative composition of air microflora in the room.

thumbnail Fig. 2.

Ratio of conditional-pathogenic microflora to constant one in the presence of plants (experiment) and without them (control).

4 Discussion

The ecological status of the room air environment is made up from quantitative and qualitative indicators: total number of microorganisms and ratio of conditional-pathogenic microflora to constant one. The microorganisms moving freely in the air belong to the constant microflora (Micrococcus, Bacillus, Sarcina) and the conditional-pathogenic one (Staphylococcus, moldy mushrooms). Sanitary-hygienic state of a premise is characterized by the total number of all microorganisms in 1 m3 of air – CFU/m3

In our experiment (control room) microorganism concentrations were in the range from 3435 to 3709 CFU/m3, which exceeded sanitary-hygienic standards (2000 CFU/m3). But those indicators were not the most high. For instance, J. M. Daisey noted that in the course of experiments carried out in schools and kindergartens were found concentrations of vital bacteria in the range from 7 CFU/m3 to 19500 CFU/m3 [15]. Microorganism concentrations in the university library were significantly lower and varied from 367 to 2595 CFU/m3 [5]. According to literature the number of bacteria in the room air environment increases due to presence of children [2]. We explain such an effect by the fact that adults are more static compared to children who often wave their hands, turn their heads, get up from their seats even during the classes. Such movements create chaotic flows of air currents in which there are different microorganisms. In the absence of air movement microorganisms gradually settle on the floor, and they are far less detectable at the level of breath of a person.

In the premises with library stock the main indicator of environmental well-being is quantity of moldy mushrooms colonies per 1m3 of air as these microorganisms influence safety of books. The condition of air is considered satisfactory if quantity of moldy mushrooms per 1m3 does not exceed 300-500 (CFU/m3) [13, 16]. However, we have paid attention not only to quantity of moldy mushrooms, but also to presence of Staphylococcus in the air. These microorganisms do not influence safety of library collection, but are a source of various diseases of the person [17, 18, 19]. It was shown in our experiment that in the air of library rooms Staphylococcus was more than moldy mushrooms. Such data are confirmed by other authors. A. Fox, & R. M. T Rosario noted that concentration of grampositive bacteria, to which Staphylococcus belongs, was usually higher than concentration of gram-negative bacteria [20, 21]. Staphylococcus, as a rule, gets to air from the mucosa of the respiratory tracts [18], but it may be on the surface of low-quality sanitary equipment [22] and even on the floor [21].

The results of our experiment show that application of ecological phytodesign method allows to improve air quality in premises of library. Thus, in a day after installation of phytomodules, value of CFU/ m3 decreased significantly, air humidity reached 30.2% – the lower limit of the comfort range for a person (30% – 60%). However, such air humidity is still below the norm recommended for storage of books and documents – 45-55%. Each of premises has its own specifics, which should be taken into account when using the ecological phytodesign method. [14, 19, 22].

The work was carried out within the framework of the State Assignment of Central Siberian Botanical Garden SB RAS with partial support of Russian Foundation for Basic Research (project r_a №17-44-540601). When preparing the publication, the materials of bioresource scientific collection of CSBG SB RAS «Collections of living plants indoors and outdoors», № USU 44053 were used.

thumbnail Fig. 3.

Change in air humidity in the room after installation of the phytomodule.

References

All Figures

thumbnail Fig. 1.

Effect of plants on quantitative composition of air microflora in the room.

In the text
thumbnail Fig. 2.

Ratio of conditional-pathogenic microflora to constant one in the presence of plants (experiment) and without them (control).

In the text
thumbnail Fig. 3.

Change in air humidity in the room after installation of the phytomodule.

In the text

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