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Which ornamental plant species effectively remove benzene from indoor air?

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Abstract

Phytoremediation—using plants to remove toxins—is an attractive and cost effective way to improve indoor air quality. This study screened ornamental plants for their ability to remove volatile organic compounds from air by fumigating 73 plant species with 150 ppb benzene, an important indoor air pollutant that poses a risk to human health. The 10 species found to be most effective at removing benzene from air were fumigated for two more days (8 h per day) to quantify their benzene removal capacity. Crassula portulacea, Hydrangea macrophylla, Cymbidium Golden Elf., Ficus microcarpa var. fuyuensis, Dendranthema morifolium, Citrus medica var. sarcodactylis, Dieffenbachia amoena cv. Tropic Snow; Spathiphyllum Supreme; Nephrolepis exaltata cv. Bostoniensis; Dracaena deremensis cv. Variegata emerged as the species with the greatest capacity to remove benzene from indoor air.

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... The removal of MAHs by plants has been investigated in several studies (for review, see Dela Cruz et al., 2014). In most experiments, their concentrations were controlled at several to several tens of ppmv (=µmol mol − 1 ) levels (Liu et al., 2007;Mosaddegh et al., 2014;Orwell et al., 2004;Sriprapat et al., 2014;Sriprapat and Thiravetyan, 2013;Wolverton et al., 1989), which are 10 3 to 10 4 times higher than their concentrations in urban, sub-urban and rural atmosphere (Garzón et al., 2015;Tiwari et al., 2010). All the above-cited studies, except for Liu et al. (2007), used static chamber method and enclosed whole potted plants; therefore, it is unclear which parts of the potted plants remove MAHs, that is leaves, soils, condensed water, or other parts inside the chambers. ...
... In most experiments, their concentrations were controlled at several to several tens of ppmv (=µmol mol − 1 ) levels (Liu et al., 2007;Mosaddegh et al., 2014;Orwell et al., 2004;Sriprapat et al., 2014;Sriprapat and Thiravetyan, 2013;Wolverton et al., 1989), which are 10 3 to 10 4 times higher than their concentrations in urban, sub-urban and rural atmosphere (Garzón et al., 2015;Tiwari et al., 2010). All the above-cited studies, except for Liu et al. (2007), used static chamber method and enclosed whole potted plants; therefore, it is unclear which parts of the potted plants remove MAHs, that is leaves, soils, condensed water, or other parts inside the chambers. As mentioned above, the flow-through chamber method is more reliable and the method enclosing plant leaves only is suitable to evaluate the leaf contribution to MAHs removal; however, no study has applied this method to MAHs so far. ...
... In previous studies, benzene and toluene were fumigated to potted plants in closed chambers at several hundreds of ppbv to several tens of ppmv levels (Liu et al., 2007;Mosaddegh et al., 2014: Orwell et al., 2004Sriprapat et al., 2014;Sriprapat and Thiravetyan, 2013;Wolverton et al., 1989). The concentration range was too high to be extrapolated to the evaluation of plant VOC removal capability in the surrounding atmosphere. ...
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Large amounts of monocyclic aromatic hydrocarbons (MAHs) are emitted into the atmosphere, but it is unclear which compounds among MAHs are effectively removed by the above-ground parts of plants. Although fumigation experiments of MAHs at unrealistically high concentrations (~ppmv) have been conducted, experiments with ambient concentrations have scarcely been conducted. In the present study, MAHs, including benzene, toluene, phenol, benzaldehyde, and benzyl alcohol, with concentrations ranging from several to several tens ppbv, were individually fumigated to four plant species, and the uptake was monitored using proton-transfer-reaction mass spectrometry and gas chromatography-mass spectrometry. No detectable uptake was observed for benzene and toluene, but phenol, benzaldehyde, and benzyl alcohol were significantly taken up by the plants. The uptake rate normalized to fumigated concentration varied from 3 to 50 mmol m⁻²s⁻¹ during the light period, depending on light intensity and compounds. The difference in uptake capability may be attributed not only to different metabolic activities but also to different values of Henry’s law constant, which regulates the partitioning of these compounds into the liquid phase in leaves. The uptake of phenol, benzaldehyde, and benzyl alcohol was affected by stomatal conductance, suggesting that stomatal opening is the main factor regulating the uptake of the three MAHs. This is the first observation that anisole is emitted when phenol is fumigated to Spathiphyllum clevelandii, suggesting that phenol is methylated to anisole within plant leaves. Anisole is more volatile than phenol, meaning that methylation enhances the emission of xenobiotics into the atmosphere by converting them to more volatile compounds. This conversion ratio decreased with an increase in phenol concentration (from 1.3 to 143 ppbv). Considering low reaction rate coefficient of anisole with OH radicals and low conversion ratio from phenol to anisole, it is concluded that plants act to effectively remove oxygenated MAHs from the atmosphere.
... An exact safe level of benzene exposure is unknown. As reported in 2000 by the European Union, the concentration of benzene in ambient air should be lower than 5 µg m −3 [142,143]. By considering the potential of plants to remove VOCs, there are some studies on benzene removal. ...
... Liu et al. [142] investigated ornamental houseplants' ability to remove benzene from ...
... Liu et al. [142] investigated ornamental houseplants' ability to remove benzene from indoor air in the laboratory. Twenty-three plant species among 73 species did not change the concentration of benzene in the air; the value of removing benzene was between 0.1-9.99% for 13 species while 17 species removed 10-20%, another 17 species removed 20-40%, and three species removed 60-80%. ...
Article
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Urban civilization has a high impact on the environment and human health. The pollution level of indoor air can be 2–5 times higher than the outdoor air pollution, and sometimes it reaches up to 100 times or more in natural/mechanical ventilated buildings. Even though people spend about 90% of their time indoors, the importance of indoor air quality is less noticed. Indoor air pollution can be treated with techniques such as chemical purification, ventilation, isolation, and removing pollutions by plants (phytoremediation). Among these techniques, phytoremediation is not given proper attention and, therefore, is the focus of our review paper. Phytoremediation is an affordable and more environmentally friendly means to purify polluted indoor air. Furthermore, studies show that indoor plants can be used to regulate building temperature, decrease noise levels, and alleviate social stress. Sources of indoor air pollutants and their impact on human health are briefly discussed in this paper. The available literature on phytoremediation, including experimental works for removing volatile organic compound (VOC) and particulate matter from the indoor air and associated challenges and opportunities, are reviewed. Phytoremediation of indoor air depends on the physical properties of plants such as interfacial areas, the moisture content, and the type (hydrophobicity) as well as pollutant characteristics such as the size of particulate matter (PM). A comprehensive summary of plant species that can remove pollutants such as VOCs and PM is provided here. This review will help in making informed decisions about integrating plants into the interior building design.
... Both systems (Trombe wall and green wall) also work to filter and purify the air, thus enhancing indoor air quality through air vents in both the Trombe walls and the green wall, which help circulate the air filtered by several indoor plants. Rhapis excels, Hedera helix and Chamaedorea erumpens are proposed for this use as they are cost-effective and have proven to contribute effectively in the passive removal of indoor pollutants and enhance indoor air quality [55][56][57][58] through a direct impact on occupants' health and productivity [56,58]. Although passive houses are generally airtight, this house was specifically designed not to depend on a heat recovery system due to the green wall's connection to an open cycle EAHE, which also serves as a form of natural ventilation. ...
... Both systems (Trombe wall and green wall) also work to filter and purify the air, thus enhancing indoor air quality through air vents in both the Trombe walls and the green wall, which help circulate the air filtered by several indoor plants. Rhapis excels, Hedera helix and Chamaedorea erumpens are proposed for this use as they are cost-effective and have proven to contribute effectively in the passive removal of indoor pollutants and enhance indoor air quality [55][56][57][58] through a direct impact on occupants' health and productivity [56,58]. Although passive houses are generally airtight, this house was specifically designed not to depend on a heat recovery system due to the green wall's connection to an open cycle EAHE, which also serves as a form of natural ventilation. ...
Article
With the increasing number of migrants and refugees, there is a need for energy-efficient and low impact temporary housing that can accommodate millions of displaced peoples worldwide. This study describes a design proposal for a premium passive refugee house that uses three main passive heating and cooling solutions (Earth Air Heat Exchanger, Trombe wall, and green wall) and is suited to the Swedish climate. The purpose of the combination of the three passive systems is to reduce cooling and heating loads to conserve a significant amount of primary energy and thus mitigate the impact of the house’s energy use on the environment through a reduction in emissions. The house is designed to fulfill its energy needs from renewable sources and produce an annual surplus of 180 kWh/m²/annum. The methodology applied is a dynamic system modeling and simulation approach using TRNSYS and ANSYS software. The simulation results showed a heating load of 7.9 kWh/m²/annum and a cooling load of 2.8 kWh/m²/annum, with total energy consumption reaching 18.4 kWh/m²/annum. Preliminary feasibility costing showed a payback time of 7.4 years out of the 25-years suggested lifetime of building using the three passive solutions. The amount of CO2 emissions is 231.1 kg CO2e/annum with a primary energy demand of 0.032 GJ/m²/annum. As a follow-up to the initial study, a proof of concept has been implemented in Lund, Sweden, in an urban living lab to verify the simulation results through a 12-month post-occupancy monitoring and evaluation study.
... The treatment of pollutants using plants (phytoremediation) is mature and often applied for remediation of contaminated soil and water polluted with organic pollutants such as hydrocarbons. Biotreatment of indoor air using potted plants has been extensively studied and all plants tested were shown to be capable of removing VOCs from indoor air (Wolverton 1997;Wood et al. 2006;Liu et al. 2007;Yang et al. 2009;Irga et al. 2013;Pacheco-Torgal et al. 2015). A comprehensive overview of the research on botanic plants related to indoor air quality is provided by Irga et al. (2018). ...
... et al. (1981),Pacheco-Torgal et al. (2015),Yoneyama et al. (2002) ActiveEnhances the flow of pollutants to the root zone compared to passive systems, increasing the VOC and PM removal capacity. Among them around 50% removal of PM 2.5 and PM 10Lohr and Pearson-Mims (1996),Liu et al. (2007),Wang and Zhang (2011), Irga et al. removal (10-75% in a single-pass configuration) proven for BTEX, methylethylketone, formaldehyde, acetone, octane, a-pinene, decane, ethylacetate and ethylhexanolDarlington and Dixon (1999), Darlington et al. (2001), Llewellyn et al. (2002), Llewellyn and Dixon (2011), Mikkonen et al. (2018), Irga et al. (2019) Biofilter Active The removal of multiple typical indoor air pollutants such as toluene and formaldehyde was shown to be higher than 90% in a single-pass configuration. A mixture of 71 VOCs was tested in a biofilter inoculated with yeasts with most compounds removed Ondarts et al. (2012), Prenafeta-Boldú et al. performed with both microporous and dense-phase membranes provided a proof of concept for different VOCs and odorous compounds Van Ras (2005), Lebrero et al. (2013) Capillary bioreactor Active High removal rates (13 or 17 times greater than those tested biotrickling filters) of methanol and toluene were obtained Mass transfer capacity was studied with methane as model compound showing removal [ 100 g m -3 capillary channel h -1 López De León et al. (2019, 2020), Rocha-Rios et al. (2013), Kraakman et al. (2021) ...
Article
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Studies on human exposure to indoor air pollution reveal that indoor environments could be at least twice as polluted as outdoor environments. Indoor air pollution has not received as much attention than outdoor air pollution, despite an adult spending now most of the time indoors as a result of the global shift in the economy from the manufacturing sector towards the service and knowledge-based sectors, which operate in indoor office environments. Additionally, the health threats caused by a long-term exposure to indoor air pollution have become more apparent over the last decades as buildings are progressively sealed against the outside climate conditions to obtain heating and cooling energy cost savings and in response to stricter safety guidelines. Currently there is not a single technology that can efficiently provide a complete and satisfactory purification of indoor air. Biological systems for improving indoor air quality are promising, but challenges need to be examined to properly address the bioavailability of low pollutant concentrations, guarantee microbial safety, and incorporate CO2-removal. This study presents the recent research advances in biological indoor air purification methods as a ‘green’ alternative to physical–chemical methods, with emphasis on current challenges and opportunities it can provide for improving Indoor Environment Quality, building energy cost savings and improvements on indoor comfort and well-being. Graphical abstract
... Bitkilerin bu özelliği, bulundukları ortamdaki nemin düzenlenmesine imkân sağlar [13]. Ayrıca bitkilerinin havayı filtreleme özelliğinden dolayı bulundukları ortamın hava kalitesini arttırarak insan sağlığını olumlu etkilediği [13][14][15][16][17][18][19][20] ve termal konfor sağladığını [21] kanıtlayan birçok araştırma mevcuttur. Bu bağlamda iç mekânda bitkileri kullanarak kirleticilerin ortadan kaldırılması etkili ve ekonomik bir strateji olmakla beraber fizyolojik açıdan da oldukça önemlidir. ...
... 4,3) işlevleri sağlaması için bitki kullanımına yer verildiği belirlenmiştir (Tablo 2). Bitkilerin birçok bilimsel çalışma ile de ortaya konulmuş hava kalitesini iyileştirme, insan psikolojisine olumlu katkı sağlama, iş verimini artırma, sınırlama, yönlendirme işlevlerinin [4,9,[13][14][15][16][17][18][19][20][21][22][23][24][25][27][28][29][30][31][32][33][34] bitki tercihinde ikinci planda kaldığı anlaşılmıştır. . Bitkisel tasarım öğelerinin her biri kendi içinde değerlendirildiğinde tüm otellerde kullanılan iç mekân bitkilerinin sağladığı bitkisel tasarım öğeleri sırasıyla form (4,7), renk (4,2) ve ölçü (4,2), çizgi (4,1) ve doku (3,7) şeklindedir. ...
... For instance, Xu et al. [56] attempted to mirror more realistic conditions in what they referred to as a "dynamic" chamber, but no mention of air exchange was explicitly found in their work. Liu et al. [57] incorporated continuous airflow into their experiments, with constant upstream benzene concentrations of about 150 ppb. However, they maintained a very small chamber volume, inflating the relative influence of the plants. ...
... For the third category, computing CADR p necessitated the use of Eq. 5. The C outlet /C inlet expression within Eq. 5 may equivalently be thought of as the fractional VOC removal, which Liu et al. [57] reported using setup II for benzene. Three of their plant species yielded 60-80% removal, 17 species yielded 20-40%, another 17 yielded 10-20%, 13 removed less than 10%, and 23 did not yield any benzene removal. ...
Article
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Potted plants have demonstrated abilities to remove airborne volatile organic compounds (VOC) in small, sealed chambers over timescales of many hours or days. Claims have subsequently been made suggesting that potted plants may reduce indoor VOC concentrations. These potted plant chamber studies reported outcomes using various metrics, often not directly applicable to contextualizing plants' impacts on indoor VOC loads. To assess potential impacts, 12 published studies of chamber experiments were reviewed, and 196 experimental results were translated into clean air delivery rates (CADR, m3/h), which is an air cleaner metric that can be normalized by volume to parameterize first-order loss indoors. The distribution of single-plant CADR spanned orders of magnitude, with a median of 0.023 m3/h, necessitating the placement of 10-1000 plants/m2 of a building's floor space for the combined VOC-removing ability by potted plants to achieve the same removal rate that outdoor-to-indoor air exchange already provides in typical buildings (~1 h-1). Future experiments should shift the focus from potted plants' (in)abilities to passively clean indoor air, and instead investigate VOC uptake mechanisms, alternative biofiltration technologies, biophilic productivity and well-being benefits, or negative impacts of other plant-sourced emissions, which must be assessed by rigorous field work accounting for important indoor processes.
... Furthermore, these articles included a total of 55 illumination records, of which 35 were expressed in quanta. The maximum value was 350 μmol m −2 s −1 (Liu et al. 2007;Irga et al. 2013;Torpy et al. 2014), and the minimum value was 0 μmol m −2 s −1 (Dela Cruz et al. 2014). In addition, 20 records were reported using illuminance with a maximum value of 20,000 lx (Sevik et al. 2017) and minimum value of 0 lx (Baosheng et al. 2009). ...
... Leaf area 24,300 (experiment) 7.50 (experiment) (Teiri et al. 2018) (Ruan 2012) Green coverage ratio 40 (field experiment) 30 (field experiment) (Li et al. 2006) (Li et al. 2006) Volume (%) 10 (experiment) 1 (field experiment) (Song et al. 2007;Song et al. 2011) ( T u d i w e r a n d K o r j e n i c 2017) ) n-Hexane 150 (experiment) 100 (experiment) (Wood et al. 2002) (Wood et al. 2002) Temperature (°C) 39.6 (experiment) 15 (experiment) (Papinchak et al. 2009) (Sevik et al. 2017) Humidity (%) 80 (experiment) 25 (experiment) (Lim et al. 2009;Panyametheekul et al. 2018) (Li et al. 2006;Liang et al. 2015;Kerschen et al. 2016) Illuminance (lux) 20,000 (experiment) 0 (experiment) (Sevik et al. 2017) (Baosheng et al. 2009) Quantum (μmol m −2 ·s −1 ) 350 (experiment) 0 (experiment) (Liu et al. 2007;Irga et al. 2013;Torpy et al. 2014 (Li et al. 2015a) ...
Article
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No study has comprehensively reviewed the effects of indoor plants on air quality; therefore, this study systematically reviewed quantitative empirical research on these effects in both English and Chinese. The information sources were the Web of Science and WanFang Data Knowledge Service Platform electronic databases. Only journal articles reporting quantitative empirical research were selected. The eligibility criteria included studies with (1) interventions of any indoor plant, excluding biofilters that combine power facilities and vegetation, (2) comparators included within the same experimental treatment or between different experimental treatments, (3) air quality effects objectively measured using any instrument, and (4) any study design. Both authors screened 95 journal articles and compiled information according to (1) intervention (plant species, foliage, or medium), (2) scientific family name of each plant, (3) study design (experiment, field experiment, or survey), (4) air quality (e.g., temperature, humidity, negative ions, radiation, and dust), (5) pollutants, (6) research environment, (7) ventilation (types and rates), (8) climate (lighting, temperature, and humidity), (9) exposure duration, (10) sampling frequency or period, and (11) number of replications. The primary effects of the potential of the indoor plants on air quality were reduced pollutant levels (particularly formaldehyde, benzene, and toluene removal), followed by increase in humidity and decrease in temperature. In addition, including various plant species could improve the effects of indoor vegetation on ameliorating air quality and microclimate conditions.
... Usually, when describing experimental conditions, details related to plant fertilisation are either omitted (Liu et al., 2007;Yang et al., 2009;Kim et al., 2011;Dela Cruz et al., 2014;Mosaddegh et al., 2014;Hörman et al., 2018;Panyametheekul et al., 2019) or it is noted that a commercially-available or any other substrate was used without indication of amounts of plant-available mineral nutrients (Yoo et al., 2006;Gawroñska and Bakera, 2015;Teiri et al., 2018). In some studies, slow-release fertilisers were used (Orwell et al., 2006). ...
Article
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The aim of the present study was to evaluate the effect of different levels of mineral nutrient availability on development and physiological performance of several common indoor ornamental plant species (Anthurium sp., Chlorophytum comosum, Epipremnum aureum, Plectranthus fruticosus, Spathiphyllum sp., and Tradescantia pallida) cultivated in hydroponics with potential use in active botanical biofilter systems. Plants were grown in expanded clay granules at four levels of mineral nutrient availability provided by two types of commercial mineral fertiliser. The growth stimulative effect of increased mineral nutrient availability depended on plant growth rate, with a lower effect on slower growing species. The need for nutrients increased in the order Anthurium < Spathiphyllum < Epipremnum < Chlorophytum < Tradescantia < Plectranthus. Tissue water content showed pronounced differences between various plant species as well as between plant organs. For several species, increase in mineral nutrient availability resulted in a significant increase in tissue water content. Chlorophyll fluorescence analysis showed that indoor plants can successfully adapt to low and moderate mineral fertiliser levels with balanced individual nutrient rates, without negative consequences to photochemistry of photosynthesis. Consequently, indoor plants can be cultivated at a relatively low concentration of mineral nutrients for optimum utilisation in active botanical biofilter systems.
... Many studies confirmed that ornamental plants are able to accumulate VOCs and reduce their concentration in the indoor environments (Aydogan and Montoya, 2011;Hörmann et al., 2017;Liu et al., 2007;Parseh et al., 2018;Soreanu et al., 2013;Teiri et al., 2018;Wetzel and Doucette, 2015;Yang et al., 2009). For example, ivy (Hedera helix L.) is considered as a bioprotective species (Sternberg et al., 2010) and is capable of absorbing atmospheric particles, as well as certain species of Nephrolepis, Epipremnum and Spathiphyllum genus (Wolverton and Wolverton, 1993). ...
Article
Currently, the population spends most of the time in indoor environments, which makes Indoor Air Quality (IAQ) very important for health and comfort. As vegetation can act as a biofilter capturing air pollutants, this study aims to assess the effectiveness of a living wall module in the removal of the Total Volatile Organic Compounds (TVOCs) for IAQ improvement. An airtight glass chamber was used to release contaminants, monitoring the TVOCs both with the chamber empty (control) and with a small Fytotextile® living wall module planted with Nephrolepis exaltata L. A substantial reduction of TVOCs was observed when the living wall was inside the chamber. In few hours, TVOCs levels were reduced below the recommended limit (following Spanish regulations). More tests are recommended considering different plant species and other variables related to the IAQ.
... Plants, bio filter system, and their associated microbes in the growing medium are known to remove certain VOCs (phytoremediation) and are thought to possibly be an effective means of removing VOCs from indoor air; however, only a very small number of VOCs to date have actually been shown to be removed (Fraser Torpy et al. 2018;Kays 2011;Kim et al. 2018; Naomi J. Paul et al. 2019;Pettit et al. 2019), i.e., acetone, benzene, benzaldehyde, n-butyraldehyde, iso-butyraldehyde, crotonaldehyde, diethyl ketone, formaldehyde, methacrolein, methyl ethyl ketone, methyl isobutyl ketone, methyl n-propyl ketone, methyl iso-propyl ketone, octane, pentane, α-pinene, propionaldehyde, toluene, trichloroethylene, and xylene (Aydongan and Montoya 2011;Chen et al. 2010;Cornejo et al. 1999;Kim et al. 2008;Kim et al. 2010;Kim et al. 2011;Liu et al. 2007;Orwell et al. 2004;Orwell et al. 2006;Oyabu et al. 2003;Son et al. 2000;Tani and Hewitt 2009;Tarran et al. 2007;Wolverton 1986;Wolverton et al. 1984;Wolverton and Wolvertion 1993;Xu et al. 2011). The phytoremediation potential of plant-microbe systems varies with plant species, microbe population, time of day, VOC composition and concentrations, and other factors. ...
Article
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The composition of volatile organic compounds (VOCs) in the air of homes and offices is often complex and can have a significant effect on the health of individuals exposed. Certain plant species and their associated microorganisms are known to remove VOCs from the air; however, the rate of removal of one VOC may be influenced by the presence of others. We investigated the effect of VOCs on toluene phytoremediation rate by comparing the interaction of toluene, xylene, and benzene, common indoor odorants. Golden pothos (Epipremnum aureum (L.) Engl.) and Cornstalk (Dracaena fragrans (L.) Ker Gawl.) were exposed to different concentrations of one or more gases in a sealed chamber. The removal of 0.9 μL L−1 toluene was little affected by the addition of 0.9 μL L−1 xylene until the concentration was ≥ 1.8 μL L−1. At 1.8 and 2.7 μL L−1 xylene, there was a progressive decline in toluene removal. Similarly, at 1 μL L−1 toluene, 1 μL L−1 of xylene did not have a significant effect on phytoremediation; however, with the addition of 1.0 μL L−1 benzene, removal of toluene declined an average of 50% in both plant species. The addition of xylene reduced toluene removal by 39% and with xylene + benzene 58% when the total VOC concentration remained constant, but total VOC removal by the plants was similar. Since homes and offices generally have a much more diverse VOC composition than described in this study, VOC interaction effects on phytoremediation are probably more complex in real-world situations.
... Indoor air can be more contaminated than outdoor air and may lead to serious health problems related to the length of exposure (Liu, 2007). People, particularly living in urban areas, spend up to 90% of their time in indoor environments (Klepeis N.E., 2001;Robinson, 1995;USEPA, 2002). ...
... Indoor air quality (IAQ) improvement can be done mainly through three ways namely, controlling the sources, designing a ventilation system to exhaust contaminated air and cleaning air (Liu et al., 2007). Plants can be used to remove indoor air pollutants. ...
Article
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Use of plants to improve Indoor Air Quality (IAQ) has received a considerable attention over the past three decades. However, little attention has been paid on managing indoor CO2 levels with plants. Although not normally regarded as toxic, at elevated concentrations, CO2 can act as a simple narcotic, and has been associated with sick building syndrome (SBS). The present study intended to investigate the effectiveness of 18 indoor plants in managing indoor CO2 levels. Indoor-acclimatized plants were placed into an airtight glass chamber (0.32 m 3) individually with 500±50 lux of supplementary lighting. The CO2 concentration inside the chamber was monitored for 24 hrs continuously using a monitoring devise with a data logger. The best performing 11 species were selected and subjected to 700±50 lux. Based on the results, three net CO2 emission patterns were observed; i) net CO2 concentration increased during the night and then maintained at a constant level during the day, ii) net CO2 concentration increased during the night and then decreased during the day, iii) net CO2 concentration decreased during night and then increased during the day. In all tested species, the response was significantly (p<0.05) higher under 700 lux compared to 500 lux. The Performance Index (PI), which is a derived parameter of OJIP chlorophyll fluorescence analysis, confirmed the healthiness of the 11 species inside the chamber. As per the PI, the species which belong to CAM pathway and species belong to family Araceae performed better in early day time and all other species performed better in the evening. Based on the results, species such as Zamioculcas zamiifolia, Dieffenbachia amoena, Philodendron hederacea, Ficus benjamina, Licuala grandis, Dracaena surculosa, Livistonia chinensis, Calathia zebrina can be recommended for office spaces to be used during the day time whereas species such as Cactus, Bromelia spp: and Sansevieria are ideal for the bed rooms during night time.
... Phytoremediation is an established method for the treatment of polluted soils and waters. The application of botanical systems to indoor environments has been shown effective for removing VOCs and PM (Liu et al., 2007;Pacheco-Torgal et al., 2015;Torpy et al., 2014;Wood et al., 2006;Yang et al., 2009). Botanical technologies can be divided into passive (e.g. ...
Article
Indoor air pollution has traditionally received less attention than outdoors pollution despite indoors pollutant levels are typically twice higher, and people spend 80–90% of their life in increasing air-tight buildings. More than 5 million people die every year prematurely from illnesses attributable to poor indoor air quality, which also causes multi-millionaire losses due to reduced employee’s productivity, material damages and increased health system expenses. Indoor air pollutants include particulate matter, biological pollutants and over 400 different chemical organic and inorganic compounds, whose concentrations are governed by several outdoor and indoor factors. Prevention of pollutant is not always technically feasible, so the implementation of cost-effective active abatement units is required. Up to date no single physical-chemical technology is capable of coping with all indoor air pollutants in a cost-effective manner. This problem requires the use of sequential technology configurations at the expenses of superior capital and operating costs. In addition, the performance of conventional physical-chemical technologies is still limited by the low concentrations, the diversity and the variability of pollutants in indoor environments. In this context, biotechnologies have emerged as a cost-effective and sustainable platform capable of coping with these limitations based on the biocatalytic action of plants, bacteria, fungi and microalgae. Indeed, biological-based purification systems can improve the energy efficiency of buildings, while providing additional aesthetic and psychological benefits. This review critically assessed the state-of-the-art of the indoor air pollution problem and prevention strategies, along with the recent advances in physical-chemical and biological technologies for indoor pollutants abatement.
... 长期摄入空气中的超量VOC, 会对人体的呼 吸系统、造血系统和神经系统等产生慢性或急性损害, 包括哮喘、急性中毒、神经系统障碍、肝功能异常, 甚至诱发白血病及产生致癌效应 [4] . 世界卫生组织 的健康影响并不相同, 如苯类化合物会损伤动物的神 经中枢, 造成神经系统障碍等 [5,6] ; 某些多环芳烃、芳 香胺、醛类、卤代烷等物质对机体有致癌作用 [7] . 随 着公共卫生的发展及人类认知的提高, 越来越多的 VOC的健康危害被确认并纳入清单或分类等级发生变 化, 如2012年甲醛被修订确认纳入1类致癌物清单中 [8] . ...
... Different plant species, which can have different effects on wellbeing, cannot be distinguished using RGB imagery. For example, the amount of volatile organic compounds removed by interior greenery varies widely by plant species [57]. These issues could be overcome by capturing interior greenery using near-infrared sensors [58], although these are more expensive than a panoramic camera. ...
Article
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Many people spend the majority of their time indoors and there is emerging evidence that interior greenery contributes to human wellbeing. Accurately capturing the amount of interior greenery is an important first step in studying its contribution to human well-being. In this study, we evaluated the accuracy of interior greenery captured using 360° panoramic images taken within a range of different interior spaces. We developed an Interior Green View Index (iGVI) based on a K-means clustering algorithm to estimate interior greenery from 360° panoramic images taken within 66 interior spaces and compared these estimates with interior greenery measured manually from the same panoramic images. Interior greenery estimated using the automated method ranged from 0% to 34.19% of image pixels within the sampled interior spaces. Interior greenery estimated using the automated method was highly correlated (r = 0.99) with interior greenery measured manually, although we found the accuracy of the automated method compared with the manual method declined with the volume and illuminance of interior spaces. The results suggested that our automated method for extracting interior greenery from 360° panoramic images is a useful tool for rapidly estimating interior greenery in all but very large and highly illuminated interior spaces.
... However, sensing the smell of common forest BVOCs may also have a role in stress relief. MTs such as α-pinene and limonene are associated with the scent of clean or "fresh air" and are often used air fresheners for indoor air in households (Liu et al. 2007). Tsunetsugu et al. (2009) analysed Japanese studies of "forest bathing" ("Shinrin-yoku") and found that sensing of a weak smell of α-pinene, a major conifer forest BVOC, induces a relaxed physiological state in humans, whereas a relatively strong smell of α-pinene, such as the one released after intensive logging of conifers, induces a stress state in the human body. ...
Article
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Living trees are the main source of biogenic volatile organic compounds (BVOCs) in forest ecosystems, but substantial emissions originate from leaf and wood litter, the rhizosphere and from microorganisms. This review focuses on temperate and boreal forest ecosystems and the roles of BVOCs in ecosystem function, from the leaf to the forest canopy and from the forest soil to the atmosphere level. Moreover, emphasis is given to the question of how BVOCs will help forests adapt to environmental stress, particularly biotic stress related to climate change. Trees use their vascular system and emissions of BVOCs in internal communication, but emitted BVOCs have extended the communication to tree population and whole community levels and beyond. Future forestry practices should consider the importance of BVOCs in attraction and repulsion of attacking bark beetles, but also take an advantage of herbivore-induced BVOCs to improve the efficiency of natural enemies of herbivores. BVOCs are extensively involved in ecosystem services provided by forests including the positive effects on human health. BVOCs have a key role in ozone formation but also in ozone quenching. Oxidation products form secondary organic aerosols that disperse sunlight deeper into the forest canopy, and affect cloud formation and ultimately the climate. We also discuss the technical side of reliable BVOC sampling of forest trees for future interdisciplinary studies that should bridge the gaps between the forest sciences, health sciences, chemical ecology, conservation biology, tree physiology and atmospheric science.
... Plants can also be used for phytoremediation, the removal of toxins from the air to ameliorate indoor air quality. The ability of species to remove benzene, formaldehyde, and other indoor air pollutants has been proven by studies (Liu et al. 2007;Aydogan and Montoya 2011). ...
Book
The open access book discusses human health and wellbeing within the context of built environments. It provides a comprehensive overview of relevant sources of literature and user complaints that clearly demonstrate the consequences of lack of attention to health in current building design and planning. Current designing of energy-efficient buildings is mainly focused on looking at energy problems and not on addressing health. Therefore, even green buildings that place environmental aspects above health issues can be uncomfortable and unhealthy, and can lead to public health problems. The authors identify many health risk factors and their parameters, and the interactions among risk factors and building design elements. They point to the need for public health specialists, engineers and planners to come together and review built environments for human wellbeing and environmental sustainability. The authors therefore present a tool for holistic decision-making processes, leading to short- and long-term benefits for people and their environment.
... Plants can also be used for phytoremediation, the removal of toxins from the air to ameliorate indoor air quality. The ability of species to remove benzene, formaldehyde, and other indoor air pollutants has been proven by studies (Liu et al. 2007;Aydogan and Montoya 2011). ...
Chapter
This chapter highlights the importance of identifying health risk factors and their parameters for healthier built environments. In Sect. 3.1, epidemiological terms such as “determinants of health”, “health risk” and “health hazards”, are introduced. In Sect. 3.2, health risk factors and their main parameters in built environments are further identified and classified into six groups: biological, chemical, physical, psychosocial, personal, and others. Detailed definition of health risk factors and their main parameters, followed by the results of epidemiological studies proving the association between potential health outcomes and health risk factors, are described in Sects. 3.3, 3.4, 3.5, 3.6 and 3.7. Identified and classified health risk factors and their parameters are the basis for the identification of single and multi-group interactions among them, described in Chap. 4.
... Having plants in your house offers a wide range of benefits for human's physical and psychological health such as providing air purification [1], reducing stress [2] and boosting productivity [3]. Many people are aware of these benefits, however, not many have plants in their home because they think they lack the ability to take care of houseplants. ...
... Furthermore, in order to accurately assess the VOC removal efficiency of plants, the traditional method of the test chamber has been improved [10], and a great deal of research has been conducted. Most of these research has focused on treating benzene in indoor air by C3 plants and has found that they have potential to improve indoor air quality [11][12][13][14][15]. However, few studies have focused on the benzene removal efficiency of crassulacean acid metabolism (CAM) plants [16], which is a type of effective phytoremediation plant and a common ornamental plant in indoor environments. ...
Article
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The concentration of benzene in indoor air has received appreciable attention due to its adverse health effects. Although phytoremediation has been considered as an eco-friendly method to remove benzene, it is unclear how to select plants with a high removal rate. In this study, we evaluated the benzene removal efficiency of four common ornamental plants, Epipremnum aureum, Chlorophytum comosum, Hedera helix and Echinopsis tubiflora, and we also explored the factors impacting benzene removal efficiency. The removal efficiency of all plants in this study averaged at 72 percent. The benzene absorption rates of Epipremnum aureum, Hedera helix and Chlorophytum comosum were 1.10, 0.85 and 0.27 µg·m−3·cm−2, respectively. This is due to the different transpiration rates and chlorophyll concentrations in the plants. The benzene removal efficiency of crassulacean acid metabolism plant (Echinopsis tubiflora) was 23% higher than C3 plant (Epipremnum aureum) under dark conditions. This can be attributed to the fact that the characteristic of Echinopsis tubiflora stomata is different from Epipremnum aureum stomata, which is still open under dark conditions. Therefore, Echinopsis tubiflora can take up more benzene than Epipremnum aureum. For different initial benzene concentrations, the benzene removal efficiency of Echinopsis tubiflora was always great (50–80%), owing to its high rate of transpiration and concentration of chlorophyll. Our findings indicate that transpiration rate and chlorophyll concentration can be used as reference parameters to facilitate ornamental plant screening for indoor air quality improvement.
... Besides this plant, other efficient species for removing formaldehyde are: Osmunda japonica, Davallia mariesii, Selaginella tamariscina, Polypodium for- mosanum, Lavandula spp., Pteris dispar, Pteris multifida, Pelargonium spp., Aloe vera, and E. aureum (Kim et al., 2010). Phytoremediation of benzene may be achieved through Crassula por- tulacea, Hydrangea macrophylla, Cymbidium "golden elf", Syngonium podophyllum, Euphorbia milii, S. trifasciata, C. comosum, Dracena sanderi- ana, H. helix, and Clitoria ternatea, with C. como- sum reportedly having the highest efficiency ( Liu et al., 2007). Toluene may be effectively removed by Schefflera elegantisima, Philodendron spp. ...
... For example, Collins et al. (2000) found that the uptake of benzene in blackberry and apple leaves was greater than that of cucumber leaves. Leaves of various indoor plants were the primary plant parts for removing benzene (Cornejo et al. 1999;Liu et al. 2007;Mosaddegh et al. 2014;Yang et al. 2009a). It was assumed that enzymes were performing the first step in the oxidative transformation of benzene in plant leaves containing copper as the prosthetic group (Ugrekhelidze et al. 1997). ...
Article
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Humans have a close relationship with nature, and so integrating the nature world into indoor space could effectively increase people’s engagement with nature, and this in turn may benefit their health and comfort. Since people spend 80–90% of their time indoors, the indoor environment is very important for their health. Indoor plants are part of natural indoor environment, but their effect on the indoor environment and on humans has not been quantified. This review provides a comprehensive summary of the role and importance of indoor plants in human health and comfort according to the following four criteria: photosynthesis; transpiration; psychological effects; and purification. Photosynthesis and transpiration are important mechanisms for plants, and the basic functions maintaining the carbon and oxygen cycles in nature. Above all have potential inspiration to human’s activities that people often ignored, for example, the application of solar panel, artificial photosynthesis, and green roof/facades were motivated by those functions. Indoor plants have also been shown to have indirect unconscious psychological effect on task performance, health, and levels of stress. Indoor plants can act as indoor air purifiers, they are an effective way to reduce pollutants indoor to reduce human exposure, and have been widely studied in this regard. Indoor plants have potential applications in other fields, including sensing, solar energy, acoustic, and people’s health and comfort. Making full use of various effects in plants benefit human health and comfort.
... [23,24] Numerous plants can remove formaldehyde from indoor air. [2,25,26] Plant leaves uptakes formaldehyde through stomata and the cuticle, and younger leaves readily absorb the formaldehyde vapors. [3,27] Besides, some researches have shown that soil microorganisms are capable of degrading pollutants and this degradation is suggested to be encouraged by root exudates. ...
Article
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Background Formaldehyde is a common hazardous indoor air pollutant which recently raised public concerns due to its well-known carcinogenic effects on human. The aim of this study was to investigate a potted plant-soil system ability in formaldehyde removal from a poor ventilated indoor air to promote dwellers health. Methods For this purpose, we used one of the common interior plants from the fern species (Nephrolepis obliterata), inside a Plexiglas chamber under controlled environment. Entire plant removal efficiency and potted soil/roots contribution were determined by continuously introducing different formaldehyde vapor concentrations to the chamber (0.6–11 mg/m³) each over a 48-h period. Sampling was conducted from inlet and outlet of the chamber every morning and evening over the study period, and the average of each stage was reported. Results The results showed that the N. obliterata plant efficiently removed formaldehyde from the polluted air by 90%–100%, depending on the inlet concentrations, in a long time exposure. The contribution of the soil and roots for formaldehyde elimination was 26%. Evaluation of the plant growing characteristics showed that the fumigation did not affect the chlorophyll content, carotenoid, and average height of the plant; however, a decrease in the plant water content was observed. Conclusions According to the results of this study, phytoremediation of volatile organic compound-contaminated indoor air by the ornamental potted plants is an effective method which can be economically applicable in buildings. The fern species tested here had high potential to improve interior environments where formaldehyde emission is a health concern.
... İç mekan süs bitkileri hava kalitesini artırdığı gibi insan-doğa arasındaki bağı güçlü kılmaktadır. Liu (2007) Gözener, 2016). Tüketici tercihlerinin belirlenmesi ile ilgili yapılan araştırmalarda genel bir çerçeve de incelendiğinde bölgesel ve yerel katkıları ve önerileri ön plana çıkmaktadır. ...
... Hence, putting potted plants in the indoor environment will be a good option because they could act as a less expensive and sustainable indoor air purifier through bioremediation process. For instance, the evidences provided by Liu et al. (2007) Wood et al. (2002) provided evidence that D. deremensis 'Janet Craig' is effective in removing benzene, while H. Forsteriana is better in removing n-hexane. It is also worth to note that, plants in hydroponic growing media removed VOC slower than potting mix (ibid). ...
Article
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People tend to spend approximately 87% of their time in the indoor environment. There is a possibility that they are exposed to volatile organic compound (VOC) and particle pollution, and to experience stress related disorder. This has potential threaten the well-being of indoor occupants if left untreated. Hence, plants were introduced to alleviate these negative impacts. This paper reviews past literature from 1990 to 2010s, to examine the relationship of plants with indoor environment and identifies how they influence people, psychologically and physiologically, and how they promote indoor environment quality. Most studies suggest that the presence of plants is associated with positive feelings and able to enhance productivity. In addition, they also may help to promote general health such as reducing blood pressure, perceived stress, sick building syndrome, and increase pain tolerance of the patient. Moreover, plants also help in improving the indoor environment quality (IEQ), for instance, they can reduce carbon dioxide (CO2), indoor ozone (O3) level, VOC, and particulate matter accumulation through bioremediation process. Despite all the benefits that the plants could offer, several studies pointed out that factors such as gender, perceived attractiveness of the space, physical characteristics of plants, and methods of interaction with plants may lead to non-identical results. Hence, the selection of the right species of plant in an indoor environment becomes mandatory in order to improve the indoor environment quality; to provide restorative effect; to invoke positive feelings and comfort of the people. In conclusion, this review may provide notable insights to landscape architects, gardeners and even interior designers to choose the right species of plant in an indoor environment, to maximize their psychological and physiological benefits, at the same time, improving indoor environment quality.
... Plants continue to function as atmospheric Þ lters indoors as they do outdoors and enhance the air quality of conÞ ned environments. Studies show that indoor plants are effective at removing VOCs (Orwell et al., 2004;Liu et al., 2007). Orwell et al. (2004) Green Dragon Tree (Dracaena deremensis 'Janet Craig') was found to be the species with the largest capacity to remove benzene from indoor air. ...
Chapter
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Healthy, peace and stress less human life through ornamental and flowering plants
... Three plants of every species were chosen for the tests and they were selected with similar characteristics of age and size (Peace lily: 0.35m height; Boston fern: 0.30 m height). The plants were selected based on information gathered by previous studies, which demonstrated that the capability of these species in uptake of some VOCs was good (Liu et al. 2007; Wolverton and Wolverton 1993;Wood et al. 2002). And they were also chosen because they can be used in Living Wall Systems (LWSs) and/or green walls, besides, they are commonly used for indoor decoration. ...
Preprint
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Potted plants have been reported to uptake VOCs and help ‘cleaning’ the air. This paper presents the results of a laboratory study in which two species of plants (Peace Lily and Boston Fern) and three kinds of substrates (expanded clay, soil and activated carbon) were tested and monitored on their capacity to deplete formaldehyde and CO 2 in a glass chamber. Formaldehyde and CO 2 were selected as indicators to evaluate the bio-filtration efficacy of 28 different test conditions; relative humidity (RH) and temperature (T) were monitored during the experiments. To evaluate the efficacy of every test the Clean Air Delivery Rate (CADR) was calculated. Overall, soil had the best performance in removing formaldehyde (~ 0.07–0.16 m ³ /h), while plants, in particular, were more effective in reducing CO 2 concentrations (Peace lily 0.01m ³ /h) (Boston fern 0.02-0.03m ³ /h). On average, plants (~ 0.03 m ³ /h) were as effective as dry expanded clay (0.02–0.04 m ³ /h) in depleting formaldehyde from the chamber. Regarding air cleaning performance, Boston ferns presented the best performance among the plant species, and the best performing substrate was the soil.
... S. Panyametheekul et al. [15] reported that Boston fern, golden pothos, Spanish moss, and spider plant remove formaldehyde faster than the artificial fern, dumb cane, aloe vera, and Chinese evergreen. Liu et al. [58] stated that VOCs are efficiently removed via Hedera helix, Tradescantia pallida, Hoya camosa, Crassula portulacea, and Hemigraphis alternata. In contrast, Aydogan and Montoya (2011) noted a quadruple variation between the least (H. ...
Article
Volatile organic compounds (VOCs) have increased public concern in terms of their adverse effects on health. Amongst VOCs, formaldehyde is significantly found indoors which can cause lung, leukemia, and nasopharyngeal cancers. Therefore, the requirement to find a suitable method and diminish the energy consumption of buildings has increased. Recent progress in vertical greenery systems has led to active systems known as active botanical biofilters. The current research represents an assessment of several essential parameters, based on the full-factorial model, for determining the functionality of a modular botanical biofilter and evaluating the role of plants and substrate to remove formaldehyde from the gas stream. Our findings showed that the maximum formaldehyde single-pass removal efficiency (SPRE) of 99.99% occurred at the lowest air flow rate (0.8 L/s) and concentration (0.3 mg/m³) through the 0.25 m² filter, with any increases in air flow rate, met with a reduction in efficiency. At the same time, the utmost Clean Air Delivery Rate (CADR) of 17.46 m³/h was achieved at 5.5 L/s and 0.3 mg/m³. However, the system met the maximum Elimination Capacity (EC) of 30.64 mg/h at the highest inlet airflow (5.5 L/s) and pollutant concentration (2.06 mg/m³). Despite the role of biofilter segment to remove formaldehyde, the botanical components were found to be responsible for the system's SPRE of 13.51–28.07%, CADR of 0.39–5.46 m³/h, and EC of 0.12–11.45 mg/h. If the system is to meet current air standards, further development is required to increase its elimination capacity.
... Three plants of every species were chosen for the tests, and they were selected with similar characteristics of age and size (peace lily: 0.35 m height; Boston fern: 0.30 m height). The plants were selected as potential air cleaners based on information gathered by previous studies, which demonstrated that the capability of these species in uptake of some VOCs was good [30,33,34], and they were also chosen because they can be used in living wall systems (LWSs) and/or green walls and are commonly used for indoor decoration. The plants were bought in a house-plant shop in the Netherlands and were repotted 25 days prior to the experiments, to minimize the stress of the plant, in a 14 cm diameter plastic pot of 1.1 L (0.0011 m 3 ) of expanded clay growth medium. ...
Article
Full-text available
Potted plants have been reported to uptake VOCs and help “cleaning” the air. This paper presents the results of a laboratory study in which two species of plants (peace lily and Boston fern) and three kinds of substrates (expanded clay, soil, and activated carbon) were tested and monitored on their capacity to deplete formaldehyde and CO2 in a glass chamber. Formaldehyde and CO2 were selected as indicators to evaluate the biofiltration efficacy of 28 different test conditions; relative humidity (RH) and temperature (T) were monitored during the experiments. To evaluate the efficacy of every test, the clean air delivery rate (CADR) was calculated. Overall, soil had the best performance in removing formaldehyde (~0.07–0.16 m3/h), while plants, in particular, were more effective in reducing CO2 concentrations (peace lily 0.01m3/h) (Boston fern 0.02–0.03 m3/h). On average, plants (~0.03 m3/h) were as effective as dry expanded clay (0.02–0.04 m3/h) in depleting formaldehyde from the chamber. Regarding air-cleaning performance, Boston ferns presented the best performance among the plant species, and the best performing substrate was the soil.
... (moth orchids), showed a significant potential of removing formaldehyde from the indoor environment (Kim and Lee, 2008). Among 73 ornamental plants, only 10 were reported to have efficacy in eliminating benzene (Liu et al., 2007). According to the observation made by Kim and colleagues in their experiment, ferns are two to three times more capable of removing formaldehyde among all the other groups of plants, depending on the leaf area parameter (Kim et al., 2010). ...
... Several studies have revealed the use and significant role of plant species in monitoring and maintaining the ecological balance of environment. This include the potency for impingement, absorption and accumulation and initial acceptors of air pollutants for clean air inboth ambient and polluted condition (Escobedo et al., 2008;Liu and Ding, 2008;Joshi and Swami, 2009), filter for dust and sink of air pollutants to check rising pollution level (Prajapati and Tripathi, 2008), evaluation of the impact of air pollution on plants as well as potential sensitivity and tolerance using chlorophyll content (Flowers et al., 2007); ascorbic acid content (Hoque et al., 2007); leaf pH (Klumpp et al.,2000) and relative water content (Rao, 2006); leaf or stomatal conductance, membrane permeability, peroxidase activity (Farooq and Beg, 1980, William and Christopher, 1986, Tripathi et al., 1991 and also the ability of plant species to detoxify the air as well as indicator of the possibility of synergistic action of pollutants (Liu et al., 2007;Jayashnee 2012;Lakshmi et al., 2008). All these imply a very close relationship between nature and plant species, and if any altered condition occurs in the atmosphere, it directly affects the physiological and biochemical constituents of plant. ...
Article
Full-text available
The screening of plant species is of environmental significance hence their sensitivity as bioindicator as well as their tolerance as biomonitoring agent in air pollution mitigation have been established. The present research was aimed at evaluating the potential response of arboreal epiphytes as bioindicator under ambient condition, with the objective of identifying species that can serve as biomonitoring baseline agent for impact prediction and judgment of air pollution. Classical conventional methods were used to evaluate the susceptibility level of the epiphytes under ambient environmental condition using four established physiobiochemical parameters: leaf extract pH, relative water content, ascorbic acid, and chlorophyll to extrapolate Air Pollution Tolerance Index (APTI) for 8 species. Result revealed three categories of APTI responses: APTI 1-10 = sensitivity; APTI 10.01-13 = intermediate and APTI 13.01-16 above = tolerance. The order of responses in sensitivity: Platycerum bifurcatum>Oleandra distenta>Nephrolepis bisserata; intermediate: Nephrolepis undulata>Nephrolepis pumicicola and tolerance: Platycerum stagelephantotis > marattia fraxinea> Platycerum grande were recorded. The order of response indicated P. stagelephantotis with higher APTI (15.19) reflecting higher tolerance level and least APTI (6.46) for N. bisserata indicating sensitivity under ambient condition as baseline against air pollution. Therefore by their level potential responses at the ambient level can be recommended for phytosequestration / mitigation hence the APTI sensitive and tolerant species can serve as bioindicator and biomonitor respectively. Such performance might be very useful in the selection of appropriate epiphytic species that can enhance the expected performance of canopy formation of greenbelt in a changing environmental condition.
... Then, using the best performing substrate size fraction with the incorporation of activated carbon adsorbents, further possible improvements in pollutant removal were tested. Finally the best performing substrate identified was tested in a full-scale botanical biofilter with plants, using the species Nephrolepis exaltata bostoniensis, as this species has previously been identified as an efficient phytoremediator of PM [23] and VOCs [7,24]. ...
Article
Functional green walls are gaining attention due to their air cleaning abilities, however the air cleaning capacity of these systems may be improved through substrate modification. This experiment investigated the capacity of several green wall media to filter a range of air pollutants. Media, consisting of differently sized coconut husk-based substrates, and with different ratios of activated carbon were evaluated through the use of scaled down model 'cassettes'. Tests were conducted assessing each substrate's ability to filter particulate matter, benzene, ethyl acetate and ambient total VOCs. While the particle size of coconut husk did not influence removal efficiency, the addition of activated carbon to coconut husk media improved the removal efficiency for all gaseous pollutants. Activated carbon as a medium component, however, inhibited the removal efficiency of particulate matter. Once the substrate concentration of activated carbon approached ∼50%, its gas remediation capacity became asymptotic, suggesting that a 50:50 composite medium provided the best VOC removal. In full-scale botanical biofilter modules, activated carbon-based substrates increased benzene removal, yet decreased particulate matter removal despite the addition of plants. The findings suggest that medium design should be target pollutant dependent, while further work is needed to establish plant viability in activated carbon-based media.
... Even so, reductions of 73 and 84% were achieved at 72 h. Other studies also considered S. wallisii as one of the least efficient species in the removal of TVOCs [28,38]. In fact, in a study assessing formaldehyde removal by 20 different herbaceous foliage species, S. wallisii figured in the lower quarter [17]. ...
Article
Full-text available
Poor indoor quality affects people’s health and well-being. Phytoremediation is one way in which this problem can be tackled, with living walls being a viable option for places with limited space. The aim of this study was to evaluate the efficiency of five plant species in a living wall to remove Volatile Organic Compounds (VOCs) and to identify whether the type of pollutant has any influence. An enclosed chamber was used to add the contaminants n-hexane and formaldehyde independently. Total VOCs were measured for three days in two scenarios: (1) empty chamber, and (2) chamber with living wall. Five living walls were prepared, each with three plants of the same species: Spathiphyllum wallisii, Philodendron hederaceum, Ficus pumila, Tradescantia pallida, and Chlorophytum comosum. There was no correlation between leaf area/fresh weight/dry weight and the contaminant reduction. In general, all five species were more efficient in reducing TVOCs when exposed to formaldehyde than to n-hexane. Chlorophytum comosum was the most efficient species in reducing the concentration of TVOCs for both contaminants, Spathiphyllum wallisii being the least efficient by far.
... Along with the advancement of mechanical devices for indoor air pollution control, in the long run, building professionals are showing great interest in indoor plant-based air purification systems for several potential mechanisms of leaf surface, stomata, and plant roots. These include adsorption and absorption capacity of gaseous air pollutants and particulate material (PM); degradation capacity of gaseous air pollutants; CO 2 removal and O 2 supply; increase in humidity; and reduction in bioaerosols (Newman and Reynolds, 2004;Orwell et al., 2004;Kohlrausch et al., 2006;Liu et al., 2007;Llewellyn and Dixon, 2011). However, the limitations of the potted plant and green wall approaches initiated the research for more advanced green wall-based air purification systems, which allow the intimate contact of polluted air with the microorganisms in the rhizosphere zone of the plants to maximize the phytoremediation process by creating an airflow through mechanical devices. ...
Article
Full-text available
The implementation of sustainable solutions for maintaining indoor air quality has become a particular concern to the building community. Research on green technologies for indoor air has highlighted the potential of active botanical biofiltration (ABB) systems, where the air is circulated through the plant root zone as well as the growing medium for maximum phytoremediation effect. ABB has been found beneficial for pollutant removal along with the potential for increasing humidity and air cooling. Assessment in laboratory condition revealed the removal efficiency of ABB systems ranged from 54 to 85% for total suspended particulate matters where gaseous pollutants such as formaldehyde and toluene removal efficiencies were 90% and over 33%, respectively, in real environment. Moreover, the esthetic value of ABB acts as an added benefit for positive mental effects. However, very limited data is available to date that demonstrates the pollutant removal efficiency of ABB systems in realistic indoor environments, and the mechanisms behind this emerging technology are still poorly understood. The purpose of this mini review study is to present a quantitative assessment of the recent advancement of ABB systems and indoor air quality. Finally, the limitations of ABB systems and research gaps are highlighted for future improvement.
Chapter
The deployment of complex biological systems in urban settings has evolved as a technology to mitigate what has come to be known as the sick building syndrome. Indoor air quality (IAQ) is a rising concern as people are spending more time indoors and buildings are increasingly sealed to reduce energy consumption. Accumulation of gaseous contaminants, including volatile organic compounds (VOCs), in the indoor air can negatively affect occupant health and productivity. This article addresses the popular and scientific literature relating to the potential for biological systems containing plants to improve IAQ through the removal and degradation of gaseous indoor contaminants. Historical literature implicates simple potted plants and their associated microbes as the means for reducing VOCs in the aerial environment. However, these claims are supported by anecdotal evidence and very few realistic, systematic investigations. In addition, these claims are not in agreement with models of microbial kinetics and gas transfer. On the other hand, botanical biofiltration, which actively forces air through a complex ecosystem, has been the subject of numerous detailed studies and received considerable attention as a means of reducing the accumulation of VOCs in occupied spaces. Evidence supporting various interpretations of the mechanisms of biological filtration will be addressed.
Article
Emerging data indicates that incumbent mechanical/physio-chemical air handling systems inadequately address common indoor air quality (IAQ) problems, including elevated CO2 levels and volatile organic compounds (VOCs), with compounding negative impacts to human health. Preliminary research suggests that active plant-based systems may synthetically address these challenges. However, in order to design system performance parameters, the significance of species selection and biogeochemical mechanisms of growth media design need further characterization towards an effective bioremediative interface with air handling systems. Here, through three different species across three different growth media designs, we investigate trade-offs between CO2 sequestration through photosynthesis and CO2 production by metabolically active root-zones (that may remediate VOCs). Across the species, hydroponic media produced 61% greater photosynthetic leaf area compared to organic media which produced 66% more root biomass. CO2 concentration changes driven by differing plant and growth media (organic vs. hydroponic) treatments were measured within a semi-sealed chamber. Repeated estimations of net CO2 concentrations throughout plant development revealed decreasing influxes of CO2 within the chamber over time, indicating evolving photosynthesis/respiration balances. Multivariate analysis indicates growth media design, through impacts to water availability, air flow rates and plant development, was a more significant driver of bioremediation performance metrics than species selection.
Article
Monitoring of air quality and the application of strategies for its improvement are perceived as key areas for reducing environmental pollution. The research on Nature Based Solutions for the mitigation of pollutant concentrations in the air has increasingly developed in the last twenty years. The purpose of this review is to evaluate whether the current knowledge about Nature-Based Solutions provides a quantitative answer of the real benefits of air phytoremediation. To address this question, the literature on air phytoremediation over the last twenty years was analyzed. Altogether, 52 variables were selected, grouped into six categories, to briefly characterize the contents, methodology and outcome of the peer-reviewed articles. Altogether, 413 plant species found in the analyzed studies were recorded. The results show the trends about the most studied pollutants and on the methodologies mostly applied, in relation to the study outcomes. The analysis demonstrated that particulate matter (PMx) was the most frequently examined pollutant, most studies on NBS are based on experiments with exposure chambers, and scaling up the results with models has been limited. Although effective reductions in pollutant concentrations have been shown in the majority of studies, there is a strong fragmentation of the approaches, most studies have looked at a single pollutant and detailed information for model parameterization is only available for a few species. Thus, the review highlights that studies of Nature Based Solutions in air phytoremediation require unification of methodologies, and should consider a broader range of pollutants and plant organisms useful for mitigating the impacts of air pollutants in indoor and outdoor human environments.
Article
Most of the time people stay in confined environments and thus are highly exposed to accumulated indoor pollutants. Indoor environmental pollution has been identified as one of the most prevalent causes for health problems, such as sick building syndrome. These health problems have been magnified with the introduction of energy efficient building concepts, coupled with limited fresh air supply, which has compromised the effective means of air purification. Further, the frequent use of chemical substances for numerous purposes contributes to indoor air pollution. Therefore, investigation of alternative techniques to improve indoor environmental quality has been extensively studied in the last two decades. In Sri Lanka, there is a potential for studying indigenous techniques to improve indoor air quality. However, verification of such techniques and quantification of their impacts has not been given much attention. The research focus of this paper is to identify those material substances that can be used to absorb pollutants and lessen their harmful impacts and thereby improve air purification. A chamber study was used to quantify air purification using different material substances and considering the following parameters: total volatile organic compound (TVOC) and Carbon Monoxide (CO) levels. Further, the results obtained in the chamber study were assessed for its projection to real applications by comparison with a study conducted in an actual indoor space. The outcome of the study has revealed that the indigenous knowledge of Sri Lanka can be used to improve indoor air quality.
Chapter
Human activities have become the source of myriad pollutants and have accelerated the pressure on natural resource depletion. Intensive farming, urbanization, rapid industrialization, and other human activities have resulted in land deterioration and degradation, a polluted environment, and a downturn in crop productivity across various sectors of agriculture. Several alternative methods have been designed and developed, but often, these processes risk environmental damage by producing secondary pollutants. Biological treatment systems have diversified applications, such as the cleanup of site contaminants in soil, water, streams, and sludge. Bioremediation, an efficacious and lucrative eco-friendly management tool, utilizes microorganisms to degrade or reduce the concentration of hazardous wastes at the contaminated site without causing additional deterioration of the environment. This chapter discusses the role of a vast array of microorganisms used in the reclamation of wastewater containing metal pollutants through bioremediation and puts forward thoughts and opportunities for further research in the field.
Article
The roles of enzymatic reactions and redox reactions caused by reactive oxygen species (ROS) in formaldehyde metabolism in tomatoes and wheat seedlings and the changes in peroxidase (POD) and catalase (CAT) activities in plants were investigated. Differences in the breakdown of added formaldehyde between fresh and boiled plant extracts were determined to calculate the contributions of different removal mechanisms. Two plant seedlings efficiently removed formaldehyde from air when its level varied from 0.65 to 1.91 mg m⁻³; meanwhile, the maximum rate at which tomato seedlings transported formaldehyde from air to the rhizosphere solution reached 182.26 µg h⁻¹ kg⁻¹ FW (fresh weight). Metabolism in plants was mainly responsible for the formaldehyde dissipation. The enzymatic contribution to formaldehyde dissipation decreased with increasing shoot exposure time or air formaldehyde level, while the redox contribution increased in importance because of an increasing level of ROS. The different enzymatic antioxidant activities of plants resulted in different levels of ROS and hence different tolerance and removal efficiencies toward formaldehyde. The self-enhancing ability of plants to remove formaldehyde via redox reactions suggested that the formaldehyde removal efficiency could be enhanced by plant adaptation to environmental stress.
Chapter
The quality of life on earth is completely dependent on the environment. The aquatic and terrestrial systems are the two major ecosystems on earth. In ancient times, our natural systems were efficient at absorbing and breaking down pollutants and maintaining the quality of our environment. But now, owing to population explosion, rapid industrialization, and urbanization, humans have produced and added a tremendous number of pollutants in enormous volumes to the environment. As a result, our environment has become polluted and unhealthy. There are various types of pollution, e.g., water, air, soil, noise, and thermal. The invention of modern technologies to exploit natural resources has also aggravated the rate of pollution. The problem of environmental pollution can be mitigated in many ways, but the most suitable methods are biological, in which green plants are used. These plants can absorb and degrade pollutants and act as both biomitigators and bioindicators. Aquatic plants can be used to treat water pollution, and terrestrial plants can be grown around industrial and urban areas to treat air pollution. The utilization of plants to treat pollution is known as phytoremediation. This treatment is considered an ecologically sustainable and cost-effective strategy to alleviate water and air pollution. In the present chapter, we discuss the role of higher plant species in mitigating pollution and the mechanisms they use.
Article
Mental health, a key component of social sustainability, costs £1.6 trillion globally and office workers are among the most affected. However, social sustainability is the least considered sustainability dimension by businesses. Although the literature associates human exposure to nature with positive mental health, there are limited critical reviews of nature exposure impact on office workers. The aim of this research was to demonstrate the impact of nature exposure on office workers by consolidating empirical research evidence and to provide insight into how it can contribute to achieving integrated sustainability. A total of 42 peer-reviewed journal articles that met the inclusion criteria were selected. A systematic review following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) framework was conducted. The results show that indoor nature exposure contributes to social sustainability through its impact on workers' health and motivation while outdoor nature exposure contributes to economic, environmental and social sustainability through its impact on workers' restoration, stress reduction and stress coping. Workplace design should therefore embed both indoor and outdoor nature exposure to maximise impacts on employees and achieve integrated sustainability. The nature exposure network developed in this research will facilitate design decisions regarding nature exposure in workplaces to maximise the impact on employees’ well-being and performance.
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The aim of this study is to determine the indoor plant preferences of the academic and administrative staff working in the units of Akdeniz University and the maintenance procedures applied to the indoor plants. In this context, totally 382 academic and administrative staffs’ offices were visited, the size of the offices were measured with laser meters, the indoor plant species were identified and questionnaires were applied to the participants by face-to-face interviews. A statistically significant result was found between the income status, gender, the units (vocational training) of the participants between keeping indoor plants in the offices. Orchids and cactus were the most preferred species. Most of the participants stated that they carried out irrigation and removal of dried branches/leaves as routine maintenance. The participants expressed their satisfaction with the existence of a reasonable number of indoor plants in the offices. The presence of a large number of indoor plants in the offices was found to cause tension and tiredness. It would be a rational solution to make it necessary to incorporate indoor plants into building design and management in the future, which is one of the cheapest and most effective methods of increasing labour productivity and achieving corporate strategic goals.
Technical Report
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Konzeptpapier für eine vertikale Begrünung mit Moosen im Citytunnel der Stadt Darmstadt zur Reduzierung von Luftschadstoffen
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Plants are the planet’s source of oxygen and the sink that removes carbon dioxide produced by burning, respiration and decay of organisms. The studies performed in small chambers indicated that plants also reduce volatile organic compounds (VOC’s). All these phenomena result in a fact that potted plants have a potential to improve IAQ and to some extent to support ventilation. Trends to “go green” increase the growing interest in the introduction of a large number of plants to offices. One should remember that work in modern offices is often associated with a high level of stress. Ornamental plants give highly significant reductions in negative mood states – reductions in anger, anxiety, depression, confusion, fatigue and stress. Leaves provide also additional sound attenuation and cooling effect due to evaporation. The paper summarises the R&D project devoted to the development of the efficient, safe and competitive systems of biofiltration based on the properties of potted plants. The paper presents examples of laboratory tests and describes first experiences from applications in two pilot office buildings.
Article
Humans face threats from air pollutants present in both indoor and outdoor environments. The emerging role of plants in remediating the atmospheric environment is now being actively investigated as a possible solution for this problem. Foliar surfaces of plants (e.g., the leaves of cotton) can absorb a variety of airborne pollutants (e.g., formaldehyde, benzene, trimethylamine, and xylene), thereby reducing their concentrations in indoor environments. Recently, theoretical and experimental studies have been conducted to offer better insights into the interactions between plants and the surrounding air. In our research, an overview on the role of plants in reducing air pollution (often referred to as phytoremediation) is provided based on a comprehensive literature survey. The major issues for plant-based research for the reduction of air pollution in both outdoor and indoor environments are discussed in depth along with future challenges. Analysis of the existing data confirms the effectiveness of phytoremediation in terms of the absorption and purification of pollutants (e.g., by the leaves and roots of plants and trees), while being controlled by different variables (e.g., pore characteristics and planting patterns). Although most lab-scale studies have shown that plants can effectively absorb pollutants, it is important for such studies to reflect the real-world conditions, especially with the influence of human activities. Under such conditions, pollutants are to be replenished continually while the plant surface area to ambient atmosphere volume ratio vastly decreases (e.g., relative to lab-based experiments). The replication of such experimental conditions is the key challenge in this field of research. This review is expected to offer valuable insights into the innate ability of various plants in removing diverse pollutants (such as formaldehyde, benzene, and particulate matter) under different environmental settings.
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Many indoor plants can remove benzene, a common volatile organic compound that has been classified as a human carcinogen. Light intensity and initial benzene concentration may affect the removal efficacy of the plants. Cordyline terminalis (L.) Kunth 'Baby Doll' is widely used for indoor decorations as this delicate potted plant can tolerate a wide range of irradiances and generates prolific branches when pinched. Potted plants of 'Baby Doll', with root-zone wrapped, were placed under light intensity of 20, 40, 60, 80, and 100 μmol.m^(-2).s^(-1) photosynthetic photon flux (PPF) in chambers containing an initial 5 μL.L^(-1) benzene for four days. In all treatments, benzene concentration in the chambers declined as analyzed with gas chromatography. Plants under 20 or 40 μmol.m^(-2).s^(-1) PPF had lower stomatal conductance, net photosynthetic rate, and benzene removal rate per leaf area than those under 80 or 100 μmol.m^(-2).s^(-1) PPF. Carbon dioxide removal rate during lighting period of day 1 increased linearly as light intensity increased. Potted plants of 'Baby Doll' were placed within chambers containing various initial concentrations of benzene under 80 μmol.m^(-2).s^(-1) PPF. Results showed that benzene removal rate of the plant increased linearly with the initial benzene concentration increased from 5 to 25 μL.L^(-1). Initial benzene concentration did not affect the CO_2 uptake and evolution of the plants. Benzene concentration did not alter leaf Fv/Fm, ranged between 0.79 and 0.81, after all treatments for five days.
Article
IntroductionSince an average human spends most of the time indoors (ranging from 85% to 90%), the understanding about ambient environment is very important. The indoor environment is majorly polluted from the indoor air pollutants like volatile organic carbon (VOC), semi-volatile organic carbon (SVOC), particulate matter, ozone, oxides of carbon and sulphur, heavy metals, biological contaminants and many more. There has been growing awareness about the adverse health effects of poor indoor air quality (IAQ) in the last two decades; researchers across the globe are performing various studies to assess the IAQ, and the situation in developing and the under-developing country is getting worse day by day due to unplanned and rapid growth.MethodologyThis work is an attempt to catalogue different types of indoor air pollutants in various buildings based on their occupancy; finally, their health effects have also been touched upon. National Building Code of India (Part IV—2005) has been taken under consideration for different types of buildings.Results and discussionIt has been observed that a number of pollutants are present in the indoor environment; hence, the determination of all the IAQ parameters consumes a lot of time and resources; a set of five to six parameters, i.e., TVOC, oxides of sulphur, carbon and nitrogen, ozone, and respirable suspended particulates, are the most effective indicators for the assessment of indoor air quality. The pollutants in indoor air are classified into three major categories, and the potential sources, health effects of these pollutants and mitigation measures to improve IAQ are listed further in the paper.
Article
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Indoor air pollution is a significant problem today because the release of various contaminants into the indoor air has created a major health threat for humans occupying indoors. Volatile Organic Compounds (VOCs) are pollutants released into the environment and persist in the atmosphere due to its low boiling point values. Various types of indoor activities, sources, and exposure to outdoor environments enhance indoor VOCs. This poor indoor air quality leads to adverse negative impacts on the people in the indoor environment. Many physical and chemical methods have been developed to remove or decompose these compounds from indoors. However, those methods are interrupted by many environmental and other factors in the indoor atmosphere, thus limit the applications. Therefore, there is a global need to develop an effective, promising, economical, and environmentally friendly alternatives to the problem. The use of the plant and associated microflora significantly impact reducing the environmental VOC gases, inorganic gases, particulate matter, and other pollutants contained in the air. Placing potted plants in indoor environments not only helps to remove indoor air pollutants but also to boost the mood, productivity, concentration, and creativity of the occupants and reduces stress, fatigue, sore throat, and cold. Plants normally uptake air pollutants through the roots and leaves, then metabolize, sequestrate, and excrete them. Plant-associated microorganisms help to degrade, detoxify, or sequestrate the pollutants, the air remediation, and promote plant growth. Further studies on the plant varieties and microorganisms help develop eco-friendly and environmentally friendly indoor air purifying sources.
Chapter
Bioremediation is an option to transform toxic heavy metals into a less harmful state using microbes or their enzymes and is an ecofriendly, cost-effective technique for revitalizing wastewater-polluted environments
Article
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The quality of the indoor environment has become a major health consideration, since urban-dwellers spend 80-90% of their time indoors, where air pollution can be several times higher than outdoors. Indoor potted-plants can remove air-borne contaminants such as volatile organic compounds (VOCs), over 300 of which have been identified in indoor air. In this study a comparison was made of rates of removal of benzene, as model VOC, by seven potted-plant species/varieties. In static test-chambers, high air-borne doses of benzene were removed within 24 h, once the response had been stimulated (induced) by an initial dose. Removal rates per pot ranged from 12-27 ppm d–1 (40 to 88 mg m–3 d–1) (2.5 to 5 times the Australian maximum allowable occupational level). Rates were maintained in light or dark, and rose about linearly with increased dose. Rate comparisons were also made on other plant parameters. Micro-organisms of the potting mix rhizosphere were shown to be the main agents of removal. These studies are the first demonstration of soil microbial VOC degradation from the gaseous phase. With some species the plant also made a measurable contribution to removal rates. The results are consistent with known, mutually supportive plant/soil-micro-organism interactions, and developments in microbially-based biofilter reactors for cleaning VOC-contaminated air. The findings demonstrate the capacity of the potted-plant microcosm to contribute to cleaner indoor air, and lay the foundation for the development of the plant/substrate system as a complementary biofiltration system.
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To assess quantitatively the association between benzene exposure and leukemia, we examined the mortality rate of a cohort with occupational exposure to benzene. Cumulative exposure for each cohort member was estimated from historical air-sampling data and, when no sampling data existed, from interpolation on the basis of existing data. The overall standardized mortality ratio (a measure of relative risk multiplied by 100) for leukemia was 337 (95 percent confidence interval, 154 to 641), and that for multiple myeloma was 409 (95 percent confidence interval, 110 to 1047). With stratification according to levels of cumulative exposure, the standardized mortality ratios for leukemia increased from 109 to 322, 1186, and 6637 with increases in cumulative benzene exposure from less than 40 parts per million-years (ppm-years), to 40 to 199, 200 to 399, and 400 or more, respectively. A cumulative benzene exposure of 400 ppm-years is equivalent to a mean annual exposure of 10 ppm over a 40-year working lifetime; 10 ppm is the currently enforceable standard in the United States for occupational exposure to benzene. To examine the shape of the exposure-response relation, we performed a conditional logistic-regression analysis, in which 10 controls were matched to each cohort member with leukemia. From this model, it can be calculated that protection from benzene-induced leukemia would increase exponentially with any reduction in the permissible exposure limit.
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Benzene is an established cause of human leukemia that is thought to act by producing chromosomal aberrations and altered in cell differentiation. In several recent studies increased levels of chromosomal aberrations in peripheral blood lymphocytes were correlated with a heightened risk of cancer, especially hematological malignancies. Thus, chromosomal aberrations may be a predictor of future leukemia risk. Previous studies exploring whether benzene exposure induces chromosomal aberrations have yielded mostly positive results. However, it remains unclear whether the chromosomal aberrations induced by benzene occur in a distinct pattern. Here, we thoroughly review the major chromosome studies published to date in benzene-exposed workers, benzene-poisoned and preleukemia patients, and leukemia cases associated with benzene expose. Although three cytogenetic markers (chromosomal aberrations, sister chromatid exchanges, and micronuclei) are commonly examined, our primary focus is on studies of chromosomal aberrations, because only this marker has so far been correlated with increased cancer risk. This review surveys the published literature, analyzes the study results, and discusses the characteristics of effects reported. In most studies of currently exposed workers, increases in chromosomal aberrations were observed. However, due to the relatively small number of affected individuals and variability in the reported aberrations, firm conclusions cannot be made about the involvement of specific chromosomes or chromosome regions. Further, in leukemia cases associated with benzene exposure, there is no evidence of a unique pattern of benzene-induced chromosomal aberrations in humans. Leukemia cases associated with benzene exposure are, however, more likely to contain clonal chromosome aberrations then those arising de novo in the general population.
Article
Results are presented of an investigation into the capacity of the indoor potted-plant/growth medium microcosm to remove air-borne volatile organic compounds (VOCs) which contaminate the indoor environment, using three plant species, Howea forsteriana (Becc. (Kentia palm), Spathiphyllum wallisii Schott. 'Petite' (Peace Lily) and Dracaena deremensis Engl. 'Janet Craig'. The selected VOCs were benzene and n-hexane, both common contaminants of indoor air. The findings provide the first comprehensive demonstration of the ability of the potted-plant system to act as an integrated biofilter in removing these contaminants. Under the test conditions used, it was found that the microorganisms of the growth medium were the "rapid-response" agents of VOC removal, the role of the plants apparently being mainly in sustaining the root microorganisms. The use of potted-plants as a sustainable biofiltration system to help improve indoor air quality can now be confidently promoted. The results are a first step towards developing varieties of plants and associated microflora with enhanced air-cleaning capacities, while continuing to make an important contribution to the aesthetics and psychological comfort of the indoor environment.
Article
Three factors influencing foliar uptake of monocyclic aromatic hydrocarbons (MAHs; benzene, toluene, ethylbenzene, xylenes) in situ were investigated. The first factor, the plant species, was found to determine absorption pattern and concentrations. Secondly, time variation studies showed that response of leaf concentrations to small changes in air concentrations only occurs after several days or weeks, whereas adaptation to a much higher level of air pollution takes several months. Thirdly, MAH leaf concentrations were observed to be dependent on mean air pollution at the sampling site. Bioconcentration factors BCFvs (g m−3 of wet leaf/g m−3 of air) for MAHs in Pseudotsuga menziesii (Mirb.) Franco leaves were determined to range from 2.7 × 104 to 4.7 × 105.
Article
An aim in developing low volatile organic compound (VOCs) emission house is to reduce the level of VOCs in domestic housing. In this study, a case study for the reduction of exposure to VOCs from a newly constructed residential house was presented. Before application, the construction materials used in the house were tested in an environmental chamber and low VOC emission materials were then selected. Design of the house abided by the following principals: maximizing the ventilation rate and avoiding the use of high VOC emission materials in the house. By improved building design and proper construction materials selection, risk of personal exposure to VOCs in the house was significantly reduced. The total VOCs (TVOCs) concentrations measured in the house ranged from non-detectable to . These values were much lower than the published values (0.48–) for new houses in Scandinavian countries and in the USA. The low TVOCs concentrations obtained in this study probably resulted from the high ventilation rates and the use of low VOCs emission materials. This study also combined the results with the three traditional ways in improvement of IAQ. The results obtained in this study confirmed that the most effective strategy for controlling IAQ was pollution prevention and the next most important was the design of ventilation rates to handle uncontrollable sources. The effectiveness of aging as a means of indoor pollution control was also reviewed.
Article
People spend the majority of their time indoors mostly in the domestic environment, where their health may be effected by significant airborne particulate pollution. The indoor/outdoor air quality at six homes in Wales and Cornwall was investigated, based on different locations (urban, suburban, rural) and household characteristics (smokers, non-smokers). The spatial and temporal variations in PM10 mass were monitored for a calendar year, including ambient weather conditions. The activities of individuals within a household were also recorded. Monitoring of PM10 took place inside (kitchen, living room, bedroom) homes, along with concomitant collections outdoors. Samples were subjected to gravimetric analysis to determine PM10 concentrations and examined by scanning electron microscopy to identify the types of particles present on the filters. The results of the study show there are greater masses of PM10 indoors, and that the composition of the indoor PM10 is controlled by outdoor sources, and to a lesser extent by indoor anthropogenic activities, except in the presence of tobacco smokers. The indoor and outdoor PM10 collected was characterised as being a heterogeneous mixture of particles (soot, fibres, sea salt, smelter, gypsum, pollen and fungal spores).
Article
The volatiles from fresh flowers and leaves of Gentiana lutea L., Gentiana punctata L. (yellow Gentiana spp.) and Gentiana asclepiadea L. (Gentianaceae Juss.) were analyzed by GC/MS and 81 compounds identified. The samples studied showed differences in the volatile profiles of flowers and leaves among the species. In the flower-oils straight chain saturated aliphatic hydrocarbons were dominant along with low concentrations of branched saturated aliphatic hydrocarbons and alkylated benzenes. These compounds were not present in the flowers of G. lutea and G. punctata and in the leaves of G. lutea. The branched saturated aliphatic hydrocarbons were the main constituents of the leaf-oil from G. ascleapidea. Terpenes were found in all flower-oils and in the leaf oil from G. punctata. Some of the identified compounds might have allelopathic activity. The results obtained confirm the accepted taxonomical scheme of the genus Gentiana and are also in agreement with the evolutionary less advanced position of the yellow species of Gentiana.
Article
Structural chromosome aberrations and sister chromatid exchanges (SCEs) in peripheral blood were studied in female workers employed in the shoe-making industry in two periods: 1987 (group I; N = 38) and 1992 (group II; N = 45). Only 11 of the workers were present in both groups and their results are presented both together and separately. Occupational exposure to benzene and toluene was confirmed through their determination in the working area, blood, and phenol in pre- and post-shift urine. The results were compared with those from the control group (N = 35). Benzene in the working atmosphere was significantly higher in 1987 compared to 1992, but was always lower than the current Croatian permissible concentration of 50 mg m−3 (in the near future this value will be changed to 15 mg m−3). A statistically significant difference was also found in biological markers of benzene exposure between the two periods of the investigation. Increased absorption in the first period occurred because of intensified production in 1987, and this decreased significantly in 1992 because of the war in Croatia. The cytogenetic study showed a significant increase in dicentric chromosomes in exposed groups I and II when compared to the control group. Statistically significant higher SCE frequencies were found in group I compared to the control group and also compared to group II. Between exposed group II and the controls no statistically significant difference in SCEs was found. Comparing the same 11 workers present in both periods the results showed no difference in chromosome aberrations between the two periods of examination. SCE frequencies were significantly higher in 1987 when greater benzene absorption occurred, confirmed by biomarkers of benzene exposure. The presented results indicate that genotoxicity may occur in workers exposed to low levels of benzene in the shoe industry.
Article
This report updates the risk assessment by Crump and Allen (1984) for benzene-induced leukemia that was used by OSHA (1987) to support its reduction of the permissible exposure limit (PEL) to 1 ppm and that also was the basis for EPA's (1985) interim "unit risk" for benzene. The present study derives new risk estimates using data from follow-up through 1987 (whereas the earlier assessment only had follow-up available through 1978), and using new exposure estimates for this cohort developed by Paustenbach et al. (1992) that account for a number of factors that were unknown or not fully evaluated in earlier exposure assessments. There was a significant excess of acute myelocytic or acute monocytic leukemia (AMML, the only forms of acute nonlymphatic leukemia observed) in this cohort, and this end point also exhibited a strong dose-response trend. AMML was the only hematopoietic or lymphatic cancer that was clearly linked to benzene exposure. However, quantitative estimates of risk based on modeling either AMML or all leukemia differed by only 20%. Differences between the two Pliofilm plant locations in the occurrence of AMML were not statistically significant (.12 < or = p < or = .21) after differences in levels of benzene exposure were taken into account. The Paustenbach et al. exposures predicted a quadratic dose response, based on a measure of exposure that weighted intensity of exposure more heavily than duration of exposure. The best-fitting quadratic models predicted an additional lifetime risk of a benzene-related death from 45 yr of exposure to 1 ppm of between 0.020 and 0.036 per thousand. Statistical confidence intervals (90%) on these estimates were barely wide enough to include risk estimates based on linear dose response models. These linear models predicted risks of between 1.6 and 3.1 per thousand.
Article
The [1-6(14)C]benzene and [1-(14)C]toluene vapors penetrate into hypostomatous leaves of Acer campestre, Malus domestica, and Vitis vinifera from both sides, whereas hydrocarbons are more intensively absorbed by the stomatiferous side and more actively taken up by young leaves. Benzene and toluene conversion in leaves occurs with the aromatic ring cleavage and their carbon atoms are mainly incorporated into nonvolatile organic acids, while their incorporation into amino acids is less intensive. Intact spinach chloroplasts oxidize benzene, and this process is strongly stimulated in light. Oxidation of benzene by spinach chloroplasts or by enzyme preparation from spinach leaves is almost completely inhibited by 8-oxyquinoline or sodium diethyldithiocarbamate, and slightly affected by alpha, alpha'-dipyridyl. Benzene oxidation by enzyme preparation is significantly stimulated by NADH and NADPH; in their presence, the benzene hydroxylation product, phenol, is formed in a determinable amount. It is supposed that the enzyme performing the first step of oxidative transformation of benzene in plant leaves contains copper as the prosthetic group.
Article
In this study apple, blackberry and cucumber crops were exposed to elevated levels of benzene under controlled conditions. Benzene was retained in fruits of all crops, but only accumulated in leaves of blackberries and apples. The retention by cucumber fruits is suggested to result from the longer pathway for the desorption of benzene as a consequence of their increased tissue depth compared to leaves. The process of accumulation in blackberry and apple leaves is unknown. The ingestion of benzene via the food-chain pathway on the basis of this study is concluded not to be significant.
Article
A daily rhythm in the activity of nitrate reductase (NR: EC 1.6.6.1) isolated from the marine red algae Gracilaria tenuistipitata is shown to be attributable to changes in amounts of the protein. The enzyme was purified in four steps: ion exchange Q-Sepharose separation, ammonium sulfate precipitation, gel filtration on Sephacryl S-300, and affinity chromatography on Affigel-blue resin. This purification procedure yielded an active purified NR of about 500-fold with a recovery of 85%. The SDS-PAGE silver staining of purified NR revealed a 110 kDa single band. Non-denaturated protein showed a molecular mass of 440 kDa on gel filtration comparing with SDS-PAGE, the enzyme is apparently composed of four identical subunits. In extracts of algae grown under either constant dim light or a light-dark cycle, the activity of NR exhibited a daily rhythm, peaking at midday phase as does photosynthesis. Staining with monoclonal antibodies, raised against NR from Porphyra yezoensis, showed that the amount of protein changes by a factor of about 12, with a maximum occurring in the midday phase.
Article
Benzene and toluene mixing ratios were measured in the indoor air of two subarctic homes during summer and winter. Benzene in the living area of these homes ranged from 1 to 25 ppbv and toluene ranged from 1 to 104 ppbv. Source strength estimate calculations supported the hypothesis that gasoline in the home's attached garage is the primary source of these compounds in living area air. These calculations demonstrated that the home with the air-to-air heat exchangers and forced ventilation had less transport of aromatics than the unventilated home. Perturbation experiment showed that a full metal gasoline can in the garage was consistent with the importance of the garage as a source for the concentration of aromatics in the air of the living spaces in these Alaskan homes. The type of ventilation system also had an important effect on the quality of air in the living area.
Article
Benzene (B) is a typical micro-pollutant present in air, especially urban air. In this study a possible correlation between personal benzene exposure and S-phenylmercapturic acid (S-PMA) as a biomarker of internal dose was evaluated in a cohort of traffic policemen. The results confirm that S-PMA is significantly correlated to benzene measured in personal air. B and S-PMA were analyzed considering seasonality, work quarters, time spent indoors, outdoors, and directing traffic, but no significant differences were recorded.
Absorption of organic compounds in indoor air by commonly used indoor plants
  • R A Wood
  • R L Orwell
  • M D Burchett
  • J Tarran
  • S K Brown
Wood, R.A., Orwell, R.L., Burchett, M.D., Tarran, J., Brown, S.K., 2000. Absorption of organic compounds in indoor air by commonly used indoor plants. In: O. Seppanen, J. Sateri (Eds.), Proceedings of Healthy Buildings 2000. Sixth International Healthy Buildings Conference, vol. 2, August 2000, Espoo, Finland, pp. 125-130.
Analysis of current situation of indoor air pollution and its control
  • W Liu
  • D Zhai
  • Y Yu
  • H Yang
Liu, W., Zhai, D., Yu, Y., Yang, H., 2003. Analysis of current situation of indoor air pollution and its control. Urban Environment and Urban Ecology 16, 53-55.
Quantification of the capacity of indoor plants to remove volatile organic compounds under flow-through conditions
  • J Tarran
  • R Orwell
  • M D Burchett
  • R Wood
  • F Torpy
Tarran, J., Orwell, R., Burchett, M.D., Wood, R., Torpy, F., 2002. Quantification of the capacity of indoor plants to remove volatile organic compounds under flow-through conditions. Final Report to Horticulture Australia, Sydney, Australia. Ugrekhelidze, D., Korte, F., Kvesitadze, G., 1997. Uptake and transformation of benzene and toluene by plant leaves. Ecotoxicology and Environmental Safety 37, 24–29.
Inspection and Quarantine of People's Republic of China (GAQSIQPRC) Ministry of Health, State Environment Protection Administration of PR China
General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China (GAQSIQPRC), 2002. Ministry of Health, State Environment Protection Administration of PR China. Indoor Air Quality Standard GB/T 18883-2002. Standards Press of China.
General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China (GAQSIQPRC)
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  • F Lee
General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China (GAQSIQPRC), 2002. Ministry of Health, State Environment Protection Administration of PR China. Indoor Air Quality Standard Guo, H., Murray, F., Lee, S.C., 2003. The development of low volatile organic compound emission house-a case study. Building and Environment 38, 1413-1422.
Directive 2000/69/EC Relating to Limit Values for Benzene and Carbon Monoxide in Ambient Air
Official Journal of the European Communities L 313 (OJL313), 2000. Directive 2000/69/EC Relating to Limit Values for Benzene and Carbon Monoxide in Ambient Air. 13/12/2000.
Quantification of the capacity of indoor plants to remove volatile organic compounds under flow-through conditions. Final Report to Horticulture Australia
  • J Tarran
  • R Orwell
  • M D Burchett
  • R Wood
  • F Torpy
  • D Ugrekhelidze
  • F Korte
  • G Kvesitadze
Tarran, J., Orwell, R., Burchett, M.D., Wood, R., Torpy, F., 2002. Quantification of the capacity of indoor plants to remove volatile organic compounds under flow-through conditions. Final Report to Horticulture Australia, Sydney, Australia. Ugrekhelidze, D., Korte, F., Kvesitadze, G., 1997. Uptake and transformation of benzene and toluene by plant leaves. Ecotoxicology and Environmental Safety 37, 24-29.
Analysis of current situation of indoor air pollution and its control
  • Liu