*,ed_ F N/LRA INTERIOR LANDSCAPE PLANTS FOR INDOOR AIR POLLUTION ABATEMENT FINAL REPORT SEPTEMBER B.C Wolverton, Principal Anne 15, 1989 Ph.D Investigator Johnson, M.S and Keith Bounds, Sverdrup This work was jointly Programs Technology Contractors of America National Aeronautics John Science Stennis Technology, supported Utilization (ALCA) by and Inc the Division, NASA Space Technology Center, Office Administration Center Laboratory MS of and the Associated and Space C Stennis Space M.S 39529-6000 Commercial Landscape CONTENTS Abbreviations and Introduction Acronyms Chemicals Economical Used Benzene Solution In The Plant Formaldehyde and and Tests Selective Analysis Discussion 5 Detector Analysis for Trace Metabolites Air Filter 8 System Acknowledgments References Pollution Carbon-Houseplant Summary Screening Air Methods Microbiological Results to Indoor Chromatograph-Mass Activated Trichloroethylene Gas v A Promising, Materials 18 18 19 FIGURES Indoor air purification Man's interaction microorganisms, Removal inside filter Removal inside carbon and filter houseplants and activated carbon experimental of benzene chambers and using golden trichloroethylene pothos from in an 8-in the air activated system experimental of benzene chambers using soil, water of high concentrations sealed combining with his environment plants, of low concentrations sealed carbon system and golden 16 trichloroethylene pothos from in an 8-in the air activated system 17 °° III PREC, EDING P:IGE E-,;'LA_',!K 't., _,"_':" FILMED TABLES ° Trichloroethylene Houseplants Benzene Chemicals During Benzene Removed a 24-h Exposure Benzene Removing Benzene after from in Potting Removal Being Period Exposed from a Sealed by 11 Experimental Chamber 12 Chamber by Houseplants 12 a Sealed Exposure Experimental Period Soil and the Same During 24-h Chamber by 13 by Potting Soil after Exposure Periods Counts 24-h Periods of a Chinese to Benzene iv Chamber Experimental for Several 10 Chamber Period Experimental Soil Bacterial Chamber by a Sealed Foliage and Chamber Experimental from by a 24-h Exposure a Sealed a 24-h All Plant Experimental a Sealed Period Removal During Removal Houseplants from Period Chamber Experimental by Houseplants Removed Houseplants ° from Experimental Period Exposure Soil During Trichloroethylene a Sealed a Sealed a 24-h a 24-h Exposure During from Removed and from a 24-h Exposure During Formaldehyde Houseplants o During Removed Houseplants , Removed 14 Evergreen Plant in a Sealed 14 ABBREVIATIONS AND Term ACRONYMS Definition ALCA Associated EPA Environmental GC gas chromatograph HP Hewlett-Packard NASA National PCA plate TCE trichlorethylene UF urea formaldehyde UFFI urea-formaldehyde cfu/g colony cm centimeter cm square g gram h hour in inch m meter mE milliliter minute m3 cubic meter p/m parts per million S second yr year /zL microliter °C degrees Landscape Contractors Protection Aeronautics count and Agency Space agar foam forming units centimeter Celsius V of America insulation per gram Administration INTERIOR LANDSCAPE INDOOR AIR PLANTS POLLUTION FOR ABATEMENT INTRODUCTION During the late in heating to help 1970s, when the energy and cooling alleviate efficiency costs, spiraling included energy other allergy-related contributed designed reduced fresh are also manufacture energy changes improved that air exchange It was determined to the workers' health a contributing factor that However, the airtight problems various equipment because of the energy upon the health problems headaches, and sealing Similarly, and efficiency of buildings synthetic building organic compounds, have been and furnishings placed in these types of materials used in their and design Man himself should living in a closed, of people to maximize the workers began to complain of various drowsiness, respiratory and sinus congestion, materials, which are known to emit or "off-gas" linked to numerous health complaints The office buildings felt at both the gas pump Two of the design and symptoms significantly was being costs superinsulation occupation of these buildings, such as itchy eyes, skin rashes, crunch were being buildings be considered poorly are present ventilated health or remodeled buildings recently have varying have been reported in the United nations of the western world of indoor to a phenomenon estimated degrees air pollution, very apparent place such as an airplane contribute organization source area This becomes in a confined All of these factors collectively One world another of indoor period called "sick building Problems of time syndrome." 30 percent air pollution when when a large number for an extended that approximately States and Canada especially of all new of this type as well as in most other highly developed Two major problems with indoor air pollution are the identification of the trace chemicals and their correlation with diseaselike symptoms Energy-efficient buildings that are filled with modern possibly furnishings interact of these chemicals The problems over the symptoms and reactive of indoor past Manchester, and high-tech with each other ten byproducts air pollution years.(1-27) England, off-gas hundreds of volatile below present may adversely Dr Tony Pickering sick building in naturally ventilated of the syndrome buildings which indicate can be attributed Now pollution that most that it is unlikely that symptoms associated some of these buildings Hospital near and has learned contained the highest of microorganisms On the other hand, the highest levels of symptoms mechanically ventilated buildings containing low levels of microorganisms his analyses which limits, by many investigators Wythenshawe extensively organics detection affect inhabitants have been studied and documented has studied are minimal equipment Even at concentrations that levels are found The results with sick building in of syndrome to microorganisms environmental is a realistic threat scientists to human and government health, agencies how can the problem agree that be solved? indoor air A PROMISING, ECONOMICAL TO INDOOR AIR POLLUTION SOLUTION The first and most obvious step in reducing from building materials and furnishings before indoor air pollution is to reduce off-gassing they are allowed to be installed The National Aeronautics Space Administration (NASA) identified indoor with sealed space 16 years ago.(1) Although contamination habitats problems for off-gassing over in these sealed environments all new materials that air pollution problems a final solution has not been found, are to be used in future space associated to the NASA trace does screen structures Another promising approach to further reducing trace levels of air pollutants inside future space habitats is the use of higher plants and their associated soil microorganisms.(28-29) Since man's existence relationship on Earth with plants he attempts problems to isolate will arise himself answer to these on Earth or in space, achieved, however this ecological in tightly Even without off-gassing into tightly air pollution problems The depends sealed buildings the existence problems take along C Stennis for over 15 years system an intricate be obvious from this ecological away of synthetic own waste products If man is to move nature's life support Space Center, NASA Professor involving it should of hundreds man's is obvious he must a life support microorganisms, sealed environments, At John puzzle upon and their associated organic would into closed system that when system, chemicals cause indoor environments, This is not easily has been attempting Josef Gitelson of the USSR to solve and his team of scientists and engineers have also been working with closed ecological systems for many years in Krasnoyarsk, Siberia.(30) Only recently, however, have critical parts of this complex puzzle begun to come together Although maintaining the balance of the complete cycle involves treating and recycling sewage, toxic chemicals, and other industrial air pollutants, only indoor In this study evaluated of using the leaves, as a possible plant air is addressed systems roots, means here soil, and associated of reducing for removing indoor microorganisms air pollutants high concentrations cigarette smoke, organic solvents, and possibly radon This air filter design combines plants with an activated The rationale for this design, volumes moving large organic chemicals, by the carbon which of contaminated pathogenic filter evolved Plant air through and their being conducted National As NASA base, along to test this hypothesis Laboratories looks in Oak toward Ridge, associated the possibility with large numbers studies, carbon and possibly such as microorganisms is based on bed where radon then smoke, are absorbed destroy the eventually converting all of these that the decayed radon products in the plant tissue Experiments for NASA been a novel approach air pollutants treatment an activated (if present), up by the plant roots and retained have has been designed from this work carbon filter as shown in Figure pathogenic viruses, bacteria, and the organic chemicals, air pollutants into new plant tissue.(31"37) It is believed would be taken of plants Additionally, of indoor from wastewater microorganisms roots ecological water and at the Department are currently of Energy Oak Ridge Tennessee of sealing people inside a Space Station, of plants the ecology of such a closed environment or moon (interactions Tenaxadsorbent he samples T wereanalyzed promptly interfaced 5890 gas chromatograph to a Hewlett-Packard an HP Ultra capillary (HP) column and flame GAS CHROMATOGRAPH-MASS FOR TRACE After chemical injection, (1/4-in.) outside air samples diameter air pump beginning using a Tekmar Model cooled ended separation the sample ANALYSIS was conducted both reached entered onto 18-cm with Tenax adsorbent, contaminants were desorbed from desorber Rtx volatiles dioxide, from the chambers the into a HP 5890 GC equipped capillary column and then followed The GC oven a temperature at °C, and a rise in temperature when the temperature MICROBIOLOGICAL Using unit with steel tubes packed chemical Restek to °C using carbon on the GC, the sample were collected 5000 automatic at °C, with a 30-s hold program air desorption (GC) equipped detector DETECTOR stainless Trace with a 30-m, 0.32 mm inside diameter, was initially ionization SELECTIVE 500-mL using the Sensidyne-Gastec tubes using a Supelco METABOLITES (7-in.) by 0.6-cm Tenax Model program of °C/min The 200 °C, for a total run time of 25.5 After an HP 5970 mass using a scanning range selective detector of 35 to 400 atomic mass Analysis of units ANALYSIS potted plants and potting soil controls, surface and subsurface regions (approximately analyzed by means of the pour plate technique 1-g samples of soil were taken from 10 cm in depth) Samples were subsequently to determine the number of "colony forming units" per gram of sample (cfu/g) Plate count agar (PCA) was utilized microbiological medium Plate count data reflect bacteriological counts as the primary Triplicate samples were taken both before and after exposure of the plants and soil to benzene and TCE Following incubation at 25 °C for 24 h, samples were examined for the presence of bacteria Due to the inherently these microorganisms After plate count cultures on PCA were then subjected identification of asexual Fungal and ACTIVATED as shown removal Complete described and fungal Sabouraud's dextrose of biochemical were examined samples agar, have elapsed were isolated respectively Stock Bacterial tests in order to aid in preliminary by light microscopy of benzene Analysis Samples of h, or until all trace AIR FILTER in Figure tissue taped volatilization tube and air pump and actinomycetes, to search for the presence spores onto a Kimwipe previously and rate of fungi until three to five days of incubation CARBON-HOUSEPLANT for simultaneous growth both bacterial to a series isolates sexual Air filters designed injected be detected data were recorded, were maintained isolates 5-min cannot slower l were tested in one of the large Plexiglas and TCE inside occurred followed Benzene the chamber and TCE in 500/_L and were allowed and 100-mL air samples on the Supelco desorber were drawn chemicals SYSTEM initially were removed chambers volumes to evaporate were drawn, for using a Tenax and HP GC that have and at 15-min intervals were been for a minimum RESULTS AND DISCUSSION The ability of houseplants sealed experimental shown in Tables chambers in Tables shown through Plants in Tables range through suited investigations through exposures to the removal found in indoor benzene, in Tables during during were exposed these were conducted and more sophisticated is demonstrated were collected Although the levels commonly soil to remove was accomplished through to 20 p/m be particularly or potting through and formaldehyde The screening the first year of studies, the second of chemicals, of which indication of one or more of these chemicals, During methods Results the final of benzene in the plants Trichloroethylene (TCE) Chamber by Houseplants they are far above year of this project, and TCE (less than p/m) from these studies are shown Removed from a Sealed During a 24-h Exposure Total Plant Surface Leaf Area (cm 2) Gerbera daisy (Gerbera in Tables Experimental Period Total Micrograms Removed Plant jamesonii) 38,938 7,161 7,581 27,292 7,960 27,064 3,474 9,727 7,242 13,760 10,325 16,520 7,215 10,101 15,275 ivy (Hedera 4,581 981 English 18,330 heix) Marginata (Dracaena marginata) lily (Spathiphyllum "Mauna Mother-in-law's tongue (Sansevieria Loa") laurentii) Warneckei (Dracaena deremensis Bamboo palm (Chamaedorea Mass (Dracaena Janet "Warneckei") seifritzii) cane massangeana) Craig (Dracaena deremensis "Janet Craig") 15 might Table Peace data and final year of this project to high concentrations atmospheres from of plants while gave a good using low concentrations analytical TCE, per Table Benzene Removed Houseplants from During a Sealed a 24-h Total Experimental Exposure Plant Surface Leaf Area (cm 2) Chamber Period Total Micrograms Removed Plant 4,581 13,894 2,871 28,710 7,242 39,107 7,960 41,392 3,085 14,500 7,581 30,324 10,325 34,073 15,275 (Gerbera 76,931 1,336 daisy 107,653 4,227 Gerbera 25,968 jamesonii) Pot mum (Chrysanthemum English (Hedera morifolium) ivy helix) Mother-in-law's (Sansevieria tongue laurentii) Warneckei (Dracaena Peace deremensis (Spathiphyllum Chinese "Mauna Loa") evergreen (Aglaonema "Silver Marginata (Dracaena Bamboo Queen") marginata) palm (Chamaedorea Janet "Warneckei") lily seifritzii) Craig (Dracaena deremensis "Janet Craig") ]0 by per Table Formaldehyde Removed from and Soil During by Houseplants a Sealed Experimental a 24-h Total Exposure Plant Surface Leaf Area (cm 2) Banana Chamber Period Total Micrograms Removed per Plant 1,000 (Musa 11,700 2,871 31,294 985 9,653 14,205 76,707 1,696 8,480 2,323 9,989 2,471 10,378 2,723 8,986 15,275 48,880 7,581 20,469 8,509 16,167 2,373 8,656 1,894 4,382 713 1,555 oriana) Mother-in-law's (Sansevieria tongue laurentii) English ivy (Hedera helix) Bamboo palm (Chamaedorea Heart leaf seifrizii) philodendron (Philodendron Elephant oxycardium) ear philodendron (Philodendron Green domesticum) spider plant (Chlorophytum Golden pothos (Scindapsus Janet elatum) aureus) Craig (Dracaena deremensis "Janet Craig") Marginata (Dracaena Peace marginata) lily (Spathiphyllum Lacy tree Chinese Aloe Loa") philodendron (Philodendron (Aglonema "Mauna selloum) evergreen modestum) vera ]! Table Chemicals Experimental Removed Chamber by Household During a 24-h Formaldehyde Plants from a Sealed Exposure Period Trichloroethylene Benzene Initial Final Percent (p/m) (p/m) Removed Mass cane 20 70 14 11 21.4 16 14 12.5 Pot mum 18 61 58 27 53 17 10 41.2 Gerber daisy 16 50 65 21 67.7 20 13 35 50 27 13 52 20 18 10 Ficus 19 10 47.4 20 14 30 19 17 10.5 Leak control 18 17.5 2.8 20 19 20 18 10 Warneckei Note: Plants were maintained Initial Final Percent in a commercial-type greenhouse Final (p/m) (p/m)(p/m)Removed Initial Percent (p/m)Removed until ready for test- ing Each test, 24-h in duration, was conducted in a sealed chamber with temperature and light intensity of 30 °C +1 and 125 footcandles _+5, respectively Table Benzene Removal from Houseplants During a Sealed Experimental Chamber a 24-h Exposure Period by Initial Final Percent (p/m) (p/m) Removed ivy 0.235 0.024 89.8 Craig 0.432 0.097 77.6 0.127 0.034 73.2 0.166 0.034 79.5 0.204 0.107 47.6 0.176 0.037 79.0 0.156 0.074 52.6 0.182 0.055 70.0 0.171 0.162 5.3 0.119 0.095 20.1 English Janet Golden pothos Peace lily Chinese evergreen M argi n ata Mother-in-law's Warn ec kei Leak Soil test control control tongue 12 Table Trichloroethylene Chamber (TCE) Removal by Houseplants from a Sealed a 24-h During Exposure Experimental Period Initial Final Percent (p/m) (p/m) Removed ivy 0.174 0.155 10.9 Craig 0.321 0.265 17.5 0.207 0.188 9.2 0.126 0.097 23.0 Warneckei 0.114 0.091 20.2 Marginata 0.136 0.118 13.2 0.269 0.233 13.4 0.121 0.120 0.141 0.128 English Janet Golden pothos Peace lily Mother-inolaw's Leak test Soil tongue control control During the first-year studies, for loss of chemicals from It was then assumed that sealed chambers and metabolic high chemical In an effort could rates chamber after leakage correcting be attributed expected removal the only controls to determine free of plants and pots with fresh potting to the plant the exact 9.2 used were chambers for controls, from these plants rates attributed