Nabarun Ghosh1, Jeff Bennert2, Mandy Whiteside1 and Rupa Patel1
1 Department of Life, Earth and
West Texas A&M University, Canyon, TX 79016.
2Air Oasis, 3401 Airway Blvd. Amarillo, TX 79118
Experimental trials at the Allergy ARTS Clinic at Amarillo revealed that the Allergic Rhinitis patients showed susceptibility to air spora, including Alternaria, Cladosporium, Curvularia, and Pithomyces. We standardized the procedure to assay the efficiency of the air purifier Xtreme 3000 in reducing the indoor aeroallergen. Distance: Sets of the Petri-plates and coated slides were placed with those distances of 1foot, 2 feet, 4 feet, 6 feet and 12 feet away from the air purifier. Period: Exposure after 24 hour, 48 hour, 72 and 120 hour treatment. The control petri-plates and slides were placed in the room without using the air purification system. Assay was done with the petri-plates prepared from Brain Heart Infusion agar (VWR) and Gelvatol coated slides with air purifier off for the control and on for the treated. The slides were examined, analyzed, and photographed using a BX-40 Olympus microscope attached to a DP-70 Digital Camera. Petri-plates were examined with an SZ-40 stereo-scope to observe and count the colonies. The control set of plates showed vigorous growth of the microbial colonies after incubation in an incubator at 37oC for 24 hours. Petri-plates closer to air purifier (2ft. and 4 ft.) produced least number of colonies after 24h., 48h. and 72 hours of treatment of the indoor air with the air purifier. There was very minor trace of inoculums from the Petri-plates from 2 ft. 4ft. and 8 ft. after 24 hours. After 72 hours of treatment of the indoor air with the air purifier there was very little microflora or propagules left in the indoor air since there were only 1-2 microbial colony produced on the Petri-plates. After a 2-month continuous exposure of the room air with the Xtreme 3000 at "High" setting we found complete eradication of aeroallergens including the fungal and bacterial spores.
Offices, working places and schools face the challenge of an increasing number of workers and children with pre-existing health conditions which are affected by the Indoor Air Quality and other environmental factors. Indoor Air Quality (IAQ) in offices is an important aspect. Indoor levels of air pollutants can be 2-5 times higher, and occasionally 100 times higher, than outdoor levels. Surprisingly, nearly 55 million people, 20 percent of the U.S. population, spend their days inside offices and schools. An estimated 50 percent of the nations schools have problems linked to Indoor Air Quality (Ref. 1). The neglect of IAQ can cause or contribute to short and long-term health problems including asthma, respiratory tract infection and disease, allergic reactions, headaches, nasal congestion, eye and skin irritations, coughing, sneezing, fatigue, dizziness and nausea. Not only does poor indoor air quality contribute to an unhealthy environment; it also hastens building deterioration. One study on an elementary school showed that if $8,140 had been spent over 22 years on preventative maintenance, $1.5 million in repairs could have been avoided by the use of a proper monitoring of aeroallergens and air purifying system (Ref. 2). In order to prevent a risky working environment the employers must be appropriately educated about indoor air quality.
The quality of the environment within buildings is a topic of major importance for public health. (Ref.3). Presently Indoor Air Quality (IAQ) is a major concern at various work places. Here is an important quote on air quality from the journal: "With all the publicity, more and more people are realizing that pollutants in the indoor air could make them sick. The worst thing that has happened to the indoor air quality marketplace in the last year or so is also mold. This is because much of the media coverage is designed to sensationalize the topic and frighten the public - so much so, that the word 'mold' always seems to be preceded by the adjective 'toxic.' Thus, homeowners and building managers are scared to death of any minor infestation that might possibly be toxic mold, and they often ignore other health issues, such as combustion byproducts, VOCs (Volatile Organic Compounds), second-hand tobacco smoke and poor ventilation." (Ref. 4)
While the fungal exposure assessment was based on the determination of fungal propagules for a long time, recent progress has led to the development of methodology for other fungal agents, e.g. the fungal cell wall components, metabolites, and allergens that may be responsible for health effects caused by fungal exposure. This proposal includes a summary of the sampling techniques and analytical methods that are currently used or are in progress for the fungal exposure assessment. (Ref.5). This study covered observations on the effect of an ionizer/air purifier in reduction of indoor aero allergens including mold spores, pollen and microbial flora.
The first phase research was divided into two steps:
1.Observation on the effect of the air purifier in reducing the concentration of bacteria and mold in the air,
2. Observation on the effect of the air purifier in reducing the concentration of aeroallergens like pollen, spores and other particulate matters concentration in the air.
To evaluate the Air Purifier Xtreme 3000 we set up the following criteria and variables.
Criteria: Evaluation of the Air Purifier Xtreme 3000 using petri-plates and coated slides to collect the microbial spores, propagules (like fungal hyphae) and aeroallergens (like pollen, spores and other particulate matters) with a standard distance of 1foot, 2 feet, 4 feet, 6 feet and 12 feet away from the air purifier. The petri-plates and slides were previously made before setting up the experiment. The slides were coated and placed in clean slide boxes and the boxes were sealed with parafilm to avoid any contamination. The petri-plates were made following standard aseptic procedure by autoclaving the media at 15lb steam pressure /sq Inch at 121oCelsius. After pouring the media the petri-plates were stored on the table top to cool down and then stored in the refrigerator after sealing the plates with parafilm. All the petri-plates from the set up were incubated in an incubator for 24 hours at 37oC.
Distance: A number of sets of the petri-plates and coated slides were placed with those distances of 1foot, 2 feet, 4 feet, 6 feet, 8 feet, 10 feet and 12 feet away from the air purifier with various time intervals.
Control set (exposure 0 hours): Assay was done with the petri-plates and coated slides keeping the air purifier off.
Treated sets: Assay was done with the petri-plates and coated slides after running the air purifier for 24, 48, 72 and 120 hours in the room.
The Air Purifier Xtreme 3000 was evaluated keeping it on a table top and placing the petri-plates prepared from Brain Heart Infusion agar (VWR). The Air Purifier Xtreme 3000 was placed on a table in a large laboratory room (15 ft x 25 ft), bacterial and mold samples were obtained from Brain Heart Infusion media plates. The petri- plates were placed surrounding the air purifier and assayed after no exposure (Control), after 24 hours and 48 hour exposure of the room air to the air purifier. All of the plates were set at the distances of 1foot, 2 feet, 4 feet, 6 feet and 12 feet away from the base of the air purifier and assayed after various time intervals of 24hours and 48 hours. The air purifier was also tested at High and low settings. The control plates and the plates exposed to the high setting of the air purifier were analyzed using a SZ-40 Olympus Stereo Microscope. The bacterial and mold specimens were further identified by Gram staining and Lacto-Phenol-Cotton-Blue Staining techniques for size, shape, and morphology. Samples were examined, counted and photographed every 24 and 48 hours using a BX-40 Olympus microscope attached to a DP-70 Olympus Digital Camera devised with Image Pro-6.0 software. Data were correlated with the distance, time of exposure to find the differences in bacteria and mold population between room air treated with and without the air purifier. Our assays revealed significant differences in microbial spore population in the room air before and after the treatment with Air Purifier 3000 at different intervals.
We standardize the techniques for evaluating the Air Purifier. We setup slides with distances of 2 feet, 4 feet, 6 feet 8 feet, 10 feet and 12 feet away from the air purifier in 4 directions. Our ultimate goal is to get samples all the way up to 12 ft. Slides were mounted with scotch brand double sticky tape and coated with Beckmans Vacuum Grease. After exposure the slides were stained with safranin-gelatin mixture and mounted with coverslip onto the tape.
For the control group, the slides and petri-plates were setup at the predetermined distances from the air purifier. We then set up our treated groups (with air purifier running) for 24 hours, 48 hours, 72 hours and 120 hours and recorded and compared the results of each set. After several trials we found that the Beckmans Grease was the most efficient in trapping aeroallergens.
Microscopic analysis of collected allergens:
The prepared slides will be examined, counted, and photographed (Fig.4 below) using a BX-40 Olympus microscope attached to a DP-70 Digital Camera attached to a computer equipped with Image Pro 6.0 Image Analysis software.
This assessment involved the optical counting of pollen grains, fungal spores and other particulate matters through a microscope and the use of a micrometer scale and graticule (100 square microns). The pollen, fungal spores and insect residues were identified using standard keys from literature and the websites (Ref. 6-10).
Figure 1 shows the experimental set up of the petri-plates and slides with specific distances from the air purifier.
We recorded the highest concentration of aeroallergens from 120 and 72 hour petri-plates (Fig.2) and slides (Fig. 4), followed by the 48 hour slides.
Least amount of aeroallergens was recorded from the 24 hour slides from the control group or untreated set. The petri-plates placed closer to the distance to the air purifier (1ft. and 2 ft.) produced least number of colonies at 24h., 48h., 72h. and 120 hours of exposure to the indoor air with the air purifier. From Fig. 3, a graph on the distribution of the number of microbial colonies before and after the treatment of indoor air with the air purifier, it is very clear that there was a gradual reduction in the number of bacterial and fungal colonies with greater interval of exposure with the air purifier.
After evaluation of our control group we set up the treated sets keeping the air purifier running. We placed the slides at the predetermined distances for 24, 48, 72 and 120 hours. After 24 hours there was little change in the aeroallergen count. The control set of plates showed vigorous growth of the microbial colonies after incubation in an incubator at 37oC for 24hours (Fig. 2). Petri-plates closer to air purifier (2ft. and 4 ft.) produced least number of colonies after 24 and 48 hours of treatment of the indoor air with the air purifier. The trace of microflora in the slides and petri-plates gradually reduced with longer treatment of the indoor air with the air purifier. After 72 hours of treatment of the indoor air with the air purifier there was very little microflora or propagules left in the indoor air since there were only 1-2 microbial colony produced on the petri-plates. After a 120 hour continuous exposure of the room air with the Xtreme 3000 at High setting we found complete eradication of aeroallergens including the fungal and bacterial spores.
We found that the Xtreme 3000 air purifier was most efficient in eradication of microflora over a longer period of time at the high setting.
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