Qualitative Assay of Indoor Air Using An Air Purifier with Special Reference to The
Reduction of Aero Allergens and Pollutants
Nabarun Ghosh Ph.D. Associate Professor of Biology
Department of Life,
Earth and Environmental Sciences West Texas A&M
University, Canyon, Texas 79016
Amanda Whiteside Research Associate
Rupa
M. Patel Research Associate
Lisa Dyer Research Associate
Introduction
Aeroallergens
are often the cause of serious allergic and asthmatic reactions,
affecting millions of people each year. To aid to the diagnosis and
treatment and reduce the ailments of these individuals suffering
from various indoor aeroallergens, a thorough understanding and control
of the indoor aeroallergens and other airborne particles are necessary.
Weather conditions and diurnal cycles play an integral role in the
passive and active discharge of spore and pollen. Warm dry weather
conditions promote passive dispersal of dry air spora, including
Alternaria, Cladosporium, Curvularia, Pithomyces and many smut teliospores.
Diurnal levels of these spores usually have peaks during the afternoon
hours under conditions of low humidity and maximum wind speeds.
Moist
weather conditions promote the active dispersal of moist air spora,
such as the explosive release of ascospores from Ascomycetes, and
the expulsion of basidiospores from the gills of the Basidiomycetes.
Pollen grains are released by the flowering plants following the particular
season for pollen production specific for each plant species. As we
recorded for the last five years the most significant aeroallergens
of the Texas Panhandle were fungal spores from Alternaria, ascospores
from Pezizales, Dreschlera, Cladosporium, Curvularia, and pollen
from short ragweed (Ambrosia artemisiifolia), grass pollen (Poaceae)
common sunflower (Helianthus annuus), hairy sunflower (Helianthus
hirsutus), buffalo bur (Solanum rostratum), purple nightshade (Solanum
elaeagnifolium) and lamb’s quarters (Chenopodium album). 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 nation’s 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.
Implementation of the Strategies and Discussion:
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. I am quoting 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, second-hand tobacco smoke and poor ventilation.” (Ref. 4) When
a mold can be seen or smelled, it poses a concern. A building with
leakage or moisture problems contributes to flourishing live mold spores.
Once a mold has established itself, it may increase quickly and colonies
can spread if enough moisture is available. Therefore moisture control
is an important aspect to preventing and controlling mold problems.
However, if an office space or residential buildings encounter a mold
problem on the premises it should be able to demonstrate that the moisture
problem is being removed using effective methods to restore the sight
to a clean condition. Although all buildings contain some mold, as
do our homes, offices, and the outdoor air, becoming indoor air quality
conscious will help in the prevention (Ref. 5).
Qualitative Assay of the Fungal Aero Allergens (Molds) after using nano nickel Technology air purifier
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. 6). The first phase of this study is aimed
at analyzing the effect of the nano nickel Technology Air Purifier
the spore and pollen counts of allergenic taxa in the indoor air
randomly sampled from different office facilities and residential
buildings. Sampling will be done using a standard spore trap (Burkard
Corporation). Petroleum jelly emulsion was applied to the tapes to
capture the allergens. This study will cover observations on the
effect of an ionizer/air purifier in reduction of indoor aeroallergens
including mold spores, pollen, dust mites, cat and dog dander, dust
mites and microbial flora. We shall use digital
and fluorescence microscopy to quantify the aeroallergens present
in a particular location. We shall also assess the air quality by
screening microbial colonies and analyzing the gaseous composition
of a room by the using of a Gas Chromatography (GC) Mass Spec. We
shall focus on a target aeroallergen and compare the composition
and concentration of each of them before and after the usage of the
nano nickel Technology Air Purifier at 2hours, 8 hours, 24 hours
and 72 hours intervals at a particular location. We shall compare
the composition and concentration of each of the following target
aeroallergens before and after the usage of the nano nickel Technology
Air Purifier:
- Mold spores, mycelia, hyphae or other fungal bodies present
in the indoor air. - Pollen from various species of flowering plants present
in the indoor air. - Microbial composition in the indoor
air focusing on particular specie: Staphylococcus aureus,
E. coli and Streptococcus. - Burnt residues, gums, resinous droplets and plant fibers
in the indoor air.
5.
Dust mites, insect droppings, other insect residues and animal
dander (cats and dogs namely). This project will be carried out
in 4 phases.
Phase I:
In the first phase we will standardize
the procedure to analyze and compare the mold spores, mycelia,
hyphae or other fungal bodies present in the indoor air. We will
also cover the comparative analysis of the other aeroallergen like
pollen.
Phase II:
In the second phase we will compare the
concentration of bacteria described above (#3) before and after
using the nano nickel Technology air purifier.
Phase III:
In the
third phase we will cover the comparative observations on burnt
residues, gums, resinous droplets and plant fibers in the indoor
air. We will also cover the study on dust mites, insect droppings,
other insect residues and animal dander.
Phase IV:
We shall compare
the gaseous composition of the indoor air before and after the
exposure with the nano nickel Technology air purifier with the
special focus on volatile organic compounds, Carbon disulfide,
d-Limonene Toulene, Hydrogen Sulfide, Benzene, Formaldehyde and
Ammonia. Bioaerosol sampling will be done following standard techniques
(Ref. 7) and by the using of the Gas Chromatography facility at
Dr. David Parker’s Lab. All the data will be analyzed and statistical
analysis will be done after comparing the data from every phase.
Graphs will be erected and data will be used for possible publication.
Data from every phase will be provided to the owners time to time
after the completion of every phase.
Report on Phase I
Fall 2006 We have
divided this research projects in four different phases. The first
phase of research was aimed at evaluating the nano nickel Technology
Air Purifier and assesses its efficiency in reducing the indoor aeroallergens
and air-microflora, especially the bacteria and mold spore concentration
in the indoor air. The first phase research was divided into two
groups: 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. The first part was carried out by Rupa M. Patel under
my supervision (Dr. N. Ghosh).
Report by Rupa M. Patel
Nano nickel
Technology Air Purifier on Microbial colonies To evaluate
the nano nickel Technology Air Purifier we set up the following
criteria and variables. Criteria: Evaluation of the Air Purifier
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 121 degree
Celsius. After pouring the media the petri-plates were stored on
the tabletop to cool down and then stored in the refrigerator after
sealing the plates with parafilm.
Variables:
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 and 12 feet
away from the air purifier with various time intervals. Time
Period: Control (exposure 0 hours): Assay done with the petri plates
and coated slides keeping the air purifier off. 24 hours: Assay
done with the petri plates and coated slides after running the air
purifier for 24 hours in the room. 48 hours: Assay done with the
petri plates and coated slides after running the air purifier for
48 hours in the room. 72 hours: Assay done with the petri plates
and coated slides after running the air purifier for 72 hours in
the room.
Space:
Size of the room: 15 ft
x 25 ft (Room 317) 8 ft x 15 ft (Room 336)
Air purifier Setting
At Low and At High
The nano nickel Technology Air Purifier was evaluated keeping it
on a tabletop and placing the petri-plates prepared from Brain Heart
Infusion agar. The nano nickel Technology Air Purifier was placed
on a table in a large laboratory room (15 ftx25 ft), bacterial and
mold samples were obtained from Brain Heart Infusion media plates.
The petri- plates were set 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. We found
significant differences in microbial spore population in the room
air before and after the treatment with The Air Purifier 3200 at
different intervals.
Report from Mandy Whiteside: nano nickel Technology Air Purifier on Aeroallergen Evaluation of a nano nickel Technology Air Purifier by Mandy Whiteside
For this
project we had to first standardize our technique. We did this by
setting guidelines on what we wanted to accomplish with this project.
We first wanted to setup slides at specific distances. So far we
have evaluated in close proximity to the nano nickel Technology air
purifier. We setup slides with distances of 1foot, 2 feet, 4 feet,
6 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. For slide
preparation we use standard microscope slides 75×25. We used scotch
brand double-sided sticky tape cut to a length of 2 inches, which
is the length of the cover slip. The tape is taken off the roll using
forceps and a needle to avoid the contamination from the oil from
our hands. To stain aeroallergens, we applied safranin gelatin to
the cover slip and then placed the cover slip on top of the tape.
On our first trial was for our control group, these slides were setup
at the predetermined distances from the air purifier. This first
trial was setup for 24 hours. The results were very discouraging
because there were very little aeroallergens on some slides to nothing
on others. We decided that we needed to add some extra adhesion glue
to the sticky tape. We thought that there was probably not enough
glue for the aeroallergens to get stuck to. There are two types of
glue that we tried the first was an acid free Ross Stick washable
glue, and the other was Beckman’s Silicone Vacuum Grease. We set
up another trial for 24 hours to test which of these two glues was
better. Half of the slides were setup with the Ross Stick glue and
the other half were setup with the Beckman’s Silicone Vacuum Grease.
We then compared the results of the two glues. Our conclusion was
that the Beckman’s Grease trapped more aeroallergens than the Ross
glue. We then set up our control
groups for 24 hours, 48 hours, and 72 hours. We compared the results
of each. We established that the most aeroallergens were on the
72-hour slides; followed by the 48 hour slides, and the slide with
the least amount of aeroallergens were the 24hour slides. After evaluation
of our control group we setup for our trail groups. We first wanted
to evaluate the low setting on the air purifier. Again we set the
slides up at the predetermined distances for 24, 48, and 72 hours.
The results were after 24 hours there was little change in the aeroallergen
count. There was more improvement after 48 hours; we found that there
were less of the aeroallergens on these slides than in the control
group. The best results were found on the 72-hour slides, we found
that there was the most improvement on these slides. There was least
concentration of aeroallergens on these slides than on the 72-hour
control group. We next wanted to evaluate
the nano nickel Technology air purifier at the high setting. As
before, we setup the slides at the predetermined distances for 24,
48 and 72 hours. The 24-hour trial we found less aeroallergen than
both the control group and the low setting group. The 48-hour trail
at the high setting, the results were also that there were less aeroallergen
than the control and the low setting. Finally, we found that there
were very little aeroallergens at all. Our conclusion from the
results that we found is that the nano nickel Technology air purifier
works best over a longer period of time and at the high setting.
Procedure for the preparation of microscopic slides:
A clean microscopic slide is coated with a thin layer
of water. The segment of tape is then laid upon the microscopic slide
with the impregnated surface using forceps so that the long edges
of the tape are parallel with the long edges of the slide. Positioning
should be such that viewing of the entire slide may be accomplished
from subsequent traverses of the slide. It is essential that
the sides of the tape be mounted parallel to the sides of the
slide so that traverses are to be truly traversed with the microscope.
The use of Gelvatol is required to secure the cover slip in place.
This compound is applied with a glass rod and is a permanent
mountant. Gelvatol is composed of 35 g Gelvatol powder (Burkard
Manufacturing Co Ltd., UK), 50 ml Glycerol, 100 ml distilled
water, and 2 g phenol. We prepared Gelvatol by mixing the Gelvatol
powder and phenol in water allowing sitting overnight. The mixture
of phenol and Gelvatol was placed on a water bath (65oC) and glycerol
and distilled water was added to it slowly while stirring produced
the proper emulsion. Upon distribution of the Gelvatol on the cover
slip, a drop of Safranin O (Sigma Cat no. 84120, Fluka, Microscopy
Grade) was placed upon the cover-slip and stirred evenly, when
set on the slide it stained the pollen and spores facilitating
the observation with a microscope. Safranin was prepared beforehand
and stored in a glass bottle. We found 1% Safranin was very effective
stain in viewing pollen, including their cell walls and colpi
(pores). The stain was comprised of 1.0 grams of Safranin O powder
dissolved in a 50:50 mixture of 95% ethanol and distilled water.
These components were dissolved in a round flask and were allowed
to boil for 15-20 minutes. After cooling to the room temperature,
this solution was filtered through
Whatman’s filter paper (Grade No. 43 Cat. no. 28481-302, 12. 5
cm in diameter, VWR) into a second round flask. After filtering,
the solution was transferred to glass vessels for long-term storage
at room temperature.
Microscopic analysis of collected allergens:
Sample
tapes from the spore trap will be analyzed regularly after the
collection and transfer of the pollen pollen sampling tape take place
at suitable intervals. Slides will be analyzed with five latitudinal
traverses corresponding to the mean concentration will be assessed.
The mean concentration will be determined mathematically by taking
a sum total of all the prepared slides and multiplying this sum by
a correction factor. Correction factors are microscope-objective
specific and are determined prior to counting. It can be expressed
as the total area sampled divided by the graticule width (8). The
prepared slides will be examined, counted, and photographed using
a BX-40 Olympus microscope attached to a DP-70 Digital Camera attached
to a Dell Computer equipped with Image Pro 6.0 Image Analysis software.
This assessment will involve 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 graticule is a scale that measures distances to the 10-2 division
of a millimeter. The graticule was calibrated using a stage micrometer.
The pollen, fungal spores and insect residues will be identified
using standard keys from literature and the websites (Ref. 9, 10,
11, 12 and 13).
Result and Discussions
Figure 1 Control (No treatment with Air Purifier)
Figure-1 shows the number of microbial colonies produced in the Control set,
before any treatment of indoor air with the air purifier.
Figure 1-A shows the distribution of microbial colonies in the Control se (No
treatment with air purifier).
From the figure-2
is 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 microbial (bacterial and fungal) colonies with greater interval
of exposure with the air purifier.
Figure 3
Figure 3 shows the petri-plates after a 24-hour treatment with the air purifier. Note
the reduction in number of colonies compared to figure-4 (Control,
no treatment with air purifier).
It was also evidenced that the petri-plates placed closer to the distance to
the air purifier (1ft. and 2 ft.) produced least number of colonies
after 24h., 48h. and 72 hours of treatment of the indoor air with the
air purifier. Figure-3 shows the level of infection after 24 hours
with distances 1 ft, 2ft. and 4 ft. away from the air purifier. There
was very minor trace of inoculums from the petri-plates from 1 ft.
or 2 ft. and 4 ft. distances after 24 hours of treatment of the room
air indicating thereby definite reduction of the microbial aeroallergen
in the room air. After 72 hours of treatment of the indoor air with
the air purifier there was almost no microflora or propagules left
in the indoor air since there was no microbial colony produced on the
petri-plates. All the experiments were carried out with setting at
High in the air purifier. Figure 1 shows the Control plates without
any treatment. All the 3 petri plates from the set up of 1ft, 2ft and
4 ft show vigorous growth of the microbial colonies after incubation
in an incubator at 37’C.
Figure 3 Effects
of treatment of air purifier on the concentration of indoor
aeroallergen concentration.
The petri plates from the set up of 24-hour treatment with air purifier from
distances 1ft, 2ft and 4 ft from the air purifier showed no significant
microbial growth. At the distance of 1 ft no microbial colony was recorded
on the petri-plate while the petri plates from 2 and 4ft showed very
minor trace of inoculums. Figure 4 shows the distribution of the aeroallergen
count after the treatment of the room air after 24hour, 48 hour and
72 hours. After 72 hours of treatment there was almost no aeroallergen
left closure to the air purifier.
Future Research
We will carry out the research in Phase-II for
- Assay for the rest of the time intervals and distances away from the air purifier
in a different room. - Identification of specific aeroallergen the concentrations of which were reduced
with the treatment of the indoor air with the air purifier. - We will also use the variable of “Space” using a different size of room to
assess the efficacy of the air purifier. - We will use digital and Fluorescent Microscopy to characterize the aeroallergens
the concentration of which is reduced by the air purifier. - We will correlate our findings on reduction of bacterial population and identifying
the specific bacteria in relation to their pathological importance.
Reference:
- Indoor Air Quality Program: Web
site: http://www.tdh.state.tx.us/beh/IAQ/default.htm - School Health: www.health.state.mn.us/divs/eh/schools/index.htm
- Journal Indoor Air: at http://alcor.concordia.ca/~raojw/crd/essay/essay000897.html
- John
Bower, owner, The Healthy House Institute, Bloomington,
Ind.: In Mold Reporter at: http://www.moldreporter.org/vol2no6/2002Air - Investigating
Mold in Minnesota Public Schools at: www.health.state.mn.us/divs/eh/indoorair/schools/mold.html - Journal Indoor Air at http://alcor.concordia.ca/~raojw/crd/reference/reference001468.html
- BIOAEROSOL SAMPLING (Indoor Air) NIOSH Manual of Analytical Methods (NMAM),
Fourth
Edition Method 0800 January 15, 1998 at: http://www.cdc.gov/niosh/nmam/pdfs/0800.pdf#search=’BIOAEROSOL%20SAMPLING’
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58th AAAAI Annual Meeting. 1-68. - Moore, P.D. 1991. Pollen Analysis, Second Ed. Blackwell Scientific Publications.
Oxford. 62-166. - Website for American Academy of
Allergy Asthma and Immunology: http://www.aaaai.org/ - Website: University of Arizona:
http://www.geo.arizona.edu/palynology/polonweb.html - Jelks, M. L. 2002. Allergy Pollen Keys with Images. Sarasota, FL.1-19.
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Sessions, S. K.1993. Review: The Art and Science of Fluorescence
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