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Prevalence of fungi in used pillows
Mariam Begum1,*, Anish Aya1, Cedric Cheong1, Heike Neumeister-Kemp1, Kevin White1,
Peter Kemp1
1 Mycologia Pty Ltd, Perth, Western Australia
*Corresponding email: mariam.begam@mould.com.au
Keywords: Asthma, Microbial products and toxins, Mould and Bacteria, Mycotoxins
1 Introduction
Regular exposure to high concentrations of
fungal spores can result in severe health effects
such as asthma, allergic reactions, respiratory
infections and mycotoxicosis.
Studies have found a substantial amount of fungi
of varying genera in used pillows and bedding
materials. As early as 1935 (Conant et al.)
isolated Rhizopus species from used pillows.
Woodcock et al, (2005) found pillows provide
an ideal environment for fungi to grow with a
high concentration of fungal spores and 4-16
different species of fungi in used pillows, Kemp
et al (2002). Such findings are expected given
the availability of moisture and nutrient sources
on or in pillows.
Given that most people spend 7-8 hours asleep
and in close contact to pillows, the duration of
exposure and the proximity of microorganisms
to the breathing zone warrants further study.
2 Materials/Methods
This investigation was carried out to determine
the prevalence of fungi in 45 used pillows. One
hundred and seventy pillows that had been used
in families for a few years were collected and
stored in clean cardboard boxes prior to study.
Forty five pillows were randomly selected,
segregated and labelled into three sample groups
of equal number: low, moderately and highly
stained, based on the amount of visible staining
present on the pillow covers.
Each pillow was individually vacuumed for one
minute using a Filter Queen™ Majestic vacuum
cleaner fitted with a Dust Scope; a large in-line
filter compartment attached to the inlet of the
vacuum cleaner. The Dust Scope was fitted with
a new filter prior the start of each vacuum test.
Filters were weighed before and after the tests to
determine the amount of dust collected from
each pillow before plating the sample. Between
each vacuum test the Dust Scope was cleaned
with alcohol wipes and the vacuum hose rinsed
with a 70% ethanol solution and allowed to dry
to prevent cross contamination.
To identify the different types of fungi present
on the filters, the collected dust from each filter
was interspersed evenly onto 2% Malt Extract
Agar plates. The filter was then re-weighed to
measure the amount of dust transferred onto
each agar plate. The plates were incubated at
room temperature for 3-5 days. After the
incubation period, the total concentration of
viable fungal colonies were counted and
recorded as colony-forming units (CFU). Fungal
genera were identified by morphology and
taxonomy via analysis under microscope.
3 Results and Discussion
The range of dust mass from the pillow tests
varied from 0.06g to 0.36g with a mean of
0.16g. Samples with a dust mass between 0.1g
and 0.15g (n=14) were the most frequent
(Figure 1) with the least number in the “low
stained” group (n=3) and most in the “highly
stained” group (n=6).
Figure 1: Distribution of dust sample mass.
Within each group distribution of mean dust
mass ranged from 0.13g to 0.20g with the
“moderately stained” group having the highest
mean mass, however there was no significant
difference (p=0.08) between the three groups.
Anova: Single Factor analysis via Microsoft
Excel was undertaken to test for significant
difference between group means.
The calculated concentration of mould per
pillow (CFU count) ranged between 22 and 563
CFU with a mean of 241 CFU. Distribution of
CFU count within the three groups (Figure 2)
appeared to be significant (P=0.04), however
there was no significant difference (P=0.90)
between “low stained” and “moderately stained”
groups. Variance in CFU count was greatest in
the “low stained” group and least in the “high
stained” group.
Figure 2: Distribution of colony forming units.
The correlation between dust mass and CFU
count in both ungrouped and grouped was weak
(R2<0.18). As such mass of dust does not appear
to correlate to CFU count.
The concentration of various types of mould per
pillow varied from very low to high (Table 1).
Yeast, Pencillium sp., Cladosporium sp. and
Rhizopus species were the main organisms with
more than 40% of pillows with the same fungal
distribution. Without exception, Yeast was the
highest contaminant present in all pillows with
concentration typically in excess of one order of
magnitude compared to other genera.
Table 1: Distribution of fungal genera.
Mean CFU
Fungi
Low
Mod
High
All
Alternaria sp.
3
2
1
6
Aureobasidium sp.
0
0
1
1
Cladosporium sp.
12
15
5
32
Epicoccum sp.
5
4
4
13
Monilia sp.
0
0
2
2
Penicillium sp.
12
12
9
33
Yeast
221
215
152
588
Rhizopus sp.
6
4
4
14
Many species of Penicilium are considered
important allergen sources (Fallah et al. 2004),
produce mycotoxins and have neurological
effects on the body (Samson et al. 2010).
Certain species of Rhizopus are important
human pathogens (Ellis et al. 2007).
4 Conclusions
Pillows with moderate to high staining are likely
to have elevated dust mass on/in them compared
to low staining however this does not appear to
correlate with CFU count.
Highly stained pillows appeared to have lower
CFU counts. The mechanisms behind such a
result was not determined but may be related to
hydrophobicity of stains or the type of textile
covering or filling. Supplementary data is
needed, to determine the ideal environmental
factors required for fungal growth on pillows.
Further investigation is required to identify
allergenic and toxigenic species in used pillows.
5 References
Conant N.F., Wagner H.C. and Rachemann F.
M.1935. Fungi found in pillows, mattresses
and furniture. J. Allergy, 7, 234.
Ellis D., Davis S., Alexiou H., Handke R. and
Bartley, R. 2007. Description of Medical
Fungi. Mycology Unit Women’s and
children’s hospital. School of Molecular and
biomedical science university of Adelaide.
Second edition
Fallah P., Burge H.A. and Gallup J.M. 2004.
Exposure potential of other common
Penicillium species in indoor environments,
Journal of Allergy and Clinical
Immunology, 113(2) S223.
Kemp P.C., Neumeister-Kemp et al (2002).
Determining the Growth and Vitality of
Micro-organisms in Carpets and Mattresses
in Non-Problem Dwellings by Measuring
CO2 Released during Respiration. Indoor
and Built Environment. Vol. 11, pp. 214-
220
Samson R.A., Houbraken J., Thrane U., Frisvad
J.C., and Andersen B. 2010. Food and
Indoor Fungi CBS Laboratory Manual
Series. Fungal Biodiversity Centre Utrecht,
The Netherlands.
Woodcock A.A., Steel N. Moore C.B., Howard
S.J., Custovic A., and Denning D.W. 2005.
Fungal Contamination of bedding. Allergy.
