What are
bioaerosols?
Bioaerosols are
airborne particles
and gases that are
living or have originated
from living organisms.
The term microbials
is often used as
a synonym but does
not necessarily
denote that the
contaminant is airborne.
Examples are:
-
Endotoxins
(bacterial by-product)
-
Mycotoxins
(fungal by-product)
-
Microbial
VOCs (fungal
and bacterial
by-products)
-
Antigens
-
Dust
mites
-
Viruses
-
Bacteria
-
Fungi
There are no
specific regulations
governing surface
microbiological
contamination
or airborne microbiological
contaminants in
indoor air (bioaerosols).
This is in part
due to the many
variables involved
with sampling
for microorganisms,
dramatic fluctuations
in background
levels of microorganisms,
lack of agreement
between researchers
about what constitutes
a "problem
situation".
However, academia
and industrial
hygiene associations
have presented
guidelines. Microbial
concentrations
and the exposure
to their by-products
(spores, antigens,
mycotoxins, endotoxins,
and volatiles)
account for a
substantial amount
of illness, allergic
reaction, and
physical discomfort.
Litigation, medical
diagnosis, and
other forces often
demand a standard
of care that includes
microbial testing
in indoor air
quality (IAQ)
investigations.
Often more than
one type of sampling
is suggested by
published guidance.
Guidance on bioaerosols
is readily available
from ACGIH1 and
AIHA2 and other
organizations.
This document
is for general
information purposes
only. Although
it may be helpful,
it is not intended
for use by healthcare
or hospital facilities,
litigation development,
or medical/epidemiological
investigations.
What
are potential
health consequences
of exposure to
bioaerosols?
The health consequences
of pathogenic
or allergenic
types and relative
concentrations
of microbiologicals
(bioaerosols)
in the indoor
environment can
range from no
reaction to severe
and insidious
health afflictions.
Microbial sampling
and proper interpretation
of results, given
that they generally
represent only
a snapshot in
time, must be
evaluated within
the context of
a well conducted
IAQ investigation.
Special environments
such as critical
care facilities
and institutions
housing or caring
for immune suppressed
individuals must
be held to more
stringent guidelines.
The synergistic
effect of exposure
to multiple fungal
genera, mycotoxins,
bacteria, and
endotoxins and
its relationship
to occupant complaints
and illness is
poorly understood.
Although infection
can even occur
in an otherwise
healthy individual
occasionally,
contaminated indoor
environments are
of particular
concern with infants,
elderly, and immune
compromised individuals
who are much more
susceptible to
infections. Health
effects can be
divided into four
general categories:
infection, toxicosis,
allergy and irritation.
Infection:
There are now
over 100 fungal
species that are
known to cause
infection in humans.
There are three
classifications
of infection caused
by fungi: systemic,
opportunistic
and dermatophytic.
Infection can
also be caused
by virus, bacteria,
and other biological
contamination.
Toxicosis:
Many fungi produce
toxic metabolites
called mycotoxins.
The health effects
from exposures
to the levels
of mycotoxins
that may be encountered
in contaminated
indoor environments
are not yet completely
known. Generally
mycotoxins are
nonvolatile and
inhalation exposure
usually occurs
only after disturbance
of a contaminated
source. Symptoms
of exposure to
mycotoxins may
include cold and
flu like symptoms,
headache, nose
bleeds, dermatitis
and immune suppression.
See the mycotoxin
section for more
information. Toxicosis
can also be caused
by exposure to
endotoxins, which
originate from
the cell walls
of gram-negative
bacteria. Reported
acute symptoms
of inhaled endotoxin
exposure include
chest tightness,
cough, shortness
of breath, fever,
and wheezing.
See the endotoxin
section for more
information.
Allergy:
Allergy is the
most common symptom
associated with
exposure to bioaerosols,
including pollen
grains, fungal
spores, house
dust mite feces,
and other allergens
(cockroaches,
cat, dog, mouse,
etc.). Any fungus
can be allergenic,
producing antigenic
proteins and polysaccharides
that can cause
allergic reactions
in sensitive individuals.
Symptoms include:
allergic rhinitis,
sinusitis, chronic
bronchitis, eczema,
atopic dermatitis,
allergic contact
dermatitis, allergic
bronchiopulmonary
aspergillosis,
hypersensitivity
pneumonitis, humidifier
fever, and asthma.
Irritation:
Fungi and bacteria
produce odoriferous
microbial volatile
organic compounds
(MVOC) during
degradation of
substrates. These
compounds, among
other contaminants,
can irritate mucous
membranes, cause
headaches and
other symptoms.
Top of Page
What
are endotoxins,
mycotoxins, and
MVOCs?
Sampling and interpretation
of endotoxins,
mycotoxins, and
MVOC's (many of
which are quite
odoriferous and
toxic) is a new
science. Adverse
health effects
potentially caused
by these contaminants
should not be
underestimated.
Determining the
concentrations
of these contaminants,
however, can be
expensive, time-consuming,
and should only
be conducted by
experienced investigators
and labs with
the proper techniques,
quality control,
analysis, and
interpretation.
In most cases,
samples must be
interpreted relative
to each other
and a control
therefore, a minimum
of three samples
must be taken
of a particular
contaminant category.
Expect these specialized
samples to take
a total of at
least three to
four hours and
cost at least
$200 each.
Endotoxins
Endotoxin is a
term for the highly
toxic outer membrane
of gram-negative
bacteria. Health
effects vary,
depending on the
individual, dosage,
and route of exposure.
The fact that
the bacteria do
not have to be
alive for endotoxins
to pose a serious
health threat
is the main impetus
for concern. Reported
acute symptoms
of inhaled endotoxin
exposure include
chest tightness,
cough, shortness
of breath, fever,
and wheezing.
Chronic effects
have be suggested.
Gram-negative
bacteria are found
everywhere in
nature. But elevated
airborne levels
are prevalent
in sewage treatment
plants, cotton
textile mills,
poultry houses,
and swine operations.
As these bacteria
are prevalent
in many water
systems, particularly
ones containing
sewage, buildings
with humidifiers
or water intrusions
(especially ones
involving sewage)
often have elevated
levels of gram-negative
bacteria.
Airborne endotoxin
may pose a much
larger risk than
formerly thought
and as such it
is likely to emerge
as a major indoor
air quality issue
in the future.
A routine analytical
technique for
detecting endotoxins
has been developed.
Results from different
labs are not comparable
and background
control samples
must be taken.
In general, little
is known about
indoor endotoxin
sources. The best
way to minimize
non-industrial
endotoxins sources
eliminate contamination
with GNB and limit
aerosolization
of material contaminated
with GNB. Closely
monitor and frequently
disinfect standing
bodies of water
including humidifiers.
Address water
incursion quickly
and properly,
especially when
sewage is involved.
Mycotoxins
Fungi are ubiquitous
to the environment
and many use organic
water-damaged
building materials
as nutrients.
During the digestion
process fungi
secrete enzymes
into the nutrient
source to break
down complex compounds
into simpler compounds,
which are taken
up by the fungi
and digested.
The digested nutrients
are classified
into two categories,
primary and secondary
metabolites. The
primary metabolites
consist of cellulose
and other compounds
that are used
for energy to
grow and reproduce.
The secondary
metabolites, called
mycotoxins, are
produced to give
fungi a competitive
edge against other
microorganisms,
including other
fungi. There are
over 200 recognized
mycotoxins, however,
the study of mycotoxins
and their health
effects on humans
is in its infancy.
Mycotoxins can
cause a variety
of short term
as well as long
term health effects,
ranging from immediate
toxic response
to potential long
term carcinogenic,
teratogenic, cardiovascular,
and neurologic
effects. Symptoms
due to exposure
to mycotoxins
include dermatitis,
cold and flu symptoms,
sore throat, headache,
fatigue, diarrhea,
and impaired or
altered immune
function, which
may lead to opportunistic
infection. Research
has implicated
many toxin producing
fungi, such as
Stachybotrys,
Penicillium, Aspergillus
and Fusarium species,
to indoor air
quality problems
and building related
illnesses. Mycotoxins
are non-volatile
and although routes
of exposure vary,
the most significant
concern addressed
here is the accumulation
of mycotoxin on
particulates,
especially fungal
spores that can
become aerosolized
and inhaled. Scientifically
valid and cost-effective
sampling for mycotoxins
is not available
for indoor air
quality studies,
at this time.
Microbial
Volatiles (MVOC)
Some investigators
are beginning
to use VOC analysis
to search for
microbial VOCs
(MVOCs). However,
only a few laboratories
currently can
apply such analysis
effectively in
building investigations.
The uncertainties
associated with
attributing VOCs
to microbial sources
preclude using
this approach
for routine investigations.
It is difficult
to determine what
portion of indoor
VOCs arise from
common fungi,
bacteria, and
other microorganisms,
but MVOCs likely
are responsible
for only a small
fraction of total
VOCs, measuring
in the low ug/m3
range. However,
a severely contaminated
building may have
a significant
MVOC contribution
derived from microbial
growth. MVOCs
nevertheless can
contribute to
the health effects
reported by the
occupants of contaminated
buildings. Many
bacteria, especially
anaerobic ones,
produce odorous
MVOCs that microbiologists
use to identify
bacterial isolates.
However, information
on the MVOCs bacteria
produce in building
environments is
even more limited
than for fungi.
Some primary fungal
metabolites are
pungent and others
evoke unpleasant
associations such
as "dirty
socks" or
"locker rooms"
or are described
as "moldy,"
"musty,"
or "mildew-like."
Still other fungi
release odors
that are considered
pleasant and are
described with
such terms as
"fruity,"
"earthy,"
or "snow-pea-pod-like."
At this time,
MVOC sampling
for non-research
IAQ assessments
is not a valid
option.
Back to Menu
Can EDC
sample for antigens;
dust mites; viruses;
and Legionella?
Sampling and interpretation
of antigen (cat,
dog, mouse, cockroach
proteins) and
dust mite concentrations
is available and
sampling is affordable.
Environmental
sampling for viruses
is not recommended.
Air sampling for
Legionella is
not recommended,
only water sampling.
Legionella is
addressed elsewhere.
Does
bacteria play
a role in indoor
air quality?
Bacteria in the
indoor environment
are common but
certain types
and concentrations
can be problematic.
Bacteria is primarily
sampled from suspected
source reservoirs
(i.e. humidifiers,
condensate pans)
or air sampling.
Isolation of bacteria
by laboratory
culture remains
the primary method
of environmental
sample analysis
(i.e. direct microscopy
is not used, in
contrast to fungal
spore analysis).
Endotoxin (from
bacterial cell
walls) sampling
and analysis is
a promising science.
Bacteria in the
environment seldom
form discrete
visible evidence
other than slime,
biofilm, or foam,
typically found
in standing water.
Fruity, sour,
or putrid odors
are often indicators
of bacterial growth.
The content of
some discussion
here may not be
applicable for
Legionella , Tuberculosis,
or other types
of bacteria where
specific medical
guidance and sampling
already exist.
Gram positive
bacteria (GPB):
This
human-shed type
of bacteria is
common indoors.
Concentrations
depend on number
of people, activity,
clothes worn,
and ventilation
rates. High levels
may be acceptable
depending on the
factors above.
Extremely high
levels of GPB
in low-activity
areas may indicate
over-crowding
or poor ventilation.
Such problems
can be identified,
however, by other
contaminants such
as carbon dioxide
or visual observations.
Some types of
gram positive
bacteria are pathogenic
but investigation
of these typically
only occurs in
healthcare and
hospital settings.
Gram
negative bacteria
(GNB):
A predominance
of this type of
bacteria indoors
suggests the presence
of fecal contamination
(from a sewage
backflow or overflowed
toilet) or standing
water (from in
humidifier reservoir)
or significant
flooding that
was not cleaned
or remediated
properly. Serious
health effects
are possible depending
on numerous factors.
Viable
bacterial spore
sampling and subsequent
incubation, identification,
and interpretation
has numerous limitations
including:
-
Refer
to the limitations
that affect
culture-based
air sampling.
-
Isolation
and identification
of bacteria
in culture is
time-consuming
and require
repeated transfers
and manipulation
of cultures.
-
False
negatives and
underestimation
of actual bacterial
contamination
problems has
been documented.
-
Little
is known about
the potential
effects for
healthy adults
and children
from a majority
of the bacteria
recovered during
air and source
sampling.
If information
about the extent
of potential gram
negative bacterial
contamination
is required then
endotoxin sampling
could be conducted.
Top of Page
How does
fungal biodiversity
and concentrations
affect environments?
Fungi or mold
just like bacteria
is everywhere.
It is critical
to life on earth.
However, elevated
fungal concentrations
and pathogenic
types are undesirable
in indoor environments.
Depending on the
environment and
human susceptibility
even low concentrations
of pathogenic
types or high
concentrations
of non-pathogenic
types can be harmful.
Further information
about fungi can
be found in other
sources that are
detailed near
the end of this
document.
No accepted guidelines
exist that formally
address microbial
genus or species
and associated
concentrations.
But what is known
is the possible
health consequences
and legal/financial
implications undesirable
bioaerosol exposure.
Each situation
or suspect environment
is typically addressed
on a case by case
basis where all
factors are evaluated
in concert. Fungi
spores can effectively
be sampled by
one or more methods
discussed below.
What
about microbiological
sampling methods?
The adverse health
consequences of
elevated concentrations
or pathogenic
biodiversity of
microbiologicals
(bioaerosols)
in the indoor
environment can
be significant
and prevented.
Microbial sampling
and proper interpretation
of results must
be evaluated within
the context of
a complete building
indoor air quality
(IAQ) investigation.
All sampling and
data interpretation
must be made on
a case by case
basis in a non-alarmist,
confidential,
and practical
manner.
One step to understanding
microbial sampling
and subsequent
results is to
recognize the
advantages and
disadvantages
of various methods
of microbiological
sampling. A comprehensive
microbial sampling
and analysis strategy
should use both
culture and non-culture
methods, given
appropriate financial
resources. If
resources are
limited culture
methods could
receive less attention
than other methods.
The top priority
should be a thorough
visual and olfactory
examination by
a qualified investigator
using written
and photo documentation.
Real time instruments
such as a moisture
meter, particle
mass monitor,
temp/humidity
meter, and other
"IAQ parameter
sensors"
should also be
used and evaluated
in concert with
microbial sampling.
The methods discussed
here are primary
applicable for
mold and bacteria.
Other methods
are available
for endotoxin
and antigen sampling.
Surface,
source, and bulk
sampling
Surface sampling
consists of placing
a medium (i.e.
culture swab,
agar plate, or
clear double-sided
tape) in contact
with a visually
contaminated surface.
At a laboratory,
the suspected
contaminant is
then either applied
to a growth media
(culture method)
for subsequent
analysis or analyzed
by direct microscopy.
Surface sampling
must be interpreted
carefully since
it is subject
to several limitations.
Resulting analysis
and identification
should appropriately
discuss the potential
for false negatives,
inherent interpretation
difficulty, and
culture limitations.
Results should
be qualitative
(identify fungal
type present)
but not quantitative.
Generally, surface
sampling should
not be used for
random or proactive
purposes but reserved
for diagnostic,
healthcare, forensic,
and water-intrusion
investigations.
Collection using
a direct tape
lift and analysis
by direct microscopy
is faster, less
expensive, and
more accurate
but can only determine
genus not species.
Bulk and source
sampling can involve
collection of
material such
as contaminated
drywall, insulation,
or return air
filters. Or a
quantity of dust
be obtained through
vacuuming or other
collection and
sent for analysis.
Non-viable and
viable analysis
methods can be
conducted. Interpretation
can be difficult
but also part
of examining specific
hypothesis so
a proper remediation
strategy can be
developed.
-
Culture-based
air sampling
method
Various types
of culture-based
sampling exist
(such as those
that use liquid
impingers),
however, direct
agar impaction
is most commonly
used. Microbial
food or "agar"
in small circular
plates (as used
by Anderson
sampler type
instruments)
or in strips
(as used by
the RCS sampler)
has been used
extensively
to grow "viable"
airborne microorganisms
for subsequent
identification.
This method
has been used
extensively
to obtain information
about viable
fungal and bacterial
contamination.
Disadvantages
of this method
include:
-
Microbial food
or agar is "selective"
meaning the
growth of certain
microbial type
can be inhibited
by the type
agar itself.
Knowledgeable
selection of
agar is required.
-
Microbial
competition,
specifically
bacteria and
fungal elements
often compete
with each other
and among themselves
for nutrients
(depending on
species and
genus). For
example, Penicillium
mold has anti-bacterial
properties.
Aspergillus
has been shown
to outgrow and
inhibit Stachybotrys.
-
Incubating
culturable or
"viable"
spores requires
several days
before to identification
is possible.
-
Various
microbials incubate
or "grow"
differently
at particular
temperatures.
-
Non-viable
or "dead"
spores can not
be counted using
this method,
even though
they are a major
contributor
to occupant
health aliments,
-
Overgrowth
can kill off
or mask colonies
resulting in
inaccurate concentrations,
-
Condensation
from agar can
cause cross
contamination.
-
Improperly
stored or transported
agar can affect
results.
-
Viable
spores can be
killed or damaged
by the inherent
nature of sampling
resulting in
false negatives
and underestimation
of contamination.
-
Direct
microscopy is
often required
anyway for proper
genus identification
of fungi (not
available for
bacteria).
Advantages
of this method include:
Slit
impaction air sampling
using direct microscopic
analysis
Slit impaction or
"spore trap"
instruments, such
as the Allergenco,
Burkhard, or Zefon
Air-O-Cell, use
a clear sticky substrate
(such as stopcock
grease) to collect
bioaerosols, typically
fungi, for subsequent
analysis by "nonviable"
direct microscopy,
typically at 400
magnification. EDC
prefers this method
as its primary method
of airborne fungal
sampling.
Disadvantages of
this method include:
-
Species can
not be determined
if such information
were needed
for medical
or legal reasons.
Fungal genera
is easier to
identify.
-
Bacteria
can not be analyzed.
-
The
viability of
organisms can
not be determined
(however, dead
organisms can
cause disease
too).
-
Currently,
there is less
concentration
guidelines in
available literature
since counts
include both
viable and nonviable
spores.
Advantages
of this method include:
-
No
special transporting
or handling
of samples is
needed.
-
Since
spore trap samples
do not need
to be incubated
they can immediately
be analyzed
by direct microscopy.
This is ideal
for clearance
sampling after
remediation.
-
There
is no concern
of selectivity
of agar or microbial
competition.
-
This
method has the
ability to allow
enumeration
and identification
of viable and
non-viable fungal
spores, pollen,
fibers, and
other bioaerosols.
-
A
significant
quantitative
advantage over
culture-based
methods has
documented for
some fungal
genus.
-
Instruments
(Zefon, Burkhard
and Allergenco)
samplers are
typically lighter,
more portable,
and quieter.
Sampling
for mold in wall
cavities
Growth of toxic
fungi in wall
cavities can occur
as a result of
a number of circumstances
ranging from construction
and design defects
to accidental
water intrusion.
Assessment of
microbial contamination
in wall cavities
presents a number
of problems. Typical
destructive testing
(see boroscope
exception) performed
to gain access
for visible inspection
and surface sampling
should be avoided.
In addition to
the aesthetic
issues associated
with destructive
testing, there
are potential
hazards to the
technician and
occupants if a
large penetration
hole exposes mycotoxigenic
fungi to the ambient
indoor air. In
response to these
issues, the WallChek
has been developed.
The WallChek is
a nondestructive
sampling device
for assessing
microbial contamination
in wall cavities.
When used correctly,
the WallChek device
can help identify
sources of fungal
growth within
wall cavities
that may not be
visible from within
the room. As with
all indoor microbial
investigations,
interpretation
is subjective
and should be
based on comparing
total numbers
and ranking of
fungal genera
of suspect and
control sample
locations. (Courtesy
of Aerotech Labs)
Visual inspection
of wall cavities,
given the limitations
of obstructing
insulation and
studs, can be
achieved using
penetrations as
small as 1/2"
holes. A borescope
can then be used
to visually observe
if extensive growth
is present.
What
quality online
sources for microbiological
guidance does
EDC suggest?
For further information
EDC finds the
following online
sources helpful.
However, explore
at your own risk.
Can EDC
provide detailed
published guidance
on microbials?
Yes, as a service
to our commercial
clients and members
EDC has provided
the following sources
of microbial guidance.
A password is required
to enter the members
only section. If
you are an EDC client
or member and do
not know your password
please contact EDC
via phone or email
(see top of the
screen).
Information that
addresses microbials
and bioaerosols
typically address
other aspects including:
sampling , data
analysis, health
relationships, biocides,
remediation, and
details on specific
agents. The sources
below, although
full of detail,
can be used by the
layman reader as
an overview or reference
guide.
Title:
Guidelines on
Assessment and
Remediation of
Fungi in Indoor
Environments
Author:
New York City
Department of
Health, Bureau
of Env. &
Occ. Disease Epidemiology
Date,
Size:
April 2000, (102KB),
6989 words
Download (Members
Only)
--------------------------------------------------------------------------------
Title:
Bioaerosols: Assessment
and Control
Author:
ACGIH (American
Conference of
Governmental Industrial
Hygienists) www.acgih.org
Date, Size: 1999,
Several hundred
pages, hardcover
Cost:
Contact ACGIH
or contact EDC
for a copy (EDC
charges $135 for
the book including
shipping)
Summary:
A classic. Overall,
the best bioaerosols
book available.
It is highly recommended
for anyone that
needs accurate
guidance.
Chapters:
There are 26 chapters
such as: Investigation
Strategy \ Health
Effects \ Building
Walkthrough \
Sampling Plan
\ Sample Analysis
\ Data Interpretation
\ Medical Roles
\ Respiratory
Infection \ Prevention
and Control \
Air Sampling \
Source Sampling
\ Data Analysis
\ Data Evaluation
\ remediation
\ Biocides \ Source
Organisms \ Bacteria
\ Fungi \ Amebae
\ Viruses \ House
Dust Mites \ Endotoxins
\ Mycotoxins \
Antigens \ MVOCs
What
is Stachybotrys,
a toxic mold?
Stachybotrys is
a mold that has
caused increased
nationwide concern
especially due
to recent (March
2000) media attention
to its potentially
toxic effects.
Although many
molds produce
mycotoxins, those
produced by Stachybotrys,
especially T-2
toxin and satratoxin
H, are extremely
toxic, are suspected
carcinogens and
are immunosuppressive.
Currently, it
is documented
that the most
effective way
to confirm airborne
presense of Stachybotrys
spores is to use
nonviable spore
trap methods.
Bulk and surface
sampling from
visible contamination
is also suggested.
The following
sources provide
timely guidance
regarding Stachy.
Title:
Update: Pulmonary
Hemorrhage/Hemosiderosis
Among Infants
- Cleveland, Ohio,
1993-1996
Author:
CDC MMWR Weekly
Date, Size: March
2000, (40KB),
2461 Words
Download (Members
Only)
Summary:
A review within
CDC and by outside
experts of an
investigation
of acute pulmonary
hemorrhage/hemosiderosis
in infants has
identified shortcomings
in the implementation
and reporting
of the investigation
described in MMWR
(1,2) and detailed
in other scientific
publications authored,
in part, by CDC
personnel (3-5).
The reviews led
CDC to conclude
that a possible
association between
acute pulmonary
hemorrhage/hemosiderosis
in infants and
exposure to molds,
specifically Stachybotrys
chartarum, commonly
referred to by
its synonym Stachybotrys
atra, was not
proven. This report
describes the
specific findings
of these internal
and external reviews.
--------------------------------------------------------------------------------
Title:
Stachybotrys chartarum:
Current Knowledge
of Its Role in
Disease
Author:
Daniel L. Sudakin,
MD, MPH
Date, Size: February
2000, (41KB),
2371 Words
Download (Members
Only)
Summary:
Stachybotrys chartarum
is one of several
species of filamentous
fungi capable
of producing mycotoxins
under certain
environmental
conditions. In
some observational
studies, the growth
of this toxigenic
mold in the indoor
environment has
been implicated
as a cause of
building-related
illness. Following
reports of a cluster
of cases of pulmonary
hemosiderosis
and hemorrhage
associated with
exposure to Stachybotrys,
public health
measures have
been recommended
which have far-reaching
implications.
Although the hazards
associated with
exposure to some
mycotoxins have
been well studied,
the health risks
from environmental
exposure to Stachybotrys
remain poorly
defined. The purpose
of this review
is to critically
evaluate the current
body of epidemiological
knowledge regarding
Stachybotrys and
to increase physician
awareness regarding
this emerging
environmental
health issue.
Top of Page
Has microbial
contamination
caused lawsuits?
Absolutely, EDC
suggests reviewing
the following
comprehensive
document.
Title:
Microbiological
Contamination
Litigation
Author:
Alexander Robertson
Date, Size: 1999,
(93KB), 6502 words
Download (Members
Only)
Sections:
Causes of action
\ Common fungi
found in water
damaged buildings
\ Fungi and mycotoxins
\ Allergic reactions
to fungi \ Destructive
and non-destructive
testing for mold
\ Interpretation
of results of
microbiological
testing \ Recent
research on mold
\ Expert testimony
in mold cases
\ Damages recoverable
in mold cases
\ Statute of limitations
for mold cases
\ Recent published
verdicts &
settlements of
mold cases in
California \ Recent
publicized mold
cases in other
states.
What
is the role of
moisture?
The documents
below provide
an extended discussion
of moisture at
its impact on
buildings and
wood.
Title:
Moisture Dynamics
in Building Construction
Date, Size: 2000,
(62KB), 4374 words
Download (Members
Only)
Sections:
How and Where
to Look for Moisture
\ Factors Contributing
to Moisture Problems
\ Looking for
Signs \ Moisture
Transport and
Movement
--------------------------------------------------------------------------------
Title:
Water and Wood
Date, Size: 2000,
(119KB), 8955
words
Download (Members
Only)
Summary:
Everything you
will ever need
to know about
moisture, wood,
and wood floors.
Please contact
EDC at 703-352-0488
if we can provide
further assistance.
1American Conference
of Governmental
Industrial Hygienists
(ACGIH). Bioaerosols:
Assessment and
Control, 1999.
2American Industrial
Hygiene Associations
(AIHA). Field
guide for the
Determination
of Biological
Contaminants in
Environmental
Samples, 1996.
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