Transcript Slide 1

Adverse Health Effects of
Indoor Mold Exposure
Overview of the 2011 ACOEM
Statement
Anthony Burton, MD MPH
General Motors-Romulus
ACOEM 2011 Statement
• American College of Occupational and
Environmental Medicine-founded 1916
• Represents more than 4,500 physicians
and other professionals in OEM
• “Adverse Human Health Effects
Associated with Molds in the Indoor
Environment”
ACOEM 2011 Statement
• A position statement of the college
• Prepared under auspices of the Council of
Scientific Advisors
• Approved by the ACOEM Board of
Directors on 2-24-11
• Revision of the 2002 position statement
• Evidence based
ACOEM 2011 Statement
• Includes: current state of scientific
knowledge with respect to mold-related
illness indoors
• Does not include: food-borne exposure;
methods of exposure assessment;
remediation procedures
Mold-Types of Health Effects
• Allergy
• Infection
• Toxicity
IgE Allergic Reactions to Mold
• IgE antibodies mediate an immediate
hypersensitivity reaction causing allergic
disease: runny nose and itchy eyes (hay
fever), asthma
• Following exposure, sensitization occurs
when IgE antibodies specific to fungal
proteins are made
• Once sensitized, subsequent exposure
can trigger allergic responses
IgE Allergic Reactions to Mold
• Molds are common and important
allergens
• Atopic individuals (those with allergic
asthma, rhinitis, eczema who have IgE
antibodies to a range of environmental
proteins) typically develop allergy to molds
• Reactions often also occur to other
allergens (animal dander, dust mites,
pollens, etc.)
IgE Allergic Reactions to Mold
• About 40% of the population is atopic
(have allergic antibodies to aeroallergens)
• About ¼ of these (10% of the population)
have antibodies to common aeroallergenic
molds
• About ½ of these (5% of the population)
will have allergic disease from molds
IgE Allergic Reactions to Mold
• Molds are much more abundant outdoors
than indoors; outdoor exposures cause
more allergic airway disease. Indoor
exposures play an important but minor role
• Common indoor allergenic molds:
Penicillium, Aspergillus
• Outdoor molds that can be found at high
levels indoors: Cladosporium, Alternaria
IgE Allergic Reactions to Mold
• Damp/water damaged homes are
associated with numerous health problems
(especially in children): asthma, wheezing,
cough, sputum production
• These health problems are likely related to
more than just mold; bacteria, bacterial
endotoxins, dust mites may all play a role
in these problems
Hypersensitivity Pneumonitis
• An immunologically mediated
hypersensitivity disease from inhalational
exposure
• Patients frequently have circulating (IgG)
antibodies detectable in blood directed
against the etiological antigen
• Also called HP or “extrinsic allergic
alveolitis”
Hypersensitivity Pneumonitis
• Most cases of HP are from occupational
exposure
• Can result from exposures related to pet
birds, humidifiers (humidifier fever), HVAC
systems
• Most HP related to water sources are due
to thermophilic actinomycetes (bacteria)
Hypersensitivity Pneumonitis
• Acute disease causes chills, fever,
shortness of breath and malaise with
onset 4 to 6 hours after exposure, lasting
18 to 24 hours
• Self-limited and reversible
• Mimics bacterial or viral pneumonia, but
resolves quickly without antibiotics
Other Allergic Diseases
• Allergic bronchopulmonary aspergillosis
and allergic fungal sinusitis
• Uncommon IgE mediated allergic disease
caused by growth of fungi in the human
airway; not linked to indoor environments
• Can occur in allergic individuals with
existing airway damage
• Allergic reaction to fungal colonization
Allergy and MoldsRecommendations
• If you have allergic airway disease,
minimize your exposure to mold and other
aeroallergens by:
– closing windows
– filtering outdoor intakes
– remediating sources of indoor mold
amplification; controlling humidity
– reducing exposure to animal allergens, dust
mites, cockroaches
Allergy and MoldsRecommendations
• If hypersensitivity pneumonitis is
suspected, need to investigate potential
sources of inhaled antigen
• In the industrial environment, focus
measures on preventing mold growth, e.g.
– in metal-working fluids
– where stored organic/agricultural materials
are handled
– reduce aerosol or particulate generation
Allergy and Molds-Summary
• For almost all allergic individuals,
reactions to molds will be limited to rhinitis
or asthma, and sinusitis may occur
secondarily
• Other effects are rare
Mold Infections
• Indoor mold exposure does not generally
lead to infection
• Some fungal infections can occur in
healthy subjects: Blastomyces,
Coccidioides, Cryptococcus, Histoplasma;
though these are typically found only
outdoors
Mold Infections
• Serious fungal infections (deep tissue
invasion) are primarily restricted to
severely immunocompromised subjects
– fungi such as Aspergillus are ubiquitous, and
Candida are human commensals
– these, and the others that are typically found
outdoors are not typically found growing
indoors
Mold Infections
• Superficial fungal infections are very
common in normal individuals; they cause
ringworm, athlete’s foot, and other
mucosal and skin infections
• Some of these can be found growing as
indoor mold or on indoor pets
• Candida albicans can be cultured from >
½ the population with no evidence of
active infection
Mold Infections-Recommendations
• Immunocompromised individuals require
caution about exposure to opportunistic
fungal infections
• Those with infections related to pets
should have their pets checked by a
veterinarian
Molds and Toxicity
• Mycotoxins: secondary metabolites of
fungi, i.e., not required for growth or
survival of the fungus
• Amount and type of mycotoxin production
is highly variable, dependent on multiple
factors
• Thus, presence of a toxigenic species
does not necessarily mean presence of
toxin
Mycotoxins
• Most descriptions of human poisonings
from mold involve eating moldy foods
• Some cases involve agricultural worker
exposure to high levels of silage or spoiled
grain products that contain high
concentrations of fungi, bacteria, and
organic debris contaminated with
endotoxins, glucans, and mycotoxins
MVOCs
• Microbial volatile organic compounds
(MVOCs): low molecular weight
aldehydes, alcohols, and ketones with low
odor thresholds; cause the musty odor
associated with mold and mildew
Sick Building Syndrome
Sick Building Syndrome
• An older term used to describe nonspecific
building-related symptoms that cannot be
associated with an identifiable cause
Building Related Symptom
• Nonspecific symptom that cannot be
associated with an identifiable cause but
that appears to be linked to time spent in a
building.
• Mucosal irritation affecting the nose, throat
and eyes
• Headache, irritability, fatigue, difficulty
concentrating; chest tightness, pressure;
skin irritation, dryness; nausea, diarrhea
Building Related Illness
• This is a diagnosable illness associated
with indoor exposure with documented
physical signs and laboratory findings
• Rhinitis, asthma, conjunctivitis, sinusitis
• Hypersensitivity pneumonitis
Building Related Complaints
• Illnesses such as rhinitis and asthma have
clearly been associated with exposure to
molds in the indoor environment
• Many symptoms are often attributed to
occupancy in a building
• Investigation generally finds no specific
cause for the reported symptoms, but
molds are often implicated when found
Mycotoxins and Human Health
Mycotoxins and Human Health
• Stachybotrys chartarum (aka S. atra), a
major focus of mycotoxicity
• Critical literature reviews concluded that
indoor airborne levels of microorganisms
are only weakly correlated with human
disease or building-related symptoms and
a causal relationship has not been
established between these complaints and
indoor exposures to S. chartarum
Stachybotrys chartarum
• Cases of pulmonary hemorrhage in infants
in Cleveland in the 1990s initially attributed
to S. chartarum
• Subsequent re-evaluations by CDC and
expert panel concluded there was no
causal link
• Illness now termed “acute idiopathic
pulmonary hemorrhage in infants”
Mycotoxins and Human Health
• To cause adverse effects, mycotoxins
must be present, there must be a route of
exposure from source to susceptible
person, with absorption of toxic dose over
a sufficiently short period of time
• Presence of mycotoxins cannot be
presumed from presence of toxigenic
species
Mycotoxins and Human Health
• Pathway for exposure indoors involves
dermal contact or by inhalation of
aerosolized spores, mycelial fragments, or
contaminated substrates
• Mycotoxins are usually large molecules,
and therefore usually not very volatile;
thus, aerosolization is required
Mycotoxins-Recommendations
• Presence of toxigenic mold indoors not
sufficient evidence for presence of
mycotoxins or that building occupants
absorbed a toxic dose
• When mold colonization is present
indoors, abate the source of moisture and
remediate the mold growth
Mycotoxins-Recommendations
• Indoor air sampling coupled with
contemporaneous outdoor sampling may
help assess presence of indoor mold
amplification as well as the extent of
potential indoor exposure
• Bulk, wipe, wall cavity samples may
indicate presence of mold but don’t tell you
much about occupant exposures
Mycotoxins-Recommendations
• Individual health complaints associated
with mold exposure require a thorough
assessment, including diagnoses
unrelated to mold
• A diagnosis of mycotoxicosis requires
specificity: consistency between signs,
symptoms with the potential mycotoxins
present, their known biological effects, and
at the exposure levels present
Summary
• Mold spores are present in all indoor
environments and cannot be eliminated
from them
• Normal building materials and furnishings
provide ample substrate for mold growth;
just add water and the mold can propagate
Summary
• When this occurs, it is mandatory to
eliminate the source of water and
eradicate the mold
• Mold growth indoors should not be
tolerated
• Current scientific evidence does not
support the existence of a causal
relationship between inhaled mycotoxins
indoors and adverse human health effects