1.1
Health Effects
Inhalation
of fungal spores, fragments (parts), or metabolites (e.g.,
mycotoxins and volatile organic compounds) from a wide variety
of fungi may lead to or exacerbate immunologic (allergic)
reactions, cause toxic effects, or cause infections.11, 12,
24
There
are only a limited number of documented cases of health problems
from indoor exposure to fungi. The intensity of exposure and
health effects seen in studies of fungal exposure in the indoor
environment was typically much less severe than those that were
experienced by agricultural workers but were of a long-term
duration.5-10, 12, 14, 16-20, 25-27 Illnesses can
result from both high level, short-term exposures and lower
level, long-term exposures. The most common symptoms reported
from exposures in indoor environments are runny nose, eye
irritation, cough, congestion, aggravation of asthma, headache,
and fatigue.11, 12, 16-20
The
presence of fungi on building materials as identified by a
visual assessment or by bulk/surface sampling results does not
necessitate that people will be exposed or exhibit health
effects. In order for humans to be exposed indoors, fungal
spores, fragments, or metabolites must be released into the air
and inhaled, physically contacted (dermal exposure), or
ingested. Whether or not symptoms develop in people exposed to
fungi depends on the nature of the fungal material (e.g.,
allergenic, toxic, or infectious), the amount of exposure, and
the susceptibility of exposed persons. Susceptibility varies
with the genetic predisposition (e.g., allergic reactions do not
always occur in all individuals), age, state of health, and
concurrent exposures. For these reasons, and because
measurements of exposure are not standardized and biological
markers of exposure to fungi are largely unknown, it is not
possible to determine "safe" or "unsafe"
levels of exposure for people in general.
1.1.1
Immunological Effects
Immunological
reactions include asthma, HP, and allergic rhinitis. Contact
with fungi may also lead to dermatitis. It is thought that these
conditions are caused by an immune response to fungal agents.
The most common symptoms associated with allergic reactions are
runny nose, eye irritation, cough, congestion, and aggravation
of asthma.11, 12 HP may occur after repeated
exposures to an allergen and can result in permanent lung
damage. HP has typically been associated with repeated heavy
exposures in agricultural settings but has also been reported in
office settings.25, 26, 27 Exposure to fungi through
renovation work may also lead to initiation or exacerbation of
allergic or respiratory symptoms.
1.1.2
Toxic Effects
A
wide variety of symptoms have been attributed to the toxic
effects of fungi. Symptoms, such as fatigue, nausea, and
headaches, and respiratory and eye irritation have been
reported. Some of the symptoms related to fungal exposure are
non-specific, such as discomfort, inability to concentrate, and
fatigue.11, 12, 16-20 Severe illnesses such as ODTS
and pulmonary hemosiderosis have also been attributed to fungal
exposures.5-10, 21, 22
ODTS
describes the abrupt onset of fever, flu-like symptoms, and
respiratory symptoms in the hours following a single, heavy
exposure to dust containing organic material including fungi. It
differs from HP in that it is not an immune-mediated disease and
does not require repeated exposures to the same causative agent.
ODTS may be caused by a variety of biological agents including
common species of fungi (e.g., species of Aspergillus
and Penicillium). ODTS has been documented in farm
workers handling contaminated material but is also of concern to
workers performing renovation work on building materials
contaminated with fungi.5-10
Some
studies have suggested an association between SC and pulmonary
hemorrhage/hemosiderosis in infants, generally those less than
six months old. Pulmonary hemosiderosis is an uncommon condition
that results from bleeding in the lungs. The cause of this
condition is unknown, but may result from a combination of
environmental contaminants and conditions (e.g., smoking, fungal
contaminants and other bioaerosols, and water-damaged homes),
and currently its association with SC is unproven.21, 22,
23
1.1.3
Infectious Disease
Only
a small group of fungi have been associated with infectious
disease. Aspergillosis is an infectious disease that can occur
in immunosuppressed persons. Health effects in this population
can be severe. Several species of Aspergillus are known
to cause aspergillosis. The most common is Aspergillus
fumigatus. Exposure to this common mold, even to high
concentrations, is unlikely to cause infection in a healthy
person.11, 24
Exposure
to fungi associated with bird and bat droppings (e.g., Histoplasma
capsulatum and Cryptococcus neoformans) can lead
to health effects, usually transient flu-like illnesses, in
healthy individuals. Severe health effects are primarily
encountered in immunocompromised persons.24, 28, 29
1.2
Medical Evaluation
Individuals
with persistent health problems that appear to be related to
fungi or other bioaerosol exposure should see their physicians
for a referral to practitioners who are trained in
occupational/environmental medicine or related specialties and
are knowledgeable about these types of exposures. Infants (less
than 12 months old) who are experiencing non-traumatic
nosebleeds or are residing in dwellings with damp or moldy
conditions and are experiencing breathing difficulties should
receive a medical evaluation to screen for alveolar hemorrhage.
Following this evaluation, infants who are suspected of having
alveolar hemorrhaging should be referred to a pediatric
pulmonologist. Infants diagnosed with pulmonary hemosiderosis
and/or pulmonary hemorrhaging should not be returned to
dwellings until remediation and air testing are completed.
Clinical
tests that can determine the source, place, or time of exposure
to fungi or their products are not currently available.
Antibodies developed by exposed persons to fungal agents can
only document that exposure has occurred. Since exposure to
fungi routinely occurs in both outdoor and indoor environments
this information is of limited value.
1.3
Medical Relocation
Infants
(less than 12 months old), persons recovering from recent
surgery, or people with immune suppression, asthma,
hypersensitivity pneumonitis, severe allergies, sinusitis, or
other chronic inflammatory lung diseases may be at greater risk
for developing health problems associated with certain fungi.
Such persons should be removed from the affected area during
remediation