Transcript Infections and indoor air problems

MOULDY HOUSE
PROBLEM
Tartu
10.3.-11.3.2004
Markku Seuri, FIOH, 2004
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DEFINITIONS
mould = microbes and their (toxic)
products in moisture and water
damaged building materials
 mouldy house = a building partly
damaged by moisture and microbial
growth
 damages can be visible or within
building structures
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Markku Seuri, FIOH, 2004
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THE MAIN DIFFICULTY
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the exposure is not known
several candidates:
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spores
toxins
microbial volatile organic compounds
microbes themselves
structures of microbes
allergens
Markku Seuri, FIOH, 2004
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LIVING EXPOSURE
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the exposure changes over time
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the microbes change:
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material
type of damage
degree of moisture
temperature
nutrition
selection of species in time
the health effects change
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SPORES
commonly measured and expressed
as colony forming units (cfu) per cubic
meter of air, gram of material
 poor relation to the health effects
 one has to consider to microbial
species, no only the amount
 measure of the damage, not of the
health effects or the risk
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MICROBIAL ALLERGENS
mould allergens exist, but most of the
health effects are not IgE related
allergies
 fungal allergens are commonly essential
enzymes in the fungus
 similarities between the allergens of
different species
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STRUCTURES OF
MICROBIAL WALL
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beeta-glucans of fungi
endotoxin of gram negative bacteria
rarely seen in the air of mouldy houses
can be a problem in renovation
can cause irritation of respiratory tract
not a probable cause of health effects
Markku Seuri, FIOH, 2004
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MICROBIAL VOLATILE
ORGANIC COMPOUNDS
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do MVOCs exist?
– MVOCs are released also from
moistened materials without microbial
growth
– a measure of moisture damage on
materials
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not capable of producing irritation in
the concentrations seen in mouldy
houses
Markku Seuri, FIOH, 2004
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MICROBIAL TOXINS
their role in causing health effects in
mouldy houses controversial
 good potential cause:
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– various health effects - many toxins
– potential (ng/g -level)
– most difficult health effects are seen in
old damages - selection of species in time
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no way to measure small quantities
(at the moment)
Markku Seuri, FIOH, 2004
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MICROBES
THEMSELVES
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not fungi commonly found in mould
damages
only less than 10% of the microbial growth
of any environmental sample can be named
interest in two groups:
– slowly growing mycobacteria
– microbes living with in amoeba
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AMOEBA AND
LEGIONELLOSIS
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Legionella is intracellular bacteria
found in natural and man-made water
systems
multiplies in 20-50 degrees of C (32-40 ideal)
survives in the environment within amoeba
can be an occupational diseases, for instance
in work place showers
an epidemic in a Finnish hospital has been
found
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AMOEBA SHELTER
OTHER BACTERIA
over 40 bacteria have been found
within amoebae
 including Chlamydia pneumoniae
 we have found amoebae in damaged
building material samples (in about
one fifth of samples sent to our
laboratories in Kuopio)
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MOULD DAMAGES AND
IMMUNOCOMPROMISED
PATIENTS
Aspergillus spp have caused
infections in hospitals, even fatal case
 at the moment there is no evidence
that the fungi in the mouldy buildings
could cause diseases to health
inhabitants
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Markku Seuri, FIOH, 2004
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SYMPTOMS AND DISEASES
FOUND IN MOULDY
BUILDINGS
irritation
 “toxic” or “general” symptoms
 increased number of respiratory
infections
 diseases
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Markku Seuri, FIOH, 2004
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IRRITATION
SYMPTOMS
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respiratory tract:
– commonly the higher, rarely the lower
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irritation of the eyes
irritation of the skin
the most common symptoms
transient
usually relieves in a few days
Markku Seuri, FIOH, 2004
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“TOXIC” OR “GENERAL”
SYMPTOMS
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symptoms like:
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headache
tiredness
aching muscles and joints
fever and chills
transient
may need a week or two to be relieved
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RESPIRATORY
INFECTIONS
normal flues
 sinusitis
 the incidence is higher in mouldy
houses
 some toxins restrain the cilial
movement in the respiratory tract in
vitro
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DISEASES 1
asthma is the most common
 mechanism is not known
 most asthma cases seen in mouldy
houses are not allergic
 the risk of asthma is about two in the
mouldy houses, but the risk is not
divided evenly among them
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DISEASES 2
allergic rhinitis have been shown
 some clusters of inflammatory
rheumatic diseases have been
published
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– the causal link not established
– the risk of these diseases seen rarely
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