Indoor Air Quality - Mold Sampling

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Monday, January 14, 2008

Indoor Air Quality - Mold Sampling

http://environmental-consulting.blogspot.com/2008/01/indoor-air-

quality-mold-sampling.html

BIOAROSOL: GENERAL INFORMATION

Bioaerosols are airborne particles of biological origin, such as

bacteria, pollen, fungi, and viruses as well as their by-products or

toxins, such as Mycotoxins and Endotoxins. Airborne contaminants of

biological origin can produce infectious and inflammatory diseases

in exposed individuals, such as Tuberculosis, Legionella, Anthrax, Q

Fever, and Inflammatory Diseases like Chronic Bronchitis, Asthma,

and Conjunctivitis.

Most building related complaints among workers arise from diverse

symptoms as a result of exposure to physical and biological agents

in buildings. A majority of health complaints in buildings with

problems are related to mucous membrane discomfort (i.e., eye, nose,

and throat irritation) headache, and fatigue. Mold Spores are known

causative agents of these problems.

Mold spores can be found anywhere, inside and outside and they can

grow effectively on almost any organic substance, such as wood,

paper, carpet, food and insulation, as long as moisture and oxygen

are present. Mold gradually destroys these things that it grows on.

In some cases indoor mold growth may not be visible or obvious. Mold

spores have been found behind dry wall, wall paper, wood paneling,

above ceiling tiles, and under carpets and carpet pads. Mold growth

has also been known to occur in pipe chases, utility tunnels, near

air handling units, on walls behind furniture, as well as underneath

roofing material. It is impossible to completely eliminate mold from

an indoor environment, but it is possible to control its growth by

controlling the level of moisture. The most important reason to

control mold growth is the potential health concerns that are

associated with airborne mold spores.

Airborne molds and fungi (bioaerosols) are often associated with

respiratory ailments. Some species are irritants of the respiratory

system and are commonly found in indoor and outdoor environments.

The growth of fungi is influenced by several environmental factors,

including light, temperature, nutrients, and most importantly,

water. Almost any carbon-containing material, (abundant in both

indoor and outdoor environments) can provide adequate nutrients for

fungal growth. The introduction of water is the single most

important cause of fungi contamination. Keeping an indoor

environment dry can essentially prevent fungal growth.

FUNGUS MOST LIKELY TO CAUSE HEALTH PROBLEMS

The most common Mold spore causing health problems is

Penicillium/Aspergillus. These contaminants can come in the form of

invasive infections, colonizations, toxicoses, or allergies. They

are opportunistic invaders, infecting various sites in individuals

with lowered resistance to diseases. These Mold Spores have also

been known to cause inflammation of the cornea, external ear,

respiratory, and urinary tract infections. Some strains have even

been known to produce mycotoxins.

A dangerous fungal by-product of Penicillium/Aspergillus is

Cladosporium. Cladosporium is a slow-growing fungus that is very

sensitive to any kind of disruption. This can allow it to become

airborne very easy. It is very common in dead and decaying plants,

and therefore it is the fungus that is most commonly found in the

outdoor environment. It is a common cause of extrinsic asthma and

hay fever. Cladosporium is often found to be a causative agent of

skin lesions, sinusitis, and pulmonary infections.

Chaetomium is frequently isolated from plant debris, soil, wood and

straw-like materials, as well as air. Indoors, it is found on damp

sheetrock and paper products in water damaged buildings.

Chaetomium is reported to be allergenic, and rarely causes toxic

diseases in immunosuppressed people. However, it is considered an

agent of peritonitis (abdominal disorder), and cutaneous lesions.

Stachybotrys, or the " black mold " , is the most debated fungus today.

It grows on moist or water damaged building materials with a high

cellulose and low nitrogen content, such as fireboard, gypsum board,

paper, ceiling tiles, wood, insulation, and dust. It requires water

or excessive moisture for days or weeks to grow. Excessive indoor

humidity can be a catalyst in the development of Stachybotrys.

Due to its wet, slimy growth characteristics, it is unusual for

spores to become aerosolized, therefore it is readily identifiable

on tape lift samples. However, when colonies of this fungus become

dehydrated, there is an increased risk for air dispersion, and

spores can then be detected through air sampling techniques.

Extreme caution should be exercised when levels of this organism are

amplified, as it has been known to produce mycotoxins that can

irritate skin and mucous membranes. Exposure can occur through

inhalation, ingestion or skin exposure when the fungus becomes

embedded in the carpets or walls. Because Stachybotrys spores are

very small, some may be drawn into the lungs when airborne spores

are inhaled.

The health effects of Stachybotrys chartarum (greenish black fungus)

were first noted as diseases in Russian and Eastern European farm

animals that ate moldy hay. The first reported human effects were

seen in agricultural workers who handled the moldy straw or hay that

was affecting the farm animals. Also, after consuming contaminated

cereal grains, people experienced symptoms such as burning

sensations in mouth, nausea, vomiting, diarrhea and abdominal pain.

Individuals with chronic exposure to Stachybotrys have reported cold

and flu-like symptoms, such as sore throats, headaches, fatigue,

runny nose and diarrhea. Individuals with chronic respiratory

disease may experience trouble breathing, and those with deficient

immune systems may be at risk for infection. The actual affect of

Stachybotrys along with human health has yet to be defined, and is

currently the subject of toxin research.

Due to the fact that it is abundant in the natural environment and

is one of the most common fungi worldwide, Alternaria is considered

another important fungal allergen. It is commonly found in soil,

seeds and plants, but specimen of Alternaria are often found growing

on carpets, textiles, in house dust, on damp areas around showers

and windows frames, and anywhere condensation occurs. It is commonly

found in water-damaged buildings, especially on building materials

that contain cellulose, such as drywall sheets. Alternaria is a dry

spore and is readily found in air samples as well as on tape lift

samples. It may be resistant to fungicide.

Alternaria produces large spores having sizes between 20-200 microns

in length and 7-18 microns in width, suggesting that the spores from

these fungi are deposited in the nose, mouth, and upper respiratory

tract. It may be related to what is commonly known as bakers'

asthma. Also, it has been associated with hypersensitivity

pneumonitis, sinusitis, deratomycosis, onychomycosis (nail

infection), subcutaneous phaeohyphomycosis, and invasive infection.

Developing an investigation strategy is crucial to air sampling of

Bioaerosols. A majority of potentially hazardous Bioaerosol

situations arise from an increase of moisture in a building. Should

a situation like this occur it becomes important to locate, isolate,

and halt whatever the source of moisture may be. These areas then

need to be cleaned. Clean up may consist of, but not be limited to:

drying, wiping down, and vacuuming with a High Efficiency

Particulate Air (HEPA) filtered vacuum.

While walking through a building all areas that may have been

affected from an increase in moisture will be the optimal target

areas to perform air testing. It is important to note that a visual

evaluation may not always reveal serious mold contamination.

Therefore, it is often time important for air sampling to be

performed.

Acremonium

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(Acremonium Conidiophores)

The Acremonium genus, formerly known as Cephalosporium, has about

100 different species, most of which are isolated from soil, hay and

organic matter. The spores are slow growing, beginning as compact

and moist, and then becoming powdery. There is widespread growth

indoors when conditions are extremely wet, and it is often found to

be growing with Stachybotrys.

Acremonium is reported to be allergenic, and an opportunistic

pathogen that has the ability to cause infection of the nail and

cornea.

Arthrinium

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(Drawing of several species of Arthrinium)

Arthrinium spores are dark brown and usually occur in grape-like

masses on white woolly colonies. The spores are flattened and have a

colorless line at the edge. When germinating they break along the

line in the manner of a clamshell. In some species the filaments

have dark cross-walls. It is commonly found on dead plants,

especially grasses and hedges, and is often isolated from air near

grassy places in the autumn.

Arthrinium should be considered an allergen. This fungus has also

been documented in various subcutaneous infections. However, no

toxic related diseases have been discovered.

Agrocybe

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Agrocybe is a wood rotting fungus that is usually found outdoors, in

the form of a mushroom, along wood chip paths and bark mulch. It can

be eaten, however, it is not recommended. Agrocybe is not a big

concern when measuring indoor air quality.

Alternaria

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(Alternaria Conidiophores)

Alternaria is composed of dark brown spores that are borne in simple

or branched chains. Colonies are fast growing, and appear to the

naked eye in black, olive green or gray hues. There are 44 species

of Alternaria, which are mostly plant parasites, and are therefore

commonly found in decaying plant materials. However, Alternaria is a

common saprophyte found in decaying wood, food, and some outdoor

air. It is also found in house dust, carpets, textiles, damp areas

around showers and window frames, and anywhere condensation occurs.

Due to the fact that Alternaria is abundant in the natural

environment and is one of the most common fungi worldwide, it is

considered an important fungal allergen. It is a known, but

uncommon, cause of asthma and other respiratory ailments, as well as

mycotic keratitis (inflammation of the eye) and phaeohyphomycosis

(infection of the sinuses). They have also emerged as opportunistic

pathogens in individuals with immunosuppressive conditions.

Arthospores

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(Arthrospore Conidiophores)

Arthrospores are a type of fungus spore composed of fragments of

hyphae (what make up fungi).

Their presence would indicate the presence of various other fungi.

Aspergillus

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(Aspergillus Culture)

There are about 200 species in the Aspergillus genus; about 20 of

them are known causative agents of human disease. Aspergillus is

commonly found in soil, compost piles, plant debris, water damaged

buildings, a wide range of substrates, and house dust. It is one of

the most common contaminants found in indoor air (some species

prefer drier conditions), as well as in water-damaged buildings.

Aspergillus is usually non-pathogenic, as most people are naturally

immune to diseases associated with it, but can become opportunistic

in the respiratory tract. It is associated with many respiratory

ailments, and it often agitates sinuses. Aspergillosis, a result of

prolonged exposure to Aspergillus, causes infections in most human

organs including the lung, nasal sinuses, as well as the skin.

BIPOLARIS

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(Bipolaris Conidiophores)

Bipolaris is a common saprophyte, and a subtropical and tropical

plant pathogen. It is commonly found on dead or dying plant

material, and its colonies are moderately fast growing.

Several of its 45 species are documented in human infection. The

Bipolaris spores are large and are often times deposited in the

upper respiratory tract. Clinical manifestations include mycotic

keratitis (inflammation of the eye), subcutaneous phaeohyphomycosis

(skin lesions), sinusitis, peritonitis (abdominal disorder), and

some cerebral and scattered infections.

Chaetomium

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(Ascospores of Chaetomium species and Chaetomium Culture)

Chaetomium is frequently isolated from plant debris, soil, wood and

straw-like materials, as well as air. Indoors, it is found on damp

sheetrock and paper products in water damaged buildings.

Chaetomium is reported to be allergenic, and rarely causes toxic

diseases in immunosuppressed people. However, it is considered an

agent of peritonitis (abdominal disorder), and cutaneous lesions.

Cladosporium

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(Cladosporium Culture)

The Cladosporium genus has about 30 different species, and is often

times a bi-product of Aspergillus/Penicillium. The spores are slow-

growing and very sensitive to any kind of disruption. It is the most

frequently found fungus in the outside air and in decaying plants.

Cladosporium spores have been found indoors, but usually with less

of a concentration, as they may need cycles of light to produce

spores. It grows indoors where there is moisture or condensation.

Houses with poor ventilation or located in damp environments may

have heavy concentrations.

Cladosporium has the ability to sporulate very heavily, and is

therefore an important fungal allergen. It is a common cause of

extrinsic asthma, and is frequently isolated as a contaminant in the

air. Cladosporium is often times found to be a causative agent of

skin lesions, sinusitis, and pulmonary infections.

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(Cladosporium Conidiophores)

Coprinus

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There are many different species of Coprinus found in the outside

environment, and they are all found in mushroom form. They are

blackish spores that grow in wet conditions. Coprinus should be

treated as an important inhalant allergen.

Curvularia

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(Curvularia Conidiophores)

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(Curvularia Culture)

Curvularia is a common saprophyte, with fast growing colonies. It

has about 35 species, which are usually subtropical and tropical

plant parasites. However, it will grow indoors on a number of

substrates.

Despite being primarily a plant parasite, three species have been

found to cause human infections, such as corneal infections and

various infections in immune compromised people.

Epicoccum

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(Epicoccum Culture)

The Epicoccum genus is made of fast growing colonies, usually with a

yellow/orange pigmentation. The spores are found in plants, soils,

grains, textiles, and paper products.

Epicoccum is a known allergen, and is occasionally isolated as a

contaminant from clinical specimens, such <!--[if !vml]--><!--

[endif]-->as skin.

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(Epicoccum Conidiophores)

Ganoderma

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Ganoderma typically grows on dead or dying hardwoods. Ganoderma

spores are known to stimulate and enhance immunity, and prevent and

suppress cancer. It is considered a powerful natural healing herb in

Chinese medicine. For many years it was used to ward off hepatitis,

bronchitis, asthma, insomnia and nephritis (kidney condition).

Hyphae

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All growing fungi have branched filaments called Hyphae. Hyphae are

linear chains of tubular structures, and eventually produce fruiting

bodies that contain reproductive spores.

Some mycotoxins are associated with Hyphae, and because it is what

gives mold its structure, and therefore its presence is a strong

indication that there are mold spores present in the air.

Paecilomyces

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(Paecilomyces Conidiophores)

Paecilomyces is a saprophyte commonly found among dead plants and

compost. It is a fast growing colony usually found in warm climates

and arid regions. However, it has been isolated from jute fibers,

paper, PVC and timber.

Paecilomyces is related to the genus Penicillium (an allergenic

fungi), but is rarely a human pathogen. However, some species have

been known to cause mycotic keratitis (inflammation of the eye) and

of hyalohyphomycosis (skin lesions) in immune compromised

individuals.

Penicillium

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(Penicillium Culture)

Penicillium spores are usually fast growing, and dense. They are

brush-like spear-bearing structures found in shades of green and

sometimes white. It is one of the most common household molds, and a

frequent food contaminant. It can be found in house dust, carpets,

wallpaper, wallpaper glue, decaying fabrics, behind paint and in

interior fiberglass duct insulation. It is commonly found in water-

damaged buildings. Penicillium is allergenic, and a common cause of

extrinsic asthma. Some species are known as potential mycotoxin

producers.

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(Penicillium Conidiophores)

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(Penicillium Conidiophores)

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(Penicillium on orange)

Pithomyces

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(Pithomyces Conidiophores)

Pithomyces colonies are fast growing, and usually become visible

because of their dark pigment. The genus contains 15 species, and is

found on litter, dead leaves and soil. It rarely grows indoors but

it can grow on paper. Pithomyces is not a known human pathogen, but

is often involved with facial eczema of sheep.

Stachybotrys

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(Penicillium culture and Penicillium Conidiophores)

Stachybotrys lives and grows extremely well on water damaged

building materials cellulose rich materials such as sheet rock,

paper, ceiling tiles, wood, insulation backing and wallpaper. It

requires water or moisture for days or weeks to grow.

Excessive indoor humidity can be a catalyst in the development of

Stachybotrys. Due to its wet, slimy growth characteristics, it is

unusual for spores to become aerosolized; therefore it is readily

identifiable on tape lift samples. However, when colonies of this

fungus become dehydrated, there is increased risk for air

dispersion, and can then be detected through air sampling techniques.

Extreme caution should be exercised when levels of this organism are

amplified, as it has been known to produce mycotoxins that can

irritate skin and mucous membranes.

Exposure can occur through inhalation, ingestion or skin exposure

when the fungus becomes embedded in the carpets or walls. Several

strains of this fungus produce a toxin that is poisonous by

inhalation. Individuals with chronic exposure to Stachybotrys have

reported cold and flu-like symptoms, such as sore throats,

headaches, fatigue and diarrhea. Individuals with chronic

respiratory disease may experience trouble breathing, and those with

deficient immune systems may be at risk for infection. The actual

affect of Stachybotrys along with human health has yet to be

defined, and is currently the subject of toxin research.

Stemphylium

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(Stemphylium Conidiophores)

Stemphylium colonies are rapid growing, and are brown, green or

black in color. Growth indoors is rare.

Stemphylium are plant pathogens and are rarely seen as causative

agents of human infection. They are, however, considered to be

allergenic.

Ulocladium

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(Ulocladium culture)

Ulocladium colonies are fast growing and brown-black or grayish in

color. The spores are commonly found on dead plants, rotten wood,

paper, textiles, and cellulose materials. This mold frequently

occurs in air and dust samples, and is also found in water-damaged

buildings.

Although Ulocladium can be very allergenic, the spores are rarely

seen as pathogenic in humans.