Biological organisms/Cornell University

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Biological organisms

Cornell University, January 2008

DEA 350 Human Factors - Ambient Environment

http://ergo.human.cornell.edu/studentdownloads/DEA350pdfs/iaqbiol.pdf

Primary Biological Aerosol Particules (PBAPs) (Jaenicke, 2005,

Science, 308, 73)

• Biological materials account for 25%-40% of airborne particulates.

• Worldwide there are 109 tons of biological materials in the air

• Profile similar in Germany (A) and Russia (

• No seasonal effects

Natural Commensals

• Estimated 65 billion bacteria per square inch of upper throat

(Stipp, Fortune, Jan, 20, 2003)

• High density of commensal bacteria helps to " crowd out " dangerous

bacteria that could cause infection.

Ventilation and Disease

• Members of the British Parliament's House of Commons complained of

a lack of " fresh air " , frequent " lassitude and heaviness " and

persistent epidemics of influenza.

• In 1904, Dr. Mervyn Henry Gordon was appointed to investigate.

• He gargled with an emulsion of harmless bacteria (B. prodigiosus)

• He put >200 agar plates around the chamber and delivered a 1-hour

oration (reciting Shakespeare) with the ventilation system off then

repeated this the next day with it on.

• He incubated the plates for 48 hours.

• The plates directly in front of him had the greatest

contamination, and even the plates at the back, 62' away, showed

contamination.

• The levels of contamination were higher with the ventilation

system on.

Houses of Parliament Experiments (Gordon, 1906)

Breathing Zone

• The breathing zone is the volume of a room in which occupants

breathe as they stand, sit, or lie down.

• It refers to the air around a person's mouth and nose.

• Respiration creates a personal cloud in the breathing zone.

Personal Microenvironment

Personal Cloud

• The Personal Cloud concept refers to the air quality in the

personal breathing zone rather than general room or ambient air.

• This is being studied using a breathing mannikin by University

researchers at.................

Building Related Illnesses

• Acute Respiratory Diseases (e.g. colds).

• Legionnaire's Disease, Pontiac Fever.

• Humidifier Fever.

• Allergic disease, Hypersensitivity pneumonitis.

• Building-related illness are caused by microorganisms associated

with building HVAC systems.

Sources of Microbiological Contaminants

• Ventilation system:

– filters

– humidifier

– ducts

• People (viruses, bacteria, fungi).

• Plants (fungi, insects, allergens).

• Floor coverings and furnishings (bacteria, fungi, allergens).

Microorganisms in HVAC Systems

• Microorganisms can live in ventilation ducts.

Viruses

HVAC and Acute Respiratory Disease (Brundage et al., 1988)

• Compared 4 army training centers over 47 month period and recorded

incidence of febrile acute respiratory disease (ARD).

• 2 centers - HVAC (95% recirculated air).

• 2 centers - natural ventilation (~50% recirculated air).

• Increase risk of ARD in HVAC centers.

Office Design and Viral Illness (Jaakkola et al., 1990)

• Tracked health of 893 workers (439 men, 454 women) in an 8 story

office building in Helsinki over 12 months.

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© Professor Alan Hedge, Cornell University, January 2008

• Frequency of colds:

– 14.9% none

– 17.1% 1 cold

– 30.0% 2 colds

– 34.1% 3 colds

– 3.9% >3 colds

• Results showed:

– 35% increase in the risk of colds when workers shared offices

– 46% increase with children

– 107% increase with allergic rhinitis

Bacteria

• Bacteria are ubiquitous.

• Many bacteria are ~1ìm.

• Ventilation duct dust can contain up to 50,000 bacteria per gram

of dust.

• Dirty HVAC filters can contain up to 6,700 bacteria per gram of

dust.

• Bacteria need 95% RH to survive.

• Bacteria cause many building-related illnesses.

Legionnaire's Disease

• 1976 - American Legion Conference, Philadelphia hotel.182 people

ill + 29 deaths.

• > 60 outbreaks worldwide in hotels, hospitals and offices.

• Legionella pneumophila can thrive in cooling towers and the tower

mist can be re-entrained into the HVAC system.

Legionella and Cooling Towers

• Optimal growth temperature ~35°C in water (~95°F).

• Bacterium thought to live in Amoebae in water.

• Bacterium killed in 8 minutes at 58°C (136°F).

• Bacterium killed in 4 minutes at 60°C (140°F).

• Killed by chlorination.

• Killed by UV light.

Legionnaire's Disease

• Bacterium common in soil.

• Bacterium causes Legionnaire's disease (pneumonia-like illness) or

Pontiac Fever (non-pneumonia illness).

• Symptoms - malaise, headache, high fever, gastro-intestinal

symptoms, respiratory failure, death.

• Legionnaire's disease mainly fatal for elderly and immune-

suppressed (e.g. AIDS patients).

• > 600 deaths per year.

Legionnaire's Disease

• 1988 - BBC London.

• Contaminated cooling towers.

• 3 deaths (including HVAC maintenance person + 1 passerby).

• 96 affected by Legionnaire's disease.

Bacterial Endotoxins

• Cell walls of gram-negative bacteria contain endotoxins.

• Endotoxins are lipopolysaccharides.

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© Professor Alan Hedge, Cornell University, January 2008

• Exposure to endotoxins can cause fever and respiratory illness.

• Toxic shock syndrome is caused by endotoxins.

• Endotoxins are implicated in " sick building syndrome "

Legionnaire's Disease

• April 1985– large outbreak at the District General Hospital in

Stafford, England

• 103 cases of the disease reported

• 28 people died

• Source of the outbreak was a cooling tower.

Legionnaire's Disease & Whirlpool Spa's

• 1996 –23 cases (2 died) in Virginia traced to a whirlpool spa

• 1999 – outbreak at Westfriese Flora (WF) in Bovenkarspel (Province

of Noord-Holland, Netherlands). The WF is a yearly exhibition of

flowers, and agricultural and consumer products

– 242 people became ill

– Legionella pneumophila was isolated from two whirlpools , eleven

fountains and a sprinkler .

Mesophilic Actinomycetes

• Thermophilic filamentous, colonial bacteria that thrive at 25 °C

(77°F) (hence mesophilic).

• Mesophilic actinomycetes (Streptomycetes sp.) found in 70%

of " sick buildings " vs. 10% of controls.

• Streptomycetes produce an intense, moldy odor.

• Mesophilic actinomycetes thrive on wet construction materials and

soil.

Allergies and Asthma

• > 50 million Americans suffer from allergic

• >50% of Americans test positive to one or more allergens

• 25% of Americans allergic to either dust mite, rye, ragweed, or

cockroach.

• Allergies are 6th leading cause of chronic disease in the US,

costing the health care system $18 billion annually.

• >26 million Americans have asthma and ~9 million are <18 years old.

• Asthma is the most common cause of childhood hospitalizations

under the age of 15.

• >5000 children die of asthma each year.

• Common triggers include fungi, pollen, pets

Fungi

• Fungi and molds are colonial organisms (~200,000 species) that

thrive on decaying matter.

• Fungal growth usually requires RH>70%.

• Fungi can grow in a wide climate range (-10°C - 65°C).

• Fungi produce toxic compounds (mycotoxins), which include the most

powerful toxins known (cause liver, kidney damage, respiratory

reactions). Many of these are used as antibiotics (e.g. penicillin).

• Health effects occur with inhalation/ingestion of mycotoxins,

fungal spores, and fungal mycelia. At least 45 species known to

cause disease (e.g

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© Professor Alan Hedge, Cornell University, January 2007

© Professor Alan Hedge, Cornell University, January 2008

Stachybotrys chartarum, Aspergillus flavus).

Classification of Fungi

• Basidiomycetes - mushrooms

• Phycomycetes - molds (e.g. Rhizopus - black bread mold)

• Ascomycetes - yeast, Pencillium (some species)

• Fungi imperfecti - Pencillium (some species), Aspergillus,

Stachybotrus chartarum (atra), etc.

Fungi

• Fungal spores 7-12 ìm diameter, but can be up to 100 ìm long

(shape varies with species).

• Spores can be detected in air at 30,000 feet.

• 30% of people show allergic reactions to fungal spores (wheeze

cough, shortness of breath).

• Dirty ventilation ducts can contain up to 6,200 colony forming

units (CFUs) per gram of dust.

• Dirty HVAC filters can contain up to 3,400 CFUs per gram of dust.

Fungi

• Health problems can be caused by spores, parts of the fungal body,

and fungal metabolites (mycotoxins).

Main Genera causing Indoor problems

• Cladosporium (25 species) - brown gray/olive green colored

colonies.

• Alternaria - likes warm, humid conditions, grows on textiles.

• Penicillium (200 species) - blue-green colonies, thrives in air-

conditioned spaces.

• Aspergillus - likes warm, humid conditions. Thrives when heating

turned on. Aspergillus fumigatus causes lung disease (Aspergillosis)

that can be fatal.

• Stachybotrys atra - produces most potent mycotoxins that cause

lung, kidney and liver damage.

Fungi: Alternaria alternata

• Grows between 2°C - 32°C.

• Optimum 25-28°C.

• Grows on wood, sick/dead plants.

• Major fungal allergen in moldy houses.

• Causes asthmatic reactions.

• Can cause skin disease.

• Produces mutagenic toxins.

Fungi: Aspergillus fumigatus

• Grows between 12°C - 57°C.

• Optimum 37-43°C.

• Human infective fungus, targets AIDS + immune compromised people.

• Cause of Aspergillosis - acts as parasite in lungs.

• Causes extrinsic allergic alveolitis (Farmer's lung) from moldy

hay, wood chips etc.).

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© Professor Alan Hedge, Cornell University, January 2008

• Produces antibacterial metabolites.

Fungi: Aspergillus niger

• Fast growing fungus.

• Optimum 20-40°C (37°C best).

• Found in house dust.

• Causes airways allergies.

• Can cause ear infections.

Fungi: Penicillium chrysogenum

• Grows between 5°C - 37°C.

• Optimum 23°C.

• Found in indoor air and house dust.

• Major fungus in moldy buildings.

• First producer of penicillin.

Fungi: Cladosporium herbarum

• Grows even at -6°C.

• Optimum 18-28°C.

• Common in outdoor air, especially in late summer/fall and in

forested areas.

• Found in dirty refrigerators, condensate reservoirs, window

frames. Even grows in aircraft fuel tanks!

• Major fungal allergen causing asthmatic reactions + hayfever.

Fungi: Stachybotris Chartarum (atra)

• Grows from 2-40°C.

• Optimum 23-27°C.

• Only grows on wet substrate (paper, gypsum board, seeds, soil,

textiles dead plants).

• Found worldwide.

• Produces several highly toxic metabolites.

• Implicated in young infant cot deaths.

Stachybotrys Chartarum

• Stachybotrys chartarum (also known as Stachybotrys atra) is a

greenish-black mold.

• It can grow on material with a high cellulose and low nitrogen

content, such as fiberboard, gypsum board, paper, dust, and lint.

Growth occurs when there is moisture from water damage, excessive

humidity, water leaks, condensation, water infiltration, or flooding.

Stachybotrys Chartarum

• In 1994, when doctors noticed that a cluster of babies in

Cleveland had developed bleeding in their lungs.

• Initial research suggested that the cause might be a toxin-

producing mold called Stachybotrys chartarum.

• Many of the lung-damaged babies lived in homes that had recently

suffered major water damage.

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© Professor Alan Hedge, Cornell University, January 2008

Moldy Buildings

Moldy Houses

• In 1998 the pipes in the Texas mansion belonging to Melinda

Ballard and Ron sprang a leak.

• Massive amounts of mold bloomed, but because most of the growth

was inside the walls the couple didn't realize what was going on for

months.

• Their son developed asthma, tremors, and learning problems, and

's memory and ability to concentrate were so seriously

impaired he lost his job. Ballard became convinced the problem was

Stachybotrys and other molds.

• The couple sued, claiming their insurance company hadn't moved

fast enough, and in 2001 a jury awarded them $32 million.

• Since then mold-related insurance claims and lawsuits have

multiplied, and builders and insurers are preparing for the worst.

Moldy Houses

• Brokovich bought a 5,200 ft2 house in Agoura Hills, CA, only

to find it teeming with mold.

• She, her husband and daughter have suffered a variety of

respiratory ailments attributed to mold exposure.

• She's spent >$600,000 on home repairs to remediate the mold

problem.

• She sued the builder ( Selleck, Tom Selleck's brother).

Moldy Buildings

Fungus on Floor Coverings

Damp Floors and Fungi

• Fungi can grow on and under persistently wet VCT floors.

Are all molds toxic?

• Neurospora crassa (orange bread mold)

• Although it looks harmful, studies have failed to show significant

health effects of exposure.