Transcript Document

INDOOR AIR QUALITY
JUDY MURPHY
Industrial Hygienist
Montana Department of Labor
Occupational Safety and Health
Bureau
Introducing……………
• Please tell us
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Your name
Where you work
What you do
Your indoor air quality experience &
concerns
Is IAQ Important?
• 30% of newly constructed or
remodeled facilities have IAQ problems
• Indoor contaminants are responsible
for half of all illnesses
• Liability issues
Liability
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Owners and managers
Architects, builders and developers
Product manufacturers
Insurers
Unions
Real estate agents, bankers and sellers
Why is There an Increase in IAQ
problems?
• More time indoors
• More chemical pollutants in buildings
• Tighter buildings and reduced ventilation
• Deferred maintenance
Common Health Effects of Indoor
Contaminants
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Eye, nose and throat irritation
Coughing and sneezing
Headaches
Fatigue
Irritability
Allergies, sinus congestion
Dizziness
Difficulty in concentrating
Health Effects Depend on Several
Factors
• The contaminant
• The amount of the contaminant
present
• The length of time a person is exposed
to the contaminant
• The vulnerability of the person
Sick Building Syndrome
• Symptoms include eye, nose and throat
irritation, headache, allergies, fatigue
• 20% or more of occupants experience same
symptoms
• No medically diagnosable symptoms
• Complaints persist for more than two weeks
• Symptoms often lessen after person leaves
building
Building-Related Illness
• Clinically defined illness or disease
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E.g. Asthma, Legionaires’ Disease,
Hypersensitivity Pneumonitis
• Symptoms depend on the disease
QUIZ
• What are some of the most common
IAQ health effects?
• What four factors determine the health
effects of an exposure to hazardous
compounds?
Regulations and Standards
• Outdoor airborne contaminant levels
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Environmental Protection Agency (EPA)
National Ambient Air Quality Standards (NAAQS)
• Indoor airborne contaminant levels in the
workplace
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Occupational Safety and Health Administration
(OSHA)
• ASHRAE Standards 62-1989, 62-2001, 622004, 62.1-2007
ASHRAE Ventilation Standards
• ASHRAE 62-1989 – Objective of
ventilation is satisfaction of 80% of
inhabitants
OSHA Permissible Exposure Levels
(PELs)
• “Time-weighted average
concentrations that must not be
exceeded during any 8-hour workshift
of a 40-hour workweek”
• Legally enforceable
• Measured in parts per million (ppm) or
milligrams per cubic meter (mg/m3)
Threshold Limit Values (TLVs)
• “Time-weighted average concentration for a
conventional 8-hour workday and a 40-hour
workweek, to which it is believed that nearly
all workers can be repeatedly exposed, day
after day, without adverse effect”
• Guidelines
• Generally more conservative than PELs
Problem - Causing
Compounds
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Chemicals
Combustion products
Respirable particles and gases
Biological aerosols
CHEMICALS
Volatile Organic Compounds
(VOCs)
• Carbon-containing compounds that
evaporate rapidly
• Examples
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Benzene
Toluene
Styrene
Perchloroethylene
Pesticides
Volatile Organic Compounds
(Sources)
• Paints, stains,
varnishes
• Waxes
• Polishes
• Solvents
• Pesticides
• Adhesives
• Wood preservatives
• Cleansers
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Lubricants
Air fresheners
Fuels
Plastics
Copy machines,
printers
• Tobacco products
• Perfumes
• Dry cleaned clothing
PESTICIDES - Symptoms
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Headache
Dizziness
Lack of coordination
Nervousness
Irritability
Insomnia
Confusion
Loss of concentration
Speech difficulties
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Depression
Impaired judgment
Memory deficits
Visual disturbances
ECG changes
Weakness
Fatigue
Paralysis
Integrated Pest Management
• IPM Steps
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Set action thresholds
Monitor and identify pests
Prevention
Control
Formaldehyde
• Used in plywood, paneling, particleboard,
wallboard, fiberglass, adhesives
• Sometimes in ceiling tiles, wallpaper,
furniture, draperies, clothing
• Even low levels can cause difficulties in
breathing, burning of eyes nose and throat,
coughing; a human carcinogen
• PEL 0.75 ppm; TLV ceiling limit 0.3 ppm
Perchloroethylene
• Solvent used in dry cleaning, metal
cleaning and degreasing
• Can cause irritation of eyes, nose,
throat and skin, liver and kidney
damage, CNS depression
• Considered an animal carcinogen and
probable human carcinogen
• PEL 100 ppm; TLV 25 ppm
Perchloroethylene
MSDS Exercise
QUIZ
• What are VOCs?
• What are some sources of VOCs
• What are some alternatives to
pesticides?
COMBUSTION PRODUCTS
Combustion Products
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Carbon monoxide (CO)
Oxides of nitrogen (NOx)
Oxides of sulfur (SOx)
Carbon dioxide (CO2)
Polycyclic Aromatic Hydrocarbons (PAH)
Tobacco Smoke components
Carbon Monoxide (CO)
• Colorless, odorless, tasteless
poisonous gas
• Produced as a by-product of
combustion
• Deprives the body of oxygen by
binding to blood hemoglobin and
displacing oxygen molecules
Carbon Monoxide
• Symptoms are headache, dizziness,
drowsiness and nausea
• Severe exposure results in vomiting,
collapse, coma and death
• PEL 50 ppm; TLV 25 ppm
• Body systems most affected are the
brain, the heart, and the developing
fetus
Carbon Monoxide
• Low levels of exposure - more frequent
attacks of angina, reduced athletic
performance, heart attacks
• Moderate exposures - loss of attentiveness,
decreased visual perception, manual
dexterity, learning ability and driving ability
• Smoking – cause of the greatest human
exposure
Carbon Dioxide (CO2)
• Colorless, odorless, tasteless gas at
room temperature
• Present in exhaled human breath
• Combustion by-product
• Naturally present in an unpolluted
environment at about 300 ppm
Carbon Dioxide
• CO2 levels above 800 ppm may indicate
inadequate ventilation
• ASHRAE recommended indoor air
quality limit for CO2 is 1000 ppm
• PEL 5000 ppm; TLV 5000 ppm
Tobacco Smoke
• Respirable particles and gases, including
benzene, carbon monoxide, formaldehyde,
hydrogen cyanide, ammonia and VOCs
• Sidestream smoke from cigarette contains
higher concentrations of some toxic and
carcinogenic substances than mainstream
smoke inhaled by smoker
Tobacco Smoke
• Causes lung cancer in nonsmokers as
well as smokers
• Increased respiratory infections in
children
• Irritation of upper respiratory tract,
coughing, wheezing, sneezing,
headache, sinus problems, asthma,
increased cardiovascular risk
QUIZ
• Which combustion by-products would
you expect to see in smog?
• Which compound is sometimes used
as a measure of ventilation efficiency?
RESPIRABLE PARTICLES &
GASES
Respirable Particles & Gases
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Asbestos
Fiberglass
Silica
Metal dust
Tobacco smoke components
Organic dust
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Pollen
Mold spores
Paper dust
• Radon
Asbestos
• Group of indestructable highly fibrous
minerals
• Separated fibers are long, thin, flexible, heat
resistant, able to be spun and woven
• Health effects: lung cancer, mesothelioma,
asbestosis, pleural plaques
• Airborne concentration in homes and schools
30 to 6,000 fibers/m3
• PEL 0.1 fiber/cc; TLV 0.1 fiber/cc
Lead
• Indestructable, non-biodegradable,
adaptable metal
• Romans used lead to line aqueducts,
as mortar, in plumbing and to sweeten
wine
• Was used in gasoline, batteries, paints,
ceramic glazes, ammunition, fishing
sinkers, metal toys
Lead
• Three quarters of the nation’s housing
contains lead-based paint
• Children are at greater risk for lead
poisoning than adults
Hand to mouth activity
Developing body systems more easily
affected
o Action level is 10 micrograms per deciliter
(μg/dl)
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Lead – Chronic Exposure
Health Effects
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Loss of appetite
Metallic taste in mouth
Anxiety
Constipation
Nausea
Palor
Excessive tiredness
Weakness
Insomnia
• Headache
• Nervous irritability
• Muscle and joint pain or
soreness
• Fine tremors
• Numbness
• Dizziness
• Hyperactivity
• Colic, with severe
abdominal pain
Chronic Effects of Lead
Poisoning in Children
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Fetal development abnormalities
Decreased intelligence
Slowed neurological development
Reading and learning problems
Reduced attention span
Chronic Effects of Lead
Poisoning in Children (cont.)
• Hearing loss
• Behavioral problems such as
hyperactivity
• Stunted growth
• Permanent damage to the brain,
nervous system and kidneys
Sources of Potential Exposure
to Lead
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Lead-based paint
Lead-contaminated dust
Lead-contaminated soil
Candle wicks
Pewter and silver products
Lead crystal
Some lead-glazed pottery and porcelain
Some imported mini-blinds
Radon
• Naturally occurring radioactive gas
• Colorless, odorless, tasteless
• Causes no symptoms of irritation or
discomfort
• No early signs of exposure
• Testing a building is the only way to evaluate
exposure
• Action level is 4 picocuries per liter (pCi/L)
Radon Health Effects
• Damage by alpha radiation to tissue of
lungs and respiratory tract
• 20,000 lung cancer deaths per year
• Non-smokers risk of lung cancer at 4
pCi/L is 2 in 1000
• Smokers risk of lung cancer at 4 pCi/L
is 20 in 1000
Testing for Radon
• Test in lowest livable area in building
• Close all doors and windows 12 hours
before testing
• Do not test in kitchen or bathroom
• Place monitor at least 20 inches above
floor
• Test during coldest months of the year
Radon Control Measures
• Increasing the ventilation in the
building
• Sealing the foundation
• Sub-slab depressurization
Sub-Slab Depressurization
QUIZ
• What are some of the health effects of
lead exposure?
• How can you tell if a building has
elevated radon levels?
BIOAEROSOLS
Bioaerosols
• Substances that are living or were
released from a living organism
• Examples
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Bacteria
Fungi
Pollen
Viruses
Dust mites
Dust Mites
Dust Mites
• Microscopic relatives of spiders
• Feed on dead skin scales and other organic
debris
• 2,000,000 in an average bed
• Dust mite feces - a common allergen
• Prefer relative humidity level above 55%
Viruses
• Smallest and simplest of all life forms
• Depend completely on their hosts for
reproduction
• Continually undergo evolutionary change
• Examples
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Influenza
HIV
Rhinovirus
Hanta Virus
• Carried in wild rodents, especially deer mice
• Can cause respiratory failure and death
• Approximately 43 % of diagnosed cases have
been fatal
• Infection is caused by inhalation of airborne
particles of infected urine, droppings or
saliva from infected animals
Hanta Virus Precautions
• Seal any holes larger than a dime
• Air out unused buildings before entering
• Wear a NIOSH-approved mask when cleaning
• Spray surfaces with disinfectant, leave for 15
minutes, then sweep
• Wash hard surfaces with disinfectant
Bacteria
• Single-celled prokaryotic organisms
• Most are very small spheres, rods or
filaments
• Reproduce by simple cell division
• Some produce endospores, which are
extremely resistant to harsh conditions
• A few require living hosts
Bacteria in Indoor
Environments
• Higher concentrations indoors than outdoors
• Majority of bacteria in air are shed from
human skin and respiratory tracts
• Examples of infectious bacteria
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Legionella spp.
Staphlococcus aureus
Mycobacterium tuberculosis
Bacterial Toxins
• Exotoxins
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Excreted
Clostridium botulinum exotoxin - one of the most
powerful poisons known
• Endotoxins
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Part of cell wall of gram negative bacteria
Highly toxic – fever, malaise, changes in white
blood cell counts, respiratory distress, shock,
even death
Mold
Mold? Where??
Mold on ceiling and walls
Mold in a closet
Mold in air duct
Fungi as Food
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Mushrooms
Soy sauce
Yeast
Bread
Cheese
Wine
Beer
Mucor species
Penicillium species
Aspergillus niger
Aspergillus fumigatus
Cryptococcus neoformans
var. neoformans
Growing Conditions
• Optimum water activity
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Above 0.90 in substrate, for most species
• Optimum temperature range
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56°F to 86°F, for most species
• Light
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Inhibits growth of some types of molds
Stimulates spore production in many
species
Fungal Metabolism
• Enzymes secreted to digest external
food sources, which are then absorbed
• Must have adequate moisture available
Metabolic Products
• Carbon dioxide, water, ethanol
• Microbial Volatile Organic
Compounds (MVOCs)
• Mycotoxins and antibiotics
MVOCs
• VOCs with distinctive offensive odors
• Possibly responsible for some illnesses
• Different compounds emitted on different
media
• Type and quantity change with phases of
growth
• Highest MVOC production is prior to and
during spore production and mycotoxin
production
Mycotoxins
• Produced to inhibit or kill competitors
• May cause serious short term and long
term health effects
• Over 200 recognized mycotoxins, and
many more not yet discovered
• Toxins production varies with the
species, the conditions and the
substrate
General Health Effects
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Sinus congestion
Sneezing
Coughing,
Eye irritation
Asthma
Bronchitis
Hypersensitivity pneumonitis
Infectious diseases, e.g. ringworm,
athletes foot, nail infections,
Histoplasmosis, Valley Fever
Mycotoxin Health Effects
• Mucous membrane
irritation
• Cold and flu symptoms
• Sore throat
• Headache
• Fatigue
• Diarrhea
• Skin rashes
• Dizziness
• Nausea
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Immunosuppression
Birth defects
Tremors
Hemorrhaging
Cytotoxicity
Hepatotoxicity
Nephrotoxicity
Cancer
Aflatoxin
• One of the most potent carcinogens
known to man
• Linked to a variety of health problems
• FDA maximum allowable level is 20
ppb
• Produced by some species of
Aspergillus
T-2 Toxin
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A tricothecene toxin
Produced by species of Fusarium mold
One of the more deadly toxins
Ingestion in sufficient quantity can cause
rapid death due to internal hemorrhage
• Implicated in alimentary toxic aleukia and
pulmonary hemosiderosis
• Damage is often permanent
Fumonisin
• Associated with some species of Fusarium
mold
• Commonly found in corn
• Has resulted in dozens of deaths of horses
and swine
• Causes “crazy horse disease” or
leukoencephalomalcia, a liquifaction of the
brain
• Chronic low-level exposure in humans has
been linked to esophageal cancer
Satratoxin H
• Produced by Stachybotrys,
Trichoderma and other molds
• High doses or chronic low doses are
lethal
• Abortogenic in animals
• Believed to alter the immune system
function
Stachybotrys chartarum (atra)
• Grows on building material with high
cellulose content and low nitrogen content
• Optimum water activity is 0.94
• Areas with relative humidity above 55% and
subject to temperature fluctuations are ideal
for toxin production
• Changing humidity may induce heavy
sporulation
• Spores are covered with slime; not easily
airborne
Stachybotrys Effects
• Chronic exposure effects: cold and
flu symptoms, sore throats, diarrhea,
headaches, fatigue, dermatitis,
intermittent local hair loss,
generalized malaise
• Toxins suppress the immune
system, affecting lymphoid tissue
and bone marrow
Stachybotrys Effects (cont.)
• Animals injected with Stachybotrys
exhibited necrosis and hemorrhage
within the brain, thymus, spleen,
intestine, lung, heart, lymph node, liver
and kidney
• Toxin is reported to be a liver and
kidney carcinogen
Stachybotrys - contaminated
straw and normal straw
Stachybotrys and other mold
on sheetrock
Stachybotrys in ventilation
tunnel
Stachybotrys on fiberglass
insulation backing
Water-Damaged Ceiling
Flooded Room After
Remediation
Water-Damaged Wallpaper
Stachybotrys, Aspergillus and
Penicillium in Basement
MOLD SAMPLING
Difficulties in Mold Sampling
• No TLVs or PELs
• Fungus might not be producing spores at the
time of sampling
• Spores might be adhering to surfaces rather
than airborne
• Spores might not survive impaction
• Spores might not grow on the media used
• Colonies might be overgrown by others and
not detected
• Organism might be very slow growing
Types of Mold Sampling
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Bulk samples
Surface samples - tape
Surface samples - swab
Air samples using impaction onto
agar
• Air samples using spore trap
methods
When Sampling Results Indicate
Serious Mold Problem
• Total indoor levels are higher than total
outdoor levels
• Fungi indoors are different from
outdoors or non-complaint areas
• Fungi are allergenic or toxigenic
• Area is likely to be disturbed
• Present or past water or high humidity
Key Remediation Steps
• Correct the moisture problem that
led to the mold growth
• Remove all contaminated porous
materials
Use proper PPE
Containment and negative pressure to
prevent spread of spores
o Minimize dust production
o Decontamination
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Key Remediation Steps (cont.)
• Clean all contaminated non-porous
materials
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HEPA vacuum
Disinfectant or soap and water
Personal Protective Equipment
for Remediation Work
• For minimal mold growth
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N-95 respirator
Gloves
• For moderate to extensive mold growth
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N-95 respirator
Gloves
Eye protection
Full-body covering
Remediation Resources
NY City Department of Health Guidelines on
Assessment and Remediation of Fungi in
Indoor Environments
• http://www.ci.nyc.ny.us/html/doh/html/epi/
moldrpt1.html
Mold Remediation in School and Commercial
Buildings (EPA)
• http://www.epa.gov/iaq/molds/index.html
Remediation and General
Information Resources
Mold in My Home: What Do I Do?
http://www.cal-iaq.org/mold0107.htm
Mold in My School: What Do I do?
http://www.cal-iaq.org//MoldinMySchool.pdf
Mold in Indoor Workplaces
http://www.dhs.ca.gov/ohb/HESIS/molds.pdf
QUIZ
• What is the first thing you should look
for when there is a suspected mold
problem?
• What kind of personal protective
equipment should you wear if you are
removing moldy sheetrock?
VENTILATION
Ventilation
• Purpose - Remove or dilute airborne
contaminants
• Supply air - mixture of outside air and
re-circulated air
HVAC Systems
• Components
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Air intakes, dampers, filters
Heating & cooling units, coils, drain pans
Ductwork
Supply vents
Exhaust vents
Plenum
ASHRAE Outdoor Airflow
Requirements, 62.1-2004
• Vbz = RpPz+RaAz
Vbz = Breathing zone outdoor airflow
Rp = Outdoor airflow rate required per
person as determined from Table 6-1
o Pz = zone population
o Ra = Outdoor airflow rate required per unit
area as determined from Table 6-1
o Az = zone floor area
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Acceptable Temperature
Ranges, ASHRAE 62.1-2004
• Dry bulb at 30% relative humidity:
• Winter: 68.5ºF – 76.0ºF
• Summer: 74.0ºF – 80.0ºF
When Good HVAC Systems Go
Bad
• Poorly balanced systems
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Areas with stale air
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Drafty areas
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Contaminant buildup
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Uncomfortable temperatures
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Odors from other areas of the building
Poorly Located Air Intakes
• Entrainment of vehicle exhaust from
parking areas
• Entrainment of bioaerosols from debris
on the ground
• Entrainment of exhaust from adjacent
roof vents, e.g. HVAC system, sewer
Poor Filters or
Poor Filter Maintenance
• Excessive dust and dirt in the supplied
air
• Insects
• Mold spores
Ductwork
• Leaks
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Energy loss
Can draw contaminants into ducts
• Duct liners
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Can degrade; particles enter supplied air
Backdrafting
• Pressure imbalance
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Air to air heat exchanger cracks
Duct leakage
Tight building
• Combustion contaminants are drawn
into the building
Ventilation to Meet Occupant
Needs
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ASHRAE Standards
Temperature
Relative Humidity
Minimum outdoor air requirements
CO2 levels below 1000 ppm
• Outdoor air supplied at 15 cfm/person
Ventilation – Engineering
Controls
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Modify ventilation system
Modify pressure relationships
Filters
Ion generators
Humidification systems
IAQ Inspection DVD
QUIZ
• How often should ducts be cleaned?
• What level of carbon dioxide indicates
adequate ventilation?
• Should a shop area be at positive or
negative pressure relative to the rest of
the building?
IAQ INVESTIGATION
Challenges When Evaluating
IAQ Problems
• Contaminants and their sources are
not always obvious
• Problems may be cyclical or episodic
• Only a few employees may complain of
a problem
• The situation may become emotionally
charged
IAQ Inspection Steps
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Building history
Brief walk-through
Symptoms
Inspection
Air monitoring
Report, with recommendations
Questionnaires
• Can identify the cause of many IAQ
problems
• Building history questionnaires
• Symptoms questionnaires
• HVAC questionnaires
EPA’s I-BEAM Software
• Available on the Internet at:
http://www.epa.gov/iaq/largebldgs/ibeam/index.html
Walk-Through Inspection
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Outside sources
Building exterior
HVAC system
Boiler room
Attic
Crawlspace
Occupied spaces
Wall cavities
Storage spaces
Look Into:
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Ceilings, walls, floors, furnishings
Water damage
Odors
Remodeling
Insulation falling into work area
Plumbing leaks and mold in
crawlspaces
Look Into:
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Fluorescent light fixtures
Frequently damp areas
Pets & aquariums
Humidifiers
Backdrafting possiblilities
Ergonomic factors
Stress & tension
Mold in basement
Vinyl wall-covering, after
flooding
Poor Outside Drainage Design
Ceiling mold
Moldy wall
Ceiling Tile Stain
Mold on AC Ductwork
Mold in Laundry Room
IAQ Tools
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EPA’s “Building Air Quality”
EPA’s “Tools for Schools”
I-BEAM software
Monitoring equipment
Monitoring Basic Parameters
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CO
CO2
Temperature
Relative humidity
Air flow rates
Formaldehyde Sampling
Ventilation
• “Dilution is the solution”
• “When all else fails, ventilate”
QUESTIONS???