INDOOR AIR QUALITY

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(No Transcript)
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INDOOR AIR QUALITY
JUDY MURPHY Industrial Hygienist Montana
Department of Labor Occupational Safety and
Health Bureau
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Introducing

• Please tell us
• Your name
• Where you work
• What you do
• Your indoor air quality experience concerns

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Is IAQ Important?

• 30 of newly constructed or remodeled facilities
  have IAQ problems
• Indoor contaminants are responsible for half of
  all illnesses
• Liability issues

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Liability

• Owners and managers
• Architects, builders and developers
• Product manufacturers
• Insurers
• Unions
• Real estate agents, bankers and sellers

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Why is There an Increase in IAQ problems?

• More time indoors
• More chemical pollutants in buildings
• Tighter buildings and reduced ventilation
• Deferred maintenance

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Common Health Effects of Indoor Contaminants

• Eye, nose and throat irritation
• Coughing and sneezing
• Headaches
• Fatigue
• Irritability
• Allergies, sinus congestion
• Dizziness
• Difficulty in concentrating

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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

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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

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Building-Related Illness

• Clinically defined illness or disease
• E.g. Asthma, Legionaires Disease,
  Hypersensitivity Pneumonitis
• Symptoms depend on the disease

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QUIZ

• What are some of the most common IAQ health
  effects?
• What four factors determine the health effects of
  an exposure to hazardous compounds?

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Regulations and Standards

• Outdoor airborne contaminant levels
• Environmental Protection Agency (EPA)
• National Ambient Air Quality Standards (NAAQS)
• Indoor airborne contaminant levels in the
  workplace
• Occupational Safety and Health Administration
  (OSHA)
• ASHRAE Standards 62-1989, 62-2001, 62-2004,
  62.1-2007

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ASHRAE Ventilation Standards

• ASHRAE 62-1989 Objective of ventilation is
  satisfaction of 80 of inhabitants

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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)

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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

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Problem - Causing Compounds

• Chemicals
• Combustion products
• Respirable particles and gases
• Biological aerosols

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CHEMICALS
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Volatile Organic Compounds (VOCs)

• Carbon-containing compounds that evaporate
  rapidly
• Examples
• Benzene
• Toluene
• Styrene
• Perchloroethylene
• Pesticides

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Volatile Organic Compounds(Sources)

• Paints, stains, varnishes
• Waxes
• Polishes
• Solvents
• Pesticides
• Adhesives
• Wood preservatives
• Cleansers

• Lubricants
• Air fresheners
• Fuels
• Plastics
• Copy machines, printers
• Tobacco products
• Perfumes
• Dry cleaned clothing

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PESTICIDES - Symptoms

• Depression
• Impaired judgment
• Memory deficits
• Visual disturbances
• ECG changes
• Weakness
• Fatigue
• Paralysis

• Headache
• Dizziness
• Lack of coordination
• Nervousness
• Irritability
• Insomnia
• Confusion
• Loss of concentration
• Speech difficulties

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Integrated Pest Management

• IPM Steps
• Set action thresholds
• Monitor and identify pests
• Prevention
• Control

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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

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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

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Perchloroethylene MSDS Exercise
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QUIZ

• What are VOCs?
• What are some sources of VOCs
• What are some alternatives to pesticides?

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COMBUSTION PRODUCTS
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Combustion Products

• Carbon monoxide (CO)
• Oxides of nitrogen (NOx)
• Oxides of sulfur (SOx)
• Carbon dioxide (CO2)
• Polycyclic Aromatic Hydrocarbons (PAH)
• Tobacco Smoke components

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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

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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

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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

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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

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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

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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

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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

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QUIZ

• Which combustion by-products would you expect to
  see in smog?
• Which compound is sometimes used as a measure of
  ventilation efficiency?

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RESPIRABLE PARTICLES GASES
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Respirable Particles Gases

• Asbestos
• Fiberglass
• Silica
• Metal dust
• Tobacco smoke components
• Organic dust
• Pollen
• Mold spores
• Paper dust
• Radon

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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

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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

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Lead

• Three quarters of the nations 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
• Action level is 10 micrograms per deciliter
  (µg/dl)

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Lead Chronic Exposure Health Effects

• 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

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Chronic Effects of Lead Poisoning in Children

• Fetal development abnormalities
• Decreased intelligence
• Slowed neurological development
• Reading and learning problems
• Reduced attention span

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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

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Sources of Potential Exposure to Lead

• 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

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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)

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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

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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

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Radon Control Measures

• Increasing the ventilation in the building
• Sealing the foundation
• Sub-slab depressurization

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Sub-Slab Depressurization
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QUIZ

• What are some of the health effects of lead
  exposure?
• How can you tell if a building has elevated radon
  levels?

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BIOAEROSOLS
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Bioaerosols

• Substances that are living or were released from
  a living organism
• Examples
• Bacteria
• Fungi
• Pollen
• Viruses
• Dust mites

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Dust Mites
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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

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Viruses

• Smallest and simplest of all life forms
• Depend completely on their hosts for reproduction
• Continually undergo evolutionary change
• Examples
• Influenza
• HIV
• Rhinovirus

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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

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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

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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

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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
• Legionella spp.
• Staphlococcus aureus
• Mycobacterium tuberculosis

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Bacterial Toxins

• Exotoxins
• Excreted
• Clostridium botulinum exotoxin - one of the most
  powerful poisons known
• Endotoxins
• Part of cell wall of gram negative bacteria
• Highly toxic fever, malaise, changes in white
  blood cell counts, respiratory distress, shock,
  even death

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Mold
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Mold? Where??
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Mold on ceiling and walls
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Mold in a closet
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Mold in air duct
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Fungi as Food

• Mushrooms
• Soy sauce
• Yeast
• Bread
• Cheese
• Wine
• Beer

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Mucor species
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Penicillium species
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Aspergillus niger
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Aspergillus fumigatus
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Cryptococcus neoformans var. neoformans
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Growing Conditions

• Optimum water activity
• Above 0.90 in substrate, for most species
• Optimum temperature range
• 56F to 86F, for most species
• Light
• Inhibits growth of some types of molds
• Stimulates spore production in many species

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Fungal Metabolism

• Enzymes secreted to digest external food sources,
  which are then absorbed
• Must have adequate moisture available

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Metabolic Products

• Carbon dioxide, water, ethanol
• Microbial Volatile Organic Compounds (MVOCs)
• Mycotoxins and antibiotics

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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

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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

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General Health Effects

• Sinus congestion
• Sneezing
• Coughing,
• Eye irritation
• Asthma
• Bronchitis
• Hypersensitivity pneumonitis
• Infectious diseases, e.g. ringworm, athletes
  foot, nail infections, Histoplasmosis, Valley
  Fever

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Mycotoxin Health Effects

• Mucous membrane irritation
• Cold and flu symptoms
• Sore throat
• Headache
• Fatigue
• Diarrhea
• Skin rashes
• Dizziness
• Nausea

• Immunosuppression
• Birth defects
• Tremors
• Hemorrhaging
• Cytotoxicity
• Hepatotoxicity
• Nephrotoxicity
• Cancer

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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

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T-2 Toxin

• 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

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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

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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

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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

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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

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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

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Stachybotrys - contaminated straw and normal
straw
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Stachybotrys and other mold on sheetrock
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Stachybotrys in ventilation tunnel
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Stachybotrys on fiberglass insulation backing
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Water-Damaged Ceiling
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Flooded Room After Remediation
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Water-Damaged Wallpaper
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Stachybotrys, Aspergillus and Penicillium in
Basement
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MOLD SAMPLING
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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

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Types of Mold Sampling

• Bulk samples
• Surface samples - tape
• Surface samples - swab
• Air samples using impaction onto agar
• Air samples using spore trap methods

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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

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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
• Minimize dust production
• Decontamination

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Key Remediation Steps (cont.)

• Clean all contaminated non-porous materials
• HEPA vacuum
• Disinfectant or soap and water

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Personal Protective Equipment for Remediation Work

• For minimal mold growth
• N-95 respirator
• Gloves
• For moderate to extensive mold growth
• N-95 respirator
• Gloves
• Eye protection
• Full-body covering

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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

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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 Mol
d in Indoor Workplaces http//www.dhs.ca.gov/ohb/H
ESIS/molds.pdf
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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?

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VENTILATION
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Ventilation

• Purpose - Remove or dilute airborne contaminants
• Supply air - mixture of outside air and
  re-circulated air

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HVAC Systems

• Components
• Air intakes, dampers, filters
• Heating cooling units, coils, drain pans
• Ductwork
• Supply vents
• Exhaust vents
• Plenum

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ASHRAE Outdoor Airflow Requirements, 62.1-2004

• Vbz RpPzRaAz
• Vbz Breathing zone outdoor airflow
• Rp Outdoor airflow rate required per person as
  determined from Table 6-1
• Pz zone population
• Ra Outdoor airflow rate required per unit area
  as determined from Table 6-1
• 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

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When Good HVAC Systems Go Bad

• Poorly balanced systems
• Areas with stale air
• Drafty areas
• Contaminant buildup
• Uncomfortable temperatures
• Odors from other areas of the building

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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

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Poor Filters or Poor Filter Maintenance

• Excessive dust and dirt in the supplied air
• Insects
• Mold spores

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Ductwork

• Leaks
• Energy loss
• Can draw contaminants into ducts
• Duct liners
• Can degrade particles enter supplied air

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Backdrafting

• Pressure imbalance
• Air to air heat exchanger cracks
• Duct leakage
• Tight building
• Combustion contaminants are drawn into the
  building

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Ventilation to Meet Occupant Needs

• ASHRAE Standards
• Temperature
• Relative Humidity
• Minimum outdoor air requirements
• CO2 levels below 1000 ppm
• Outdoor air supplied at 15 cfm/person

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Ventilation Engineering Controls

• Modify ventilation system
• Modify pressure relationships
• Filters
• Ion generators
• Humidification systems

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IAQ Inspection DVD
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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?

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IAQ INVESTIGATION
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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

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IAQ Inspection Steps

• Building history
• Brief walk-through
• Symptoms
• Inspection
• Air monitoring
• Report, with recommendations

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Questionnaires

• Can identify the cause of many IAQ problems
• Building history questionnaires
• Symptoms questionnaires
• HVAC questionnaires

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EPAs I-BEAM Software

• Available on the Internet at http//www.epa.gov/i
  aq/largebldgs/i-beam/index.html

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Walk-Through Inspection

• Outside sources
• Building exterior
• HVAC system
• Boiler room
• Attic
• Crawlspace
• Occupied spaces
• Wall cavities
• Storage spaces

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Look Into

• Ceilings, walls, floors, furnishings
• Water damage
• Odors
• Remodeling
• Insulation falling into work area
• Plumbing leaks and mold in crawlspaces

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Look Into

• Fluorescent light fixtures
• Frequently damp areas
• Pets aquariums
• Humidifiers
• Backdrafting possiblilities
• Ergonomic factors
• Stress tension

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Mold in basement
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Vinyl wall-covering, after flooding
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Poor Outside Drainage Design
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Ceiling mold
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Moldy wall
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Ceiling Tile Stain
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Mold on AC Ductwork
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Mold in Laundry Room
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IAQ Tools

• EPAs Building Air Quality
• EPAs Tools for Schools
• I-BEAM software
• Monitoring equipment

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Monitoring Basic Parameters

• CO
• CO2
• Temperature
• Relative humidity
• Air flow rates

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Formaldehyde Sampling
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Ventilation

• Dilution is the solution
• When all else fails, ventilate

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QUESTIONS???