INDOOR AIR QUALITY

JUDY MURPHYIndustrial Hygienist

Montana Department of LaborOccupational Safety and Health

Bureau

Introducing……………

• Please tell uso Your nameo Where you worko What you doo 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

• 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

• 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 diseaseo 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 levelso Environmental Protection Agency (EPA) o National Ambient Air Quality Standards (NAAQS)

• Indoor airborne contaminant levels in the workplace o Occupational Safety and Health Administration

(OSHA)• ASHRAE Standards 62-1989, 62-2001, 62-

2004, 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

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

CHEMICALS

Volatile Organic Compounds (VOCs)

• Carbon-containing compounds that evaporate rapidly

• Exampleso Benzeneo Tolueneo Styreneo Perchloroethyleneo Pesticides

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

PESTICIDES - Symptoms

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

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

Integrated Pest Management

• IPM Stepso Set action thresholdso Monitor and identify pestso Preventiono 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

• 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

• Asbestos• Fiberglass• Silica• Metal dust• Tobacco smoke components• Organic dust

o Polleno Mold sporeso 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 adultso Hand to mouth activityo Developing body systems more easily

affectedo Action level is 10 micrograms per deciliter

(μg/dl)

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

Chronic Effects of Lead Poisoning in Children

• 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

• 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

• Exampleso Bacteriao Fungio Polleno Viruseso 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

• Exampleso Influenzao HIVo 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 bacteriao Legionella spp.o Staphlococcus aureuso Mycobacterium tuberculosis

Bacterial Toxins

• Exotoxinso Excretedo Clostridium botulinum exotoxin - one of the most

powerful poisons known• Endotoxins

o Part of cell wall of gram negative bacteriao 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

• 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 o Above 0.90 in substrate, for most species

• Optimum temperature range o 56°F to 86°F, for most species

• Light o Inhibits growth of some types of moldso 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

• 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

• 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

• 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

• 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

materialso Use proper PPEo Containment and negative pressure to

prevent spread of sporeso Minimize dust productiono Decontamination

Key Remediation Steps (cont.)

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

Personal Protective Equipment for Remediation Work

• For minimal mold growtho N-95 respiratoro Gloves

• For moderate to extensive mold growtho N-95 respiratoro Gloveso Eye protectiono 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.htmMold in My School: What Do I do?http://www.cal-iaq.org//MoldinMySchool.pdfMold in Indoor Workplaceshttp://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

• Componentso Air intakes, dampers, filterso Heating & cooling units, coils, drain panso Ductworko Supply ventso Exhaust ventso Plenum

ASHRAE Outdoor Airflow Requirements, 62.1-2004

• Vbz = RpPz+RaAz

o Vbz = Breathing zone outdoor airflowo Rp = Outdoor airflow rate required per

person as determined from Table 6-1o Pz = zone populationo Ra = Outdoor airflow rate required per unit

area as determined from Table 6-1o Az = zone floor area

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 o Areas with stale airo Drafty areaso Contaminant buildupo Uncomfortable temperatureso 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

o Energy losso Can draw contaminants into ducts

• Duct liners o Can degrade; particles enter supplied air

Backdrafting

• Pressure imbalanceo Air to air heat exchanger crackso Duct leakageo Tight building

• Combustion contaminants are drawn into the building

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

Ventilation – Engineering Controls

• 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

• 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/i-beam/index.html

Walk-Through Inspection

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

Look Into:

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

crawlspaces

Look Into:

• 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

• EPA’s “Building Air Quality”• EPA’s “Tools for Schools”• I-BEAM software• Monitoring equipment

Monitoring Basic Parameters

• CO• CO2

• Temperature• Relative humidity• Air flow rates

Formaldehyde Sampling

Ventilation

• “Dilution is the solution”

• “When all else fails, ventilate”

QUESTIONS???