HL1115 Influences on Health at Work

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Indoor Air Quality

• Sean Mahar, PhD, CIH, CSP, PE

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Problems

• Sick Building Syndrome
• Asthma
• Allergies
• Building Related Illnesses

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Sick Building Syndrome

• In "sick building syndrome" (SBS) building
  occupants experience acute health and comfort
  effects that appear to be linked to time spent in
  a building, but no specific illness or cause can
  be identified.
• In "building related illness" (BRI) symptoms of
  diagnosable illness are identified and can be
  attributed directly to airborne building
  contaminants

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Sick Building Syndrome

• Occupants complain of symptoms associated with
  acute discomfort, e.g., headache eye, nose, or
  throat irritation dry cough dry or itchy skin
  dizziness and nausea difficulty in
  concentrating fatigue and sensitivity to odors.
  
• The cause of the symptoms is not known.
• Most report relief soon after leaving the
  building.

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Asthma

• Characterized by episodes of airflow obstruction
  in the bronchial tubes.
• Symptoms caused by this obstruction include
  coughing, chest tightness, wheezing and shortness
  of breath.
• Although problems are often separated by
  symptom-free periods, asthma is a chronic illness.

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Common Asthmagens

• Isocyanates
• Solder fume
• Metals
• Latex
• Vegetable dusts
• Animal proteins
• Enzymes

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Allergic Reactions

• Include
• Allergic Alveolitis
• Rhinitis

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Allergic Alveolitis

• Also known as
• Hypersensitivity Pneumonitis (HP) or
• Extrinsic Allergic alveolitis (EAA)
• Other names include
• farmers lung
• bagassosis
• pigeon fanciers lung

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Allergic Alveolitis

• Acute symptoms include fever, chills, dyspnea,
  leukocytosis 4-6 hours after exposure and may
  recur on re-exposure.
• Chronic disease shows progressive dyspnea,
  fatigue, low-grade fever, weight loss, chronic
  nonproductive cough, and bibasilar crackles.

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Allergic Alveolitis

• a restrictive type impairment
• type III and IV hypersensitivity reaction

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Farmers Lung

• source moldy crops
• organisms
• Thermoactinomyces sacchari
• Thermoactinomyces vulgaris
• Micropolyspora faeni

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Bagassosis

• source moldy sugar cane
• organisms
• Thermoactinomyces vulgaris
• Micropolyspora faeni
• Aspergillus species

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Pigeon Fanciers Lung

• source pigeon dust and bloom
• substance
• proteins

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Rhinitis

• A reaction that occurs in the eyes, nose and
  throat when airborne irritants or allergens
  trigger the release of histamine.
• Histamine causes inflammation and fluid
  production in the fragile linings of nasal
  passages, sinuses, and eyelids.

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Rhinitis

• sneezing
• congestion
• runny nose
• itchy nose, throat, eyes, and ears

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Rhinitis

• Allergic rhinitis
• pollen
• dust mites
• mold
• animal dander

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Rhinitis

• Nonallergic rhinitis
• fumes
• odors
• temperature
• smoke
• other irritants

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Building Related Illnesses

• Include
• Legionairres Disease (Legionllosis)
• Pontiac Fever
• Humidifier Fever

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Legionella pneumophila

• Discovered in 1976 when an outbreak of pneumonia
  at an American Legion convention in Philadelphia
  led to 29 deaths.
• Causative agent for both Legionellosis and
  Pontiac Fever

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Legionella pneumophila

• motile, Gram-negative, anaerobic rod
• reproduce to high numbers in warm, stagnant water
  (90-105 F)

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Legionellosis

• Symptoms include fever, chills, and a cough,
  which may be dry or may produce sputum.
• Can also include muscle aches, headache,
  tiredness, loss of appetite, and, occasionally,
  diarrhea.
• Laboratory tests may show kidney function
  abnormalities.

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Legionellosis

• Chest X-rays often show pneumonia.
• Difficult to distinguish from other types of
  pneumonia by symptoms alone.
• Time between exposure to the bacterium and the
  onset of illness is 2 to 10 days.

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Legionellosis

• Middle-aged and older persons, particularly those
  who smoke cigarettes or have chronic lung disease
  at primary risk.
• Immunocompromised people (AIDS, cancer patients,
  etc ) also at increased risk.

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Pontiac Fever

• Symptoms include fever and muscle aches and do
  not have pneumonia.
• Recovery in 2 to 5 days without treatment.
• Time between exposure and illness generally a few
  hours to 2 days
• Anyone is at risk

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Primary Components, Dry Air

• Nitrogen 78.084
• Oxygen 20.9476
• Argon 0.934
• Carbon Dioxide 0.0314

CRC Handbook of Chemistry and Physics, 1997
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Minor Components, Dry Air

• Neon 0.001818
• Methane 0.0002
• Helium 0.000524
• Krypton 0.000114
• Hydrogen 0.00005
• Xenon 0.0000087

CRC Handbook of Chemistry and Physics, 1997
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Airflow in buildings

• Infiltration
• Exfiltration

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Contaminants

• Asbestos
• Carbon Dioxide (CO2)
• Carbon Monoxide (CO)
• Formaldehyde (HCHO)
• Lead (Pb)
• Mold
• Nitrogen Dioxide (NO2)

• Odor
• Ozone (O3)
• Particles
• Radon (Rn)
• Sulfur Dioxide (SO2)
• Volatile Organic Compounds (VOCs)
• Water Vapor

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Asbestos

• Building materials, insulation
• Diseases of IAQ concern
• Lung cancer
• Mesothelioma
• UK Legislation CAWR requires assessment and
  management in all UK commercial properties

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Carbon Dioxide (CO2)

• Often used as a surrogate for IAQ measures
• No health effects below 7000 to 20,000 ppm
• As a surrogate it is kept below outdoor conc.
  700 ppm
• Maintaining CO2 concentrations within 700 ppm of
  outdoors should provide acceptable perceived air
  quality in terms of human body odor, it does not
  necessarily imply adequate control of these other
  pollutant sources

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Carbon Monoxide (CO)

• Leaking vented combustion appliances, unvented
  combustion appliances, parking garages
• Recommended IAQ level
• 3 ppm above outdoor level (alert)
• 9 ppm (health)
• Alert level an indication of abnormal indoor
  concentration
• Health level based on effects on persons with
  coronary artery disease, average exposure for 8
  hours.

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Formaldehyde (HCHO)

• Pressed-wood products, furniture and furnishings
• Recommended IAQ level
• 120 µg/m3 (0.1 ppm)
• Based on irritation of sensitive people,
  30-minute exposure (WHO).

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Lead (Pb)

• Paint dust, outdoor air
• Recommended IAQ level
• 1.5 µg/m3
• Based on adverse effects on neuropsychological
  functioning of children, average exposure for 3
  months (WHO 0.5-1 µg/m3 for 1 year).

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Nitrogen Dioxide (NO2)

• Leaking vented combustion appliances, unvented
  comb. appl. Outdoor air
• Recommended IAQ level
• 100 µg/m3
• Based on providing protection against adverse
  respiratory effects, average exposure for 1 year.

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Odor

• Occupants, fungal (mold) sources, VOC sources,
  outdoor air
• Predicted acceptability to 80 or more of
  occupants or visitors
• CO2 concentration can be used as a surrogate for
  occupant odors (odorous bioeffluents).

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Ozone (O3)

• Electrostatic appliances, Office machines, Ozone
  generators, Outdoor air
• Recommended IAQ level
• 100 µg/m3 (50 ppb)
• Based on potential for adverse acute and chronic
  effects, and an additional margin of protection,
  8-hr exposure (WHO) continuous exposure (FDA)

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Mold

• Current bogeyman of US IAQ community

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Particles

• PM10, PM2.5, Dust, Smoke, Deteriorating
  materials, Outdoor air 50 µg/m3
• Based on protecting against respiratory morbidity
  in the general population and avoiding
  exacerbation of asthma, average exposure for 1
  year, no carcinogens. Indoor concentrations are
  normally lower guideline level may lead to
  unacceptable deposition of "dust."

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Radon (Rn)

• Soil gas
• Recommended IAQ level
• 4 pCi/liter
• Based on lung cancer, average exposure for 1
  year.

Rn
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Sulfur Dioxide (SO2)

• Unvented space heaters (kerosene), outdoor air
• Recommended IAQ level
• 80 µg/m3
• Based on protecting against respiratory morbidity
  in the general population and avoiding
  exacerbation of asthma, average exposure for 1
  year (WHO 50 µg/m3 if with PM)

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Volatile Organic Compounds (VOCs)

• organic (carbon-based) compounds that evaporates
  at ambient temperatures
• New building materials and furnishings,
  consumable products, maintenance materials,
  paint, mold, outdoor air
• Recommended IAQ level
• 300-3000 µg/m3 (complaints possible)
• gt3000 µg/m3 (complaints likely)

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Volatile Organic Compounds (VOCs)

• Odor and irritation responses to organic
  compounds are highly variable. The three
  guidelines for this class of compounds represent
  ranges where odor and irritation complaints are
  seldom observed (comfort range) where complaints
  can become significant in buildings (comfort -
  discomfort range) and where significant
  complaints are likely (discomfort range). Average
  indoor concentrations in most buildings are well
  below 1000 µg/m3.

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Water Vapor

• Humidity shouldn't exceed 60 during occupied
  periods, and no greater than 70 during
  unoccupied periods
• (to minimize the potential for microbial growth
  in indoor spaces. Moisture is the primary factor
  that limits the growth of fungi on construction
  and finishing materials.)

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Diagnosis

• Determine fresh air
• Measure temperature
• Measure likely contaminants
• CO2 as surrogate
• Question occupants

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Summer Temp
Source Temp type Optimum, C Acceptable range, C
CIBSE Guide A Dry resultant 20 20-22
ANSI/ASHRAE 55-1992 Operative 24.5 23-26
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Winter Temp
Source Temp type Optimum, C Acceptable range, C
CIBSE Guide A Dry resultant 20 19-20
ANSI/ASHRAE 55-1992 Operative 22 20-23.5
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Humidity
Source Relative humidity range,
CIBSE Guide A 40-70
ANSI/ASHRAE 55 30-60
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Fresh Air
Source Outdoor Air, l/s/occupant
CIBSE Guide B 8
ANSI/ASHRAE 62-1989 10
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Question Occupants

• NIOSH I-BEAM
• Stockholm Indoor Environment Questionnaire
• MM40

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MM40

• Work Environment
• Draught, temp odour, noise, etc.
• Work Conditions
• Interest, co-workers, etc.
• Past/Present Diseases Symptoms
• Asthma, hay fever, etc.
• Work Environment Symptoms
• Fatigue, headache, dry skin, etc.

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Assessing Odors

• Odor assessment
• Odor units
• Difficulties in assessing nuisance, in particular
  aspects such as aesthetics

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Assessing Odors

• Odor concentrationThe number of odor units per
  unit of volume. The numeric value of the odor
  concentration, expressed in odor units (E/ m3)
  equals the number of times that the air should be
  treated with odorless air to reach the odor
  threshold.

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Assessing Odors

• Odor thresholdThe concentration of a gaseous
  substance, expressed in µg/m3, which will be
  discerned from odorless air by at least half of
  an odor panel. The odor threshold per definition
  has an odor concentration of 1 odor unit/m3.

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Assessing Odors

• Odor standardA standard for odor, expressed as a
  maximum concentration, which may not be crossed.

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Assessing Odors

• Serious odor nuisanceA degree of odor nuisance
  which exceeds the maximum admittable level for
  human health. Both health effects and personally
  experienced effects play a part here. In practice
  a level of odor nuisance is determined by
  questionnaires in which people can describe the
  degree of odor nuisance they have experienced.

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Assessing Odors

• Zero-effect levelThis is the highest possible
  odor concentration in which people do not
  experience odor nuisance yet.

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Questions?
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