Indoor Environmental Quality: Health Effects, Asthma, and
Asthma Triggers
John W. Martyny, Ph.D., CIH
Tri-County Health Department
Sources of IAQ Pollutants
Outdoor pollution Indoor pollution Building material off-gassing Inadequate ventilation
Forms of Indoor Pollutants
Particles Liquids Fumes Mists Gases Vapors Physical Agents
Dose Response
The higher the dose the greater the response.
Exceptions: Allergens Carcinogens
Chronic vrs. Acute Effects
Acute Immediately after exposure May disappear quickly
Chronic May appear months or years after initial
exposure Symptoms may slowly appear and not be
reversible.
Examples of specific pollutants
Carbon Monoxide Sources:
forklifts, floor polishers, combustion sources
Health Concerns: headache, fatigue, poor vision, lack of
coordination, CNS problems, coma, death.
Normal Concentration: Less than 10 ppm
Accepted Limits: ACGIH - 25ppm (lower at altitude)
Nitrogen Oxides Sources:
Fossil fuels, welding, outside air
Health Concerns: Upper respiratory irritation, pulmonary edema,
asthmatic reactions.
Normal Concentration: Less than 0.1 ppm
Acceptable Limits: Nitrogen dioxide - 2 ppm
Fibrous Particles Types - Asbestos & Fiberglass Sources:
Insulation, duct lining, etc.
Health Concerns: Dermatitis, respiratory disease, cancer
Normal Concentration: Varies
Acceptable Limits: Asbestos - 0.1 f/cc Fiberglass - 1 f/cc
Formaldehyde Sources:
Insulation, pressed wood prod., textiles, etc.
Health Concerns: Mucous membrane irritation, chest tightening,
asthmatic reactions, cancer.
Normal Concentration: Less than 0.01 ppm
Acceptable Limits: 0.3 ppm
Suspended Particles
Sources: Smoking, printers, building materials
Health Concerns: Eye Irritation, upper resp. irritation, etc.
Normal Concentration: Less than 0.01 mg/m3
Acceptable Limits: 5 - 10 mg/m3
Volatile Organic Compounds Sources:
Glues, carpeting, copy machines, cleaning compounds, paints, etc.
Health Concerns: Odors, headache, mucous membrane irritation,
nausea, dizziness, etc.
Normal Concentration: Not well defined (TVOC = < 1mg/m3)
Acceptable Limits: Varies with compound
Lead Sources:
Lead paint, lead products, indoor firing ranges.
Health Concerns: Children - Decreased learning, neurotoxicity. Adults - neuotoxicity, joint pain, weight loss, CNS
damage
Normal Concentration: <1 ug/m3
Acceptable Limits: < 50ug/sq.ft. floor space
Radon
Sources: Soil, building materials
Health Concerns: Lung cancer
Normal Concentration: 1.5 pci/l
Acceptable Limits: 4 pci/l
Ozone Sources:
Copiers, air cleaners, outside air.
Health Concerns: Upper resp. irrit, pulmonary edema, asthmatic
reactions.
Normal Concentrations: Less than 20 ppb
Acceptable Limits: 50 -100 ppb
Environmental Tobacco Smoke
AKA
Passive Smoking Involuntary Smoking Side-Stream Smoke Secondhand Smoke
ETS Components
Composed primarily of sidestream smoke and exhaled mainstream smoke
complex mixture of >4,000 compounds Contains: > 40 carcinogens (e.g., benzene, nitrosamines,
polycyclic aromatic hydrocarbons),
respiratory irritants (e.g., ammonia, formaldehyde,
sulfur dioxide),
reproductive toxicants (e.g., carbon monoxide,
nicotine).
Why Focus on Children?
Need is the greatest Children particularly
susceptible Exposure is involuntary Most children of smokers are exposed in the home
What’s the Problem 27% of homes with children age 6 &
under, regularly allow smoking 9-12 million children under 5 are
exposed in the home 38% of children 2 mos. - 5 yrs are
exposed in the home
What’s the Problem
Up to 1 million children have their asthma worsened (costing $200 million annually)
Estimated 700,000 - 1.6 million doctor
visits for ear infections 150,000 - 300,000 cases of
bronchitis and pneumonia
annually in toddlers
Lower Respiratory Tract Infections
e.g., pneumonia, bronchitis, bronchiolitis very strong, consistent evidence for infants
and young children (up to about 3 years) strongest effect from maternal smoking, but
also evidence from paternal smoking increased risks of about 50 to
100% for young children;
higher for young infants
Respiratory Symptoms
Chronic cough, phlegm, and wheezing strong consistent evidence, especially
for preschool children increased risks of about 20 to 40% Asthma exacerbations
Middle Ear Disease
strong evidence for acute and chronic middle ear disease
fluid in the middle ear is the most common reason for operations in young children in the U.S.
increased risks of up to
about 20 to 40%
Other Health Effects
Decreased lung function – small (<10%), but significant reduction in lung growth/function
Decreased Fetal Growth– consistent evidence of small effect for nonsmoking mothers during pregnancy
Emerging Science
Cognitive and Behavioral Effects– Poor performance in school and standardized and behavioral tests
Cardiovascular Effects– Adults and Children (stronger for adults)
Childhood Cancer– Suggestive evidence of leukemia & brain tumors
SIDS - Suggestive evidence of association
Conclusions
Strong international scientific consensus that ETS exposure causes increased risk of a variety of health effects in children
Increased risks of common ailments, coupled with widespread exposure, result in large public health impacts and financial costs
ETS exposure and resultant health effects in childhood may also increase the risk of further adverse effects in adulthood
Hypersensitivity Illnesses
Types of Hypersensitivity Illnesses
Allergies Allergic Rhinitis Hypersensitivity Pneumonitis Asthma
Allergies
An immune-mediated state of hypersensitivity that results from exposure to an allergen.
Hypersensitivity is an exaggerated or inappropriate immune response.
Examples: hay fever, food allergies, horse serum
Common Indoor Allergens
Pollen grains and fungal spores Bacteria, protozoa, and fungi House dust mites Cockroaches Birds Mammals
Immune System Responses Depend Upon
Source material Host factors Duration of exposure Intensity of exposure
Source Material
Can it be allergenic? Will it penetrate into the lungs? Will it be removed quickly? Have there been prior exposures?
Antigens
Must be recognized by the body as foreign.
Typically are relatively large molecules or are attached to larger molecules.
Plant and animal proteins are potent antigens. Chromium, beryllium, etc.
Single amino acids and simple sugars are usually not antigenic.
Host Factors
??????? Is the person atopic? Do other family members have
hypersensitivity diseases? IgM, IgG, and IgE levels. IgE is primarily responsible for release of
histamine (Clinical allergy symptoms).
Duration and Intensity of Exposure
Will the allergen be in the lungs for a long period of time?
Can the respiratory tract remove the material? Will the exposure be constant?
Allergic Rhinitis
Prevalence rate of 10% - 20% of population.
Sympt. - Runny and congested nose, inflamed throat and eyes, sneezing, etc.
Caused by IgE mediated inflammation and histamine release.
Allergens - dust mites, fungi, pollen, cats and dogs.
Hypersensitivity Pneumonitis
Caused by repeated or continuous exposure to antigenic substances.
Flu symptoms - chills, fever, malaise, cough, difficulty breathing.
Granulomatous lesions within the lung. Easily misdiagnosed.
Sarcoidosis
Hypersensitivity Pneumonitis (Cont)
Frequently named after exposure: pigeon-breeders disease, farmers lung.
Attack rate may vary from 15% to >50%.
Examples: Hot tubs, Pools, Mold exposure.
Asthma
www.epa.gov/iaq/asthma/index.html
What is Asthma? Chronic Inflammatory Disorder of Airways Characterized by:
Recurrent Episodes of Airflow Limitation Airway constriction
- Usually Reversible * Spontaneously, or * with Appropriate Treatment
What Happens During Attack?
Airways Narrow
Mechanism:
- Tightening muscles surrounding airways
- Swelling of inner lining of airways
- Increase in mucus production &/or
inflammation
Asthma Symptoms
Coughing
Wheezing
Chest Tightness
Shortness of Breath
Asthma Facts
Over 27 million Americans have been diagnosed with asthma
Approx. 11 million Americans had at least 1 asthma attack in the past year
On average, 14 people die each day from asthma
Asthma Facts $6.2 billion spent on asthma in 1990 Self-reported prevalence rate increased
75% from 1980-1994 National asthma-related hospitalizations
increased 80,000 between 1979-1980
and 1993-1994
Rise in atopic diseases
Allergies, eczema etc
Atopy [familial tendency to certain hypersensitivities] also on increase
Why? Research is ongoing…
High-Risk Populations (for asthma)
Children Low-income, urban residents Minorities Those with hereditary predisposition Allergic individuals
Emerging Science
Overweight = Possible risk factor
# of Siblings = Possibly protective
# of Early Life infections = Possibly
protective
Children and Asthma
In 1980, 2.3 million American children had asthma. By 1995, the number of children with asthma had risen to 6 million.
7.3% of children under age 18 have asthma Asthma is the most common chronic illness in
childhood & the leading cause of missed school days due to chronic illness
Asthma mortality for children is 5X higher than adults
Low-Income, Urban Residents and Asthma
Likely contributing factors:
- poverty
- exposure to higher levels of
allergens & air pollution episodes
- limited access to medical care
Minorities and AsthmaAfrican-Americans Children are 4X more likely to die from asthma than
Caucasian children (in 1995) Children have 3X greater hospitalization rate than
Caucasian children
Some Hispanics Prevalence of asthma is 11.2% in Puerto Ricans
compared to 3.3% for non-Hispanic whites
Hereditary Predisposition and Asthma
Children with one asthmatic parent have ~25% greater risk of developing asthma than children of non-asthmatic parents
Children with two asthmatic parents have ~50% greater risk of developing asthma than children of non-asthmatic parents
Common Asthma Triggers
Allergens
- molds
- dust mites
- cockroaches
- animal dander
- pollens
- foods
Irritants
- ETS
- strong odors
- aerosols
- VOCs
- ozone
- particulate
matter
Common Asthma Triggers Other - viral respiratory infections - emotional expressions (stress, crying, laughing) - changes in weather (cold air, wind, humidity) - exercise - medications - endocrine factors (pregnancy, menstrual cycle, thyroid disease)
EPA Targeted Triggers
Irritants (e.g. ETS) Dust Mites Cockroaches And Rodents Animal Dander Molds