Transcript HOST RESPONSE: THE PATHOLOGY OF INFECTIOUS DISEASE

Health Effects of Particulate Air
Pollution
Stuart L. Abramson, M.D., Ph.D.
November 10, 2004
Shell Center for Sustainability at Rice
University
www.epa.gov/nheerl/research/pm
• “Research indicates that air pollution in the
form of particulate matter, or PM, at
concentrations currently allowed by
national standards (the National Ambient
Air Quality Standards, or NAAQS) is linked
to thousands of excess deaths and
widespread health problems. Part of the
EPA’s mission is to protect human health by
strengthening the scientific basis of air
quality regulations.”
PM Health Effects
• Some effects are known, others likely
unknown—consider the “precautionary
principle”—may be more effects seen with
ultrafine particles (<0.1 microns)
• Political and economic implications to be
considered
Questions to answer
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Who? is affected
Where? does exposure take place
What? characterizes the particles involved
When, Why and How? are certain health
effects seen (morbidity and mortality)
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Who is most sensitive to effects
of
PM?
The youngest
– Minute ventilation standardized for body mass is
significantly greater in infancy (400 ml/min/kg) and
early childhood than in adults (150 ml/min/kg); radii of
developing airways are smaller and have less mature
anti-oxidant and detoxification capacity
• The oldest
– Often due to chronic underlying disease (e.g. lung,
heart, diabetes); also less active repair mechanisms in
response to lung injury
• Those of any age with chronic disease
• All in-between have been in the youngest category
and many will reach the oldest category—
so……IT’S EVERYONES PROBLEM
Locations of PM exposure
• Outdoors
• Indoors
– Miscellaneous indoor exposures (cigarettes,
candles, wood-burning stoves, fireplaces, etc.)
– In vehicle in traffic
– Occupational exposures
– Hobbies
Characterization of PM
• PM10 (“coarse”; primarily oxides or salts of
elements found in dirt—e.g. Fe, Ca, Si, Al)
• PM2.5(“fine”; sulfates, nitrates, ammonium,
organic and elemental carbon, acid aerosols)
• Ultrafine (<100 nm)
• How does PM composition (including diesel
exhaust particles) in Houston differ from other
areas?
Heath Effects Indices
• General morbidity and mortality absenteeism, EC,
hospitalizations
• Respiratory exacerbations (asthma, COPD,
bronchitis, emphysema)
• Cardiovascular rhythm disturbances, vascular
changes (atherosclerosis, heart attacks)
• Immunological/Cancer rates (HAPs, PAHs)
• Neuropsychological
• Reproductive (low birth weight)/Endocrinological
Factors involved in the
development of health effects
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Amount of exposure
Duration of exposure
Co-exposures; combinatorial effects?
Constitutional factors (age, sex, ethnicity)
Symptoms of PM exposure
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Shortness of breath
Chest tightness
Chest pain
Palpitations
Coughing
Wheezing
Fatigue
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Eye irritation
Nasal irritation
Throat irritation
Headache
Others (e.g. cognitive
impairment)
Health effects of particulate
matter (PM) air pollution
• Based on epidemiological studies & others (e.g.
animal studies)
• Respiratory—increase in asthma attacks, COPD
exacerbations, decreased lung function, bronchitis,
and more allergic sensitization
• Cardiovascular—increased risk of heart attack,
rhythm disturbances, vascular changes (increase
risk of stroke--Kuenzli et al. AHA Scientific
Session, November 20004, New Orleans)
• Cancer—increased risk of lung cancer
PM health effects
• Asthma and COPD exacerbations,
decreased lung function, bronchitis sx,
effects on lung development
– Brunekeef B and ST Holgate, Lancet, 2002
– Gauderman WJ et al. N Eng J Med, 2004—
prevalence of FEV1<80% predicted was 4.9x
greater in subjects with high PM2.5 exposure
from ages 10-18 years
Selected Criteria Air Pollutants
(with similar effects on respiratory disease)
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Ozone
Sulfur dioxide
Nitrogen dioxide
PM (2.5 or 10 microns)
– effects on asthma may include:
• increased bronchial reflexes, analogous to histamine or
methacholine
• increased inflammation
• enhancement of early or late phase response
• enhancement of sensitization to allergens
Asthma: Pathophysiology
Airway lumen narrowing
Mucous gland
hypertrophy
and hyperplasia
Edema
Epithelial
damage
Airway smoothmuscle hypertrophy,
hyperplasia, and
bronchoconstriction
Inflammatory
cell infiltration
Mucus
hypersecretion
Thickening
of basement
membrane
Vascular
dilation
Goblet cell
hyperplasia
Adapted from Expert Panel Report. Guidelines for the Diagnosis and Management of
Asthma. NIH, NHLBI. 1991. NIH publication 91-3042.
Mechanisms for Effect of
Cigarette Smoking on Asthma
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Decreased airway caliber
Decreased level of lung function
Allergy
Increased airway responsiveness
Increased inflammatory markers
Gene by environment interactions
Cigarette smoke exposure
• “Firsthand unfiltered toxic gaseous
exposure”—get rid of secondhand or
“passive” label
Emphysema—marked thinning of alveoli
Rhinitis (allergic and other) may
be associated with the
development of other diseases
due to common passageways
PM health effects, cont.
• Increased heart rate, arrhythmias,
cardiovascular mortality
– Dockery DW, Environ Health Perspect, 2001
PM may narrow arteries
• Kuenzli et al. (2004) looked at a sample of
800 adults (at least 40 years old) via
ultrasound of carotid arteries
– For every 10 point increase in PM2.5, carotid
arteries were 4% narrower
– For women over 60, every 10 point increase led
to more than 15% narrowing
– The above data suggest increased risk for stroke
with increased PM2.5 exposure
www.epa.gov/pmresearch
PM Health Effects--Numbers of
interest
• In a 151 city study, a 10 microgram/cubic meter
increase in mean particulate matter resulted in a
4% increase in overall mortality, 6% increase in
cardiopulmonary mortality, and an 8% increase in
lung cancer mortality (Pope CA et al., JAMA
2002)
• Comparative findings in a 20 city study, showing
0.51% increase in the relative rate of death from
1987-1994 for all causes and 0.68% increase in
death from cardiovascular and respiratory causes
for the same incremental increase in PM (Samet
JM et al., N Eng J Med, 2000)
PM health effects, cont.
• Increased allergic sensitization (DEP)
• Reproductive effects (PAHs with low birth
weight, premature birth—small effects)
– Sram RJ; Perera FP et al., Environ Health
Perspect, 1999
Diesel Exhaust Particles and
Asthma
• The combination of diesel exhaust particles
and specific allergens is synergistic in the
development of allergic sensitization and
asthma (Saxon and Diaz-Sanchez,
Immunopharmacology, 2000)
Polycyclic Aromatic Hydrocarbon Metabolism
Casillas et al. , Annals of Allergy, Asthma, & Imm, 1999
“Typical” diesel exhaust particle
Casillas et al., Ann All Asthma Immunol 1999
Health Effects Reference for
Houston,TX
• “Assessment of Information Needs for Air
Pollution Health Effects Research in
Houston, Texas” (2003); Report by
BRIDGES to Sustainability and Mickey
Leland National Urban Air Toxics Research
Center to the Texas Council on
Environmental Technology, 67 pages.
www.bridgestos.org
Environmental Health