Health Effects of Particulate Air Pollution

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Health Effects of Particulate Air Pollution

• Stuart L. Abramson, M.D., Ph.D.
• November 10, 2004
• Shell Center for Sustainability at Rice University

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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 EPAs mission is to protect human
  health by strengthening the scientific basis of
  air quality regulations.

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PM Health Effects

• Some effects are known, others likely
  unknownconsider the precautionary
  principlemay be more effects seen with
  ultrafine particles (lt0.1 microns)
• Political and economic implications to be
  considered

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Questions to answer

• 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 categorysoITS
  EVERYONES PROBLEM

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Locations of PM exposure

• Outdoors
• Indoors
• Miscellaneous indoor exposures (cigarettes,
  candles, wood-burning stoves, fireplaces, etc.)
• In vehicle in traffic
• Occupational exposures
• Hobbies

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Characterization of PM

• PM10 (coarse primarily oxides or salts of
  elements found in dirte.g. Fe, Ca, Si, Al)
• PM2.5(fine sulfates, nitrates, ammonium,
  organic and elemental carbon, acid aerosols)
• Ultrafine (lt100 nm)
• How does PM composition (including diesel exhaust
  particles) in Houston differ from other areas?

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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

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Factors involved in the development of health
effects

• Amount of exposure
• Duration of exposure
• Co-exposures combinatorial effects?
• Constitutional factors (age, sex, ethnicity)

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Symptoms of PM exposure

• Shortness of breath
• Chest tightness
• Chest pain
• Palpitations
• Coughing
• Wheezing
• Fatigue

• Eye irritation
• Nasal irritation
• Throat irritation
• Headache
• Others (e.g. cognitive impairment)

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Health effects of particulate matter (PM) air
pollution

• Based on epidemiological studies others (e.g.
  animal studies)
• Respiratoryincrease in asthma attacks, COPD
  exacerbations, decreased lung function,
  bronchitis, and more allergic sensitization
• Cardiovascularincreased risk of heart attack,
  rhythm disturbances, vascular changes (increase
  risk of stroke--Kuenzli et al. AHA Scientific
  Session, November 20004, New Orleans)
• Cancerincreased risk of lung cancer

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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, 2004prevalence
  of FEV1lt80 predicted was 4.9x greater in
  subjects with high PM2.5 exposure from ages 10-18
  years

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Selected Criteria Air Pollutants(with similar
effects on respiratory disease)

• 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

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Asthma Pathophysiology
Airway lumen narrowing
Epithelial damage
Mucous gland hypertrophyand hyperplasia
Airway smooth- muscle hypertrophy, hyperplasia,
and bronchoconstriction
Edema
Inflammatory cell infiltration
Mucushypersecretion
Vascular dilation
Thickening of basement membrane
Goblet cellhyperplasia
Adapted from Expert Panel Report. Guidelines for
the Diagnosis and Management of Asthma. NIH,
NHLBI. 1991. NIH publication 91-3042.
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Mechanisms for Effect of Cigarette Smoking on
Asthma

• Decreased airway caliber
• Decreased level of lung function
• Allergy
• Increased airway responsiveness
• Increased inflammatory markers
• Gene by environment interactions

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Cigarette smoke exposure

• Firsthand unfiltered toxic gaseous exposureget
  rid of secondhand or passive label

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Emphysemamarked thinning of alveoli
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Rhinitis (allergic and other) may be associated
with the development of other diseases due to
common passageways
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PM health effects, cont.

• Increased heart rate, arrhythmias, cardiovascular
  mortality
• Dockery DW, Environ Health Perspect, 2001

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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

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www.epa.gov/pmresearch
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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)

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PM health effects, cont.

• Increased allergic sensitization (DEP)
• Reproductive effects (PAHs with low birth weight,
  premature birthsmall effects)
• Sram RJ Perera FP et al., Environ Health
  Perspect, 1999

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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)

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Polycyclic Aromatic Hydrocarbon Metabolism
Casillas et al. , Annals of Allergy, Asthma,
Imm, 1999
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Typical diesel exhaust particle Casillas et
al., Ann All Asthma Immunol 1999
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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

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Environmental Health