Latest news on PM 2.5 – Implications for Public
Health
      Southern California Particle Center
      Director: John R. F...
Early evidence for PM2.5 related
         health effects-1997
• Series of studies that reported associations between
  dai...
PM 2.5 impact-increase in relative risk
  For every Increase of 10ug/m3


1. Short-term exposure and mortality:
          ...
2008 California Air Resources Board Analysis-New
estimates of PM2.5 premature relative risk
Summary: Health effects associated with
 PM exposure to traffic related pollutants

• Effects on CNS and autonomic nervous...
Conclusions
 There’s been progress evaluating PM effects for different
  time-scales of exposure and in the exploration o...
Mitochondria: An Important Subcellular Target
                of PM and a Source of ROS Generation
                Mag. x ...
How small are these particles?
            coarse: 2.5-10 um
                 fine: <2.5
              ultrafine: <0.1



...
Pathways of Oxidative Stress
                                            High                             Low
            ...
Mobile Source Studies
•Particle mass remains relatively
constant with distance from
freeway; size distribution
changes con...
Nel et al., Science, 2006
Distribution of DTT based redox
                activity
DTT activity   Particle fraction   Volatile fraction   Ratio
    ...
Distribution of electrophiles based on GAPDH
           inhibition and inhibition of PTP1B
        EC for inhibition   Par...
Aortic atherosclerotic
                                                lesions
Aortic lesion area (µm2/section)   70000
  ...
Results: More asthma within 150 m of
                                   major roads
                       2.5
   Asthma O...
Residential Proximity to Freeway Truck
  Traffic and Preterm & LBW babies
      Infants born between 1997-2000 in Los Ange...
Does PM Affect other Organ
                                            Systems?
                                          ...
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Civic Exchange - 2009 The Air We Breathe Conference - Latest News on PM 2.5 — Implications for Public Health

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Civic Exchange 2009 The Air We Breathe Conference - Experts Symposium 9 January 2009

Latest News on PM 2.5 — Implications for Public Health
presented by Dr John Froines (South California Particle Centre)

http://air.dialogue.org.hk

Published in: Health & Medicine, Education
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Civic Exchange - 2009 The Air We Breathe Conference - Latest News on PM 2.5 — Implications for Public Health

  1. 1. Latest news on PM 2.5 – Implications for Public Health Southern California Particle Center Director: John R. Froines, Ph.D. • University of California, Los Angeles • University of Southern California • University of California, Irvine • Michigan State University • University of Wisconsin-Madison • University of Tsukuba, Japan
  2. 2. Early evidence for PM2.5 related health effects-1997 • Series of studies that reported associations between daily changes in PM and daily mortality • Harvard Six Cities and American Cancer Society prospective cohort studies • Utah valley studies • Health endpoints: respiratory hospitalizations, lung function and respiratory symptoms, school absences, and mortality including lung cancer • Annual mean Standards: U.S Federal 15 ug/m3; State of California 12 ug/m3; WHO 10 ug/m3
  3. 3. PM 2.5 impact-increase in relative risk For every Increase of 10ug/m3 1. Short-term exposure and mortality: 0.4% to 1.5% increase in risk 2. Long-term exposure and mortality:  6% to 17% increase in risk 3. Cardiovascular mortality: Short term  0.6% to 1.8% increase in risk Popeand Dockery, J.Air&Wastemanagement Association,56,709-742 Pope and Dockery, J.Air&WasteManageAssoc,56,709- 742
  4. 4. 2008 California Air Resources Board Analysis-New estimates of PM2.5 premature relative risk
  5. 5. Summary: Health effects associated with PM exposure to traffic related pollutants • Effects on CNS and autonomic nervous system • Low birth weight/preterm babies • Increase in asthma and other respiratory disease in children and adults • Decrease in lung development and function in children • Atherosclerosis exacerbation in adults • Cancer
  6. 6. Conclusions  There’s been progress evaluating PM effects for different time-scales of exposure and in the exploration of the shape of the concentration-response function.  There is emerging evidence of PM-related cardiovascular health effects and a growing knowledge of mechanistic pathways  Associations identified between adverse health outcomes and traffic density  Increased emphasis on role of ultrafine particles.  Significant role of vapor condensation and semi-volatile particles and evidence for a key role of vapors
  7. 7. Mitochondria: An Important Subcellular Target of PM and a Source of ROS Generation Mag. x 6000 Mag. x 21000 Mag. x 6000 Mag. x P 21000 P M Untreated Fine M M P M UFP P Coarse M M M M P P Mitochondria are redox active organelles RAW 264.7 Li, N., Sioutas S, Cho A, Schmitz D, Misra C, Sempf J, Wang M, Oberly T, Froines J, Nel A (2003). "Ultrafine Particulate Pollutants Induce Oxidative Stress and Mitochondrial Damage." Environmental Health Perspectives 111(4): 455-460.
  8. 8. How small are these particles? coarse: 2.5-10 um fine: <2.5 ultrafine: <0.1 Human Hair PM10 PM0.1 PM2.5 (60 µm diameter) (10 µm) (0.1 µm) (2.5 µm)
  9. 9. Pathways of Oxidative Stress High Low GSH/GSSG GSH/GSSG Ratio Ratio oxidative stress Level of Cell response pathway: Normal Anti- Inflammation Toxicity oxidant Defense Dose dependent induction of Dose antioxidant enzymes-UF Source: Xiao, et al. 2003
  10. 10. Mobile Source Studies •Particle mass remains relatively constant with distance from freeway; size distribution changes considerably. •Zhu et al, Aerosol Science and Technology, 38,2004; Zhu et al, Atmospheric Env, 36, 2002 •Concentrations of nanoparticles (<20 nm) are much higher in winter than summer, suggesting that these particles are volatile, formed by condensation of organic vapors. •Volatile vs non-volatile particle
  11. 11. Nel et al., Science, 2006
  12. 12. Distribution of DTT based redox activity DTT activity Particle fraction Volatile fraction Ratio (Particle/vapor) (nmoles (nmoles DTT/min/m 3 ) DTT/min/m 3 ) RIV041607 No data * 0.155 RIV042507 0.514 0.160 3.21 RIV050707 0.769 0.284 2.71 RIV102507 1.239 0.159 7.79 • DTT based redox activity higher in particle phase.
  13. 13. Distribution of electrophiles based on GAPDH inhibition and inhibition of PTP1B EC for inhibition Particle fraction Volatile fraction Ratio (Particle/vapor) GAPDH m3 m3 RIV041607 Not available 0.50 ND RIV042507 88.32 0.42 210.3 * RIV050707 4.13 0.16 25.8 RIV102507 2.88 0.17 16.9 PTP 1B inhibition Particle fraction Volatile fraction Ratio (Particle/vapor) RIV041607 ND 0.17 NA RIV042507 ND 0.18 NA RIV050707 ND 0.09 NA • Values are concentrations of air mass equivalents, in m3, needed to inactivate GAPDH by 50%. • Smaller values are more potent. ND: not • GAPDH data show higher levels of electrophiles in vapor phase compared to particles. • Electrophiles in vapor phase inhibit two thiol enzymes, GAPDH and PTP1B.
  14. 14. Aortic atherosclerotic lesions Aortic lesion area (µm2/section) 70000 P<0.0001 P= 0.002 60000 P= 0.02 P= 0.02 50000 40000 30000 20000 10000 0 NE FA FP UFP Condition Source:
  15. 15. Results: More asthma within 150 m of major roads 2.5 Asthma Odds Ratio 2 1.5 1 0.5 0 <75 75-150 150-300 >300 Distance to Major Road (meters) McConnell, et. al. AJRCCM 2005;2:A522
  16. 16. Residential Proximity to Freeway Truck Traffic and Preterm & LBW babies Infants born between 1997-2000 in Los Angeles County, Ritz et al.,
  17. 17. Does PM Affect other Organ Systems? Lung 10 ng 13C/g organ Liver per µg/m3 8 * * 6 1.5 µg 13C/gram Lung 4 1.0 * * Organ * 2 * * * Olfactory 0.5 * * * * Cerebellum 0 0.0 Cerebrum 0.5 10 24 0.5 10 24 0 1 2 3 4 5 6 7 Hours after Exposure Days after Exposure Brain Inflammation Markers Tissue from Mice Exposed at BH2 2002 Control UF F+UF TNF! (ng/mL) 2.0 ±0.1 2.2±0.1 2.5±0.2 IL-1! (ng/mL) 1.6±0.2 2.7±0.3* 2.0±0.4* NFkB (units x 10-3) 8.5±4.4 11.0±1.6** 10.7±3.0** Sources: Campbell et al, Neurotoxicology, 2005; Oberdorster et al., EHP, 2005

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