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Civic Exchange - 2009 The Air We Breathe Conference - Latest News on PM 2.5 — Implications for Public Health
 

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 ...

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

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    Civic Exchange - 2009 The Air We Breathe Conference - Latest News on PM 2.5 — Implications for Public Health Civic Exchange - 2009 The Air We Breathe Conference - Latest News on PM 2.5 — Implications for Public Health Presentation Transcript

    • 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
    • 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
    • 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
    • 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 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
    • 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
    • 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.
    • 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)
    • 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
    • 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
    • Nel et al., Science, 2006
    • 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.
    • 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.
    • 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:
    • 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
    • Residential Proximity to Freeway Truck Traffic and Preterm & LBW babies Infants born between 1997-2000 in Los Angeles County, Ritz et al.,
    • 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