Composition of PM 2.5 in the Urban Atmosphere Overall Episode PM 10>50μg/m 3

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1 Why worry about PM 2.5 and Black Carbon? Dr Ian S Mudway MRC-PHE Centre for Environment & Health, King s College London

2 Composition of PM 2.5 in the Urban Atmosphere Overall Episode PM 10>50μg/m 3 Yin and Harrison, 2008

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4 Who died? Deaths Registered in London Administrative County Classified by Age (Bates, 1995) < Month Mo. Years Years Years Years Years of Age Old of Age of Age of Age of Age of Age Week Before the Episode Week After the Episode Before/ After Episode Ratio The greatest relative increase in mortality was from bronchitis, which rose nine-fold

5 Health Effects of Ambient Pollution Se everity Death 1952 London Fog Hospital admissions Hospital Admissions rose by 50% Doctor visits Respiratory admissions by 160% Asthma attacks, medication use, symptoms lung function changes, immune cell responses, heart rate or heart rate variability responses Proportion of effected population

6 Fe, Pb, Zn, Sn, Sb Hunt A et al. EHP, 111: , 2003.

7 Health impact of fine particulate pollution Total particles (μg/m 3 ) Fine particles (μg/m 3 ) Sulfate particles (μg/m 3 ) Steubenville St. Louis Harrimen Watertown Topeka Portage Dockery DW, et al. N Engl J Med 1993;329(24):

8 The Six Cities study Dockery DW, et al. N Engl J Med 1993 Dec 9;329(24):1753-9

9 Short Term Long Term Short Term = % Daily mortality rate using daily PM mass concentrations avgs Long Term = 6 17% Annual mortality rate using annual PM mass conc avgs 1-Klemm and Mason, Ostro et al., Anderson et al., Schwartz et al., 2000, Schwartz et al., Dominici et al., Katsouyanni et al. 2003, Analitis et al., Laden et al., Pope et al., Jerrett et al., 2005 Percent Perce Mortality ent Risk Risk Increase Increase (95% CI) (95% CI) (1) (2) US 6 cities Cali 9 cities 10 µg m -3 P PM2.5 (3) (4) (5) (6) Single US city studies US 10 cities US 14 cities NMMAPS US cities 20 µg m -3 P PM10 (7) APHEA 2 cities 10 µg m -3 PM M2.5 (8) (9) (10) Harvard 6 cities ACS US cohort ACS LA cohort

10 As a result of poor air quality: Published December 2010 UK population lost 340,000 years of life in 2008 This loss of life is equivalent to 29,000 deaths the average loss of life would have been 2 years, (though the actual amount would vary between individuals). The burden can also be represented as a loss of life expectancy from birth (for everyone) of 6 months 10

11 PM Reduction & Mortality: 6 Cities follow-up Period d1: Period 2: Laden F et al/ Am J Respir Crit Care Med Mar 15;173(6):

12 Kulkarni et al, 2006 (NEJM); Leicester, UK 64 healthy school children, 8-15 yr Association between carbon content of airway macrophages, lung function and PM 10 at home address Gauderman et al, 2004 (NEJM); southern California 1, yr old children, 12 communities, 8-yr follow up Lung function growth significantly reduced in areas with higher levels of traffic-related pollutants (NO 2, PM 2.5, EC) reduction in growth of FEV 1 of ~80 to 100 ml clinically low FEV 1 at age 18 Gauderman et al, 2007 (Lancet); southern California Same study, local vs. regional pollutant levels Living <500m from freeway associated with reduction in FEV 1 growth of ~80mL significantly ifi lower attained FEV 1 by 18 yrs 12

13 Responses to PM in the Real World Does short term exposure to real world atmospheres (diesel traffic and background) cause respiratory effects in asthmatics? Hyde Park Oxford Street PM 10 =72 µg m -3, PM 2.5 =11.2 µg m -3, PM 10 =125 µg m -3, PM 2.5 =28.3 µg m -3, 11.7 ppb NO 2 18,300 particles cm ppb NO 2 63,700 particles cm -3 McCreanor al. (2007) New Eng J Med 357:

14 Responses to PMi in the Real lworld Impaired dlung function Inflammation McCreanor J et al. N Engl J Med Dec 6;357(23):

15 Summary of Air Pollution Related Health Effects- Epidemiology Evidence Synthesis Health Outcome Mortality All-cause and Cardiovascular mortality Association with Traffic Air Pollution Exposure Sufficient Asthma and Respiratory - Children Asthma onset and prevalence Asthma is more common in children living in the street buffers with the highest concentrations of traffic-related pollution Exacerbation of asthma symptoms Children living in hot spots of traffic-related pollution experience more symptoms and exacerbations Respiratory Symptoms Lung function TRAFFIC Living in proximity to high concentration of traffic air pollution may be associated with reduced lung function Sufficient Sufficient Suggestive but not sufficient HEI (2010) Special Report 17

16 Establishing children s actual exposures To traffic derived pollutants

17 Take Home Messages 1. The evidence base that PM 2.5 exposures have profound chronic effects on public health is robust. In the UK only smoking confers a greater environmental/lifestyle risk to health. 2. PM 2.5 mass is a crude, but useful way of investigating these health impacts, but this does not address the toxic component. 3. Traffic pollution has been associated with a number of negative health outcomes, despite only comprising a small component of PM 2.5 mass. 4. Black carbon has been proposed as a useful tracer of traffic (diesel ) emissions. 5. Toxicologically it s unlikely that small carbonaceous particles are the smoking gun, but they do focus our attention on primary vehicle emissions.