1 / 44

Aaron J Cohen Health Effects Institute

The Global Burden of Disease attributable to Ambient Air Pollution: estimates from the GBD 2010 project. Aaron J Cohen Health Effects Institute on behalf of the GBD 2010 Ambient Air Pollution Expert Group and the GBD 2010 Collaboration.

cheche
Download Presentation

Aaron J Cohen Health Effects Institute

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Global Burden of Disease attributable to Ambient Air Pollution: estimates from the GBD 2010 project Aaron J Cohen Health Effects Institute on behalf of the GBD 2010 Ambient Air Pollution Expert Group and the GBD 2010 Collaboration

  2. The Global Burden of Disease attributable to Ambient Air Pollution: estimates from the GBD 2010 project • What is GBD 2010? • Drivers of global health patterns relevant to the ambient air pollution-attributable burden • Methods for estimating exposure and risk • The global and regional burdens attributable to ambient air pollution • Conclusions and implications

  3. Global Burden of Disease 2010 • A systematicscientific effort to quantify the comparative magnitude of health loss for 187 countries from 1990 to 2010. Last major update was for 2000 under the auspices of WHO • Covering 291 diseases and injuries, 1,160 sequelae of these diseases and injuries, and 67 risk factors or clusters of risk factors • GBD 2010 study initiated in 2007 funded by Bill and Melinda Gates Foundation • Summary papers published in a dedicated triple issue of the Lancet December 15th, 2012

  4. http://www.thelancet.com/themed/global-burden-of disease

  5. GBD 2010 Team 488 authors from 303 institutions in 50 countries

  6. Ambient Air Pollution Expert Group H Ross Anderson (Co-Chair) SGHMS U London Markus Amann IIASA/Vienna Michelle Bell Yale University Michael Brauer U British Columbia Bert BrunekreefU Utrecht Richard BurnettHealth Canada Aaron Cohen (Co-Chair) Health Effects Institute Frank Dentener EC-JRC Majid Ezzati Harvard University Bryan HubbellUSEPA Kan Haidong Fudan University Michal Krzyzanowski WHO/Euro-Bonn Francine Laden Harvard University Stephanie London NIEHS Randall Martin Dalhousie University Sumi MehtaUN Fnd Clean Stoves Program Bart Ostro California EPA Kiran Dev Pandey World Bank Arden Pope Brigham Young U Beate Ritz UCLA Isabelle Romieu IARC Amir Sapkota U Maryland Kirk Smith UC Berkeley George ThurstonNew York University Rita van Dingenen EC –JRC Aaron van Donkelaar Dalhousie University

  7. Four Key Drivers of Rapid Changes in Global Health Patterns • Demographic transition – increasing population size, substantial increase in the average age in most regions and falling death rates. • Cause of death transition – fraction of deaths or years of life lost shifting from communicable, maternal, neonatal and nutritional to non-communicable diseases and injuries despite the HIV epidemic. • Disability transition – steady shift to burden of disease from diseases that cause disability but not substantial mortality. • Risk transition – shift from risks related to poverty to behavioral risks.

  8. Dramatic Demographic Shifts: Mean Age of Death Rising Rapidly

  9. Percent of DALYs* from Non-Communicable Diseases in 2010: Over 60% in Nearly All Countries Outside of Sub-Saharan Africa • Disease Burden = Disability-Adjusted Life Years (DALYs) or healthy years of life lost

  10. GBD 2000: Mortality attributable to leading risk factors Ezzati et al. 2002; WHO 2002

  11. GBD 2010: Improving estimation of Ambient Air Pollution Burden • Estimate exposure for populations in rural areas and cities <100,000 • Utilize expanded evidence base on air pollution and specific outcomes to estimate burden • Develop and apply new methods for estimating exposure-response functions

  12. Comparative Risk Assessment 2010:Methods • Calculate the proportion of deaths or disease burden holding other independent factors unchanged • Counterfactual analysis: What if risk exposure was at a different level – e.g., lower PM2.5 or normal blood pressure or BMI? • 67 risk factors and clusters of risk factors • 20 age groups, both sexes, 187 countries, and for 1990, 2005, and 2010

  13. Estimating the Global Burden of Disease due to Ambient Air Pollution Worldwide Health Evidence Country- Specific Mortality, Disease Exposure to Outdoor Air Pollution Concentration –Response Relationships Global Burden, DALYs, Mortality Baseline Incidence

  14. Risk factor definition: Ambient air pollution • Air pollution exposures are mixtures • Relative contribution of different pollutants a function of location-specific • Economic/development, social, technological factors • meteorology, topography, geography (transport) • Literature (measurements) for small number of selected pollutants • PM (TSP, PM10, PM2.5), O3, NOx, SO2, CO…

  15. Air pollution metrics PM2.5 • Most robust indicator in epidemiologic studies • Biological plausibility supported by toxicology, dosimetry, studies of acute exposures, controlled exposures • General indicator of combustion source air pollution • Also incorporates respirable fraction of crustal PM (“dust”) • Evidence does not support differential risk based on PM2.5 mixture composition

  16. Air pollution metrics Ozone • Represents somewhat distinct mixture from PM (photochemical oxidation) with different seasonal, spatial and temporal patterns • Epidemiologic associations (independent from PM) with premature mortality • Extensive literature of adverse respiratory impacts in controlled exposures

  17. PM ground-level measurements (2005) • Measurements: North America, Europe, Australasia • Estimates (from PM10): Asia, Latin America • No info: 7 / 21 GBD region

  18. Global estimates of PM2.5 at 10km x 10km scale • Combined estimates from satellites (AOD), chemical transport models and ground-level measurements • Estimates include contribution of all sources of PM2.5

  19. 1.4 million grid cells in total • Linked to global gridded population (including urban-rural indicators) • Allows for country-level burden estimation

  20. Estimated 2010 levels of PM2.5 in China

  21. Estimated population-weighted ambient air pollution levels - PM2.5 -increased worldwide and in China 1990-2010 50% increase in population-weighted PM2.5 1990 → 2010: 10% increase in global population-weighted PM2.5

  22. Household solid fuel emissions also contribute to Ambient Air Pollution • Global: household emissions contribute ~15% (4 µg/m3) of PM2.5 • China: household emissions contribute ~ 15% of ambient PM2.5– about 7µg/m3

  23. Estimated 2005 seasonal (3 month) hourly maximum ozone concentrations (ppb) TM5 model

  24. GBD 2010 estimates based on systematic review of worldwide evidence on health effects of air pollution • Evidence on adverse health effects of ambient air pollution comprises thousand of peer-reviewed studies, including over 400 epidemiologic studies in China and other parts of Asia since 1980 (HEI Special Report 18 2010) • Causes of mortality included in GBD estimates for Ambient Air Pollution Exposure were chosen based on systematic reviews of the evidence for: • Ischemic Heart Disease and Cerebrovascular Disease (US EPA 2009; American Heart Association 2011; WHO 2006; Burnett et al. 2013 in preparation) • Chronic Obstructive Pulmonary Disease (Schikowski T et al. 2013 In Press) • Lung Cancer ( Samet and Cohen 2006; IARC Monographs 92, 105, et al.) • Acute Lower Respiratory Tract Infection <5 yrs(Mehta S et al. 2011) • Pre-term Birth and Term Low Birth weight (Sapkota A et al. 2011) • Asthma (Anderson HR et al. 2009; 2011)

  25. Diseases affected by air pollution are the top 5 causes of the global burden of disease in 2010 (Lozano R et al. 2012)

  26. A model for estimating the global attributable burden: Integrated exposure-response function (IER) • All cohort studies of PM2.5 and mortality from chronic disease have been conducted in the US and Western Europe • New models needed to estimate exposure-response functions at high levels of PM in Asia, other regions • IERs estimate E-R functions using results of studies of second-hand smoke (SHS) , household air pollution (HAP), and active tobacco smoking (ATS) (Burnett R et al. 2013 Submitted) • Key model assumptions: • Risk is a function of PM2.5 inhaled dose regardless of source (Pope et al. 2009; 2011) • Consistent with risk observed in current cohort studies • Predict risk for highest PM2.5 concentrations consistent with risks from SHS, HAP, active smoking From: Pope CA et al. EHP 2011

  27. Exposure-response function estimation • Compiled study‐level estimates of the RR of mortality associated with any or all of ambient air pollution, second‐hand smoke (SHS), household air pollution (HAP), and active smoking (AS) for the following causes: ischemic heart disease (IHD), stroke, lung cancer, chronic obstructive pulmonary disease (COPD), and acute lower respiratory infection (ALRI) in children • Convert SHS, HAP, and AS to equivalent PM2.5 ambient 24 hour exposure. • Observed relationship between PM2.5 and CV RR suggested function must be able increase sharply for low concentrations and plateau at very high cigs/day levels (>25~17,000 µg/m3). • An exponential decay model with a power of concentration – the Integrated Exposure Response function (IER) – is one function that has these properties. • Model implicitly assumes that RR in ambient range cannot be greater than that for source with highest PM2.5 concentration • AS for mortality • HAPs for ALRI • Evaluated a range of non‐linear functions with up to three parameters for fitting the integrated exposure‐response (IER) relationship and evaluated goodness-of-fit using the Bayesian Information Criterion – IER was the functional form that provided the best overall fit

  28. Ambient Air Pollution Cohort Mortality Studies Used to Estimate Integrated Exposure-Response Functions

  29. Integrated Exposure-Response Function for IHD 7 µg/m3 Burnett RT, et al. 2013 Submitted

  30. GBD risk functions predict risks from recent Chinese cohort study Burnett et al. 2013 Submitted

  31. Quantifying Uncertainty • Multiple sources of uncertainty for both the risk function and estimated attributable burden of disease quantified and expressed as uncertainty intervals • Uncertainty in the estimated risk function parameters • Uncertainty in the estimate of PM2.5 • Uncertainty in the counterfactual concentration • Uncertainty in the estimated baseline mortality rates • Sensitivity analyses • Uncertainty due to model form explored via sensitivity analysis comparing different model forms • The influence of wind-blown dust on the burden estimates will be addressed by an analysis in which the counterfactual is increased in dusty regions

  32. Burden of disease attributable to risk factors in the world in 1990

  33. Burden of disease attributable to risk factors in the world in 2010

  34. Risk Factors for global deaths and DALYs in 2010 3.2 million deaths and 76 million DALYs

  35. Risk factor ranks in 2010 by GBD region

  36. Leading risk factor by country in 2010

  37. Top 20 Mortality Risk Factors in the US, India, and China in 2010 Ambient PM2.5 caused an estimated 1,234,000 deaths; 14.9% of all deaths in 2010

  38. Deaths Attributable to Ambient PM2.5 by Cause in the US, India, and China in 2010 Deaths Attributable to Ambient Particulate Matter Pollution in 2010 US Total attributable deaths = 103027 India Total attributable deaths = 627426 China Total attributable deaths = 1233891

  39. DALYs Attributable to Ambient PM2.5 by Cause in the US, India, and China in 2010 DALYs Attributable to Ambient Particulate Matter Pollution in 2010 US Total attributable DALYs= 1820412 China Total attributable DALYs= 25227281 India Total attributable DALYs= 17759991

  40. Ozone and Mortality from COPD in 2010 152,000 (52K, 267K) COPD deaths in 2010

  41. Some conclusions and implications of the GBD 2010 estimates • Ambient air pollution now ranks among the top 10 global risk factors for lost years of healthy life • Attributable deaths and DALYs much larger than previously estimated: 3.2 million deaths and 76 million DALYs in 2010 due in large part to mortality from IHD and stroke • GBD 2010 estimates larger than estimated for 2000 : • Urban and rural populations included • Larger risk coefficients • Increases in PM2.5 levels in some regions , e.g. East and South Asia • Increased rates of IHD, stroke in developing Asia and elsewhere

  42. Some conclusions and implications of the GBD 2010 estimates • Developing Asia contributes over 2/3 of the air pollution-attributable burden of disease due to regional increases in both pollution levels and rising rates of cardiovascular disease: stroke and ischemic heart disease: 4th and 7th leading risk factor in East and South Asia, respectively • The burden of disease attributable to ambient air pollution in East and South Asia has increased from 1990 to 2010 due in large part to increased PM2.5 levels and increased rates of death from stroke and heart disease • Air pollution is an increasingly important cause of lung cancer in developing Asia contributing to ̴̴ 20% of lung cancer in China in 2010 • Ambient air pollution contributes to the decreasing but still large burden of childhood ALRI in Asia

  43. Some conclusions and implications of the GBD 2010 estimates • The combined public health impact of air pollution, ambient and household, is substantial, and developing Asia experiences some of the highest levels of exposure and the largest burdens of disease from both risk factors in the world • Given widespread exposures, interventions can be very (cost) effective • It will require substantial improvements in air quality to achieve the largest benefits from air pollution reduction in very polluted settings

  44. Thank You ! Aaron Cohen acohen@healtheffects.org for more information on the GBD Collaboration http://www.healthmetricsandevaluation.org/gbd

More Related