Transportation and Mobility: Progress and Challenges

Transcription

1 Transportation and Mobility: Progress and Challenges Reflections on Critical Review by Dr. Christopher Frey Trends in On-road Transportation Energy and Emissions Rashid Shaikh, Ph.D. Director of Science Health Effects Institute Air & Waste Management Association Annual Meeting June 26, 2018

2 Trends in On-road Transportation Energy and Emissions Dr. Frey s paper: Impressive manuscript Encyclopedic and comprehensive In this presentation, I will Highlight a few key issues, as they pertain to health effects Global Estimate and Trends Do regulations work? Effects at Low Levels 2

3 Scale of the problem GBD 2016 Estimates: Air Pollution consistently among topranked global risk factors Outdoor PM contributed to ~ 4 million premature deaths (7.5% of all deaths) Also, > 100 million years-of-healthy-life lost 3

4 Features of GBD Estimates Strengths: A systematic, comprehensive regional and global research program of disease burden that assesses mortality and disability from major diseases, injuries, and risk factors. Organized by the Institute for Health Metrics and Evaluation (IHME) HEI leadership for outdoor air pollution Annual updates Other Features: For PM2.5, based on risk estimates for certain outcomes PM and ozone only Uncertainties in exposure estimates Unresolved issues about the exposure-effect estimates, esp. at low levels The best estimates we have Case Study of China Illustrates important issues 4

5 China: Mortality from Major Sources Coal, industry, domestic the major contributors to disease burden in China 2013 Subsector Mean PM 2.5 Deaths All Ambient PM ,000 Total Coal ,000 Powerplant Coal ,500 Industrial Coal ,500 Non Coal Industial ,000 Domestic Coal ,000 Domestic Biomass ,500 Traffic ,500 Open Burning ,000 Source sector contributions to mean population-weighted ambient PM 2.5 and PM attributable deaths in China, GBD MAPS China Report,

6 Estimated Impact of Regulations: Chinese mortality from most sources of ambient PM 2.5 will grow by 2030 even with new controls Transport, Industry (non-coal) and biomass also contribute to health burden Coal the single largest contributor to health burden

7 China: Between Now and 2030 Under four different energy efficiency and air pollution control scenarios, population-weighted mean exposure to PM 2.5 is projected to decrease significantly However, the overall health burden is expected to increase by 2030 Effect of populating aging and disease patterns Urgent need for even more aggressive strategies to reduce emissions 13 th Five-Year Plan. 7

8 What about Industrialized Countries? Take the US as an example We have come a long way 8

9 LDVs: Tailpipe Emissions Reductions (HC + NO x ) (g/mile) Light-duty gasoline vehicle emissions California US Federal US on-road fleet 10% per year Median concentration in exhaust (ppm) CO NO HC Model Year Year Increasingly stringent regulations (left) have led to large decreases in CO, NO, HC emissions from on-road fleet (right). Data sources: Left, and are emissions measured for on-road U.S. fleet from Fegraus et al SAE (1973) The data for are the California, and Federal U.S. regulatory requirements. Right: G.A. Bishop, D.H. Stedman, On-Road Remote Sensing of Automobile Emissions in the Chicago Area: Fall 2014, CRC Report E-106 (2015). From: Tim Wallington, Ford Motor Company

10 VOC Trends in Ambient Air: Los Angeles Concentration (ppb) CO Ethane Ethene Acetylene Propane Propene i-butane n-butane i-pentane n-pentane Benzene Toluene VOC concentrations measured in ambient air near Los Angeles in ; redrawn from Warneke et al. (2012). Data source: Warneke, C., J. A. de Gouw, J. S. Holloway, J. Peischl, T. B. Ryerson, E. Atlas, D. Blake, M. Trainer, and D. D. Parrish (2012), Multiyear trends in volatile organic compounds in Los Angeles, California: Five decades of decreasing emissions, J. Geophys. Res., 117, D00V17, doi: /2012jd Year Large reductions (factors of 30-65) in VOC concentrations over past 50 years in Los Angeles area. From: Tim Wallington, Ford Motor Company

11 We ve Come a Long Way: Improvements in PM and NOx Diesel Emission Standards EPA Heavy-Duty Engine Emission Standards Oxides of Nitrogen (g/bhp-hr) Steady State Test NOx + HC NOx (Unregulated) NOx + HC PM (Unregulated) PM Transient Test NOx PM Urban Bus PM Model Year NOx NOx PM NOx + HC NOx Particulate Matter (g/bhp-hr)

12 We ve Come a Long Way: Diesel Engines: Dramatic Progress on Mass and Particle Numbers Source: HEI ACES Study: 12

13 Source: HEI ACES Study

14 But Problems remain! Frey paper highlights many issues Recent headlines 14

15 We have come a long way! Can we demonstrate improvements in human health in response to regulations? 15

16 Accountability Research How do we know that environmental policies work? Accountability Research: Evaluating the extent to which air quality interventions improve public health Part of a broad effort to assess the performance of environmental regulatory policies 16

17 The Chain of Accountability 17

18 The Southern California Children s Health Study Southern California has been subject to intense air pollution interventions over many decades Children s Health Study: John Peters, Jim Gauderman, Frank Gilliland, and their colleagues at University of Southern California; funded by CARB, NIH, HEI POLICIES: ~20 regulations for mobile and stationary sources, and other area sources, during POLLUTION: Emissions modeling and ambient monitoring HEALTH: Lung function growth (FEV 1 and FVC) and respiratory symptoms (bronchitis, cough, phlegm) in several cohorts of adolescents during 1994 to 2011 [ages 11 15, the most active period of lung growth] 18

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20 Lung Function Growth vs. Mean Pollutant Level Similar results for FVC and respiratory symptoms N Engl J Med (2015) 372: ; JAMA. (2016) 315:

21 Summary: Accountability Studies Chain of Accountability provides a useful construct to assess the effectiveness of regulatory actions Regulatory changes often overlap with (many) other changes and trends: Important but challenging to dissect these out Detecting changes in public health indicators associated with clear improvements in air quality. remains difficult when there are simultaneous secular improvements in the same health indicators. (Dockery et al.) On balance, Clean Air Act Regulations have had a tremendous beneficial impact in the US 21

22 An Additional Consideration Emerging evidence at very low levels of exposure Health effects at or below current standards 22

23 Informing Air Quality Standards Decisions at Lower and Lower Levels 2012 paper on effects at lower levels in a Canadian Census Cohort (CanCHEC) Are they real? Questions about exposure estimates Confounders? HEI is funding three excellent teams for this research Goal: rigorous testing of lowlevel associations PM associations below 8 µg/m 3 23

24 HEI studies assessing health effects of low levels of air pollution Geographical areas PI: Michael Brauer, U British Columbia (~ 6 million) PI: Francesca Domenici, Harvard (~ 61 million) PI: Bert Brunekreef, Utrecht (~25 million) 24

25 Key Features Study populations with millions in the US, Canada and Europe; administrative and traditional cohorts Satellite data and ground level exposure measurements; high quality exposure assessment models at high spatial resolutions Development of new statistical methods Studies actively underway; middle of year two Early results from the US and Canadian studies published (but not yet reviewed by HEI) 25

26 Early Results from the Medicare Cohort First results in 61 million Medicare enrollees Analyzed for PM and Ozone effects Traditional Cox Proportional Hazard Models Controlled for possible confounders But did not have data on smoking, some others confounders

27 Results For PM Strong associations Stronger for males than females Stronger relationship for minority groups For Ozone Smaller association Some negative associations for Hispanics, Asians ( protective effect?) N Engl J Med 2017;376: DOI: /NEJMoa

28 Conclusions and Next Steps Evidence for Concentration Response relationships PM: Almost to zero (no threshold?) Ozone: To at least 30 ppb Though wider confidence intervals Additional analyses underway Causal and other statistical models More detailed analysis of Medicare Survey population (smaller population but with confounders such as smoking) Medicaid data Medicare data are public Dominici will make all statistical codes and data available With detailed descriptions on how to access and analyze the Medicare data

29 Looking Ahead We HAVE come a long way! Vehicle air pollution is down substantially even with increased vehicles, travel in industrialized countries Enhancements in internal combustion are improving fuel economy, GHG emissions, safety Powertrain electrification is making (rapid) inroads But, Internal combustion engines are here to stay, at least in the near term BUT Very rapid increases in mobility demand around the world Very rapid increases in automobile numbers There IS still work to do: To fine-tune and enhance the IC technologies And accelerate replacement of the older fleet To build the technology and market for electric drive And, to put it all together for enhanced and equitable mobility 29

30 Thank you Rashid Shaikh 30