Air Pollution Sources

Transcription

1 Air Pollution Sources Three Necessities of Life Need Daily Amount Max. Deprivation Food 3 pounds 5 weeks Water 5 pounds 5 days John D. Spengler, Ph.D. Akira Yamaguchi Professor of Health & Human Habitation Harvard School of Public Health Air 50 pounds 5 minutes Copyright 2007 J.D. Spengler, Ph.D. This presentation may not be reproduced, in whole or in part, without the express written permission of the author. Copyright 2006 J.D. Spengler, Ph.D. This presentation may not be reproduced, in whole or in part, without the express written permission of the author. Air Pollution Definition Air pollution is the presence in the air of substances put there by the acts of man in concentrations sufficient to interfere with: Health Comfort Safety Full use and enjoyment of property Air Quality as a Public Good Cost nothing to use Use is not restricted Quality is not diminished by number of users If through actions of other users the value/quality of the public good is diminished, then it is the obligation of a government to protect its value Harvard University / ENVR E 101 1

2 Risk Management Paradigm Risk Management Paradigm Sources Regulations Transmission Ambient pollution levels Exposure Dose Health Effects S t a n d a r d s Sources Regulations Transmission Ambient pollution levels Exposure Dose Health Effects S t a n d a r d s Environmental Management Environmental Management Risk Management Paradigm Sources Regulations Transmission Ambient pollution levels Exposure Dose Health Effects S t a n d a r d s Pollutants and Sources Environmental Management Harvard University / ENVR E 101 2

3 Air Pollutants Over three thousand (3000) substances have been measured in air Regulate emissions of very few (< 200) Ambient Air Quality Standards for only six (6) substances Air Pollutants Primary pollutants Oxides and particulates CO (monoxide; binds hemoglobin), CO 2 (dioxide; global warming) N 2 O, NO, NO 2 SO 2 PM (particulate matter) Lead Mercury VOCs (volatile organic compounds) Secondary pollutants O 3 (ozone) Nitric acid; sulfuric acid Ozone Ozone is a secondary pollutant Formed from O 2 + VOC + NO X + sunlight Harvard University / ENVR E 101 3

4 Primary vs secondary pollutants Ways to Perceive Air Pollution Definition Primary pollutants are emitted directly to the atmosphere by the sources (SO 2 ) Secondary pollutants are formed in the atmosphere through chemical processes (O 3 ) Atmosphere is an oxidizing medium Pollutants serve as fuel Fate of pollutants Visibility Odor Effects on climate Effects on organisms, vegetation and materials Effects on humans Respiratory, irritation, death Air Pollution Historical Perspective Volcanoes, fires, wood burning Wood and charcoal burning (London Paris) Industrial sources (steal production) Power plants (low vs high stack) Urban air pollution (photochemical air pollution) Air toxics (incinerators to dry cleaners) The Scale of Air Pollution Problems Indoor air pollution sources (local) Industrial sources (local) Urban air pollution (local) Acid rain (regional) Ozone depletion (global) Greenhouse effect (global) Harvard University / ENVR E 101 4

5 Air Pollution Impacts..we are perturbing our atmosphere (environment) at a faster rate than we can understand or predict the consequences we are undergoing a geophysical experiment (Revelle and Suess, 1957 Natural vs Anthropogenic Sources Sea Particles (Natural Source) Crustal Particles Harvard University / ENVR E 101 5

6 Wildfires Indoor Pollution Urban Pollution Mobile vs Stationary Sources Different Regulations Harvard University / ENVR E 101 6

7 Stationary Sources Mobile Sources Harvard University / ENVR E 101 7

8 Sulfur Dioxide (SO 2 ) Anthropogenic Sources: Sulfur in Fuels ~ 80% Industrial Processes ~ 20% Natural Sources Volcanoes Biological Removal 1 to 4 days oxidation to SO 4 SO 2 Pollution from Burning Coal Nitrogen Oxides (NO, NO 2 ) Anthropogenic Sources: High Temperature Combustion Automobile, Trucks, etc. ~ 50% Fuel Combustion ~ 45% Natural Sources Biogenics in Soil Lightning, Forest Fires Removal 2 to 5 days oxidation to NO 3, NO 4 Carbon Monoxide (CO) Anthropogenic Sources: Automobiles ~ 75 % Agricultural ~ 10 % Natural Sources Forest Fires Removal 1 to 3 months photochemical reactions with CH 4 and OH Harvard University / ENVR E 101 8

9 Ozone Hydrocarbons Transport and Pollution Anthropogenic Sources: Secondary pollutant t produced dby hydrocarbons, Nitrogen oxides, & sunlight Transportation 55% Industry 15% Organic Solvents 10% Nt Natural lsources Plants & Trees Removal: ~ Hours for reactions in atmosphere Internal Combustion Engine Emission Controls for Cars Harvard University / ENVR E 101 9

10 Four Stroke Gasoline Engine Air/Fuel Ratio Source: How Stuff Works ( Sources of Automobile Pollutants Hydrocarbon Emissions Fuel Evaporation 20% Percentage estimates prior to application of emissions controls Engine Exhaust 60% Crankcase Vapors 20% Harvard University / ENVR E

11 Vapor Recovery Vapor Recovery Diesel Diesel exhaust Elemental Carbon (EC) Ultra low sulfur diesel, 2006 New emissions standards, 2007 Idling laws Unburned Fuel (PAHs) Sources of PM 2.5 Modified from Health Effects Institute, 1995 Harvard University / ENVR E

12 Diesel exhaust diesel particulate matter (DPM) A complex mixture of hundreds of compounds in gaseous or particle form Gaseous components include CO2, O2, N2, water vapor, CO, NOx, SOx, low molecular weight hydrocarbons, aldehydes (e.g., formaldehyde, acetaldehyde, acrolein), benzene, 1,3 butadiene, polycyclic aromatic hydrocarbons (PAHs) and nitro PAHs. Particles composed center elemental carbon core and adsorbed organic compounds, small amounts of sulfate, nitrate, metals, other trace elements. No unique component Composition varies depending on source, fuel, and engine characteristics Formation of Smog Diurnal Smog Pattern Assessing the Health Benefits from Nationwide Reductions of Ozone Air Pollution Los Angeles, CA. Courtesy of the EPA Berman JD 1, Curriero FC 1, Breysse PN 1, Fann N 2, Hollingsworth JW 3, Pinkerton KE 3, Rom WN 3, Szema AM 3, White RH 4 1 Division of Environmental Health Engineering, JHU Bloomberg School of Public Health; 2 US EPA, Office of Air Quality Planning and Standards; 3 ATS Environmental Health Policy Committee; 4 Dept. of Health Policy and Management, JHU Bloomberg School of Public Health Harvard University / ENVR E

13 BenMAP Analytic Approach Air Quality Changes from 2007 Ozone Rollbacks Create an Air Quality Grid for Ozone Pollution 3 years of AQS county level data ( ) Matched US population data Daily 8hr Max. Attainment (40ppb background) Interday quadratic rollbacks to 75, 70and 60ppb Select Health Risk Estimates and Pool Morbidities Mortality (Total, Non Accidental, and Cardiopulmonary) ER Visits Hospital Admissions (Respiratory) School Loss Days Acute Respiratory Symptoms (eg. restricted activity) Largest exceedance Northeast corridor Southern California (vehicular exhaust) Additional areas Midwest, Appalachia, & Texas, (utilities/ refining) Colorado & Utah Report Changes in Health Estimates by Nationwide results Largest 15 Metropolitan Statistical Areas Mortality Results for Selected Metropolitan Areas Prevented All Cause Mortalities (Bell et al. 05 using 2007 data) Health impacts vary by city vary by region significant annual changes NYC and LA comprise 40% of all prevented mortalities (Top 15 cities) Overall prevented mortality is very low (<1 death/year), but widespread Southern California shows highest impact Other localized areas include Northeast corridor Urban centers Harvard University / ENVR E

14 Particulate Matter (PM) Q. Where do fine particles come from? A. Lots of places Anthropogenic Sources: Industrial Processes ~ 50% Fuel Combustion ~ 25% Natural Sources Erosion, Fires, Condensation Removal Settling, Clouds, & Rain Particle Sizes Primary vs Secondary PM Primary particles are directly emitted by sources (soot, soil, sea salt, pollen ) Secondary particles are formed in the atmosphere (sulfates, nitrates, secondary organics ) Harvard University / ENVR E

15 Particulate Fate PM monitoring Wet deposition: Clouds & Rain Dry deposition: Gravitational settling, impaction (hours months) Coagulation into larger particles (seconds) Fossil Fuel Power Plants US Coal Reserves Harvard University / ENVR E

16 Tall Stacks Power Plant Particle Formation Pollution in the US SOx/NOx dominate Eastern Regional Background Particles IMPROVE/CASTNet Data ( ) Harvard University / ENVR E

17 Acid Deposition The Value of Urban Visibility Which day would you rather visit Chicago? PM 2.5 < 10 ug/m3 PM ug/m3 Visibility in Washington, D.C. Visibility Impairment (SO 2 ) Copyright 2004 J.D. Spengler, Ph.D. This presentation may not be reproduced, in whole or in part, without the express written permission of the author. Harvard University / ENVR E

18 Sulfate Sources in National Parks Air Quality Outlook Copyright 2004 J.D. Spengler, Ph.D. This presentation may not be reproduced, in whole or in part, without the express written permission of the author. Pollution in California Central Valley SF pollution blowing off shore Harvard University / ENVR E

19 MISR Path and Orbit MISR Animation Terra Ground Track Results Growth in emissions and economy 75 Harvard University / ENVR E

20 Air Pollution in China Air Pollution in central China Only Blue Sky in China Units Milligram/m 3 = 10 3 g/m 3 Microgram/m 3 = 10 6 g/m 3 Nanogram/m 3 = 10 9 g/m 3 Picogram/m 3 = g/m 3 Harvard University / ENVR E

21 ppm, ppb, ppt Units for gases and particles Definition (molecules, moles, volume) ppm = 10 6 ppb = 10 9 ppt = microgram/m 3 = ppm x 40.9 (MW) = ppb x (MW) Both micrograms/m 3 (milligrams/m 3 nanograms/m 3 ) and ppm (ppb, ppt) can be used for the gases Advantages of ppm, ppb, ppt units Only micrograms/m 3 (milligrams/m 3 nanograms/m 3 ) can be used for particles Harvard University / ENVR E