What are the two general major categories/sources of air pollution? Hint: Read page 526

And The Answers Are……… Natural Sources Anthropogenic Volcanic Ash Sandstorm Dust Pollen Anthropogenic Particulates Oxides of Nitrogen and Sulfur Greenhouse Gases VOC

Air Pollution Outdoor Air Pollution

Stationary and Mobile Sources of Air Pollution Two Sources of Air Pollution 1. Stationary Sources: have a relatively fixed location Point Sources: Fugitive Sources: Area Sources: 2. Mobile Sources: move from place to place while emitting pollutants Ex) Airplanes

General Effects of Air Pollution Visual quality of the environment Vegetation, Animals, Soil Water Quality Natural and Artificial Structures Human Heath

Human Health & Air Pollution

Primary and Secondary Pollutants, Natural and Human Primary Pollutants Those emitted directly into the air Hydrocarbons, particulates, etc. Secondary Pollutants Produced through reactions between primary pollutants and normal atmospheric compounds Ozone

Major Air Pollutants Sulfur Dioxide (acid rain) Nitrogen Dioxide / Nitrogen Oxide Carbon Monoxide Ozone and Other Photochemical Oxidants Volatile Organic Compounds Particulate Matter Hydrogen Sulfide Hydrogen Fluoride Hazardous Gases Lead

Outdoor Air Pollutants – Sulfur Dioxide (SO2) Properties: colorless gas with irritating odor Effects: produces acid rain (H2SO4), breathing difficulties, eutrophication due to sulfate formation, lichen and moss are indicators Sources: burning high sulfur coal or oil, smelting or metals, paper manufacture Class: sulfur oxides EPA Standard: 0.3 ppm (annual mean) Combines with water and NH4 to increase soil fertility

Outdoor Air Pollutants – Nitrogen Dioxide (NO2) Properties: reddish brown gas, formed as fuel burnt in car, strong oxidizing agent, forms Nitric acid in air Effects: acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth Sources: fossil fuels combustion, power plants, forest fires, volcanoes, bacteria in soil Class: Nitrogen oxides (NOx) EPA Standard: 0.053 ppm

Outdoor Air Pollutants – Carbon Monoxide (CO) Properties: colorless, odorless, heavier than air, 0.0036% of atmosphere Effects: binds tighter to Hb than O2 Sources: incomplete combustion of fossil fuels. 60 - 95% from auto exhaust Class: carbon oxides (CO2, CO) EPA Standard: 9 ppm 5.5 billion tons enter atmosphere/year

Outdoor Air Pollutants – Ozone (O3) Properties: colorless, unpleasant odor, major part of photochemical smog Effects: lung irritant, damages plants, rubber, fabric, eyes, 0.1 ppm can lower PSN by 50% Sources: Created by sunlight acting on NOx and VOC , cars, industry, gas vapors, chemical solvents, fuel combustion products Class: photochemical oxidants

Outdoor Air Pollutants – Suspended Particulate Matter (PM10) Properties: particles suspended in air (<10 um) Effects: lung damage, mutagenic, carcinogenic, teratogenic Sources: burning coal or diesel, volcanoes, factories, unpaved roads, plowing, lint, pollen, spores, burning fields Class: SPM: dust, soot, asbestos, lead, PCBs, dioxins, pesticides EPA Standard: 50 ug/m3 (annual mean)

Size of Selected Particulates

Total Suspended Particulates (TSP) for several large countries

Outdoor Air Pollutants – VOCs (Volatile Organic Compounds) Properties: organic compounds that evaporate easily, usually aromatic Effects: eye and respiratory irritants; carcinogenic; decreased visibility due to brown haze; liver, CNS, or kidney damage; damages plants Sources: evaporation of solvents or fuels, fossil fuels, plants (largest source), aerosols, paint thinners, dry cleaning Class: HAPs (Hazardous Air Pollutants) Concentrations indoors up to 1000x outdoors 600 million tons of CFCs

Outdoor Air Pollutants – Lead (Pb) Properties: grayish metal Effects: accumulates in tissue; affects kidneys, liver and nervous system (children most susceptible); mental retardation; possible carcinogen; 20% of inner city kids have [high] Sources: particulates, smelters, batteries Class: toxic or heavy metals EPA Standard: 1.5 ug/m3 2 million tons enter atmosphere/year

US Emissions of Six Major Air Pollutants Note that there have been significant reductions.

Urban Air Pollution Potential for Air Pollution Determined by: Rate of emission Downwind distance Average wind speed Elevation Atmospheric Inversion: Occurs when warmer air is found above cooler air and it poses a particular problem when there is a stagnant air mass

Factors that influence Air Pollution formation and intensity Local climate (inversions, air pressure, temperature, humidity) Topography (hills and mountains) Population density Amount of industry Fuels used by population and industry for heating, manufacturing, transportation, power Weather: rain, snow,wind Buildings (slow wind speed) Mass transit used Economics

Questions 1. How would you define smog. 2 Questions 1. How would you define smog? 2. What are the two types of smog and how do they form? Hint: Read pages 540-541

Smog Smog A mixture between smoke and fog that produces unhealthy urban air Two Types Sulfurous Smog / Industrial Smog / Fossil Fuels Photochemical Smog / Sunlight & Pollutants

Formation of Industrial Smog

Formation of Industrial Smog Procedure Chemical Reaction 1. Carbon in coal or oil burned C + O2 -> CO2 2C + O2 -> CO 2. Unburned carbon -> soot C 3. Sulfur in oil and coal reacts with O2 S + O2 -> SO2

Formation of Industrial Smog Procedure Chemical Reaction 4. Sulfur dioxide reacts with O2 to form sulfur trioxide 2SO2 + O2 -> 2SO3 5. Sulfur trioxide reacts with H2O SO3 + H2O -> H2SO4 6. Sulfuric acid reacts with atmospheric ammonia to form brown, solid ammonium sulfate H2SO4 + 2NH3 -> (NH4)2SO4

Formation of Photochemical Smog

Formation of Photochemical Smog Time Description 6 - 9 A.M. Morning commute increases NOx and VOCs N2 + O2 -> 2 NO NO + VOC -> NO2 NO2 -UV-> NO + O 9 - 11 A.M As traffic decreases NOx and VOCs react 2NO + O2 -> 2NO2

As sunlight becomes intense, NO2 breaks down and Ozone increases Time Description 11 A.M. – 4 P.M. As sunlight becomes intense, NO2 breaks down and Ozone increases NO2 -UV-> NO + O O2 + O -> O3 Nitrogen dioxide also forms nitric acid 3NO2 + H2O -> 2 H2NO3 + NO Nitrogen dioxide also reacts with VOCs released by autos, industry, etc. NO2 + VOCs -> 2 PANs Peroyacyl nitrates (toxic) 4 P.M. - sunset As sun goes down the production of ozone halts Net Result: NO + VOC + O2 + UV -> O3 + PAN

Pollution Control Particulates Automobiles Sulfur Dioxide Coal Gasification: converts coal to gas to remove sulfur Scrubbing: gas desulfurization

Air Pollution: Legislation and Standards Clean Air Act Amendments of 1990 Comprehensive regulations enacted by U.S congress that address acid rain, toxic emissions, ozone depletion and automobile exhaust Air Quality Standards Attempt to control air pollution Tougher Standards for PM 2.5 and Ozone Air Quality Index

Specific Air Pollution Treatment Technology Traditional Move factory to remote location Build taller smokestack so wind blows pollution elsewhere New Biofiltration : vapors pumped through soil where microbes degrade High-energy destruction: high-voltage electricity Membrane separation: diffusion of organic vapors through membrane Oxidation: High temperature combustor

Specific Air Pollution Treatment Technology Continued… New continued… Vapor phase carbon absorption: gases pumped through series of carbon filled canisters which absorb contaminants Electrostatic precipitators: Electrostatically charged surfaces attracts particles Sulfur removal: mix crushed limestone with fuel Nitrogen oxide control: staged burners or catalytic converters Hydrocarbon control: closed system to prevent release before treatment with afterburners Hybrid, electric and hydrogen powered vehicles

Air Pollution Indoor Air Pollution

Pathways, Processes and Driving Forces Chimney Effect (Stack Effect) Process whereby warmer air rises in buildings to upper levels and is replaced in the lower portion of the building by outdoor air drawn through a variety of openings, such as windows doors or cracks in the foundation or walls

Sick Building Syndrome A condition associated with an indoor environment that appears to be unhealthy The symptoms people report cannot be traced to any one particular cause

Environmental Tobacco Smoke Secondhand smoke 2 sources Smoke exhaled by smokers Smoke emitted from burning tobacco The most hazardous indoor pollutant

Questions Read a closer look 25. 1 (p 562-3) 1 Questions Read a closer look 25.1 (p 562-3) 1. Please explain why radon is a problem? 2. Is radon a large hazard? If so why? If not, why? Hint: Read pages 540-541

Radon Gas Radon Health hazard when leaked into homes Naturally occurring radioactive gas Colorless, odorless, tasteless Only identified through proper testing Health hazard when leaked into homes Exposure is associated with lung cancer

How Radon Enters Houses Please read page 574 and explain how radon enters houses.

Major Indoor Pollutants 1, 1, 1-Trichloroethane Aerosol sprays Dizziness, breathing irregularities Asbestos Pipe insulation, ceilings, floor tiles, oven mitts Lung Cancer and asbestosis Benzo-a- pyrene Tobacco smoke, woodstoves Lung Cancer Carbon Monoxide Faulty furnaces, cigarette smoke Headache, heartbeat irregularities, death, CO has 250x affinity for Hb than O2

Major Indoor Pollutants Continued… Chloroform Pulp and paper mills, water and wastewater plants Cancer Formaldehyde Paneling, particle board, furniture, carpeting, adhesives Nausea, dizziness, irritation of throat, eyes, and lungs Methylene chloride Paint strippers and thinner – persistent Nerve disorders, diabetes Nitrogen oxides Furnaces, stoves, fireplaces and vents Headaches, irritated lungs Para-dichlorobenzene Air fresheners, mothballs

Major Indoor Pollutants Continued… Radon – 22 Soil and rock near house foundation, concrete Lung cancer Styrene Carpets, plastics, Kidney and liver damage Tetrachlor- ethylene Dry-cleaning fluid Nerve disorders, damage to liver and kidneys, cancer Tobacco Smoke Cigarettes and other smoking sources Lung cancer and heart disease Organic Material Dust mites, fungal and algal spores, dust (human skin), animal dander, hair, carpet fibers, fur Allergies, coughs, sneezing, eye irritation, sore throats, difficulty breathing http://www.metricmind.com/ac_honda/main.htm