Effects and Sources of Air Pollutants CE 524 January 2008 Slides noted as AWMA are from: Understanding Air Quality from the Air and Waste Management Association Do not make copies of these slides for distribution

Major Provisions of 1970 CAAA Established NAAQS Primary – allows adequate margin of safety to protect public health Secondary – protects public from effects of air pollution Plants, animals, visibility, public enjoyment of life & property Set new source performance standards for new stationary sources National Emission Standards for Hazardous Air Pollutants (NESHAPS) applied to existing and new plants Required states to submit state implementation plans (SIPs) Method to set AQ standards for air quality regions within state

Air Quality Criteria Based on levels to protect human health Sensitive members of the population Developed based on relationship between exposure and short and long-term health and welfare effects Effects are expected to occur when pollutant levels exceed criteria for specified time period Short-term -- immediate protection Chronic exposure Pollutant levels cannot legally be exceeded during specific time period in a specific geographical area

National Emission Standards Limit amount or concentration of pollutant emitted from a source Helps maintain or improve existing air quality in a region to meet state or local standards Based on what is achievable with current technology

Basis for Regional Standards Availability of technology Presence of monitoring stations Ability to enforce standards Understanding of synergistic effects of different pollutants Preparation of diffusion model (predicting ambient concentrations) Accurate estimates of growth or decline in industry or population

Criteria Air Pollutants Carbon Monoxide (CO) Hydrocarbons Oxides of Nitrogen (NOx) Sulfur Dioxide (SO 2 ) Particulate Matter (PM 10 ) Lead (Pb) Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

Current NAAQS PollutantAveraging TimePrimary StandardSecondary Standard CO 8 hr9 ppmSame 1 hr35 ppmSame NO 2 Annual average0.05 ppmNone SO 2 Annual average0.03 ppmNone 24 hr0.14 ppmNone 3 hrNone0.5 ppm PM 10 Annual arithmetic mean 50  g/m 3 Same 24 hr 150  g/m 3 Same PM 2.5 Added 1997 Annual arithmetic mean 15  g/m 3 Same 24 hr 150  g/m 3 Same Ozone1 hr0.12 ppmSame 8 hr0.08 ppmSame Lead3 months 1.5  g/m 3 same

Hydrocarbons Result when fuel molecules in the engine do not burn or only partially burn React in the presence of nitrogen oxides and sunlight to form ground-level ozone, a major component of smog Ozone irritates the eyes, damages the lungs, and aggravates respiratory problems most widespread urban air pollution problem. A number of exhaust hydrocarbons are also toxic, with the potential to cause cancer. Source: EPA 400-F August 1994 Fact Sheet OMS-5

Particulate matter Dispersed airborne solid and liquid particles (specific size criteria in chapter) Settles out of air at rate which is function of size and weight (measured in micrometer µ = cm) Dust, water vapor, etc Affect health and visibility

Particulate Matter (PM 10 ) Also regulating PM 2.5 PM10 is a general term for tiny airborne particles (under ten microns), e.g., dust, soot, smoke Primary sources are fuel-burning plants and other industrial/ commercial processes Some are formed in the air They irritate the respiratory system and may also carry metals, sulfates, nitrates, etc. Some overall decreases seen but trends may be masked by meteorological changes Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

Health Effects of PM Particles directly enter respiratory system Particles themselves may be toxic Particle may interfere with mechanisms which clear the respiratory tract Particle may act as carrier of absorbed toxic substance 20 to 60% of particles between 1 and 2.5 µm breathed will penetrate into lungs Enter deep tissue

Sulfur Dioxide (SO 2 ) Sulfur trioxide This term is used for a number of compounds containing sulfur Primarily caused by burning of coal, oil and various industrial processes They can affect the respiratory system They react in the atmosphere to form acids, sulfates and sulfites Substantial reductions due to controls at the sources and through use of low sulfur fuels Make up 5 to 20% of total suspended particles Major damage to materials Contributes to acid rain Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

Oxides of Nitrogen (NOx) Nitrogen dioxide is the prominent one (it's the yellow-brown color in smog) NOx results from high temperature combustion processes, e.g. cars and utilities They affect the respiratory system They play a major role in atmos- pheric reactions Overall levels unchanged but transportation sources are cleaner Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

Carbon Monoxide (CO) Odorless, colorless gas Caused by incomplete combustion of fuel and air Most of it comes from motor vehicles Reduces the transport of oxygen through the bloodstream Poses immediate health risk in high concentrations (> 750 ppm) Hemoglobin has 240 times affinity for CO as for oxygen Affects mental functions and visual acuity, even at low levels Improvements are being made but there are still problems in some urban areas Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

Lead (Pb) Long known as one of the worst toxics in common use Emitted from gasoline additives, battery factories and non-ferrous smelters Affects various organs and can cause sterility and neurological impairment, e.g. retardation and behavioral disorders Infants and children especially susceptible Control of mobile sources has been exceptionally successful Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

Other Air Pollutants Carbon dioxide Chlorofluorocarbons Formaldehyde Benzene Asbestos Manganese Dioxins Cadmium Still others which are yet to be fully characterized Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

Categories of Air Pollution Ambient: air pollution in outdoors Focus of class Regulated by EPA Indoor Air pollution indoors, buildings EPA studies issues but no federal regulations Occupational Pollutants in the workplace (mining, chemical operations, etc) Regulated by OSHA Personal exposure Persons willful exposure Cigarette, gases, etc

Global Warming Certain gases in the troposphere absorb some of the infrared radiation reflected from the earth Carbon Dioxide is the major one (50%). Others include methane (18%) and CFCs (14%). CFCs also are responsible for destroying the stratospheric ozone layer The United States produces over 20% of the world's "greenhouse" gases Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

The Extent of Air Pollution Today Overall, 54 million metric tons from mobile sources in 1990 (43% of total) Mobile Sources Stationary Sources CO VOCs NOx SO 2 Lead PM 10 Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

Who is Affected by Air Pollution? Ozone CO NO 2 PM 10 SO 2 Lead Millions of people living in counties with air quality that exceeds each NAAQS (1990 data) Over 74 million people are subjected to high levels of at least one of these pollutants Fundamentals of Air Pollution and Motor Vehicle Emissions John T. White, EPA

World wide WHO indicates that 2.4 million people die from causes directly attributable to air pollution More than for car accidents

Visibility Although not a pollutant, visibility is a major pollution concern Haze Smog

Air Toxics Get stuff from EPA

When is it a problem Classified as pollutant once their presence results in damage to humans, plants, animals or materials Concentration 1 volume of gaseous pollutant = 1 ppm 10 6 volumes (pollutant + air) percent by volume = 1 ppm

Non-attainment areas