Outdoor Air Pollution Flashcards
What happened in Donora, PA, 1948?
- Donora, Washington County, on the Monongahela River
- Industrial town with population of 14,000
- Temperature inversion
- Between Oct. 26 and 31, 20 people asphyxiated and over 7,000 hospitalized or became ill
Name two secondary pollutions?
- Acid Rain
- Ozone (O3)
What happened during the “London Killer Smog of 1952”?
Cold dec, a lot of people burned homes (sulfur dioxide was trapped causing deaths)
Explain the History of Air Pollution Legislation
- Air Quality Act of 1955
- first federal legislation on air pollution
- provided funds for federal research - Clean Air Act of 1963
- authorized research into techniques for monitoring and controlling air pollution - Air Quality Act of 1967
- air pollutant emission inventories, ambient monitoring techniques, and control techniques
Explain the Clean Air Act of 1970.
- Major shift in focus
- Comprehensive federal and state regulations
- Enforcement
- EPA created in 1970
Explain the Provisions of the Clean Air Act and Amendments.
- Established National Ambient Air Quality Standards (NAAQs)
- Established requirements for Sate Implementation Plans to achieve NAAQs
- Authorized National Emission Standards for Hazardous Air Pollutants
- Increased enforcement authority
- Authorized requirements for control or motor vehicle emissions
What are the Intentions of the Clean Air Act and Amendments?
- everybody should have equal protection (establish uniform national standards)
- Protection of most susceptible subgroups
(elderly, infants, pregnant women, and sufferers form chronic heart and lung diseases
What are the Criteria Pollutants for the Clean Air Act?
- Emitted from many large diverse sources, including mobile and stationary sources
- Greatest overall threat to human health
- Presupposition: adverse health effects not cancerous and their dose-response relationship exhibits a threshold
- 6 criteria pollutants (PM, SOx, NOx, O3, CO, Pb)
What is NAAQs?
National Ambient Air Quality Standards for criteria pollutants
- Primary standards set limits to protect public health.
- Secondary standards set to protect against public welfare effects, such as damage to farm crops and vegetation
What is Particulate Matter (PM)?
- Heterogeneous mix of solid and liquid droplets
- Smaller particles stay suspended and travel great distances
- Smaller particles can travel deep in the airways
- Ultrafines/ nanoparticles: aerodynamic diameter less than or equal to microns
Explain PM10
aerodynamic diameter <10 microns
Explain PM25
aerodynamic diameter <2.5 microns
What are Sources of Particulate Matter?
cars, trucks, buses, factories, construction sites, tilled fields, unpaved roads, stone crushing, and burning of wood
Name 3 Particles of Particulate Matter.
- Coarse Particles
- Fine Particles
- Ultrafine Particles
What are Coarse Particles?
- 10< diameter< 2.5um
- Mechanical sources (crushing, grinding,; dust from paved or unpaved roads)
What are Fine Particles?
- diameters <2.5 um
- Remain suspended and travel great distances
- Can penetrate all sites of the respiratory tract
- Examples: photochemical smog, diesel exhaust, tobacco smoke
What are Ultrafine particles?
- diameters <0.1 um
- can penetrate deep within lungs, cells, translocate
- inflammation effects
What happens when Om gets further into the lungs?
More hazardous (fine particles) spread throughout the lungs
What is Ozone (O3)?
- Secondary pollutant
- Chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in the presence of heat and sunlight.
- Distinctive, sweet odor
Explain Ozone Formation.
Hydrocarbons (VOCs) + NO2 –> O3
- needs sunlight for formation
What is Nitrogen Oxide (NOx)?
- Nitrogen dioxide (NO2): reddish brown gas
- Nitrogen oxides form when fuel is burned at high temperatures, as in a combustion process.
What are primary sources of NOx?
motor vehicles, electric utilities, and other industrial, commercial, and residential sources that burn fuels
What is Carbon Monoxide (CO)?
- colorless, odorless gas formed from incomplete fuel combustion
- auto emissions, industrial emissions, forest fires
What is Sulfur Dioxide (SO2)?
- colorless gas formed from burning sulfur- containing fuels
- dissolves in water vapor to form acids
- over 65% of SO2 from coal-burning utilities
What is Acid Rain?
- emissions of SOx and NOx in the atmosphere react with water, oxygen, and oxidants to form acidic compounds
- compounds fall to the earth in either dry form ( gas and particles) or wet form (rain, snow, and fog)
- acidification of water, making it unsuitable for some fish and other wildlife
- tree damage
- decay of buildings, statues
What are health effects of HAPs?
pulmonary, cardiac, vascular, neurological, cancer, reproductive toxicity
What are sources of HAPs (1996)?
- mobile sources (50%)- cars, buses, trucks, etc
- major sources (26%)- chemical plants, steel mills, oil refineriess and hazardous waste incinerators
- area and other sources (24%)- dry cleaners and gas stations
Explain Regulation of HAPs.
Assume no threshold so no NAAQs
Emission standards set
- National Emissions Standards for Hazardous Air Pollutants (NESHAPs)
- Provide ample margin of safety
- Also called Maximum Achievable Control Technology (MACT)
- Take into account cost/ feasibility
What are the 6 chemicals NAAQs protects against?
- O3
- SOx
- NOx
- CO
- PM
- Pb
What are HAPS that are highly toxic and have no safe levels?
- pesticide
- dry cleaning solvents
- dioxin
- incinerators and other factories
- emission standards
