Air pollution and control
Smoking is the most important air pollution in the U.S.
400,000 die annually from diseases related to smoking. This is 20% of all mortality. Associated costs are estimated at $100 billion annually.
1990 amendments to clean air act
Acid rain Urban air pollution Toxic emissions Ozone depletion
stratospheric ozone
Circumpolar vortex isolates Antarctic air and allows stratospheric temperatures to drop and create ice crystals at high altitudes. --absorb ozone and chlorine molecules
indoor air pollution
EPA found indoor concentrations of toxic air pollutants are often higher than outdoor
One of the principal ways lakes suffer from acid deposition is that:
Fish eggs die & fish populations fall
acid rain controls
Fuel switching Coal washing Coal mixing with alkaline treated municipal sludge Scrubbers Fluidized bed combustion Reduced consumption of electricity
cause of acid rain
H2SO4 and HNO3 from industrial and automobile emissions
Clean Air Act 1970
Identified critical pollutants. Established ambient air quality standards.
acid rain
It is caused by sulfur dioxide & nitrogen oxides being released into the environment Coal-burning power plants & Motor vehicles
effects of acid rain
Leach nutrients in the ground Kill nitrogen-fixing microorganisms that nourish plants Kill fish Release toxic metals
ozone
O3 layer in the stratosphere shields the biosphere by absorbing incoming uv radiation. (in the troposphere it is a pollutant)
Volatile Organic Compounds (VOCs)
Organic chemicals Generally oxidized to CO and CO2 Plants are largest source. 400 million tones of methane produced by natural wetlands and rice paddies
bronchitis
Persistent inflammation of airways in the lung that causes mucus build-up and muscle spasms constricting airways
Hazardous Air Pollutants (HAP)
Require special reporting and management as they remain in ecosystems for a long period of time, and tend to accumulate in animal tissues. Include carcinogens, neurotoxins, endocrine disrupters
stratospheric ozone depletion
Stratospheric ozone levels are rapidly droping over south pole. At ground-level, ozone is a pollutant, but in the stratosphere it screens UV radiation
criteria pollutants
Sulfur Dioxide Nitrogen Oxides Carbon Monoxide Ozone Lead Particulates
criteria pollutants
The 1970 amendments to the Clean Air Act required EPA to set National Ambient Air Quality Standards for certain pollutants known to be hazardous to human health. EPA has identified six criteria pollutants: sulfur dioxide, carbon monoxide, lead, nitrogen oxides, ozone, and particulate matter.
particulate matter
aerosols-( solid particles or liquid droplets suspended in the atm) when smaller that 2.5 micrometers they can enter the lungs and cause damage
cap and trade programs
begun in 1990,set maximum amounts for pollutants, but let facilities facing costly cleanups pay others with lower costs to reduce emissions on their behalf
Fluidized bed combustion
burn coal with sand & lime with air - very costly-would require tearing down existing plants - good solution for new plants.
secondary pollutants
converted to a hazardous form after entering the air and mixing with other air components
fugitive emissions
do not go through smokestack (Dust from strip mining, rock crushing, building construction/destruction)
Electrostatic Precipitators
fly ash particles pick up electrostatic charge as they pass between large electrodes in waste stream, and accumulate on collecting plate
emphysema
irreversible chronic obstructive lung disease in which airways become permanently constricted and alveoli are damaged or destroyed.
sulfur dioxide
is a corrosive gas which reacts with water vapor in the air to cause acid rain
temperature inversions
occur when a stable layer of warm air lies above cooler air, reversing the normal temperature decline with increasing height, and prevents convection currents from dispersing pollutants.
acid precipiation
pH 5.5 or less
Montreal Protocol (1987)
phased out use of CFCs. HCFCs were substituted, which release less chlorine.
Aesthetic Degradation
reduce quality of life by increasing stress
Chlorofluorocarbons (CFCs)
release chlorine and fluorine in the stratosphere, which deplete ozone layer. CFCs banned in developed countries but still used elsewhere in propellants and refrigerators
primary pollutants
released directly from the source
coal washing
removing sulfur - costly economically & environmentally
Toxic Release Inventory
requires manufacturers to report on toxin release and waste management. Most HAP are decreasing but mercury and dioxins (from plastics) are increasing.
synergistic effects
the injury caused by the combination is more than the sum of the individual exposures.
grasshopper transport
volatile compounds evaporate from warm areas; travel to poles where they condense and precipitate. Contaminants bioaccumulate in food webs. Whales, polar bears, sharks have dangerously high levels of contaminants (such as HAP).
Clean air act 1963
was the first national legislation in the United States aimed at air pollution control. revised in 1970
