Chapter 19: Atmospheric Pollution Flashcards
Donora, PA
In the first 5 days, 20 people died
In 1 month, 50 more people died, 6,000 got sick, and 800 animals died
When does inversion occur?
When temperature gradient is flipped
Inversion
Warm air sits on top of cool air
- there is no flow
Air pollutants
substances in the atmoshpere (gases and aerosols) that have harmful effects
What did the Industrial Revolution change?
the mixture of atmospheric gases and particles
Industrial smog
An irritating, grayish mix of soot, sulfur compounds, and water vapor
Where does industrial smog occur?
In industrialized, cool areas that use coal
- China, India, Korea, eastern European countries
Photochemical smog
A brownish, irritating haze in warm, sunny areas
What causes photochemical smog?
When pollutants from vehicle exhaust are acted upon by sunlight
Examples of photochemical smog
Nitrogen oxides, volatile organic compounds
Where does photochemical smog occur?
In cities with huge freeway systems
What do long-term temperature inversions allw pollutants to do?
build up to dangerous levels
- can cause air pollution
Air pollution disasters
Air pollution reaches lethal levels
- under severe temperature inversions
Atmospheric brown cloud (ABC)
1 - 3 km blanket of pollution over south/central Asia
What are ABC’s similar too?
North Temperate Zone’s aerosol pollution
What are ABC’s made of?
black carbon and soot
How long to ABC’s last?
year round
Where do ABC’s come from?
burning biomass and fossil fuels (coal, diesel)
Impacts of atmospheric brown clouds
dimming over large cities
less rainfall
heating of air
decreased reflection of snow and ice
Primary pollutants
direct products of combustion and evaporation
Examples of primary pollutants
VOCs, CO, Nitrogen Oxides, Sulfur Dioxide, lead, air toxics
Secondary pollutants
reactions of primary pollutants in the air
Examples of secondary pollutants
ozone, peroxyacetyl, nitrates, sulfuric and nitric acids
Evaporation
creates gaseous and particulate products
Strong winds
pick up dust and other particles
What does the complete combustion of fossil fuels produce? (combustion is not always complete)
CO2 and water vaper
Incomplete combustion of fossil fuels and refuse
Create gaseous and particulate products
VOC’s (volital organic compounds)
can be carcinogenic
CO
invisible, odorless gas, poisonous, blocks oxygen delivery to tissues
Nitrogen oxides
lung irritants, major source of acid rain
Sulfur dioxide
breathing problems, major source of acid rain
Lead
toxic, causes brain damage in children (from combustion of leaded fuels and manufacture of batteries)
Radon
radioactive gas that can accumulate in homes (2nd leading cause of lung cancer)
Ozone
O3, toxic and damaging to lungs
Peroxyacetyl Nitrates
PAN’s, damaging to plants, forests, and mucous membranes of eyes and lungs
What was added to gasoline to reduce engine knock
Lead
U.S. air concentrations have dropped by…
99% because we went to unleaded gasoline
How is radon produced?
By spontaneous decay of fissionable material in rocks and soils
What are sulfuric acids and nitric acids caused by?
Burning fuels
Acid precipitation
any precipitation (rain, fog, mist, snow) more acidic than usual
Acid deposition
acid precipitation plus dry-particle fallout
Natural sources of sulfur dioxide
volcanoes, sea spray, microbial processes
Natural sources of nitrogen oxides
lightning, biomass burning, microbial processes
U.S. source of sulfur dioxide
fuel (coal) combustion
Source of nitrogen oxides
transportation
Acute exposure to air pollutants
can be life threatening
Chronic exposure
long-term exposure that causes gradual deterioration and premature mortality and affects the respiratory and circulatory systems
Chronic obstructive pulmonary disease (COPD)
lung disease that m akes it hard to breath
- 4th leading cause of death (affects 18 million in the U.S.)
What is COPD from?
smoking and burning woord or dung for fuel for indoor stoves
Studies of thousands of adults show stron evidence of harm caused by…
fine particulates and sulfur pollution
- (asthma, chronic bronchitis, cardiovascular problems)
What does lead poisoning cause?
Mental retardation, learning disabilities in children, and high blood pressure in adults
The major source of lead
leaded gasoline
What dramatically reduced lead in the environment?
The EPA mandated elimination of leaded gasoline
Diesel
a likely human carcinogen
Benzene
clearly correlated with cancer
Where is benzene found?
in motor fuels, solvents, explosives, smoke, medicines
What is benzene linked to?
leukemia, blood disorders, damaged immunity
Ozone damages
crops, orchards, and forests.
Trees weakened by ozone were susceptible to pine beetles
Where does ozone enter plants?
Through the stomata
Symptoms of ozone damages
black flecks, yellow leaves
Damage to trees and wild plants…
May exceed crop damage
Sulfur dioxide and sulfur or nitrogen oxides corrode…
metal
Effects of acid deposition
significant fish declines in lakes in Sweden, Ontario, and Adirondacks
Imact of acid deposition on aquatic ecosystems
an environment’s pH affects enzymes, hormones, and other proteins
A low pH overwhelms regulatory mechanisms,
killing or weakening the organism
A pH below 5…
kills organisms or impairs their reproduction
What can acid precipitation leach?
heavy metals from solids as the water percolates through it, which are absorbed by organisms and are highly toxic
Buffer
a substance that absorbs hydrongen ions
Limestone (CACO3)
obtained from soil
A natural buffer protecting many lakes
limestone
The Clean Air Act
reduced SO2 and NOx emissions
Imacts of acid deposition on forests
trees lose needles and become more susceptible to frost
tree growth is reduced
Ambient standards
levels protecting human health and the environment
Criteria pollutants
the most widespread and objectionable
Examples of criteria pollutants
Particulates, SO2, CO, NOx, ozone, lead
National Ambient Air Quality Standards (NAAQS)
set primary standards for criteria pollutants
The Clean Air Act Amendments of 1990 (CAAA)
targeted specific pollutants more directly
What particulates are the most dangerous to the lungs
particulates smaller than 2.5 micrometers (microns)
Where are particulates still emitted from?
steel mills, power plants, cement plants, smelters, construction sites, diesel engins, wood-burning stoves, fires
Where is disposal of refuse now through?
landfilling
What releases almost half of all air pollution
cars, trucks, and buses
reductions in pollutant emissions are due to
- smaller cars
- catalytic converters
- the EPA requiring cleaner burning fuels
Where is gasoline routed through?
converters where chemical reactions occur, where harmful pollutants are chaged to less harmful pollutants
Harmful
hydrocarbons, CO, NO’s
Less Harmful
CO2, H2O, N
To control ozone
address the VOC’s and NOx that form it
Another way to reduce emissions
hybrid electric vehicles
The Clean Air Interstate Rule (CAIR)
sets new lower caps on SO2 and NOx in 28 states
The Clean Air Mercury Rule (CAMR)
caps and reduces mercury emissions from coal-fired power plants
Title IV of the CAAA
mandates reduced SO2 and NOx
How are industires meeting Title IV requirements
- switching to low-sulfur coal
- adding scrubbers
- trading emission allowances while saving money
Air quality has improved, along with health benefits
reduced acid deposition, some freshwater recovery, imroved forest conditions
Stratospheric ozone
protects Earth from harmful ultraviolet radiation
Chlorofluorocarbons (CFCs)
destroy the ozone layer
What are CFC’s used in?
refregerators, air conditioners, and heat pumps
How were ozone levels in 1985?
50% lower than usual
The Artic
has 25% depletion but no ozone hole
Worldwide ozone losses from 2002 to 2007
3% - 6%
Ozone losses of the 1980s will have caused 12 million people in the U.S. to develop…
skin cancer
Who was the leader in CFC production and use?
U.S.
HCFCs
short-term substitutes that will gradually be phased out (contain no chlorine)
