1. Options: washing away air pollution with artificial rain
?sucking it up with giant vacuum cleaners ?
Shanghai has given its cops nose insert mini-filters
A study published in the British medical journal the Lancet
attributed 1.2 million premature deaths in 2010 to bad air

2. Types and behavior
US pollution
Distribution
Carbon cycle and weather
Ozone & acid rain cases
Solutions

3. Gaseous pollutants
CO and CO2
SO2
NO, NO2 [NOx ]
O3 and CFCs –
[chlorofluorocarbons]
Particulates
Soot, ash, & smoke
Dust (released from industrial processes)
Not a minor component - from 35 million tons/year (mainly
combustion) to 180 million tons/year (mostly industrial)
Residence times vary widely, from a few years to millions of years –
related to amount in the atmosphere, so N & O hang around longest

4. CO2 - carbon dioxide - combustion, and natural
like respiration, volcanic eruptions
Varying residence time and fluxes
Rapidly, steadily increasing
CO – carbon monoxide – vehicles, combustion
Not abundant but deadly
Very short residence time – fluctuating concentration
SO2 - sulfur dioxide – from combustion of coal
forms acid rain – pH << 6
very short residence time (days or hours)
Mostly decreasing at least in US
NOx – nitrogen oxides – “smog ozone” interacts at several levels
reacts in sunlight to form opaque NO2, + ozone (O3), acids, etc
Emissions steadily increasing
VOC – volatile organic compounds – breakdown products of industrial
process, plastics, petroleum, etc

5. $16 billion annual U.S. expense (direct costs) vs $40B globally
Major gas sources:
Transportation: [1] CO,
[1] NOx, [1] VOC, [1]
CO2
Energy: [1] SO2,
CO2,NOx
Industry: VOC, SO2,
CO2
Transportation ranks
first in several
categories
Particulates are heavily influenced by industry, greatly
reduced in recent years

6. Comparing two classes shows
complex, interesting history
Sulfur
Nitrogen

7. Comprised of sources and
sinks
CO2 and CO are emitted
and travel through this
cycle
Combustion and other
emissions greatly alter
the proportions
Major effects: greenhouse
gases, plant building,
hydrocarbon formation
These gases interact with lithosphere, biosphere and
hydrosphere in often complex chemistry
Other compounds have similar cycles, sources and sinks

8. Thermal Inversion
Warm, polluted air tends to rise, cooling as
it goes
a cool air mass can have an overlying air
mass trap the rising warm pollutantbearing air mass; this condition is made
worse by an air mass with stagnant
conditions
Pollutants are
concentrated in the
lower air mass and
trapped, yuk!
Topography, climate may amplify the problem

9. Ozone (O3) is a „chemically out of place
pollutant‟ – good high up, bad low down
In upper atmosphere the ozone layer absorbs
harmful ultraviolet radiation
Chlorine and fluorine are chemically active
ions that rip O3 apart & reduce O3
concentrations
Recently, banning
CFCs has returned
ozone to upper
atmosphere

10. An acid solution has more Hydrogen-ions (H+) – measured in pH
Several common gases combine with water and air to make acids
Acid rain is harmful to plants,
health of rivers and lakes,
and animals – also causes
increases in the build up of
heavy metals (lead, zinc,
selenium, copper, and
aluminum) leached from
rocks and soils

11. Global solutions

12. Air Quality Standards – Clean Air Act (1970)
strong legislation that created the
EPA - Environmental
Protection Agency
Regulations cover catalytic
converters and high fuel
economy standard for new
cars
Result: dramatic reduction in emissions, especially the most
harmful categories

13. Thanks for taking a look at the Environmental Geology slides!