chapter 18
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Options: washing away air pollution with artificial rain ?sucking it up with giant vacuum cleaners ?Shanghai has given its cops nose insert mini-filtersA study published in the British medical journal the Lancet attributed 1.2 million premature deaths in 2010 to bad air
A possible solution to China's smog:
Giant vacuum cleaners
Chapter 18air pollution
Types and behaviorUS pollution DistributionCarbon cycle and weatherOzone & acid rain casesSolutions
Types of Air PollutionGaseous pollutants
CO and CO2
SO2
NO, NO2 [NOx ]O3 and CFCs –[chlorofluorocarbons]
ParticulatesSoot, ash, & smokeDust (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
Major Emissions
CO – carbon monoxide – vehicles, combustionNot abundant but deadlyVery short residence time – fluctuating concentration
SO2 - sulfur dioxide – from combustion of coalforms acid rain – pH << 6very 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, etcEmissions steadily increasing
VOC – volatile organic compounds – breakdown products of industrial process, plastics, petroleum, etc
CO2 - carbon dioxide - combustion, and natural like respiration, volcanic eruptionsVarying residence time and fluxesRapidly, steadily increasing
US air pollution$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
US gas emissionsComparing two classes shows
complex, interesting history
Sulfur
Nitrogen
The global carbon cycleComprised of sources and
sinksCO2 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
Air Pollution and WeatherThermal InversionWarm, polluted air tends to rise, cooling as
it goes a cool air mass can have an overlying air
mass trap the rising warm pollutant-bearing air mass; this condition is made worse by an air mass with stagnant conditions
Topography, climate may amplify the problem
Pollutants are concentrated in the lower air mass and trapped, yuk!
OzoneOzone (O3) is a ‘chemically out of place
pollutant’ – good high up, bad low downIn upper atmosphere the ozone layer absorbs
harmful ultraviolet radiationChlorine and fluorine are chemically active
ions that rip O3 apart & reduce O3 concentrations
Recently, banning CFCs has returned ozone to upper atmosphere
Acid RainAn 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
Chinese Smog Created By Our
Demand for Cheap Goods Comes to L.A.
Global solutions
Air Pollution regulation
strong legislation that created the EPA - Environmental Protection Agency
Regulations cover catalytic converters and high fuel economy standard for new cars
Air Quality Standards – Clean Air Act (1970)
Result: dramatic reduction in emissions, especially the most harmful categories
The end
Thanks for taking a look at the Environmental Geology slides!