Transcript Ch.18 Review

CH.18 REVIEW
18.1 WHAT IS THE NATURE OF THE
ATMOSPHERE
• The of gases that surround the earth is called the atmosphere
• There are several layers that make up the atmosphere
• Layers: troposphere, ozone layer, stratosphere, mesosphere, and
the thermosphere
• The density is the number of gas molecules
• The density various throughout the different layers
• The lower levels have more density because gravity pulls the
molecules to the surface
• The force or mass of a column of air per unit is the atmospheric
pressure
• Because of the lower amount of gas molecule in the air the the
atmospheric pressure decreases with altitude
• 75-80% of the air mass that is n earth is found in the troposphere
• The troposphere is the atmospheric layer that is closest to the
earth
• The troposphere is about 11 miles above the sea level
• When you take a deep breathe at least 99% of the air you just
breathed is nitrogen and oxygen
• The rest is water vapor as well as dust and soot particles, ozone,
methane, and argon
• The CO2 as well as greenhouse gases in the air is what causes the earths
short-term weather and long-term climate
• The climate is the average weather in an area that is measured by the
temperature and the precipitation
• Researchers think that soot and other particles in brown clouds
are absorbing sunlight and heat from above glaciers
• The black soot that falls above the glaciers is decreasing their
ability to reflect sunlight
• This causes the glaciers to absorb solar energy which increases
their melting process
• The slow melting of glaciers is signaling the warming atmosphere
and the climate change, but researchers point out that the south
Asian brown clouds are covering up the problem and are also
contributing to it.
• The stratosphere is the second layer of the atmosphere
• It contains less matter but is composed similar to the troposphere
• The atmospheres small amount of ozone is located in the
stratosphere
18.2 WHAT ARE THE MAJOR OUTDOOR
ARE POLLUTION PROBLEMS
• The presence of chemicals in the air that can harm organisms is air
pollution
• Almost any chemical in the air can become a pollutant is
• Pollutants can come from human or natural resources, for
example: dust, volcanic eruptions, burning fossil fuels
• Outdoor pollutants are classified in two ways: Primary and
Secondary pollutants
• Primary pollutants are chemicals emitted directly into the air from
natural resources
• Secondary pollutants are pollutants that form when primary
pollutants react to each other
• The major pollutants are Carbon oxides, Nitrogen oxides and nitric
acid, sulfur dioxide and sulfuric acid, particulates, ozone, volatile
organic compounds (VOCs)
• Industrial smog- unhealthy mix of carbon dioxide, suspended
droplets of sulfuric acid, and a variety of solid particles
• Photochemical reaction: any chemical reaction
activated by light
• Photochemical smog: mixture of primary and
secondary pollutants formed under the influence of UV
radiation from the sun.
• Five natural factors that reduce outdoor air pollution:
particles heavier than air settle out as a result of
gravitational attraction to the earth, rain and snow,
salty sea spray from the oceans, winds, chemical
reactions
• Six natural factors that can increase outdoor air
pollution: urban buildings, hills and mountains, high
temperatures, VOCs, grasshopper effect, temperature
inversions
18.3 WHAT IS ACID DEPOSITION AND
WHY IS IT A PROBLEM?
• Acid deposition- acid rain
• Acid deposition is mostly a regional problem
• Many acid-producing chemicals generated in one country are
exported to other countries by prevailing winds.
• The worst acid deposition occurs in Asia
• Acid deposition can damage statues, buildings, contributes to
human respiratory diseases, and can leach toxic metals from soil
and rocks. It can also harm aquatic ecosystems.
• Acid deposition can also leach nutrients from forests and damage
crops
• Mountain top forests are the terrestrial areas hit the hardest by acid
deposition
• Most of the worlds lakes and forests are not being destroyed, this
problem is mostly harming lakes and forests that lie downwind from
coal-burning faculties
18.4 WHAT ARE THE INDOOR MAJOR
AIR POLLUTANTS
• Indoor air pollution is the worlds most serious air
pollution problem
• Since 1990 the EPA has placed indoor air pollution at
the top of the list of sources of cancer risks
• Living organisms and their excrements can also
contribute to indoor air pollution
• Another living source of indoor air pollution is fungal
growth and mold
• The chemical that causes more developed countries
difficulty is formaldehyde
• Radon-222 is a colorless, odorless, radioactive gas that
is produced by the natural radioactive decay of
uranium
• When the gas is released outdoors it disperses quickly
and becomes harmless
• When it builds up in buildings it can become deadly
• This gas quickly decays into solid particles
• Your chances of getting cancer from radon depends
on how much is in your home
18.5 WHAT ARE THE HEALTH EFFECTS
OF AIR POLLUTION
• Our respiratory system has a number of ways to
protect itself
• Hairs in our noses filter out large particles
• Sticky mucus in the lining of our upper respiratory tract
captures smaller particles
• Thousands of hair like structures called cilia line our
respiratory tract and expels pollutants
• According to WHO 2.4 million people worldwide die
prematurely each year because of air pollution
• The EPA estimates that the annual number of deaths
related to indoor and outdoor air pollutants are
150,000 to 350,000
• According to the EPA each year more than 125,000
Americans get cancer from breathing fumes.
• According to the EPA diesel trucks emit as much
particle matter as 150 cars
18.6 HOW SHOULD WE DEAL WITH AIR
POLLUTION
• The united states provides and excellent example of
how a regulatory system approach can reduce air
pollution
• Congress directed the EPA to establish air quality
standards
• A limit to help protect health is the secondary
standard, it is intended to prevent environmental and
property damage
• The EPA also established national emission standards
for more than 188 hazardous air pollutants
• One approach to reducing pollutant emissions has
been to allow producers to buy and sell government air
pollution allotments
• With the goal of reducing SO2 emissions, the Clean Air
act of 1990 authorized an emissions trading program
• Between 1990 and 2006 the emissions trading system
helped to reduce SO2 emissions from power plants by
53%
• Ways to prevent air pollution is to walk, bike, or use
mass transit
• Little effort has been put into reducing indoor air
pollution even though it poses a greater threat than
outdoor air pollution
• In less-developed countries indoor air pollution could
be reduced
• In more-developed countries household plants could
bring some relief to the pollution
• Since 1970, most of the worlds more-developed
countries have enacted laws and regulations that
have significantly reduced outdoor air pollution
• Most of these laws emphasize controlling outdoor air
pollution by using output approaches
• Environmental and health scientists argue that the next
step is to shift our emphasis to preventing air pollution