PollutionPollution

PollutionPollutionAny substance (matter or energy) that is

added to the biosphere by humans at a rate greater than what can be rendered harmless by the environment. ◦ Anything that can cause harm to the environment

by human activity.Two main types of Pollutions:

◦ Point Source Pollution – where pollutants are released from a single identifying site. Ex: a factory or sewage plant

◦ Non-Point Source Pollution – where pollutants are released from many unidentifying areas. ex: agricultural areas, urban traffic

POINT SOURCE VS NON-POINT SOURCEPOINT SOURCE VS NON-POINT SOURCE

Draw your own table in your notes.Using the information from your warm-up last class and textbook/companion bk :

1.Determine 3 specific areas of Denton where we can find these pollution sources. Name these areas.2.Determine which type of pollutants comes from each source.3.Where in Denton will these pollutants be affected.

Point Source Non-Point Source

1. 1.

2. 2.

3. 3.

Atmosphere & Air Atmosphere & Air PollutionPollutionA little background: •The atmosphere is the envelope of gases that surround our planet•It is a very thin layer compared to the radius of the Earth•We refer to this layer informally as “air”•The majority of the energy that drives the atmosphere is from the Sun.•The atmosphere receives most of this energy from the surface.•Imbalances of energy drive the winds. Eventually, all energy degrades down to friction.

We commonly express the state of the atmosphere by measuring it using the following variables:◦ Pressure◦ Temperature◦ Wind◦ Humidity◦ Cloud cover◦ Precipitation type and amount◦ Visibility (distance one can see

horizontally)

Dry air (neglecting water vapor) is composed of the following gases:

Nitrogen (N2) = 78%

Oxygen (O2) = 21%

Argon (Ar) = 1%Trace GasesDust, bacteria, and other

particulates

Trace Gases◦Gases that are only found by

examining a million or billion air molecules

◦Examples include: Carbon Dioxide (CO2) = 340 ppmv Neon (Ne) = 18 ppmv Helium (He) = 5 ppmv Methane (CH4) = 2 ppmv

Hydrogen (H2) = 0.5 ppmv

TroposphereTroposphere

StratosphereStratosphere

Mesosphere/Mesosphere/ThermosphereThermosphere

STRUCTURE AND SCIENCE OF STRUCTURE AND SCIENCE OF THE ATMOSPHERETHE ATMOSPHERE

The atmosphere consists of several layers with different temperatures, pressures, and compositions.

Figure 19-2Figure 19-2

Atmospheric Circulation Atmospheric Circulation (convection)(convection)

• Heated air rises at equator

• Cooler air descends at poles

Maximum Sun warming

Solar Energy and Global Air Solar Energy and Global Air Circulation: Distributing HeatCirculation: Distributing Heat

Global air circulation is affected by the uneven heating of the earth’s surface by solar energy, seasonal changes in temperature and precipitation.

Figure 5-3Figure 5-3

Coriolis EffectCoriolis effect deflects north-south

winds into east-west winds

Coriolis Effect breaks upCoriolis Effect breaks upGlobal CirculationGlobal Circulation

On Earth the large circulation cell breaks up into 3 smaller ones, moving diagonally

Other worlds have more or fewer circulation cells depending on their rotation rate

Convection Currents Convection Currents Convection cells Convection cells

TotalAtmosphere Circulation

Hadley CellHadley CellAir rises at the Equator due to high insolation

at the surface (convection)The belt of rising air and clouds is called the

Intertropical Convergence Zone (ITCZ)Large amounts of latent heat are released in

the ITCZAir blows in at the surface to replace the

rising air; these winds are the trade windsWind speeds beneath the ITCZ are low, and

this zone is also called the doldrumsAir sinks in the subtropics as part of the

Hadley Cell and forms the subtropical highsThe winds in the subtropical highs are also

very slow, and this zone is called the “horse latitudes”

Polar CellPolar CellThermally-direct cell at high latitudesRising air occurs at a boundary

between cold, polar air and warmer air in the mid-latitudes, called the polar front

Extremely cold air at the poles lead to surface high pressure

Winds blowing from the north to the south turn to blowing from the east due to the Coriolis force, so the surface winds are called the polar easterlies

Ferrel CellFerrel CellThis cell is thermally-indirect (hot air sinks and

cold air rises)The upper branch of the Ferrel Cell predicts

easterly winds aloft, but they are observed to westerly

Even though the complete cell doesn’t exist, the rising air at the polar front, the sinking air at the subtropical high pressures, and the correct surface winds exist

Surface flow from the south turns to the blowing from the west, resulting in our wind zone of the “prevailing westerlies”

The mid-latitudes is a very complex region, with many secondary circulation features (storms) present

Sea BreezeSea Breeze

These are ocean-to-land breezes that occur during the day.

Land BreezeThese are land-to-ocean breezes that occur at night.

Valley BreezeValley BreezeAs the wind blows from the plains into a valley between two mountains, the wind must divert into a smaller area. This causes high winds to form through the valleys.

Mountain BreezeMountain Breeze

Cool air coming from the top of the mountain sinks down on the eastern slope, causing increased winds on the mountain.

Air PollutionAir Pollution

Pollution – any contaminate to the Earth or Atmosphere so that the environment systems are negatively affected.

Regularly monitored air pollutants:Sulfur Dioxide, Oxides of

Nitrogen, ozone (O3), volatile organic compounds and particles.EPA Regulations: Denton

Air PollutionAir Pollution

Primary Pollutants – methane, ozone, dust particles, microorganisms, and chlorofluorocarbons (CFC’s)

Causes of Primary Pollutants – factories, cars, wind and soil, volcanoes, forest fires, pollen, decaying plants, salt particles from the sea, and refrigerants.

AIR POLLUTIONAIR POLLUTION

Some primary air pollutants may react with one another or with other chemicals in the air to form secondary air pollutants. Figure 19-3Figure 19-3

Major Air PollutantsMajor Air Pollutants

Carbon oxides: ◦Carbon monoxide (CO) is a highly toxic gas that

forms during the incomplete combustion of carbon-containing materials.

◦93% of carbon dioxide (CO2) in the troposphere occurs as a result of the carbon cycle.

◦7% of CO2 in the troposphere occurs as a result of human activities (mostly burning fossil fuels). It is not regulated as a pollutant under the U.S. Clean

Air Act.

Major Air PollutantsMajor Air PollutantsNitrogen oxides and nitric acid:

◦Nitrogen oxide (NO) forms when nitrogen and oxygen gas in air react at the high-combustion temperatures in automobile engines and coal-burning plants. NO can also form from lightening and certain soil bacteria. NO reacts with air to form NO2.

NO2 reacts with water vapor in the air to form nitric acid (HNO3) and nitrate salts (NO3

-) which are components of acid deposition.

Major Air PollutantsMajor Air PollutantsSulfur dioxide (SO2) and sulfuric

acid:◦About one-third of SO2 in the troposphere

occurs naturally through the sulfur cycle.◦Two-thirds come from human sources,

mostly combustion (S+ O2 SO2) of sulfur-containing coal and from oil refining and smelting of sulfide ores.

◦SO2 in the atmosphere can be converted to sulfuric acid (H2SO4) and sulfate salts (SO4

2-) that return to earth as a component of acid deposition.

Major Air PollutantsMajor Air PollutantsSuspended particulate matter (SPM):◦Consists of a variety of solid particles

and liquid droplets small and light enough to remain suspended in the air.

◦The most harmful forms of SPM are fine particles (PM-10, with an average diameter < 10 micrometers) and ultrafine particles (PM-2.5).

◦According to the EPA, SPM is responsible for about 60,000 premature deaths a year in the U.S.

Major Air PollutantsMajor Air PollutantsOzone (O3):

◦Is a highly reactive gas that is a major component of photochemical smog.

◦It can Cause and aggravate respiratory illness. Can aggravate heart disease. Damage plants, rubber in tires, fabrics,

and paints.

Major Air PollutantsMajor Air PollutantsVolatile organic compounds (VOCs):◦Most are hydorcarbons emitted by the

leaves of many plants and methane.◦About two thirds of global methane

emissions comes from human sources.◦Other VOCs include industrial solvents

such as trichlorethylene (TCE), benzene, and vinyl chloride. Long-term exposure to benzene can cause

cancer, blood disorders, and immune system damage.

Major Air PollutantsMajor Air PollutantsRadon (Rn):

◦Is a naturally occurring radioactive gas found in some types of soil and rock.

◦It can seep into homes and buildings sitting above such deposits.

Water PollutionWater PollutionPoisoned Waters – Frontline PBS

Take notes: answer the questions (set 1)1)Where does waste from our toilets and sink wind up?

2) What about chemicals that we use to clean our homes, wash our cars, fertilize our lawns?

3)What happens to our makeup, deodorant, shampoos and other personal care items when we take a shower?

4) What about pharmaceuticals tossed in the toilet?

Question set 2Question set 21) Where does your drinking water come from?

Can you think of anything that might pollute that source of water?

2) What problems have scientists detected in nature that they believe are caused by “emerging contaminants”?

3) Are humans potentially vulnerable to some of these same chemicals?

4) What should the government and/or industry do about these emerging contaminants?

5) What can you do to make water safer for yourself, your community and the fish?