Environmental ScienceEnvironmental ScienceAir & Water Quality IssuesAir & Water Quality Issues

Your nameYour nameUniversity of MaineUniversity of Maine

Dept. of…Dept. of…

Environmental ScienceEnvironmental Science

InterdisciplinaryInterdisciplinary Traditional science, politics, social Traditional science, politics, social

organization, economics, ethics, …organization, economics, ethics, … Pollution and PolicyPollution and Policy

Addressing environmental problems and Addressing environmental problems and concerns is not an easy taskconcerns is not an easy task

Perceptions and opinions varyPerceptions and opinions vary Scientific knowledge and government Scientific knowledge and government

policy do not always agreepolicy do not always agree

Air QualityAir Quality

Global WarmingGlobal Warming Greenhouse EffectGreenhouse Effect 1 1 ooC average temperature rise last centuryC average temperature rise last century

Ozone DepletionOzone Depletion Protective layer allows our existenceProtective layer allows our existence

Primary Air PollutantsPrimary Air Pollutants Affects us directlyAffects us directly

Warming/Cooling is a Natural Warming/Cooling is a Natural ProcessProcess

(Pleistocene Epoch: last 4 million (Pleistocene Epoch: last 4 million years)years)

~ 100,000 years: Earth’s climate ~ 100,000 years: Earth’s climate cyclecycle 80-85,000 years: “Ice Age”80-85,000 years: “Ice Age” 15-20,000 years: warming period15-20,000 years: warming period

We are currently about 18,000 years We are currently about 18,000 years into Earth’s latest warming periodinto Earth’s latest warming period

Global WarmingGlobal Warming

Greenhouse GasesGreenhouse Gases

Carbon Dioxide, COCarbon Dioxide, CO22

Chlorofluorocarbons (CFCs), CClChlorofluorocarbons (CFCs), CCl33FF Methane, CHMethane, CH44

Nitrous Oxide, NONitrous Oxide, NOxx

NN22 + O + O22 2NO + O2NO + O22

2NO (nitrogen oxide)2NO (nitrogen oxide)2NO2NO22 (nitrogen dioxide) (nitrogen dioxide)

Carbon Dioxide, COCarbon Dioxide, CO22

Most abundant of the greenhouse Most abundant of the greenhouse gasesgases

Contribution to global warming: 55%Contribution to global warming: 55% Produced naturallyProduced naturally

RespirationRespiration Volcanic activityVolcanic activity

Volcanic ActivityVolcanic Activity

Carbon Dioxide continued…Carbon Dioxide continued…

Most abundant of the greenhouse Most abundant of the greenhouse gasesgases

Contribution to global warming: 55%Contribution to global warming: 55% Produced naturallyProduced naturally

RespirationRespiration Volcanic activityVolcanic activity

Produced unnaturallyProduced unnaturally Waste product of combustionWaste product of combustion

Gasoline, coal, oil, natural gas, biomass, …Gasoline, coal, oil, natural gas, biomass, …

FactoriesFactories

AutomobilesAutomobiles

Steady Increase in COSteady Increase in CO22 ConcentrationConcentration

COCO22 Sink Sink

Plants and trees Plants and trees absorb COabsorb CO22, but…, but…

Massive Massive deforestation deforestation makes the problem makes the problem worseworse South American South American

Rain Forests, …Rain Forests, …

Chlorofluorocarbons (CFCs)Chlorofluorocarbons (CFCs)

Contribution to global warming: 24%Contribution to global warming: 24% Entirely the result of human activityEntirely the result of human activity

Refrigerant gasesRefrigerant gases Cleaning solventsCleaning solvents Propellants in aerosol containersPropellants in aerosol containers

15,000 times more efficient at 15,000 times more efficient at trapping heat than carbon dioxidetrapping heat than carbon dioxide

CFCs, continued…CFCs, continued…

Many international efforts since 1987 Many international efforts since 1987 aimed at reducing CFCsaimed at reducing CFCs

In 1996, the U.S. stopped producing CFCsIn 1996, the U.S. stopped producing CFCs CFC concentrations in the atmosphere CFC concentrations in the atmosphere

have stabilized and are expected to have stabilized and are expected to declinedecline

Many developing nations still produce Many developing nations still produce CFCsCFCs

Methane, CHMethane, CH44

Contribution to global warming: 15%Contribution to global warming: 15% Biological SourcesBiological Sources

Several kinds of bacteriaSeveral kinds of bacteria Abundant in wetlands and rice fieldsAbundant in wetlands and rice fields Stomachs of ruminant animals such as cattleStomachs of ruminant animals such as cattle

Methane, CHMethane, CH44

1 billion cows worldwide1 billion cows worldwide A single cow can produce more than 14 A single cow can produce more than 14

cubic feet of methane each daycubic feet of methane each day

Nitrous Oxide, NONitrous Oxide, NOxx

Contribution to global warming: 6%Contribution to global warming: 6% Primary sourcesPrimary sources

Fossil fuelsFossil fuels FertilizersFertilizers

ResultResult

Ozone, OOzone, O33

Good ozone vs. bad ozoneGood ozone vs. bad ozone Ozone layer (good ozone)Ozone layer (good ozone)

Stratosphere 8-15 miles upStratosphere 8-15 miles up Absorbs 99% of damaging UV radiationAbsorbs 99% of damaging UV radiation

OO33 + UV light + UV light O O22 + O + O OO22 + O + O O O3 3

The AtmosphereThe Atmosphere

Ozone DepletionOzone Depletion

Reduction in ozone layer first Reduction in ozone layer first observed in the 1970sobserved in the 1970s

CFCs are the main culpritCFCs are the main culprit Chlorine radicals strongly react with OChlorine radicals strongly react with O33

Cl + OCl + O33 And if that’s not bad enough…And if that’s not bad enough… ClO + O ClO + O

ClO + OClO + O22

Cl + OCl + O22

Bad News about OzoneBad News about Ozone

CFCs destroy ozone and remove atomic CFCs destroy ozone and remove atomic oxygen as well (Ooxygen as well (O33 can’t recombine) can’t recombine)

It can take 10-20 years for CFC It can take 10-20 years for CFC molecules to reach the stratosphere!molecules to reach the stratosphere!

CFC molecules can react and destroy CFC molecules can react and destroy ozone molecules for up to 120 yearsozone molecules for up to 120 years Ozone depletion will worsen well into this Ozone depletion will worsen well into this

century before any improvements are seencentury before any improvements are seen

Primary Air PollutantsPrimary Air Pollutants

Carbon monoxide, COCarbon monoxide, CO Incomplete burning of fossil fuelsIncomplete burning of fossil fuels Single largest source: the automobileSingle largest source: the automobile 100 ppm can cause dizziness and 100 ppm can cause dizziness and

headachesheadaches

Primary Air Pollutants, Primary Air Pollutants, continuedcontinued

ParticulatesParticulates Very small pieces of solid materialVery small pieces of solid material Particles can accumulate in the lungsParticles can accumulate in the lungs

Repeated exposure > serious health effectsRepeated exposure > serious health effects Carcinogenic materialsCarcinogenic materials

Primary Air Pollutants, Primary Air Pollutants, continuedcontinued

Nitrous oxide, NONitrous oxide, NOxx

Primary source: automobile enginePrimary source: automobile engine NONOxx reacts with UV light to form smog reacts with UV light to form smog

NN22 + O + O22 2NO 2NO 2NO + O2NO + O22 2NO 2NO22

NONO22 + UV light + UV light OO22 + O + O O O33

NO + ONO + O

SmogSmog

Two destructive components of smogTwo destructive components of smog Ozone (bad ozone)Ozone (bad ozone)

MutagenMutagen Destroys chlorophyll in plantsDestroys chlorophyll in plants Injures lung tissueInjures lung tissue

Peroxyacetyl nitratesPeroxyacetyl nitrates Eye irritantsEye irritants

Smog, continuedSmog, continued

Smog is a serious Smog is a serious problem in many problem in many large citieslarge cities

Especially those Especially those cities ringed by cities ringed by mountainsmountains

So why does any of this matter to So why does any of this matter to you?you?

Because we are not immuneBecause we are not immune

The northeast is this nation’s The northeast is this nation’s tailpipetailpipe

Ground-level OzoneGround-level Ozone

Ozone isn’t the only pollutant Ozone isn’t the only pollutant flowing through the northeastflowing through the northeast

Water Quality IssuesWater Quality Issues

Acid RainAcid Rain Air pollutants react with moisture in Air pollutants react with moisture in

atmosphereatmosphere Sulfur dioxide and nitrogen dioxideSulfur dioxide and nitrogen dioxide

SOSO22 + H + H22O + ½OO + ½O22 2NO2NO22 + H + H22O O HNO HNO22 + +

HH22SOSO44 (Sulfuric acid)(Sulfuric acid)

HNOHNO33 (Nitric acid) (Nitric acid)

Acid-base pH scaleAcid-base pH scale

pH 7.0 ~ neutralpH 7.0 ~ neutral pH 5.6 ~ acid rain pH 5.6 ~ acid rain (25 times more acidic than (25 times more acidic than

pure water)pure water)

pH 3.0 ~ highly acidpH 3.0 ~ highly acid

Lakes become acidicLakes become acidic

Healthy lakes have a Healthy lakes have a pH over 6.0pH over 6.0

At a pH of 5.5, many At a pH of 5.5, many desirable species of desirable species of fish have been fish have been eliminatedeliminated

Birth defects Birth defects commoncommon

Trees and vegetation Trees and vegetation declinedecline

Limestone deterioratesLimestone deteriorates

You Can’t Hide From Acid You Can’t Hide From Acid RainRain

The northeast is highly prone to The northeast is highly prone to severe acid rainsevere acid rain pH 3.0 to 4.0 not uncommonpH 3.0 to 4.0 not uncommon pH 2.3 worst recorded (1000 times more pH 2.3 worst recorded (1000 times more

acidic than pure water)acidic than pure water)

Other Water Quality IssuesOther Water Quality Issues

Oil SpillsOil Spills

Thank youThank you

The EndThe End