BIOLOGY 157: LIFE SCIENCE: AN

ENVIRONMENTAL APPROACH (Air Pollution)

AIR POLLUTION

• Non-Anthropogenic ---- caused by non-human processes (volcanoes, decomposition, etc.)

• Anthropogenic ----- produced by human activities

• Some things which can be air pollutants: SO2 (sulfur dioxide) CO2, CO (carbon dioxide, carbon monoxide) H2S (hydrogen sulfide) CH4 (methane) NO2, NO, N2O (various nitrogen oxides) O3 (ozone) HCN (hydrogen cyanide) Lead, Selenium, Fluorine Particulates (soot, dust) Numerous Organic Compounds

PRIMARY AND SECONDARY AIR POLLUTANTS (I)

• Primary Air Pollutants those that are directly released from various

activities SO2, CO2, CO, H2S, NO, particulates

• Secondary Air Pollutants those that result from the reaction of primary

with other primary or primary with various ‘normal’ constituents of the atmosphere; the sun usually catalyzes the reactions

Ozone (O3), Peroxyacyl Nitrates (PAN’s), H2SO4, HCL, HNO3 , NO2, N2O

PRIMARY AND SECONDARY AIR POLLUTANTS (II)

EMISSIONS OF MAJOR AIR POLLUTANTS IN THE U.S. (I)

EMISSIONS OF MAJOR AIR POLLUTANTS IN THE U.S. (II)

SIZE OF SUSPENDED PARTICULATE MATTER

TYPES OF SMOG

• Grey Air (= Industrial Smog, Sulfurous Smog, London Smog)

• colder more moist climates

• mainly results from smoke (particulates) + SO2

• London (UK); Lewiston (ID) / Clarkston (WA)

• Brown Air (= Photochemical Smog, Los Angeles Smog)

• warmer (and sometimes drier) climates

• primary pollutants (COx, NO, Hydrocarbons) + SUN yields secondary pollutants (ozone, PAN’s)

• Los Angeles; Donora (PA) near Pittsburgh, 1948

FORMATION OF PHOTOCHEMICAL SMOG

INDOOR AND OUTDOOR AIR POLLUTION

• Which is the more serious problem?

• Generally the indoor

• what is outside tends to get inside

• many different things tend to be produced / released indoors from materials / processes

• things that are produced inside often are trapped there

• we tend to spend much more time indoors than out

INDOOR AIR POLLUTANTS

FACTORS AFFECTING AIR POLLUTION SEVERITY

• Type of pollutant (light / heavy)

• Degree of Urbanization (Urban Heat Dome)

• Wind (speed and direction)

• Altitude

• Latitude

• Humidity

• Terrain (Mountains / Valleys / Temp. Inversions)

URBAN HEAT DOME

TEMPERATURE INVERSIONS

EFFECTS OF AIR POLLUTION (I)

• Health

lethargy (lead and others)

headaches (CO, arsenic)

temporary breathing difficulties (SO2, H2S)

emphysema (ozone, particulates)

chronic bronchitis (particulates)

bone / teeth malformation (fluorine)

mental impairment (lead, mercury)

EFFECTS OF AIR POLLUTION (II)

• Deterioration of stone and metals in buildings (SO2, H2SO4, NO2, HNO3)

• Breakdown of rubber products (ozone and acids)• Reduction in plant growth and plant health

(ozone, acids)• Climate - warming from greenhouse gases such as CO2,

N2O, CH3, chlorofluorocarbons (CFC’s) - cooling from particulates• Habitat Destruction (acidification of lakes and

high mountain ecosystems)• Ozone Depletion in the Stratosphere increases UV

light; increases mutations and cancers (CFC’s)

ACID DEPOSITION

• Dry / Wet

• pH of 5.6 or less

• unimpacted precipitation has a pH of 5.7

• with water in the atmosphere:

~ CO2 goes to carbonic acid

~ SO2 goes to sulfuric acid

~ NO2 goes to nitric acid

• Acid deposition is more likely to have an effect in high mountains and in areas low in bases (little or no neutralizing capability)

ACID DEPOSITION

ACID DEPOSITION AND SOIL pH

AREAS IN WHICH U.S. LAKES AND STREAMS ARE ESPECIALLY

VULNERABLE TO ACID DEPOSITION

HARMFUL EFFECTS OF AIR POLLUTANTS ON TREES

GREENHOUSE EFFECT AND GLOBAL WARMING

• Is the Earth warming?

• Yes.• Is this due to the greenhouse effect or to some cycle

that can affect climate?

• ??????????

• What are the major greenhouse gases?

• CO2, N2O, CH4, CFC’s, (H2O ?)• Could the Earth also cool from human activities

and enter an ice age?• Yes - and there have been ‘recent’ short duration

cooling events!• Global warming could be a positive feedback

system!!!!!

GREENHOUSE EFFECT

AUTUMN EFFECT (NUCLEAR WINTER)

SOME POINTS CONCERNING THE EARTH’S TEMPERATURE

• current average surface temp. is 150C (= 59OF)

• without an atmosphere it would be -180C (= 0OF)

• estimated average temp. during coldest part of last ice age was only 5OC (9OF) less than today

• last major ice age ended 12,000 years ago

• sea levels are 300 feet higher that at the peak of the ice age (and are still rising!)

• greenhouse gases have increased dramatically since 1850 (actually since 1950!)

• CO2 has gone from 280 ppm to 380 ppm since 1850(a 36% increase)

THE MAJOR GREENHOUSE GASES

• Gas % impact compared contribution to CO2 per to global warming molecule

• CO2 64 ---------

• CFC’s 11 10,000 to 20,000

• CH4 19 25

• N2O 6 230

PROJECTED GROWTH OF GREENHOUSE GASES

PATTERN OF GLOBAL CO2 EMISSIONS (1950 & 1980)

PATTERN OF GLOBAL CO2 EMISSIONS (2000)

RISE IN ATMOSPHERIC CO2

INCREASE IN GLOBAL TEMPERATURE

HUMAN ACTIVITIES THAT CAUSE GLOBAL WARMING