(NOT FINISHED 7.6, 7.8?) Unit 7: Atmospheric Pollution

(7.1) Introduction to Air Pollution

  • air pollution: pollution that’s in the atmosphere that’s harmful to humans + animals

    • primary pollutant: emitted directly into the atmosphere

      • carbon monoxide + dioxide, sulfur dioxide, nitrogen oxides. nitrous oxide, ammonia, hydrocarbons (includes VOCs), particulate matter (PM)

      • EX: (natural) pollen, volcanic ash, VOC from plants, (human/anthropogenic) fossil fuels

    • secondary pollutant: primary pollutants + atmospheric gases, water vapor, sunlight

      • EX: tropospheric (ground-level) ozone (O3), acid rain

  • National Ambient Air Quality S tandards (NAAQS) has 6 criteria pollutants (SPLONC) that are seen as super harmful

    • sulfur dioxide (SO2), particulate matter (PM), lead (Pb), ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO)

      • lead causes anemia, behavioral disorders, lowered IQ, reading/learning disabilities, nerve damage (for children) and hypertension, cardiovascular disease (for adults)

  • burning of coal releases impurities into the atmosphere

    • impurities include sulfur ( → sulfur dioxide), toxic metals (lead, mercury, nickel, arsenic), soot (aka particulate matter)

  • fuels come from source plant matter which has: carbon, hydrogen, nitrogen, oxygen, sulfur

    • biogeochemical cycles

    • when burned → pollutants (causes negative impacts on humans and environment)

      • primary pollutants + atmospheric things = secondary pollutants

  • introductory EFFECTS of fossil fuel pollution

    • irritates eyes, nose, throat

    • inhale → lung conditions/damage

    • damages plant tissue during photosynthesis/respiration

(7.2) Photochemical Smog

  • volatile organic hydrocarbons (VOCs): compounds that can vaporize at room temperature

    • EX: gasoline (human), trees, plant oil (natural)

  • (CAUSE) PHOTOCHEMICAL SMOG: primary pollutants (nitrogen oxides, VOCs) + sunlight → ozone, PANs, aldehydes (VOC), nitric acid (aka photochemical smog)

    • source: urban areas with lots of cars

    • produced early in the day and stays around in the day

    • higher in the summer and sunny warm climates

  • EFFECTS

    • photochemical smog

      • irritates eyes, nose, throat

      • worsen heart/lung consitions, can cause lung cancer

    • ozone

      • worsen bronchitis, emphysema

      • trigger asthma + permanent damage to lung tissue

      • enters plants → burn tissue → leaf damage + less survival for plants

  • SOLUTIONS

    • catalytic converters in cars: converts NO → O2 + N2

      • produces CO2 and H2O

      • enforce emission testings/standards for vehicles

    • reducing VOCs

      • pump gas at night (with no sunlight)

      • don’t spill fuel, tighten gas cap closely

    • improve fuel efficiency

    • reduce use of internal combustion

      • make fewer trips (bike, walk, use public transportation)

    • reduce health impacts

      • wear mask

      • minimize outdoor activities during hot days/seasons

(7.3) Thermal Inversion

  • temperature or thermal inversion: a warmer layer sits on top of the cooler surface of air in the troposphere

    • normal conditions: altitude increases → temperature decreases

    • traps cooler/denser air → air doesn’t rise → pollutants (particulate matter, photochemical smog) don’t disperse

  • factors that influence TI

    • geography (valleys, nearby mountain ranges, coastal/prevailing winds)

      • traps cool air in more frequently

    • pollution (high industrialism, vehicles, large cities)

      • EX: los angeles, mexico city

(7.4) Atmospheric CO2 and Particulates

  • natural sources of CO2

    • carbon cycle: respiration, ocean outgassing (diffusion), decomposing biomass

    • geological processes (volcanoes)

    • ecosystem disturbances (wildfires)

    • not necessary a pollutant since it naturally maintains global temperatures

      • EXCESS CO2 is a pollutant since it’s too much (from fossil fuels)

  • particulate matter: solid/liquid particles that are small enough to be inhaled

    • size unit = micron (1 micron = 0.001 millimeter)

    • PM must be less than 10 microns to be inhalable

      • 2.5 - 10 microns = upper respiratory concern

      • under 2.5 = low respiratory concern

    • natural sources of particulate matter

      • pollen, spores, bacteria, dust + dust mites, airborne soil, seasalt

      • geological processes (sulfates, volcanic dust)

      • ecosystem disturbances (ash/soot from wildfires)

(7.5) Indoor Air Pollutants

  • can come from materials made in buildings

    • VOCs from furniture

    • lead from old lead paint

    • asbestos in old edifices

  • natural sources:

    • mold

      • can infect respiratory passageways

      • found in homes, schools, buildings with poor ventilation

      • water leaks + lots of humidity creates undected mold

    • dust

      • contain particulates

    • radon (natural occuring gas resulting from decaying uranium)

      • rocks/soils contain uranium

      • uranium decays into radon 222 → gas escapes into atmosphere → seeps into homes/buildings built on soils or through cracks

      • can dissolve in groundwater → go into water cources

      • can cause lung cancer

      • solutions:

        • sealing up cracks

        • using radon detectors that are readily available

  • human-made sources

    • asbestos (tiny shards of glass)

      • can cause lung cancer when inhaled

    • combustion (smoke)

      • releases carbon monoxide

        • can cause carbon monoxide poisoning

        • it’s an asphyxiant (can suffocate you)

          • impairs ability of red blood cells to carry oxygen throughout body → dizziness, nausea, suffocation

      • can come from candles burning, fireplaces, cookstoves, unvented space/kerosene heaters, cigarette smoke, smoke from nearby wildfires

NOT FINISHED (7.6) Reduction of Air Pollutants

(7.7) Acid Rain

  • regular rain PH = 5.6, acid rain PH = 4.3

  • chemical sources for acid rain

    • NO2 from cars + water → nitrous/nitric acid

    • coal burning plants releases nitrogen oxides, sulfur dioxides → reacts with water → sulfurous/sulfuric acid

    • natural sources (volcanoes, geysers) can emit nitrogen oxides

  • acid rain formation

    • nitric/sulfuric acid is in the form of dry deposits or rain/snow

    • human sourced pollutants + pollutants already in atmosphere → water cycle → comes down through wet deposition

MR. SMEEDS (7.8) Noise Pollution

  • noise pollution: noise loud enough to cause headaches, hearing loss, physiological stress

    • EX: construction, transportation, manufacturing plants, domestic activity (neighbor’s music, lawn mowing, home projects)

    • aquatic noise pollution come from ship engines, military sonar, seismic air blasts looking for oil + gas

  • effects (on wildlife)

    • can disrupt animal communication, migration

      • EX: caterpillar heats beat faster when exposed to highway noise

      • EX: whales lose essential communication method

    • can prevent predators hearing prey (vice versa too) → decreases chances of survival

    • (aquatic) seismic surveying ships hits ocean floor → sound is echoed and is really loud