Air Resources & Pollution Environmental Science

Clean Air Components

Air Pollution – harmful substances build up in the air to unhealthy levels (gases, solids, or liquids) Almost all air pollution is the result of human activities!

Primary vs. Secondary Air Pollutants Primary Pollutants Put directly into the air from a human activity  Car exhaust  Smoke stacks  Incinerators  Fireplaces Secondary Pollutants Come from the reaction of a primary pollutant with another pollutant or an environmental factor  Ground-level ozone  Smog  Acid rain

Types of Primary Air Pollutants PollutantSourceEffects Carbon monoxide (CO) Cars, trucks, buses, some industrial processes Interferes with oxygen absorption, can cause death Nitrogen Oxides Burning fossil fuels, power plants, some industry Respiratory problems, brownish haze, acid precipitation Sulfur dioxide Mostly burning fossil fuels Acid precipitation, respiratory problems, harm plants Volatile Organic Compounds (VOCs) Burning fuels, gasoline & oil spills Smog, health problems harm plants Particulatesconstruction, agriculture, fires, vehicles, industrial processes Respiratory problems, reduce visibility, corrode metals, erode stone & concrete

Vehicle Exhaust Passenger vehicles usually account for around 90% of all vehicle exhaust. History of cleaning up auto exhaust in the U.S.: Clean Air Act of 1970 gave EPA authority to regulate auto emissions 1.reducing/eliminating lead in fuels 2.Catalytic converters– cleans pollutants from auto exhaust

Catalytic Converters Pollutants from the car exhaust react with chemicals in the apparatus

Smokestack scrubbers

Temperature Inversions – a contributing factor to air pollution problems in many metropolitan areas  A shift in the natural atmosphere, where the air above is warmer than the air at the surface.  Pollutants are trapped at the surface with the cooler air.  Certain geographic features cause this, for example a city located in a valley

Health Effects of Air Pollution Short Term (reversible)  Headache  Nausea  Eye, nose, throat irritation  Coughing  Chest tightness  Upper respiratory infections Long Term (ongoing & chronic)  Emphysema  Lung cancer  Heart disease  Worsening of asthma and emphysema

Indoor Air Pollution– air quality inside a building is poor  Compounds found in carpets, upholstery, building materials, paints  Radon gas– comes from the ground, seeps into buildings  Asbestos—used for insulation & fire retardant, banned in the 1970s  Can cause “sick-building syndrome”

Noise Pollution – can affect human health and quality of life  Caused by traffic, construction, factories, home appliances (such as air conditioners), airports, lawn equipment  Health problems include hearing loss, high blood pressure, stress, loss of sleep

Light Pollution — inefficient lighting that is directed upward  Wastes energy  Urban areas, diminishes the view of the night sky  Billboards, signs, street lights, building exteriors

Acid Precipitation– has pH  Rain, snow, or sleet  Caused by burning fossil fuels  H 2 0 vapor in atmosphere reacts with sulfur dioxides and nitrogen oxides to form nitric acid and sulfuric acid  Causes pollution in surface water—rivers, lakes, & streams  Acid shock (occurs in spring during acid-snow melt) kills aquatic organisms  Causes erosion to metal & stone/concrete  Causes acidification of soils  Completely changes soil chemistry  Causes some nutrients to wash away  Causes metals to dissolve in soils

Acid Precipitation

The Greenhouse Effect – a natural phenomenon caused by our atmosphere…keeps Earth warm and determines weather patterns  Greenhouse gases– methane, carbon dioxide, water vapor  Occurs in the troposphere (the first layer of our atmosphere)

Global Warming – an exaggeration of the greenhouse effect  Caused by excessive greenhouse gases  created by burning of fossil fuels  industrialization & vehicles

Ozone Depletion  Ozone layer is found in the stratosphere (2 nd layer of the atmosphere)  Atmospheric ozone filters UV radiation from the sun Depletion of the ozone layer is caused by chlorofluorocarbons (CFCs)  Freon  Aerosols  Styrofoam Recent efforts to reduce CFCs have resulted in repaired ozone, but CFCs are still used in developing countries where they are cheap

There is no real relationship between global warming and ozone depletion. Ozone depletion does NOT cause global warming!!! Ozone depletion causes more UV rays to reach Earth increased skin cancer increased mutations in plants increased cataracts