- Slides: 27
Outdoor Air Pollution Primary vs. Secondary Air Pollutants • Primary Pollutant – a • Secondary Pollutant – pollutant that is put directly when primary pollutants into the air by human activity. react with other primary • Examples: CO, NOx, PM, pollutants or natural SOx, VOCs substances to form a new • Sources: Electricity pollutant. Production, Industry, • Example: Ground-level Transportation, Other ozone Sources
Motor Vehicle Emissions FACTS: • Almost 1/3 of our air pollution comes from gasoline burned by vehicles. • The Clean Air Act - passed in 1970 (amended in 1990) – gives the EPA the authority to regulate vehicle emissions • EPA required the gradual elimination of lead in gasoline lead pollution has dropped more than 90% in the United States. • Catalytic Converters – now required in all vehicles – clean exhaust gases of pollutants before the exhaust leaves the tail pipe. • Cars and trucks today burn fuel 35% more efficiently and with 95% fewer emissions of pollutants than they did 30 years ago.
Types of Air Pollutants
Pollution Sources in the United States - 1998 Types of Air Pollution in the United States - 2000 Mobile and stationary sources
Outdoor Air Pollution Industrial Smog – Primary air pollutants from burning fossil fuels
Photochemical Smog – Primary & Secondary air pollutants that hang over urban areas and reduce visibility. From vehicles & industry.
Warmer air Increasing altitude Inversion layer Cool layer Mountain Valley Decreasing temperature Temperature Inversion – causes pollution to get trapped near the ground.
Descending warm air mass Increasing altitude Inversion layer Sea breeze Mountain range Decreasing temperature
Los Angeles Mexico City
Regulations Scrubbers - machines that remove pollutants from exhaust by spraying gases with water. Electrostatic Precipitators – machines that remove dust particles from smoke stacks by electrically charging the dust particles, causing them to stick to each other & the chamber.
Effects of Air Pollution • Short Term – headache, nausea, irritation, cough, infections • Long Term – asthma, emphysema, lung cancer, heart disease
Chloroform Para-dichlorobenzene Tetrachloroethylene 1, 1, 1 Trichloroethane Formaldehyde Benzo-a-pyrene Nitrogen Oxides Styrene Tobacco Smoke Asbestos Carbon Monoxide Methylene Chloride Indoor Air Pollution Radon-222
Air quality indoors is often much worse than air quality outside Most Common Indoor Air Pollutants Radon Cigarette Smoke Carbon Monoxide Nitrogen Dioxide Formaldehyde Household Pesticides Lead Household cleaners Ozone Asbestos
Viruses Bacteria Fungi • yeasts • molds • mildews Dust Mites Pollen
Sick Building Syndrome Sick-Building Syndrome – Tightly sealed buildings often lead to the people who are inside showing symptoms of allergic reactions. Symptoms: eye or skin irritations, allergic reactions, nausea, asthma, headaches, respiratory infections, depression, and fatigue. Medical costs ~ $ 1 Billion / year Overall costs ~ $ 50 Billion / year
Indoor Air Pollution and the Asthma Epidemic • # of asthma sufferers has doubled since 1970 • Exactly why is unknown, but thought to be linked to increased indoor air pollution
Outlet vents for furnaces and dryers Open window Openings around pipes Cracks in wall Slab joints Wood stove Furnace Clothes dryer Cracks in floor Radon-222 gas Sump pump Uranium-238 Slab Radium-222 Soil Radon
Radon Gas – Radioactive gas • Produced by the decay of uranium in Earth’s crust • Colorless & odorless. • 2 nd leading cause of lung cancer in U. S.
The Reading Prong Radon in North Carolina Radon Gas – Radioactive gas that is Zone 1 Highest Potential (greater than 4 p. Ci/L) produced by the decay of uranium in Zone 2 Moderate Potential (from 2 to 4 p. Ci/L) Earth’s crust. Colorless & odorless. 2 nd Zone 3 Low Potential (less than 2 p. Ci/L) leading cause of lung cancer in U. S.
Asbestos – mineral whose fibers are valued for their strength and resistance to heat. - Used as insulator and fire retardant. - Fibers lodge in lungs and cause mesothelioma.