Air Pollution 2

Smog: An Urban problem Industrial smog – gray-air smog. Forms when coal or oil is burned. Mix of CO, CO2, SO2 Photochemical smog – brown-air smog. Forms through light driven chemical reactions of primary pollutants and normal atmospheric compounds. Ex. Ground level ozone.

Confined Animal Feeding Operations More than 25 studies of CAFO workers show that 25-30% of them report serious respiratory problems Iowans living within a two-mile radius of a 4,000-hog unit reported more respiratory and other symptoms than did people not living near a CAFO Institute for Agriculture and Trade Policy, University of Iowa. A typical confinement holds 2500 hogs

Depletion of The Ozone Layer High Altitude ozone absorbs UV radiation and allows life on our planet. 1970’s researchers discovered Chlorofluorocarbons (CFCs) were depleting stratospheric ozone View of South Pole from NASA Total Ozone Mapping Spectrometer

The destruction of ozone by CFCs CCl3F + UV light CCl2F + Cl (CCl3F is a CFC) followed by: Cl + O3 ClO + O2 followed by: ClO + O Cl + O2 followed by: Cl + O3 ClO + O2 (same as first step above) followed by: ClO + O Cl + O2 (same as second step above) (these reactions are repeated thousands of times to destroy thousands of ozone molecules)

Acid Rain Forms as a result of reactions between Sulfur dioxide or Nitrogen oxides (from coal fired power plants) and water. Droplets may travel 100s of miles before falling as precipitation. Effects of Acid Rain Leach nutrients such as Ca and Mg Mobilizes toxic metals such as Al, Zn and Cu. Al in lakes kills fish – damaging their gills, disrupting salt balance

Acid Precipitation 3NO2 + H2O 2HNO3 + NO (HNO3 is nitric acid and causes acid precipitation) 2SO2 + O2 2SO3 followed by: SO3 + H2O H2SO4

Indoor Air Quality The quality of the air in our homes and school may be worse than the air outside!

Sources of Indoor Air Pollution VOC levels are consistently higher indoors (up to ten times higher) than outdoors. Examples include: paints and lacquers paint strippers cleaning supplies pesticides building materials and furnishings Photocopiers and printers correction fluids carbonless copy paper Glues and adhesives permanent markers

Sources of Indoor Air Pollution Furnaces and poorly ventilated space heaters contribute carbon monoxide Pressed wood (shelving) may contribute formaldehyde especially when new. Formaldehyde irritates mucous membranes and induces skin allergies Mold – spores will always be present in air. Only become a problem where moisture allows mold to grow

Radon Radon is a radioactive gas. It comes from the natural decay of uranium that is found in nearly all soils. It moves up through the ground to the air above and into your home through cracks and other holes in the foundation. Your home traps radon inside, where it can build up. Any home may have a radon problem. Radon in indoor air is estimated to cause about 21,000 lung cancer deaths each year in the United States. EPA recommends all homes be tested for Radon

Asbestos Sources include deteriorating, damaged, or disturbed insulation, fireproofing and floor tiles The most dangerous asbestos fibers are too small to be visible. After they are inhaled, they can remain and accumulate in the lungs. Asbestos can cause lung cancer, mesothelioma (a cancer of the chest and abdominal linings), and asbestosis (irreversible lung scarring that can be fatal). Symptoms of these diseases do not show up until many years after exposure began.

Air Quality at School Twenty percent of the U.S. population spend their days in our elementary and secondary schools. In the mid-1990s 1 in 5 of our nation's schools reported unsatisfactory indoor air quality 1 in 4 schools reported ventilation as unsatisfactory. Students are at greater risk because of the hours spent in school facilities and because children are especially susceptible to pollutants.