AIR QUALITY

Consider: An oxygen tank costs $50. 1,000,000 Americans wouldn’t need 2 tanks per week for emphysema/bronchitis if air pollution is decreased. A savings of $5.2 billion dollars yearly. Why do you care? Insurance/Taxes

The Atmosphere  Whole mass of air around the earth Components: Components: 78% N 2, 21% O 2 Water, Carbon dioxide (0.03%), helium, etc. make up the remainder. Realize- earth’s circumference is 24,800 miles. Atmosphere is FINITE!!!

Layers of the Atmosphere

DID YOU KNOW? Mexico City has some of the worst air quality in the world. Over 22 million people in a valley 7575 ft above sea level. Cars are less efficient, pollutants are trapped in valley, little air quality legislation for business all result in “bad air”.

Air Pollution  any substance in the air that causes harm to living organisms. TWO TYPES: 1.Natural—volcanoes, pollen, forest fire smoke, salt 2.Human Activity—produced by US!!!

2. Human Activity cont. Two forms of Pollution Due to Human Activity a.Primary—released directly into the atmosphere as a pollutant. Includes: soot, CO, NO x, SO x, VOC’s (volatile organic compounds), CO 2

Human Activity cont. b. Secondary—primary pollutants combine with other compounds to produce pollutants Includes: *Smog—smoke + fog *Ozone—UV light + exhaust + Oxygen *Acid ppt—SO x + NO x + H 2 O vapor

Temperature Inversions  Cold, cloudy weather in a valley surrounded by mountains can trap air pollutants (left).  Areas with sunny climate, light winds, mountains on three sides and an ocean on the other (right) are susceptible to inversions. Figure 19-5

Sunlight plus Cars Equals Photochemical Smog  Mexico City is one of the many cities in sunny, warm, dry climates with many motor vehicles that suffer from photochemical smog. Figure 19-4

Sunlight plus Cars Equals Photochemical Smog  Photochemical smog is a mixture of air pollutants formed by the reaction of nitrogen oxides and volatile organic hydrocarbons under the influence of sunlight.

Acid Precipitation  Cars/Factories/PowerPlants  NOx + SOx + H 2 O  HNO 3 + H 2 SO 4 Kills plants by leaching nutrients into the soil, destroys leaves. Kills fish, invertebrates by “suffocation”. Destroys buildings, paint, etc.

ACID PRECIPITATION  Acid deposition consists of rain, snow, dust, or gas with a pH lower than 5.6. Figure 19-6

Fig. 19-9, p. 451 Emissions SO 2 NO x Acid deposition H2O2H2O2 O3O3 Others Direct damage to leaves & bark Reduced photo- synthesis and growth Susceptibility to drought, extreme cold, insects, mosses, & disease organisms Soil acidification Tree death Leaching of soil nutrients Release of toxic metal ions Root damage Reduced nutrient & water uptake Acids Lake Groundwater PANs

DID YOU REALIZE? 1/3 of air pollution comes from cars1/3 of air pollution comes from cars 2/3 sulfur oxides and 1/3 nitrogen oxides come from electrical plants2/3 sulfur oxides and 1/3 nitrogen oxides come from electrical plants Companies buy/sell emission rights!!Companies buy/sell emission rights!!

DID YOU KNOW?  The first Clean Air Law was designed in the 1200’s by King Edward I. He was tired of the smell from burning low quality coal.  He made it illegal and hung a violator in 1273!!!  Moral of the Story—don’t burn stinky stuff!!

CLEAN AIR ACT  1970 and 1990—EPA regulations for air quality.  Reduced carbon, nitrogen and sulfur oxides as well as particulates.  Cut lead pollution by 98% by got rid of leaded gasoline, mandated catalytic converters Catalytic Converter- Reduced vehicular pollutants 20X!!!!  32% less pollutants in air than in  Problem – 220 million Americans still breathe air 100X more polluted than desired.

Chloroform Benzo-  -pyrene Styrene Radon-222 Methylene Chloride Tobacco Smoke Carbon Monoxide Asbestos Nitrogen Oxides 1, 1, 1- Trichloroethane Particulates FormaldehydeTetrachloroethylene Para-dichlorobenzene Fig , p. 453

Case Study: Radioactive Radon  Radon-222, a radioactive gas found in some soils and rocks, can seep into some houses and increase the risk of lung cancer. Sources and paths of entry for indoor radon-222 gas Sources and paths of entry for indoor radon-222 gas. Figure 19-13