Air & Air Pollution “Is anyone out there, ‘cause it’s getting harder and harder to breathe.” Maroon 5 (2002)

The Atmosphere Exosphere ◦“Outer space” Thermosphere ◦Where satellites orbit Mesosphere ◦Where meteorites burn Stratosphere ◦Where ozone is found Troposphere ◦Where life occurs

The Troposphere Extends to about 65,000 feet elevation. Home to life and all weather we encounter. Could be represented as the skin of an apple. Greenhouse gases trapped here have made Earth hospitable and allow water to occur in 3 states of matter. Approximately, 78% Nitrogen, 21% Oxygen. Is changing at an alarming rate.

Greenhouse gases in the Troposphere. Water vapor CO 2 Ozone ◦Ozone in the troposphere is harmful, ozone in the stratosphere is beneficial. Go figure. Methane Nitrous Oxide CFCs Levels have been rising, primarily CO 2.

The Stratosphere Extends to about 160,000. Ozone layer resides here. The next generation of air travel is likely to exploit the low barometric pressure of the stratosphere.

Mesosphere and Thermosphere The largest portion of the atmosphere. Extends to about 300,000 feet. Extra-terrestrial objects encounter air pressure and most burn up, causing “shooting stars”. Thermosphere extends to about 2 million feet. Temperatures soar as a result of solar radiation (up to 2,730 °F). International Space Station (ISS) orbits in this region. There exists a large quantity of “space junk” in this region. Occasionally, objects leave orbit and plummet to Earth.

Exosphere Known as “outer space”. Extends to the “event horizon”. Microgravity. All other objects in the universe are found in the exosphere.

Air Pollutants Primary – Chemicals and particulates released directly into the air. Secondary - Primary pollutants interacting with one another in the atmosphere to form new compounds. Air pollution causes loss of income, illness, and death.

Smog (Smoky Fog) Photochemical (Brown-Air) Smog – caused by chemicals reactions activated by light. Result of reaction are Secondary pollutants such as ozone, and aldehydes. These cause respiratory distress and can damage crops and trees. Since these reactions are driven by sunlight, their occurrences vary seasonally.

Smog (Smoky Fog) Industrial (Gray-Air) Smog – caused by large amounts of particulate matter thrown up from coal burning factories. Typical of “steel towns” such as London, England, Allentown and Pittsburgh, PA, and, until recently, Baltimore, MD.

Indoor Air Pollution Dust Material “off-gassing”

Clean Air Act (12/31/70) Has 3 major provisions. ◦1. Emissions limitations – we are on track to meet standards as set.  Emissions standards for vehicles are most effective and have been very effective. ◦2. Ozone Protection – we are on track to meet standards as set. ◦3. Prevention of Air Quality Deterioration – we are ahead of schedule to meet standards as set.

Acid Deposition When carbonaceous material (containing nitrogen and sulfur compounds) are burned in the presence of oxygen, carbon-, nitrogen, and sulfur-oxides are relaesed. These oxides react with water in the atmosphere to form acids. This weak acid solution reaches the earth in the form of precipitation. Acid precipitation has a cumulative effect on plants, animals, and structures. Soils are too acidic for vigorous plant growth. Edifices are wearing away and must be repaired/replaced. Health effects Trillions of dollars are being spent annually to combat the effects of this deposition.