1. Air Quality

2. Pollution
Pollutants are harmful substances in the air, water, and soil. Air pollution affects the health of all living things. Some pollution occurs naturally and some is a result of human activity.
Sources of Air Pollution
1. Natural Sources: events like forest fires, soil erosion, dust storms, and volcanoes release smoke, dust, ash, and dangerous gases into the air.

4. Natural Air Pollution: Iceland Volcano
Iceland’s Eyjafjallajokull volcano erupted in 2010.
The “E” volcano shot smoke and ash (CO2, SO2 and SiO2) 7 miles up into the atmosphere, and prevailing winds carried this ash across Europe.
100,000+ flights were cancelled over 8 days, resulting in a $1.2 billion loss to the airline industry.
Main impact of this event was economic.

6. 2. Human-Caused Air Pollution
Most human-caused air pollution is created when people burn fossil fuels (coal, oil, gasoline) to produce electricity and fuel transportation.
Burning these fuels releases the following pollutants into the air:
Photochemical smog -- Pollutants/smoke mix with H2O vapor and react with sunlight to form “bad” ozone
CO2 -- greenhouse gas linked to global warming
Carbon monoxide (CO) – can creat “bad” ozone
SO2 -- makes it difficult for blood to transport oxygen to the cells, forms acid rain
Nitrogen dioxide (NO2) -- can cause lung damage, forms acid rain

7. Human Air Pollution: London’s Killer Fog
From December 5-9, 1952, a “Killer Fog” took the lives of over 4,000 people in London, and made over 100,000 people sick with respiratory infections.
SO2 and soot from burning coal combined with water vapor to form a 30-mile wide air mass of poisonous smog over London.
The “Killer Fog” was caused by human and natural factors:
In response, England passed the Clean Air Act of 1956
Natural Factors
Human Factors
1. Unusually cold winter in London
1. Lots of coal burned to heat homes
2. High-pressure air front = little air movement over London
2. City buses and cars burning diesel fuel added to pollution

9. Improving Air Quality
Over the past 50 years, many laws have been passed to reduce air pollution in the U.S. and globally.
The environmental protection agency (EPA) monitors and regulates air pollution in the U.S.
Globally, air quality has generally improved because of:
1. Improved technology in cars and power plants
2. Stricter laws on air pollution
However, there are more cars on the road and more power plants than in the past, so air quality is still an issue.
Regulations must constantly be made to control air pollution.