1. Environmental Concerns

2. Ozone
In the Stratosphere there is a layer of the gas ozone, which occurs naturally.
It forms a thick cloudlike layer that surrounds the Earth.
If this layer of protection were not present there could be no life on Earth as we know it.

3. Ozone shields the Earth from harmful UV radiation
Overdoses of UV radiation can cause minor problems to people such as sunburn and skin wrinkling or more major problems like skin diseases or death
UV radiation can also damage crops.

5. Ozone
One of the most serious problems of UV radiation is the damage caused to phytoplankton.
Phytoplankton are tiny, often microscopic, plants living in the ocean.
Phytoplankton are at the base of the ocean’s important food chains, so their well-being affects the entire marine world.

7. Ozone Ozone is a form of the element Oxygen (O).
Oxygen molecules usually consist of two atoms of oxygen
When oxygen molecules are struck by UV radiation, a chemical change occurs which bonds a third atom of oxygen onto the molecule.
This molecule, made up of three atoms of oxygen, is the gas called ozone. (O₃)

8. Ozone
Ozone is not a stable gas. It is constantly breaking down into oxygen molecules.
This process is a natural cycle.

9. Ozone
In 1985 scientists found a hole in the ozone layer over Antarctica.
This meant that an increased amount of UV radiation would reach the Earth’s surface.
One explanation is that weather conditions over the South Pole allow chemicals called chlorofluorocarbons(CFCs) to destroy ozone.

11. CFC’s
Until recently, most people thought these chemicals did not have negative effects on the environment.
They were used as coolants for refrigerators and air conditioners. They were also used to manufacture Styrofoam, cleaners for electronic equipment, and as propellants in aerosol sprays.

12. CFCs
Over time, CFCs float up to the stratosphere, they are transformed by the sun into molecules that destroy ozone molecules.
CFCs can last hundreds of years, destroying millions of ozone molecules.
The CFCs interrupt the natural cycle of production and decomposition of ozone.
The amount of ozone in the stratosphere is decreasing and the amount of oxygen is increasing.

14. CFCs CFCs from refrigerators and air conditioners are now recycled.
CFCs are no longer used in aerosols in the US
Not all countries are phasing out these chemicals.
The CFCs currently in the atmosphere can last for hundreds of years.

15. The second kind of ozone is created at ground level.
Ozone in the troposphere causes many problems.
Ozone in the troposphere is one of the two primary components in Smog.
Smog is a low-lying visible layer of polluted air

17. Smog
When we breathe in ozone, it can cause chest pains, headaches, and sore throats.
Exposure to ozone can damage lung and eye tissue and lower resistance to diseases.
Ozone can also lower the yields of important crops such as soybeans, kidney beans, wheat, and cotton.
It has a negative impact on forests and ecosystems.

18. Temperature Inversion
Temperature inversion increases the amount of smog concentrated over a particular area.
In a temperature inversion a layer of cold air is trapped next to the Earth’s surface by a warmer layer of air above it. This warm layer of air cannot rise, so the air is motionless. Wind is unable to enter and remove smog from the area. Therefore the warm layer allows pollution to build up to levels necessary for ozone production.

20. Smog
Smog and ozone pollution are usually associated with cities having large concentrations of cars, trucks, and industries.
Wind and weather systems can transport ozone to other regions.
Smog is a problem everywhere.

21. Pollution
The 1990 Clean Air Act required the manufacture of cleaner cars.
Factories have lowered amounts of VOCs and NO₂ they are releasing into the atmosphere.

22. Particulate Matter
Ozone is one of the main ingredients of smog. The other main ingredient is particulate matter.
Particulate matter is made up of very small solid particles and liquid droplets in the air.
Too small to be seen with the human eye, but when there is a large percentage it appears couldy or hazy.

23. Sources of particulate matter
Natural sources
Dust
Forest fires
Volcanic eruptions
One volcanic eruption results in millions of tons of particulate matter entering the atmosphere.
Pollen

24. Sources of particulate matter
Other sources
Industries
Vehicles (a car traveling down a dirt road)
Because of the many different sources, particulate matter is hard to control.

25. Particulate Matter
The presence of particulate matter in the air is a health hazard.
It affects the human respiratory tract
The ones who suffer most are children, the elderly, or people who already suffer from lung or breathing disorders.

26. Pollen
Pollen is one of the natural kinds of particulate matter that is bothersome to many people.
Pollen particles are tiny, dust-like grains that seed plants produce.
In NC pine pollen is abundant
It is the yellow dust that you see on cars, decks, and sidewalks in the springtime.
Pine pollen is not the biggest problem for most people because the particles are so big.

27. Haze
When particulate matter suspended in the atmosphere, visibility decreases.
Cloud-like concentrations of particulate matter are called haze.
Haze is usually produced over urban and industrial areas, but it can travel hundreds of kilometers.

28. The Human Factor
Human activities have had a significant effect on our atmosphere.
Scientific studies show that factories, automobiles, fires, and land clearing introduce particles and gases into the atmosphere. This alters the quality of our air.

29. The Human Factor
The United States Environmental Protection Agency (EPA) divides pollutants into two categories.
Point source pollution can be traced to one specific place, like a smokestack
Non-point source pollution sources include mobile, area, and biogenic sources. (like vehicles, and hog farms)

31. The Human Factor
The pollution of the atmosphere is a problem that cannot be ignored
People must take certain measures to comply with EPA standards.
We can ride a bike or carpool
Someday humans could have a positive impact on air quality.