Learning Goal:Explain the sources of air pollution and causes of acid rain, the affect it has on ecosystems and humans, and how it can

be reduced.

Agenda:

• Discuss aspects of air pollution & acid rain

• Conduct an experiment to determine which source was the greatest contributor to acid rain and what can be used to neutralize it

Homework:

• Complete the analysis questions from the activity

What is Air Pollution?

• Any substance released into the atmosphere that causes damage to the environment, human health, and/or quality of life.

Sources of Air Pollution1. Stationary and Area Sources

– power plants, chemical and manufacturing industries.

2. Mobile Sources – vehicles, recreational vehicles, boats,

planes, and trains.

3. Agricultural Sources – fertilizers, herbicides, pesticides, and

animals produce manure that emits gases.

4. Natural Sources – erupting volcanoes, fires, sea spray, dust

storms, pollen

What is Acid Rain?

• Precipitation with a pH lower than 5.6• Affects ecosystems• Damages buildings• Ruins monuments• Affects health• Costs money

Where does it come from?

• Coal burning power plants (electric utilities)

• Automobile emissions (NOx, CO, VOCs)

How it works• Sulfur dioxide and

nitrogen oxides released into the air combine with water and become sulfuric acid and nitric acid.

• These acids fall to earth as rain, snow, sleet, or hail.

How it affects ecosystemsAffects Buffering Capacity - the ability of lakes and soils to

neutralize the acidity or alkalinity of it’s environment is reduced

Soil:• It brings out soil toxins which end up in the water and

absorbed through the roots of trees.• High-elevation forests soak in acidic clouds, which strip leaves

of nutrients and break down trees' ability to resist cold. Bodies of Water:• It increases nitrogen in the water, which increases algae

growth.• Bacteria then decompose the dead algae and soak up the

water's available oxygen (dissolved oxygen). • Fish, shellfish, sea grass beds and coral reefs die in the algae-

choked, oxygen-depleted waters. • Scientists estimate that 10 percent to 45 percent of human-

produced nitrogen that winds up in coastal waters comes from atmospheric deposition [Source: Environmental Protection Agency].

• Trees killed by acid rain in the Smoky Mountains.

How it affects buildings and monuments

• Erodes building materials like marble and limestone more rapidly than normal

• Causes metals to rust rapidly

How it affects health

• Biodiversity is reduced – alters populations in oceans, lakes, rivers, streams

and ponds.

• Human health– The sulfate and nitrate particulates of dry

deposition can cause asthma, bronchitis and heart problems.

– The NOx also reacts with other chemicals in the air to form ground-level ozone, which aggravates and weakens the respiratory system. (source: http://science.howstuffworks.com/acid-rain.htm)

What can be done?

• Power plants use:– Low sulfur coal– Wet scrubbers (trona)– Electrostatic precipitators– Flue gas desulphurization systems – low NOx burners

• Vehicles use:– Catalytic converters help remove NOx

• Use alternative forms of energy – Wind, nuclear, solar and hydropower don’t release

SOx, NOx

• Liming the waters to buffer the acidity• Reduce energy use and automobile use

Liming process