How Clean is our Air? Investigating Air Pollution

What is Air? Invisible, tasteless, and odorless mixture of gases that surrounds us Two categories Inside air Air found inside buildings Ambient air Air (atmosphere) outside

What is Air? Major components of air Nitrogen -78% Oxygen – 21% Argon – 0.9% Carbon dioxide % Trace gases Neon, ammonia, helium, methane, krypton, hydrogen

Air Quality Availability of quality air is critical to both plants and animal Both ambient and inside air quality is important

What is Air Pollution? The presence of materials in the air that damage air quality Anything other than the natural gases present Results from Natural events Human activity

Types and Sources of Air Pollution Two major types of air pollutants Particulate matter Gases

Particulate Matter Small particles similar to dust and droplets of liquid Most visible and noticeable type of air pollution Most air pollution is of this type In cities, 90% is due to human intervention

Particulate Matter Examples: Smoke from factories Burning trash and forest fires Dust from roads and mines Lint Pollen

Gases Difficult to identify Remain in the atmosphere for years Classifications of gas pollutants Carbon forms Sulfur oxides Nitrogen oxides

Carbon Forms Released through combustion or burning of materials that contain carbon Include Hydrocarbons Carbon monoxide (CO) Carbon dioxide (CO 2 )

Hydrocarbons Volatile organic compounds (VOC) Compound containing carbon that forms when sunlight reacts with chemicals in the atmosphere Sources of chemicals Evaporating gas and oil Paints, primers, sealers Organic chemicals (toluene, benzene, phenols, chloroform)

Carbon Dioxide and Carbon Monoxide Internal combustion engines release carbon gases Complete combustion = carbon dioxide Incomplete combustion = carbon monoxide One billion metric tons of carbon monoxide released every year by vehicles alone Carbon dioxide is a major component of smog

Sulfur Oxides High level can be detected by a “rotten egg –type” odor Common sulfur oxides Sulfur dioxide(SO 2 ) Sulfur trioxide(SO 3 )

Sulfur Dioxide Produced when fuels containing sulfur are burned Coal and oil Natural sources Volcanoes Sea spray Dust from soil Sulfur dioxide is the second major component of smog

Sulfur Trioxide One major gas that causes acid rain Able to combine with water vapor to form sulfuric acid (H 2 SO 4 ) Very strong acid quickly reacts with materials when contract is made Acid rain can cause damage to plants and property.

Nitrogen Oxides Formed during combustion of fuels with nitrogen Common forms Nitrogen monoxide (NO) Nitrogen dioxide (NO 2 ) The effects of nitrogen oxides are similar to those of of sulfur oxides. Another major gas that causes acid rain

The Effects of Air Pollution Human health problems mostly respiratory diseases Common diseases Lung Cancer Emphysema Bronchitis Black lung diseases

The Effects of Air Pollution All air comes in through nostrils small hairs and moist membranes that filter dust and some gases Materials that get past the small hairs may be absorbed by the mucous membranes in lungs.

The Effects of Air Pollution

Air pollution affects lungs of other animals similar to humans Feed produced in areas near high air pollution may be poisoned Acid rain can also destroy wild fish population in lakes and streams if in a strong enough concentration

The Effects of Air Pollution Air pollution may cause damage to fruits, vegetables, flowers, trees, lawn grasses, and other plants. Several pollutants can destroy leaf tissue in plants. Plant cannot manufacture the needed chlorophyll

Protecting Air from Pollution Controlling emissions Scrubbers can be used on factory stacks Use fuels that produce less sulfur, carbon, and nitrogen Maintaining engines less fuel is burned = fewer pollutants Reusing and recycling Practicing safety