POLLUTION

Air Pollution• Naturally occurring – dust, pollen, volcanic

eruptions• Human caused - Industrial burning,

automobile exhaust • Two types of air pollution:

– Primary: put directly into the atmosphere(ex: volcano, vehicles & coal burning)

– Secondary: forms in the atmosphere through chemical reactions(ex: ozone, smog)

Industrial Air Pollution

• Many industries and power plants burn fossil fuels to generate energy– (creates sulfur

dioxide, carbon dioxide, soot & carbon monoxide in atmosphere)

SmogDepends on:- local climate- Fuels used- Population density- Open fires

Natural Dilution

• Convection currents usually carry pollutants away from ground.

• Air close to ground is usually warmer than air at higher altitudes– less pressure at high

altitudes– less particles– therefore lower

temperature

Natural Dilution- When temperature inversions occur, pollution is

trapped near the surface- When air movement is low – disrupts convection

currents (at night, during a cold day, in a valley)- Cool air settles close to ground, warm air forms a

blanket above it

Thermal Inversions

Indoor Air Pollution Sources:industrial

chemicals,insulation,carpets,paint,

radon,carbon

monoxide,asbestosA “high risk

health problem”

Indoor Air Pollution

Can be reduced by:

- Modifying building codes to prevent radon

- Requiring exhaust hoods for applicances

- Set emissions standards for building materials

- Use office machinery in ventilated areas

Radon Gas

- Produced by decay of uranium found in

Earth’s crust.- Seeps through small openings in

buildings & sticks to dust particles

Radon Gas

• - Dust is inhaled by inhabitants & damages lung tissue

• - Many houses with basements have radon detectors

Asbestos• - Silicate mineral -

forms fibers that are heat-resistant, thin, strong, and flexible

• - Used for insulation and fire resistance in building materials

• - Found to be dangerous when inhaled and banned in 1970s

Asbestos

• - Exposure to asbestos particles cause severe damage to lung tissue

• - Causes difficulty breathing and possible heart failure

• - Rain, sleet, or snow containing a high concentration of acids due to air pollution

• - Sulfur dioxide and nitrogen oxides combine with water vapor

• to produce sulfuric acid and nitric acid- A regional problem

Acid Precipitation

• Flows into lakes, rivers, and streams.• Can kill/harm organisms

Acid Precipitation

- Normal precipitation is slightly acidic – carbon dioxide

forms carbonic acid

- Acid precipitation has pH of <5.6

- Typical rain in Eastern US is 4.6

Acid Precipitation

Acid Precip. Damage

- Causes a drop in pH of soil and water (acidification) that results in loss of soil nutrients & plant root damage

Acid Precip. Damage

- Can kill aquatic plants and animals.- Causes aluminum to leach out of soil

surrounding a lake. – accumulates in gills – fish suffocate

Acid Precip. Damage

- Acid shock - runoff of very acidic water into lakes and streams

- Decreases number of eggs produced at a time– many eggs do not hatch– birth defects common

Acid Precip. Damage

- Bodily harm to humans– Toxic metals released soil can be

absorbed by crops, water, and fish

- Economic impact– Decreases in numbers of fish– Damaged trees

- Aesthetic impact– harm to buildings

Acid Precip. Damage

Statue on a German castle built in 1702

Photograph from 1908 Photograph from 1968

Chlorofluorocarbons

• Nontoxic• Used in air conditioners, aerosol

spray cans, sterilants at hospitals and cleaners for computer chips.

• Take 10-20 years to reach stratosphere.

• Greatest contributor = air conditioners

Review…

• Carbon dioxide• Ozone• Layers of atmosphere

Who is affected?

• Infants• Elderly• People with heart and respiratory

disease• Pregnant women

Water Pollution

• Two main causes of water pollution:– 1. Industrialization – 2. Rapid human population growth

Water Pollution

• Comes from two types of sources: • 1. Point sources• 2. Nonpoint sources

Point-Source Pollution

• Comes from a specific site

Nonpoint-Source Pollution• Comes from multiple sources

Wastewater

- Contains wastes from homes or industry

- Wastewater treatment plants filter and treat water

Wastewater Treatment Process

Sewage Sludge

• - Byproduct of wastewater treatment • - Large volume of sludge is created each

year• - If toxic

– incinerated, and ash is buried in a secure landfill

• - Low toxicity– used as fertilizer– combined with clay to make bricks

Eutrophication

• Is accelerated when nutrients (P, N) enter water from fertilizer runoff, sewage, detergent.

Eutrophication

- Decreases dissolved O2 in water

- Due to build up of organic matter- Can convert body of water into

swamp or marsh.

Thermal Pollution

- Temperature increase in a body of water caused by human activity

- Result of industrial use

Thermal Pollution

- Decreased levels of oxygen- Death of aquatic organisms

(suffocation)- Destruction of entire habitat

Groundwater Pollution

- Common pollutants:PesticidesArtificial fertilizersLandfillsIndustrial wasteLeaking septic/waste tanks

Cleaning Up Groundwater Pollution- Big problem- Length of time to recycle ground

water- Pollution can remain after water is

recycled

Ocean Pollution

- DumpingWastewaterGarbage

- Most (85%) ocean pollution come from coastal land

- Coral reefs exist near coasts and are deeply impacted

Oil Spills

- Cause 5% of pollution in oceans - Mostly from cities and towns

Water Pollution in Ecosystems

• U.S. states limit amount of fish consumed from certain bodies of water

Water Pollution in Ecosystems

Biomagnification - accumulation of pollutants at successive levels of food chain.

Cleaning Up Water Pollution- The Clean Water Act (1972)

designed to restore and maintain clean water in US

- Goal: make surface water clean enough for fishing and swimming by 1983Missed goalResulted in stricter water-

quality standards nation-wide

Cleaning Up Water Pollution- Marine, Protection, Research, and

Sanctuaries Act (1972) Prevent ocean dumping

- Oil Pollution Act (1990) All oil tankers traveling in U.S. waters

must have double hulls by 2015