Pollution and Waste

Chapter 6

100 years ago…

This was the first time humans became concerned with pollution

But they were only concerned with its effects on human life, not on Earth’s ecosystems

Pollution

Any product or material • produced by humans in quantity and

• disposed of in a way that interferes with the health of living organisms, natural environments, and Earth’s processes

Today, pollution is the result of 2 factors:

• Technological advances since the Industrial age

• Increased population densities associated with urbanization (particularly in the MDCs of the northern hemisphere)

Types of pollutants

Persistent > remain in the environment for many years without breaking down• Mostly made by humans and come from

industrial activities

• Stable and often toxic

• Includes• Pesticides such as DDT

• Synthetic compounds such as CFCs and PCBs (polychlorinated biphenyls)

• Heavy metals such as mercury, lead, and cadmium

Types of pollutants (cont’d)

Non-persistent• Biodegradable, so do not stay in environment

• Includes• Human waste

• Food

• Some synthetically produced materials

• Some pesticides and chemical compounds that break down quickly

Air pollution

Primary• Comes from industrial and manufacturing processes

• Mining, refining, and combustion

Secondary• Results when primary pollutants interact with each

other or with other compounds

• 2 main types

• Smog

• Acid rain

Primary air pollution includes

Carbon dioxide- from burning fossil fuels (coal, natural gas, oil) • Carbon is completely oxidized

Carbon monoxide- from burning fossil fuels• Carbon is completely oxidized

• Health risk, or poisonous

Primary air pollution includes

Hydrocarbons• These organic compounds contain carbon

and hydrogen

• Come from automobile exhaust and factory smokestacks

• Component of smog

• Cause respiratory problems

Primary air pollution includes

Particulates- tiny pieces of solid materials, that come from• Smoke

• Asbestos (insulation)

• Dust from construction, demolition, and mining

• Ash• Cause respiratory problems

• Can be carcinogenic

Primary air pollution includes

Sulphur dioxide- from burning fossil fuels that contain sulphur• Strong odour

• Irritates throat and lungs

Nitrogen oxides- from burning fossil fuels• Harmful to respiratory system

• Can react and form secondary pollutants

Secondary air pollution: smog

Term originally used in 1950’s in London, England

Special weather conditions prevented lower air levels (with pollutants) to rise and be dissipated

Severe respiratory problems developed “killer fog” blamed for 400+ deaths

2 types of smog:

Industrial- • reduced in MDCs due to emission-control

regulations

• Increasing in LDCs

Photochemical-• Hovers over cities on hot calm days

• Due to thermal inversion (page 133)

Secondary air pollution: acid rain

Burning fossil fuels and industrial processes release sulphur and nitrogen oxides into the atmosphere

These compounds dissolve in cloud droplets

They can move 1000’s of miles before falling to Earth

Acid deposition

Liquid and dry acid accumulates on earth, in water, in soil, on vegetation, and on buildings

Effects:• New plants, root systems, forests

• Fish in lakes and rivers

• Salmon, loons in Kejimkujic Lake

• Corrodes stone, cement, cars, roofs

• Causes respiratory problems and allergic reactions in people

Water pollution: One of the most serious environmental concerns Some of the world’s largest rivers are among

the most polluted• Rhine in Europe• Hudson in the US (New York)• Vistula in Poland• Volga in Russia• Ganges in India• St. Lawrence (more than 30 hazardous chemicals

identified)• 22 other US and Canadian rivers are severely polluted• Malaysia- 40 rivers are biologically dead

Water pollution: Lakes and oceans

Lakes lack outflows or currents to remove pollutants • Great Lakes in N.A. on-going efforts by US and

Canada to start clean-up

Oceans are no longer safe either Storm drains – drain to larger bodies of water

• Have had motor oil, paint and paint thinners; plastic and foam containers; antifreeze; yard waste

Hazards of Water pollution:

Diseases (cholera, dysentery, hepatitis) caused by bacteria, viruses, and protozoa from human and animal wastes

Excessive growth of algae from too much nitrogen and phosphorus –this kills off some organisms because it blocks light to deeper areas of water

Hazards of Water pollution:

Suffocation of fish, aquatic vegetation and other organisms from sediment built up from erosion

Oil spills kill seabirds, fish, and animals Synthetic compounds and heavy metals are

toxic• So congenital defects

• Disabilities

• Health problems