Pollution - yorku.ca · PDF fileSC/NATS 1510, Pollution 26 Toronto’s problem ... major headache

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PollutionMaltreating our water, earth, and air


The legacy of Silent Spring• Rachel Carson made us

aware of the extent to which we have abused the environment.– In 1970 the U.S. formed the

Environmental Protection Agency.

– Industrialized countries everywhere formed ministries of the environment or like agencies.


Focal points of pollution

• Three main areas received the post attention:– Water– Earth– Air

• Each one has its own concerns. We deal with each separately here.

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Abusing the water

• Water pollution in the United States was dramatically brought to the attention of Americans on June 22, 1969, when the Cuyahoga River in Cleveland, Ohio, caught fire, so polluted was it with oil slicks and combustible debris.


The Clean Water Act

• The U.S. responded with the “Clean Water Act” in 1972, which was intended to restore American waterways to their natural state.

• Problem:– What was their natural state?

• Before any human interference?• Before industry?• Before the chemical industry?


Beavers and wetlands

• To consider what the waterways of North America might have been like before human interference, consider, for example, what they were like before beavers were heavily hunted.

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The vital role of beavers• Beavers build

homes of tree trunks and branches (“lodges”) in shallow waters that protect them from their main predators.

– In order to assure that the top of the lodge is above water, but the entrances at the bottom are below water, they build dams that slow the drainage of water.


Deforestation

• Human civilization seems to bring on deforestation everywhere it occurs.

• Forests hold the soil in place and become a habitat for microorganisms that clean and preserve the water.– Only recently have we begun to

realize the importance of natural forests.


Deforestation, 2

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Farming and irrigation

• Irrigated farming is much more productive than dry farming, but it requires a lot of water.– Not only can the farmland

become waterlogged and too saline to grow crops, where mechanized means exist for pumping in water, the water supply is threatened.


The Ogallala Aquifer

• The breadbasket of American farming is in the prairies in the MidWest, where irrigation waters come from an underground aquifer, the Ogallala.– This water is not a renewable resource. It

was trapped underground millions of years ago.

– It has now been depleted to about ½ of its former size.


Dams• Another

diversion of natural water flow for human use is the construction of giant dams to provide electricity, flood control, and irrigation for otherwise dry farmland.

James Bay Dam in Quebec

Three Gorges Dam in China

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The Problem with Giant Dams• Dams hold back the normal

flow of sediment, which contains nutrients the soil needs.– Ruinous for farming in Egypt

after the Aswan High Dam was built.

– Sediment also prevents downstream erosion.

• Salmon runs have been ruined as the fish cannot go upstream to spawn.


Effluent• The easiest

way to get rid of liquid waste is to dump it into the water system.

• From its beginnings, industry has done so, especially the chemical industry.


The Great Lakes problem

• Many chemical industries are located on the shores of the Great Lakes and have routinely dumped their waste into the lakes, from which we get our drinking water.

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PCBs – Polychlorinated Biphenyls

• A wonder chemical first manufactured in 1929.• Used as insulators in electrical transformers

because they would not catch fire, and in many other products.

– So useful, they began to be used everywhere.– Part of their usefulness is because they do not

degrade easily.


PCBs in the Great Lakes

• Like DDT, PCBs accumulate in the water system and become more concentrated up the food chain.

• Like DDT, PCBs are toxic to animals, especially fish.

• Like other effluents, they have been dumped in excess into the Great Lakes.


Mercury• Mercury has been widely

used as a catalyst in the production of caustic sodas. – When it had done its job it was

discharged into the water supply, presumably to remain on the bottom of the lake or river because of its weight.

– However, it was consumed by bacteria that made it into an organic compound that made its way up the food chain into fish.

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Mercury poisoning

• In 1932 it was discovered in the Minamataregion of Japan that the local fish were contaminated with mercury, and these were being consumed by people who then suffered brain damage.– Now called Minamata Disease.– A great deal of mercury has been

discharged into the Great Lakes.


Detergents

• Detergents, which (usually) contain phosphates are of course discharged into the water system.– Result: Sudsy waterways, and

rapid plant growth in water from the phosphate content.

– Lake Erie called “dead”because it was choked with algae.


Oil spills

• The industrialized world runs on oil, much of it imported across the oceans by huge tankers.

• Given the amount of supertanker traffic, it is inevitable that there will be accidents.

• These are ruinous to the coastal regions near the spill.

The Exxon Valdez spill in Alaska in 1989.

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Sewage and the Toilet• It is vital that

civilizations dispose of their human waste without contaminating their drinking water.

• To that end, the flush toilet has been a boon.

• But where does the sewage go?


Sewage and the River

• Typically, sewage was dumped into a nearby river, which may also have been the source of drinking water for the same community or for one downstream.

• In the mid-19th century, the Thames River in London, England, was dangerously contaminated.

19th century British cartoons depicting the polluted Thames River: “The Great Stink.”


Abusing the Earth

• From Anita Gordon and David Suzuki’s It’s a Matter of Survival:

– A typical North American goes through and discards 7 kilograms of junk mail and 54 kilograms of newsprint each year. Each day, North Americans use hundreds of thousands of plastic tampon holders. Each hour, we throw away more than 2.5 million non-returnable, non-recyclable plastic bottles…. Modern life is a garbage maker’s perpetual-motion machine….

A landfill site.

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Waste disposal• A major problem of cities:

– Waste disposal.• Possible solutions:

– Landfill sites – easily become toxic.

– Incineration – good for getting rid of solid waste, but at the cost of producing air pollution.

– Recycling – promising, but (1) expensive and may use more resources than it saves, and (2) it may just reinforce the throwaway culture.


Toronto’s problem• In February, 2006, Toronto is

in desperate need to find a new trucking company to haul its garbage to a landfill site in Michigan when the current company’s contract runs out March 31.– The present shipper does not

want to continue.– What if Toronto stopped

shipping its garbage to Michigan?


Not in my backyard….• From the Toronto Star, February 14, 2006:

– “If Toronto stopped shipping its garbage to Michigan today, by Friday morning the city would have run out of storage room.

– “In December, Michigan state senate voted 34-1 for a bill to bar Canadian trash….

– “Early last year Southgate township, near Collingwood, showed interest in taking Toronto’s garbage as a way to make money and keep property taxes down. But just days after the idea became public last January, the wrath of local residents forced council to vote against the plan.

– “In 2000 a plan to ship garbage 600 km north to the open-pit Adams Mine fell through – one reason was fierce opposition from people sivingsouth of the site. In 2004, the province passed the Adams Mine Lake Act, which prevents it from ever being used for landfill.”

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Hazardous Waste• A special problem of

industrialization.• Landfill sites filled with waste

materials that pose a health hazard can easily leach dangerous chemicals into the water table, or spew toxic fumes up out of the ground.

• This is especially a problem where a landfill site was filled, then closed and landscaped for housing to be built upon it.


The case of Love Canal• In the 1890s, an

engineer named William T. Love designed an industrial canal in Niagara Falls, New York.

• It was never completed, but the site for it was named “Love Canal” and was later used as a dump for 30 years, starting in 1920, by the city of Niagara Falls, NY, the U.S. Army, and then by the Hooker Chemical Company.


Love Canal, 2

• The Hooker Chemicals and Plastics Corporation dumped 20,000 tonnes of chemical waste, including PCBs, dioxins, and pesticides into the canal trench in barrels that eventually rusted and leaked.

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Love Canal, 3

• When the landfill site was full, it was covered over and donated to the city of Niagara Falls, which allowed a residential housing development on the site.


Love Canal, 4

• In the 1970s, the area was noted for bad odours. – Toxic chemicals began to leach into the basements of

homes.– There was a high incidence of childhood cancer and

miscarriages.• It became a national disgrace.

– Local resident Lois Gibbs, above left, who had children in a school built right above the dump led the local campaign for remedial action.

– Celebrities such as Jane Fonda, above right, came to Love Canal to make speeches against government intransigence.


Love Canal, 5

• Finally in 1980, President Jimmy Carter signed into law a bill to relocate the residents at government expense and to clean up the site.

– Above, President Carter standing with Lois Gibbs at the signing of the Love Canal Bill.

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So, where to dump hazardous wastes?

• Dumping hazardous wastes in North American residential neighbourhoodsresulted in unpleasant consequences.

• Solution: – Dump them in the 3rd World.


Koko, Nigeria

• In 1988, the Nigerian government discovered that an Italian construction company, using forged papers, had smuggled tonnes of toxic and radioactive wastes into Nigeria and deposited them in barrels into the backyards of willing residents of the village of Koko who “rented” the space to them for a fee.


Legitimate Nuclear Waste Disposal

• Nuclear power, though controversial, is still an attractive way to produce electricity.

• But disposing of spent fuel rods is a major headache.– Nuclear waste remains dangerous for

thousands of years.

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Possible schemes for disposal

• Burial in the ocean or at the north or south poles.– Problem: Not knowing

what materials would be strong enough to isolate the waste from the environment.

• Shooting into the sun.– Problem: Better be very

sure the rocket escapes Earth orbit.


Possible schemes for disposal, 2

• The current scheme(s):– To bury the waste in geologically safe locations.

• For the U.S., the chosen site is Yucca Mountain in Nevada.

• For Canada, a hole in the Canadian shield.

The American disposal siteThe Canadian disposal plan.


Abusing the air• Industry is synonymous

with air pollution.– In the 18th and 19th

centuries, a smokestack was the sign of progress.

• Until recently, most homes were warmed by open fires, fueled by wood or coal.– In the 3rd World, this is still

the usual practice.

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The Case of London, England

• London was notorious for its peasoup smogs, caused by coal fires. – It was a constant hazard to the

lungs, and made poor visibility throughout the winter.


Electricity

• A far cleaner fuel to heat homes is electricity.– But electricity is a

secondary form of energy.– First the electricity has to

be made by tapping another power of nature.

– Much electricity is still made by burning coal.


Cars and Trucks• Motor vehicles mostly run on

internal combustion engines, which produce pollutants:– Carbon dioxide– Carbon monoxide– Nitrogen oxides, leading to ozone– Smoke– Until the 1980s, North American

gasolines contained tetraethyl lead, which improved combustion, but produced considerable pollution.

• Lead is still used in gasolines in the 3rd World

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Urban motor vehicle smog

• In a major city, like Los Angeles, that has virtually no public transportation, nearly everyone drives a car to get anywhere.

– Two cars for every three people. – The result is the worst urban air pollution in the

world.


Industrial Air Pollution• Despite

stringent regulations, many industries simply cannot function without producing copious amounts of air pollution.


The Case of Chlorofluorocarbons• In 1930, Thomas Midgley

demonstrated the wonder properties of chlorofluorocarbons (CFCs) by inhaling a lungful of the gas and then exhaling it over a lit candle, which it extinguished.

– The point: CFCs were non-toxic and non-flammable, therefore safe.

• The use of CFCs: – As a refrigerant, freon, it could be

cooled by compression and then absorb heat from warm bodies.

– Another CFC product was used to make styrofoam, used as an insulating material in construction and for hot drink cups.

– As a propellant for aerosol sprays.– The big push came with air

conditioning in the 1960s, using freon. First businesses, and then homes, and then cars, buses, and trucks.

Thomas Midgley

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The Ozone Layer• High in the stratosphere, 10 to 50

km above the surface of the Earth, is a layer of oxygen gas in the unusual form O3, ozone.

• This form of oxygen effectively blocks much of the Sun’s light in the smallest wavelengths, UV-C and UV-B.– Light at those wavelengths is

disruptive to living organisms.– Life would not have evolved out of the

sea were it not for the ozone layer that formed back when all life was in the sea, where it is protected from ultraviolet rays.


The problem of chlorine• The element chlorine appears

in many wonder chemicals, DDT, for example. – Chlorine is effective because it

is so reactive.– CFCs amazed the chemical

community because it is a chlorine compound, but it is very stable.

• Because it has no hydrogen bonds, which are weaker.

• But CFCs can be broken apart by ultraviolet rays.


The Destruction of the Ozone Layer

• An enormous amount of CFCs were being emitted into the atmosphere.

• Some of that would migrate up to the stratosphere, where UV rays would break it apart.

• Broken apart, the free chlorine atoms would quickly bond with the ozone, destroying it.– A single chlorine atom can destroy

100,000 ozone molecules.• When discovered, the U.S. banned

the use of CFCs as a propellant.– Canada, Sweden, & Norway did too.

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The Hole in the Sky

• Concern with possible depletion of the ozone layer led to regular measurements of its density.

• From 1981 onwards, a large hole in the ozone layer over Antarctica has been recorded.

• In 1987, a conference was held in Montreal which led to an agreement to limit CFC consumption signed by 164 countries.

Blue indicates the hole in the ozone layer, Sept 11, 2003.


International agreements

• Thus began the era of international agreements to regulate and control industrial practices that lead to pollution of the environment on a global scale.

– Many industries have complied by changing some of their industrial processes.

– But the authority of an international agreement extends only to the signing countries.

– This has had mixed success so far.

CFC reductions after the Montreal Protocol of 1987

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Pollution - yorku.ca · PDF fileSC/NATS 1510, Pollution 26 Toronto’s problem ... major headache