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19.2: Pollution of the Land

Difficulty Level: At Grade Created by: CK-12
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Lesson Objectives

  • Define hazardous waste and describe its sources.
  • Describe some of the impacts of hazardous waste on human health and on the environment.
  • Detail some ways that people can control hazardous wastes.


  • Superfund Act
  • Superfund site


Sometimes human activities degrade the land with pollutants. In the United States, lands that are extremely polluted become one of the Superfund sites destined for cleanup.

Love Canal

The story of Love Canal, New York, begins in the 1950s when a local chemical company placed hazardous wastes in 55-gallon steel drums and buried them. Love Canal was an abandoned waterway near Niagara Falls and was thought to be a safe site for hazardous waste disposal because the ground was fairly impermeable (Figure below). After burial, the company covered the containers with soil and sold the land to the local school system for $1. The company warned the school district that the site had been used for toxic waste disposal.

Steel drums were used to contain 21,000 tons of hazardous chemicals at Love Canal.

Soon a school, a playground, and 100 homes were built on the site. The impermeable ground was breached when sewer systems were dug into the rock layer. Over time, the steel drums rusted and the chemicals were released into the ground. In the 1960s people began to notice bad odors. Children developed burns after playing in the soil, and they were often sick. In 1977 a swamp created by heavy rains was found to contain 82 toxic chemicals, including 11 suspected cancer-causing chemicals.

A Love Canal resident, Lois Gibbs, organized a group of citizens called the Love Canal Homeowners Association to try to find out what was causing the problems (Figure below). When they discovered that toxic chemicals were buried beneath their homes and school, they demanded that the government take action to clean up the area and remove the chemicals.

A resident of Love Canal protests the hazardous waste contamination in her neighborhood.

A video of Lois Gibbs describing the origin of the Love Canal problem: http://www.youtube.com/watch?v=PrzqFPego4A.

In 1978, people were relocated to safe areas. The problem was instrumental in the passage of the the Superfund Act in 1980. This law requires companies to be responsible for hazardous chemicals that they put into the environment and to pay to clean up polluted sites, which can often cost hundreds of millions of dollars. Love Canal became a Superfund site in 1983 and as a result, several measures were taken to secure the toxic wastes. The land was capped so that water could not reach the waste, debris was cleaned from the nearby area, and contaminated soils were removed.

What is Hazardous Waste?

Hazardous waste is any waste material that is dangerous to human health or that degrades the environment. Hazardous waste includes substances that are:

1. Toxic: causes serious harm, death, or is poisonous.

2. Chemically active: causes dangerous or unwanted chemical reactions, such as explosions.

3. Corrosive: destroys other things by chemical reactions.

4. Flammable: easily catches fire and may send dangerous smoke into the air.

All sorts of materials are hazardous wastes and there are many sources. Many people have substances that could become hazardous wastes in their homes. Several cleaning and gardening chemicals are hazardous if not used properly. These include chemicals like drain cleaners and pesticides that are toxic to humans and many other creatures (Figure below). While these chemicals are fine if they are stored and used properly, if they are used or disposed of improperly, they may become hazardous wastes. Others sources of hazardous waste are shown in Table below.

This farm worker wears special clothes for protection from the hazardous pesticide in the container.

Hazardous Waste
Type of Hazardous Waste Example Why it is Hazardous
Chemicals from the automobile industry Gasoline, used motor oil, battery acid, brake fluid Toxic to humans and other organisms; often chemically active; often flammable.
Batteries Car batteries, household batteries Contain toxic chemicals; are often corrosive.
Medical wastes Surgical gloves, wastes contaminated with body fluids such as blood, x-ray equipment Toxic to humans and other organisms; may be chemically active.
Paints Paints, paint thinners, paint strippers, wood stains Toxic; flammable.
Dry cleaning chemicals Many various chemicals Toxic; many cause cancer in humans.
Agricultural chemicals Pesticides, herbicides, fertilizers Toxic to humans; can harm other organism; pollute soils and water.

Impacts of Hazardous Waste

The pollution at Love Canal was not initially visible, but it became visible. The health effects from the waste were also not initially visible, but they became clearly visible. The effects of the contamination that were seen in human health included sickness in children and a higher than normal number of miscarriages in pregnant women. Toxic chemicals may cause cancer and birth defects. Why do you think children and fetuses are more susceptible? Because young organisms grow more rapidly, they take in more of the toxic chemicals and are more affected.

Sometimes the chemicals are not so easily seen as they were at Love Canal and the impacts are seen statistically. For example, contaminated drinking water may cause an increase in some types of cancer in a community.

Why is one person with cancer not enough to suspect contamination by toxic waste? One is not a statistically valid number. A certain number of people get cancer all the time. To identify contamination, a number of cancers above the normal rate, called a cancer cluster, must be discovered. A case that was made into a book and movie called A Civil Action involved the community of Woburn, Massachusetts. Groundwater contamination was initially suspected because of an increase in childhood leukemia and other illnesses. As a result of concern by parents, the well water was analyzed and shown to have high levels of TCE (trichloroethylene).

Lead and mercury are two chemicals that are especially toxic to humans. Lead was once a common ingredient in gasoline and paint, but it was shown to damage human brains and nervous systems. Since young children are growing rapidly, lead is especially harmful in children under the age of six (Figure below). In the 1970s and 1980s, the United States government passed laws completely banning lead in gasoline and paint.

(a) Leaded gas sold in the US for decades. (b) Homes built before the 1970s may contain lead paint. Paint so old is likely to be peeling and poses a great threat to human health. About 200 children die every year from lead poisoning.

Mercury is a pollutant that can easily spread around the world. Sources of Mercury include volcanic eruptions, coal burning, and wastes such as batteries, electronic switches, and electronic appliances such as television sets. Like lead, mercury damages the brain and impairs nervous system function. More about the hazards of mercury pollution can be found in the Human Actions and the Atmosphere chapter.

Preventing Hazardous Waste Pollution

Nations that have more industry produce more hazardous waste. Currently, the United States is the world’s largest producer of hazardous wastes, but China, which produces so many products for the developed world, may soon take over the number-one spot.

Countries with more industry produce more hazardous waste than those with little industry. Problems with hazardous wastes and their disposal became obvious sooner in the developed world than in the developing world. As a result, many developed nations, including the United States, have laws to help control hazardous waste disposal and to clean toxic sites.

As mentioned above, the Superfund Act requires companies to clean up contaminated sites that are designated as Superfund sites (Figure below). If a responsible party cannot be identified, because the company has gone out of business or its culpability cannot be proven, the federal government pays for the cleanup out of a trust fund with money put aside by the petroleum and chemical industries. As a result of the Superfund Act, companies today are more careful about how they deal with hazardous substances.

Superfund sites are located all over the nation and many are waiting to be cleaned up.

The Resource Conservation and Recovery Act of 1976 requires that companies keep track of any hazardous materials they produce. These materials must be disposed of using government guidelines and records must be kept to show the government that the wastes were disposed of safely. Workers must be protected from the hazardous materials.

To some extent, individuals can control the production and disposal of hazardous wastes. We can choose to use materials that are not hazardous, such as using vinegar as a cleanser. At home, people can control the amount of pesticides that they use (or they can use organic methods of pest control). It is also necessary to dispose of hazardous materials properly by not pouring them over the land, down the drain or toilet, or into a sewer or trashcan.

Lesson Summary

  • Hazardous wastes are dangerous to human health and the environment. The many sources of hazardous waste include household chemicals, gasoline, paints, old batteries, discarded appliances, and industry.
  • Once toxic chemicals are released into the environment they can cause health problems or even death, and they can degrade the environment for other organisms.
  • Developed countries such as the United States produce most of the world’s hazardous waste but have the most advanced laws to deal with them.

Review Questions

1. Who was responsible for the tragedy at Love Canal? What was the role of private individuals in fixing the problem? What was the role of government?

2. How does the United States Superfund Act help control hazardous wastes?

3. What is the difference between corrosive and flammable?

4. What is often the first indicator that a region has a problem with toxic waste?

5. Organic farming is a method of growing food crops with natural alternatives to chemical pesticides. How does organic farming help control hazardous wastes?

6. Why is storing hazardous wastes in barrels and burying them deep in the ground a bad idea? How might that approach be made safer?

7. What hazardous wastes are common in ordinary households? What can you do to reduce the impact you make on the environment from the use of hazardous wastes?

8. Which do you think is easiest and hardest to keep track of: hazardous waste that is present as a gas, liquid, or solid? Why?

Further Information / Supplemental Links

Points to Consider

  • What are the best ways to either prevent or safely dispose of hazardous materials?
  • What is the effect of hazardous wastes on other living things?
  • Is it important for each generation to leave the world a safe place? If one generation doesn't do this, who pays the price?

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