Natural disasters, such as floods and earthquakes, can cause soil contamination, but they are not as common as industrial activities, agricultural practices, and household waste.

Dioxin is a highly toxic chemical that was used in the production of Agent Orange, a defoliant used during the Vietnam War. It was also found in high levels in the soil at Love Canal, a community in New York State that was built on a former chemical dump.

Asthma is not typically caused by soil contamination. However, other health effects, such as cancer, birth defects, and neurological disorders, can be caused by exposure to contaminated soil.

CERCLA, also known as Superfund, is the federal law that regulates the cleanup of contaminated soil and groundwater. It was enacted in 1980 in response to the Love Canal disaster.

Natural attenuation is not a method for cleaning up contaminated soil. It is a process by which the natural environment breaks down or removes contaminants over time.

Phytoremediation is the process by which plants absorb and break down contaminants in the soil. It is a natural and cost-effective way to clean up contaminated soil.

Physical contamination is not a type of soil contamination. It refers to the presence of foreign objects in the soil, such as rocks, glass, and metal.

Bioremediation is the process by which bacteria and other microorganisms break down contaminants in the soil. It is a natural and cost-effective way to clean up contaminated soil.

The Exxon Valdez oil spill was an oil spill that occurred in Prince William Sound, Alaska, in 1989. It was not a case study of soil contamination because the oil did not contaminate the soil.

Excavation and disposal is the process by which contaminated soil is excavated and disposed of. It is a common method for cleaning up contaminated soil.

The climate is not a factor that can affect the severity of soil contamination. The type of contaminant, the concentration of the contaminant, and the soil type are all factors that can affect the severity of soil contamination.

Natural attenuation is the process by which contaminants are broken down or removed from the soil by natural processes, such as biodegradation, volatilization, and adsorption.

Heart disease is not a health risk associated with soil contamination. Cancer, birth defects, and neurological disorders are all health risks associated with soil contamination.

The Environmental Protection Agency (EPA) is the federal agency that is responsible for regulating soil contamination. The EPA sets standards for soil contamination and enforces those standards.

Burning trash is not a method for preventing soil contamination. It can actually release harmful chemicals into the air and soil.