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Types of Soil Pollutants

By Debra Durkee ; Updated September 21, 2017
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Pollution is a bad thing, no matter how you look at it. We can smell it when the air gets polluted and taste it when the water has gone bad, but the soil is another element that is extremely susceptible to different types of pollution.

Soil pollution not only has a negative effect on the plants that grow in it and rely on it for nutrients, but also on the animals--and people--who in turn rely on those plants for sustenance. A vicious cycle, it's important to be aware of the different types of soil pollution and, in the end, stop it.


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Pesticides are chemicals applied to crops, trees and flowers to kill harmful bugs and diseases that might otherwise kill the plants. Unfortunately, repeated use of these chemicals isn't always a good thing for the soil. The Environmental Protection Agency estimates that there are more than 5 billion pounds of pesticides used each year in the United States alone, and not all of these chemicals break down in the soil.

Some can remain there for decades.

DDT was once a commonly used pesticide, until the EPA deemed it unsafe and banned it. Traces of DDT can still be found in the soil that it was used in up to 40 years ago, and it is still making its way into the structure of the plants grown in that soil today.

From the soil, those pesticides that don't break down cannot only easily leech into the water, but can also be tracked into homes on clothes and pets.

Industrial Toxins

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Close proximity to unregulated or even maintained industrial sites can introduce a myriad of contaminants to the soil, many of which won't break down quickly.

Industrial contaminants can be anything from lead to cleaning solvents. One of the most common toxins found within miles of almost any industrial site is called dioxin, which is created during an incineration process. It's so common, in fact, that it's found nearly everywhere in almost every soil sample that's collected.

Many industrial soil pollutants enter the ground by way of industrial fallout. Chemicals are released into the air, and when it rains, the contaminants are carried into the soil.

Acid Rain

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According to the EPA, acid rain is rain which contains a higher than normal amount of nitric and sulfuric acids. Acid rain can come from a number of different sources both natural and man made-- including volcanoes, decaying plant matter and the consumption of fossil fuels.

Winds can spread these contaminants over hundreds of miles.

When they fall to the ground as rain or snow, they enter the soil where they can have a devastating effect on the plants and animals. In drier areas, they can fall to the ground as dry deposition. In this form, the chemicals can turn into dust or dirt particles, and contaminate the soil in this way.

Acid rains effects different soils in different ways. All soil has a buffering capability, which refers to its ability to absorb the acid and neutralize it. In areas such as the mountains of the northeast United States, the soil has a very low capacity for neutralizing these acids. When the acid content builds up, it begins to dissolve other nutrients and minerals in the soil--nutrients that trees and plants need to thrive. Effects of acid rain are usually seen this way, when plants are, over time, deprived of crucial nutrients and begin to slowly die.