Soil Toxins

Sewage

• Sewage sludge is created by sewage plants when they clean the water that comes into them, in preparation for releasing it back into the natural environment. Vast amounts of sewage sludge are created every year, and much of it is spread on agricultural fields. While composted feces is not a health threat, sewage is a different substance, because it is made up of everything that has gone into toilets and drains, including pharmaceuticals, biohazards, paint, toxic chemicals and anything else that someone decided to flush down a toilet. The volume of these toxins is increased when they contaminate the sewage flow as a whole, and the results are added to soil by sewage sludge spreaders.

Clostridium Botulinum

• Clostridium botulinum is a bacteria that causes botulism. Botulism is a relatively rare condition, and when it does strike someone, it is usually the result of bad food. The bacteria also exists in soil under some conditions and can occasionally migrate to humans and animals. This bacteria is killed when it is heated above 175 degrees Fahrenheit for 10 minutes, which makes it a simple matter to kill it in food when the food is cooked. But this doesn't help deal with the bacteria in soil, since there is no practical method of doing this to large amounts of soil.

Heavy Metals

• Heavy metals contaminate soil through a variety of human activities, including landfills, mining, the production of chemicals and the use of pesticides. These metals, which include lead, cadmium and arsenic, are deadly to humans and other animals when they are ingested in excessive amounts. Damage usually results from chronic exposure over a long period of time. Heavy metals exist in natural soils but at concentrations that are too low to pose a threat. Removing heavy metal contamination from soil is an extremely expensive and invasive process, and as a result many contaminated areas have not been cleaned up.

Solutions

• Conventional methods of toxic soil remediation often involve simply removing the soil and disposing of it as toxic waste. More promising methods exist in the form of phytoremediation, using the natural healing properties of plants to decrease levels of toxins in soil. Some plants appear to be immune to toxins that are harmful to humans. In a manner similar to carbon capture that reduces greenhouse gases, plants can take in toxins, drawing them out of the soil and holding them in their fibers and leaves. This method of soil purification is in its early stages but holds great promise for the future.