Pollution comes in many forms, and one form of pollution can often increase other forms, such as when rain washes solid waste off the surface of the ground and into water. Soil pollution is a rather insidious form of contamination because of both the range of pollutants and the amount of remediation that the pollution can sometimes require.
Soil pollution is the contamination of soil with harmful substances that can adversely affect the quality of the soil and the health of those living on it. Pollution can be the result of an accident or carelessness, or done on purpose through illegal dumping. Pollution is also a by-product of activities as normal as driving or maintaining a farm.
Soil pollution can result from contaminated water absorbing into the soil. Agricultural chemicals can coat the soil, and litter can work its way into the dirt. Pollutants in the air can settle on the ground, such as was the case in Tacoma, Washington, where the State of Washington Department of Ecology says airborne smelter pollutants fell to the ground and contaminated nearly 1,000 square miles. Polluted acid rain can end up in soil, too, and metal-contaminated dust on roads can wash into the soil as part of rain-induced run-off. The Food and Fertilizer Technology Center warns that heavy-metal contamination can not only reduce crop yields due to poor soil quality, but result in the crops absorbing the metals.
The effects of soil pollution reach across the spectrum from water and air to vegetation, and to human health and society as well. While the specific effects depend on the pollutant, in general they include further environmental contamination as the polluted soil washes into water or is kicked up into the air, and poisoning, such as from lead-tainted soil. The Environmental Protection Agency notes that children can end up accidentally ingesting polluted soil as they play in it.
The EPA began the Superfund program in 1980 to clean up contaminated sites. A Superfund site undergoes an extensive evaluation to determine the types of pollutants and the severity of the contamination, at which point the cleanup process is mapped out. The process does not end when the site is clean, though, as long-term strategies are then implemented to bring the site back to a usable condition.
Another definition of soil pollution is when soil itself pollutes a stream or other body of water. The soil can ruin the habitats of aquatic creatures and block visibility for boaters, which Maine’s Bureau of Land and Water Quality says increases the risk of hitting an underwater obstacle. Soil particles in water affect drinking quality, even if the soil isn’t otherwise polluted, and can injure fish.