The solid as well as the liquid waste were disposed off in the land through which the soil was being damaged. Even though the waste are well regulated in order to prevent such contamination but still there are certain unintentional spills and leaks which might damage the land at the sites. Contaminants may range from oil, petrol, heavy metals and solvents to radioactive substances. The various sources of contaminant are not just industries, there are certain other sources like agriculture activities, dry cleaning, petrol distribution, deposition from the atmosphere, inadequate waste disposal, etc. These contaminants cause severe harm to human health and adversely affect the normal living condition of a human being. There are various contaminant elements that occur as a range of compounds among which some are highly soluble, accessible for biological uptake and toxic, whereas others are not much hazardous. For instance, arsenic is a common chemical addition to soils for older industrial sites and exists in various inorganic and organic forms. Toxicity depends on actual compound oxidation state, yet chemical analyses of suspect soils seldom reveals any such details and it usually indicates the metal concentration present (SEPA, n.d.).
Interaction takes place between the various contaminants in the soil environment. These increases the potential toxicities of different contaminants involved where as in many cases competition between individual contaminant reduces the overall toxic potentials (SEPA, n.d.).
The effects of contamination don’t last long once the contaminant reaches the soil. It breaks down or becomes neutralized, might be washed away by the rain, or remain in the soil building up to a high concentrations. When contaminants are made up, they may not be enduring. However soil can sometimes remain polluted for an indefinite period (SEPA, n.d.).
It doesn’t mean that there is a problem if the ground is contaminated. It