Soil contamination happens when manmade chemicals, including heavy metals and hydrocarbons, get into the earth and alter what should be the natural soil environment.
It is often said to result from the practices of non-organic farming, improper waste disposal or industrial activity and common chemicals involved include lead, solvents, pesticides, polynuclear aromatic hydrocarbons like naphthalene and petroleum hydrocarbons. Often an expert soil remediation service is needed to help with the issue.
Improper waste disposal and agriculture
Farming methods have been known to cause issues as farmers use insecticides and pesticides to destroy insects and pests. Herbicides used to kill weeds can also be an issue and these chemical combinations can result in soil contamination.
Specialist companies such as https://soilfix.co.uk/services/groundwater-soil-remediation-services may be called in to deal with the aftermath of the use of cheap-to-manufacture synthetic insecticides such as Dieldrin, Aldrin and DDT. These chemicals have been made in huge quantities ever since the 1930s, with DDT being used hugely until the end of the 1970s when it began to be recognised that it was having detrimental environmental effects.
A global challenge
DDT gave an insight into the spread of such chemicals, as despite it only having been sprayed on agricultural land, it was found in large quantities in mammals and fish around the globe, as well as in snow in the Antarctic. Read more about this at https://www.ncbi.nlm.nih.gov/pubmed/5346606. It has also been linked with a fall in the number of birds because it makes eggshells more brittle.
Meanwhile, in northwest Malaysia and the city of Perlis, research has shown a presence of worrying levels of heavy metals in the soil. This is due to anthropogenic activities like smelting and mining.
The improper disposal of waste is a major contributor to soil contamination. This includes the use of biosolids, a form of treated sewage used as a fertiliser.
Munitions are also linked to contamination, especially biological weapons and various other kinds of weaponry. These can leach into the soil and cause a major upset of the natural balance.
Potential effects on health
There is much evidence that contaminated soil can negatively impact human health. Overexposure to a substance known as benzene, for example, is linked to increased leukaemia rates. Lead and chromium, meanwhile, have been linked to congenital issues and various other health conditions.