Natural causes are much more uncommon, but typically result from runoff accumulating in the soil, which can carry many contaminants and eventually become severe enough to have an impact. Natural sources of a chemical can also cause this, as too much of any chemical can be harmful to soil. 

The majority of soil pollution is causes by humans, which can range from disposing waste improperly to excess fertilizer leaking into soil or water. While many may have heard of oil spills out at sea due to ships sinking or improper management of oil rigs, oil can also leak from gas stations when the pump is left unattended. Specifically in urban regions, construction sites are a major source of soil pollution, as it contains many harmful contaminants that can easily leach into the soil. Mining activities such as fracking can also damage the soil, as it literally injects a chemical mix into the ground in order to extract oil. This oil can often leak into nearby soil along with the chemical mix as a result of this. While these are the major sources, there are many other sources that are a result of careless human activity.

Now that we know the causes, it is also important to identify the effects of soil pollution. Soil pollution effects children the most due to having weaker immune systems and less biomass to be affected by chemicals. Additionally, children play with the ground much more. Soil pollution can cause diseases such as organ damage and various forms of cancer. Minor effects would include headaches and rashes. 

Overall, while air pollution is typically more recognized, the various causes and effects of soil pollution show that it is just as significant as other forms of pollution.