Soil Pollution:
When the natural soil is contaminated by xenobiotic chemicals, the result is soil pollution. A volcanic eruption that spews lava with toxic elements robbing the land of its ability to regenerate or a destructive flood that washes in with its contaminants may also have the same effects. But considering their limited occurrence and destructive ability, the authors will concentrate on man-made causes and their effects.
Sources of Soil Pollution:
The main sources of soil pollution are:
1. Coal Ash: The ash generated by burning coal, primarily in thermal power stations is one of the major causes of land pollution. Bourne by air, it creates a clock of coal dust and tar within a radius forcing the soot-bedecked vegetation to wither away to a dusty death. The lead and zinc that the coal slag carries with it, is in some cases extremely hazardous and is known to have not only made barren vast tracts of land around power plants but has also caused untold miseries to the ecosystems that harbored them apart from exposing humans to serious health hazards.
2. Sewerage: The contamination of groundwater by untreated sewerage and the effect they have on the land is something that is of serious concern, especially in developing and less developed countries, where the lack of resources stops communities from setting up treatment plants and the pressure on scare land is further aggravated by the contamination by the discharge of sewerage. Treated sewerage is often termed as sludge and is used as fertilizer, which too has a long-term detrimental effect on the land as even post-treatment it carries a number of heavy metals and other contaminants.
3. Pesticides and Herbicides: Intense cultivation to meet the growing needs of an ever-hungry population has forced the man to use more chemical fertilizers and bio-engineered, genetically modified inputs to increase the yield per unit of land. The chemicals that have seeped into the land have, in their wake, created the basic chemistries that were prevalent before their introduction leading to drastic falls in crop yields. The cropping pattern and ultimately the carrying capacity of the land made them barren.