**4. Natural source of soil pollution**

Some of natural event also can be the cause of soil pollution like earthquakes, landslides, hurricanes, and flood. These natural disasters cause transpose to the composition of soil which leads to the contamination. For example weathering of naturally occurring sulphide-bearing rock make mineralized zones of arsenopyrite (gossans), Most of these minerals present a high spatial variability and many of

them can be found in higher concentrations in deeper layers. However, As is slightly bioaccessible if getting from natural sources [6]. Soils and rocks are also natural sources of the radioactive gas Radon (Rn). High natural radioactivity is common in acidic igneous rocks, mainly in feldspar-rich rocks and illite-rich rocks.

However, There are other numerous of ways of soil contamination, for example, • Seepage from a landfill • Discharge of mechanical waste into the dirt • Percolation of defiled water into the dirt • Rupture of underground stockpiling tanks • Excess utilization of pesticides, herbicides or compost • Solid waste drainage • The most well-known synthetics associated with causing soil contamination are: • Petroleum hydrocarbons • Heavy metals • Solvents Soil contamination happens when these synthetic substances hold fast to the dirt, either from being straightforwardly spilled onto the dirt or through contact with soil that has effectively been tainted.

### **4.1 Effects of soil pollution**

Impacts of soil pollution are not confined to soil and its biota but are carried over to every aspect of the environment and affect every organism from the earthworm to humans. Some of adverse effects are as follows:

#### a. **Human health**

Since we are dependent on the land for our food, pollution from the soil is transferred to us in this manner. Bioaccumulation of toxins occurs in our bodies, causing chronic poisoning, and leading to various diseases. Reproductive health, birth and developmental defects, neurologic effects, malnutrition, and mutations in the cells of the body leading to cancers; all these are on the increase today [7]. Considering direct impact of soil on human health because inhalation of polluted soil which have vaporized and contamination of it. Crops and plants grown on polluted soil absorb much of the pollution and then pass these on to us [8]. This could explain the sudden surge in small and terminal illnesses. Long term exposure to such soil can affect the genetic make-up of the body, causing congenital illnesses and can be carcinogenic, due to this congenital disorder or other chronic health problem created that cannot be cured easily. For example leukemia disease which is associated with higher concentration of benzene and its exposure is chronic to human health. Due to high concentration of mercury and cyclodienes, induce sufficient concentration of PCBs and cyclodienes can damage Kidney and liver toxicity. Carbamates and organophosphates can cause Neurological disorders. Arsenic, asbestos or dioxins, cause cancer and lower IQ caused by lead or arsenic, bone diseases through lead, fluoride or cadmium In fact, it can sicken the livestock to a considerable extent and cause food poisoning over a long period of time. The soil pollution can even lead to widespread famines if the plants are unable to grow in it.

#### b. **Growth of plants**

Contamination of soil can affect the ecological balance. Plants are mostly unable to adapt to the abrupt changes in the chemistry of the soil and this affects the microorganisms which are found in soil. This Substantial change causes soil disintegration. Enormous plots of land become infertile; unfit to help any life on it. Indeed, even the plants that do develop on these terrains will retain the poisons and move to the natural way of life. The natural

equilibrium of any framework gets influenced because of the inescapable tainting of the soil. Most plants cannot adjust when the science of the soil changes so fundamentally in a brief timeframe. Growths and microbes found in the dirt that dilemma it together start to decrease, which makes an extra issue of soil disintegration. The fruitfulness gradually reduces, making land inadmissible for horticulture and any neighborhood vegetation to endure. The soil contamination makes enormous plots of land become dangerous to wellbeing. In contrast to deserts, which are appropriate for its local vegetation, such land cannot uphold most types of life.
