This document discusses organic and inorganic pollutants in soils. It notes that heavy metals such as cadmium, lead, chromium, copper, zinc, mercury and arsenic are present in soils due to industrial discharges and sewage sludge. Heavy metal levels are increased by industry, agriculture, waste incineration, fossil fuel combustion and road traffic. Pollution of agricultural soils by heavy metals can lead to reduced crop yields and their introduction into the food chain. The document also discusses nitrogen, phosphorus and pesticides as organic pollutants in soils, and their negative effects such as eutrophication and destruction of soil microorganisms.

1. ORGANIC ANDINORGANIC POLLUTANTSIN SOILS
Abdul Aleem Memon
Ph.D Student
Ph.D-2K15-SS-32

3. A substance or energy introduced into
the environment that has undesired
effects, or adversely affects the
usefulness of a resource. A pollutant may
cause long- or short-term damage by
changing the growth rate of plant or
animal species, or by interfering with
human amenities, comfort, health, or
property values

4. Heavy metals, such as cadmium, lead,
chromium, copper, zinc, mercury and
arsenic etc..

5. • Heavy metals in soil are basically due to industrial
discharges.
• Certain heavy metals eg. Zn, Cu, Ni, Cd and Pb are also
present in significant levels in sewage sludge and reach the
soil where they become part of life cycle and affects
adversly.

6. Soil contamination by heavy metals, such as
cadmium, lead, chromium, copper, zinc,
mercury and arsenic, is a matter of great
concern.
Heavy metals are present naturally in the
soil, but their levels are increased by:

7. • industry (non-ferrous industries, power
plants, iron, steel and chemical industries);
• agriculture (irrigation with polluted
water, use of mineral fertilisers)
• waste incineration;
• combustion of fossil fuels; and
• road traffic.

8. Pollution of agricultural soils by heavy
metals may lead to reduced yields and
elevated levels of these elements in
agricultural products, and thus to their
introduction into the food chain.
Heavy metal deposits on grassland soils
remain predominantly in the top few
centimetres and are directly ingested with
soil by grazing animals.

9. Heavy metals are toxic and inhibit the soil's
microorganic activity. Their concentration in the
soil can remain for decades or even centuries.
Reduction of heavy metal emissions is the most
direct way to decrease the atmospheric
deposition of these elements and their build-up
in the soil. Despite the great increase in traffic,
for example, a reduction in lead emissions has
been achieved through incentives to use
unleaded petrol.

10. Implementing complex measures that
reduce soil acidification could more
efficiently reduce heavy metals. On
agricultural land, heavy metal quantities
can be decreased by using low-metal
content resources for fertilisers, replacing
inorganic pesticides with organic products,
and other similar methods.

12. • N and P derivatives
• Pesticides
• PAHs (polycyclic aromatic hydrocarbons)
• BTEX (benzene, toluene, ethylbenzene and xylene)
• PCPS
• NAPL
• Plastics, biopolymers
• Dyes
• Phenols, Chlorophenols
• Choroanilines
• Bleach Plant effluents
• Nitro Compounds etc…

13. Nitrogen and phosphorus are elements
essential to all forms of life and are
therefore relevant to soil systems and food
crops. Although they are important plant
nutrients, excessive application may lead
to nitrogen or phosphate saturation in the
soil, and eventual contamination of the
groundwater. The amount of leaching
depends on the soil, the local climate and
the style of crop management.

14. Phosphorus
Phosphorus accumulates in the upper layer of
soil in regions with high livestock densities. In
soils saturated with phosphorus, especially
those with shallow groundwater, high
phosphorus concentration occurs in the upper
groundwater layer and in surface water,
resulting in eutrophication.

16. Nitrogen
The problem of nitrate pollution is
recognised internationally and is usually
associated with intensive agriculture
practices. Good agricultural practices
that alleviate the problem are:

17. • the selection of crops that require fewer nutrients;
• a timely application of fertiliser (in the growing
season);
• improved methods of manure application;
• shortening the length of the grazing season; and
• reducing the intensity of grassland use (by lowering
cattle density).

18. Pesticides pollute the soil directly by
affecting the organisms that reside in it.
Soil, however, can act as a vector for the
pollution of surface water and
groundwater. Organic pollutants enter the
soil via atmospheric deposition, direct
spreading onto land, contamination by
wastewater and waste disposal.

19. In addition to pesticides, organic
contaminants include many other
components, such as oils, tars,
chlorinated hydrocarbons, PCBs and
dioxins. There is such a wide variety of
organic substances that their detection
and monitoring in the soil is practically
impossible.

20. Pesticides (mainly fungicides, herbicides
and insecticides) are used in agriculture to
protect crops and to ensure a quality
harvest. Persistent or mobile pesticides are
especially dangerous, as are those that
affect non-targeted organisms.

21. The use of pesticides may lead to:
• destruction of the soil's micro-flora and fauna,
leading to both physical and chemical
deterioration;
• severe yield reduction in crops; and
• leaching of toxic chemicals into groundwater
and potentially threatening drinking water
resources.

22. Some improvements in application and legislation
may reduce the side effects of pesticides, such as:
• banning broad-spectrum and highly mobile
pesticides;
• employing integrated pest-management;
• enforcing biological control; and
• developing biotechnologies.

23. THANK YOU….