• Soil pollution is the contamination of soil with harmful
substances that can adversely affect the quality of the soil and
the health of those living in it.
• failure due to corrosion of underground storage tanks
• application of pesticides,
• oil and fuel dumping,
• leaching of wastes from landfills ,
• direct discharge of industrial wastes to the soil.
• Health hazards:
• Direct affect on human health.
• Contamination of ground water aquifers.
• Chronic exposure to chromium, lead and other metals, petroleum,
solvents, and many pesticide and herbicide can be carcinogenic,
can cause congenital disorders.
• Household Chemical Disposal
• Planting and Reforestation
• crop rotation
• Agrochemical,is a generic term for the
various chemical products used in agriculture. In most
cases, agrichemical refers to the broad range of pesticides,
including insecticides, herbicides, and fungicides.
• Rodenticides (for rodent control)
• Insecticides (for insect control)
• Fungicides (for fungus control)
• Herbicides (for weed control)
• Molluscicide (for Snails)
• Nematicides (for nematode control)
• While agrochemicals increase plant and animal crop production,
they can also damage the environment.
• Excessive use of fertilizers has led to the contamination of
• the runoff of fertilizers into streams, lakes, and other surface
waters can increase the growth of algae, leading to the death of
fish and other aquatic animals.
• Some older pesticides, like the powerful insecticide DDT
(dichlorodiphenyltrichloroethane), remain active in the
environment for many years.
• In North America, for example, it is believed that millions of
wild birds are killed each year from exposure to the agricultural
• A pesticide is any substance used to kill, repel, or control
certain forms of plant or animal life that are considered to be
• Broad spectrum pesticides (Diazinon, Trichlorfon)
• Narrow spectrum pesticides
• Systemic pesticides (Imidacloprid )
• RISK OF EXPOSURE TO PESTICIDES
• Farmers and their families and other persons who use chemical
pesticides regularly are at greatest risk for achieving toxic
levels in their bodies.
• Agricultural Health Study,
• Cost effectiveness
• Protection of the environment
• Quality, quantity and price of produce
• Residues in food
• Entrance in the food chain
• Ground water contamination
• 4000 and 19000 deaths each year, according to world health
• Chlorpyrifos cause severe birth defects as it is used widely as an
• They cause behavioral problems, hormonal disruptions, neurological
An insecticide is a pesticide used against
insects. They include ovicides and larvicides
used against the eggs and larvae of insects
respectively. Insecticides are used in
agriculture, medicine, industry and the
TYPES OF INSECTICIDES
1) Organic +type
Organochlorine (OC) – These insecticides are
produced by combining an organic molecule with
chlorine. The most well-known insecticide of today,
DDT, is classified as an organochlorine and works by
attacking the nerve cells of insects
• Organophosphates (OP) –
These types of insecticides are a combination of
an organic molecule and phosphates. They attack the
insect’s nerve cells and are somewhat similar to the
chemical agents of nerve warfare.
• Other types organic insecticides are
Carbamates , Pyrethrum and
2) Inorganic types:
Inorganic insecticides commonly contain
ingredients such as arsenic, lead, copper,
• Paris Green
This product was utilized in the past as
an insecticide for protecting fruit against
insect contamination. This chemical
compound, containing copper and
arsenate, is extremely toxic and used in
fireworks as well as some paints.
• Silica Gel
This product is found in certain
insecticide dusts and works to suffocate
pests. It is more commonly used for
ticks, termites and mites
Properties of perfect insecticide
Properties of insecticides are as follows:-
• High toxicity to target pest
• Selective toxicity so beneficial insects are not
• No harmful residue
• Cheap and safe to manufacture
• Stabile under storage
• Non corrosive
• Residues readily and cheaply detectable
BENEFITS OF INSECTICIDES:
Humans have attained important benefits
from many uses of insecticides, including:
• increased yields of crops because of
protection from defoliation and diseases;
• prevention of much spoilage of stored
• prevention of certain diseases, which
conserves health and has saved the lives of
millions of people and domestic
Disadvantages of insecticides are as follows:-
• recovery of treated populations
Pest populations quickly recover and bounce back, leading to
repeated insecticide applications.
• Resistance. Large reproductive ability and short generation time
help speed selection of resistant individuals and insecticides are
than applied at ever increasing concentrations.
• Selective kill and environments alteration can lead to minor
pests becoming major pests.
• Residues can be long lived and dangerous.
• Insecticides and their applications can be costly and time
DEFINITION OF FUNGI
• A pesticide used to kill fungi, especially those that cause
• Streptomycin is a fungicide
• Two fungicides are copper sulfate pentahydrate (CuSO4) and
Hexachlorobenzene (C6Cl6). Today more than 80% of fruit and
vegetable crop acres in the U.S. are treated with fungicides
TYPES OF FUNGI
• Mobility in a plant: remain on the surface of plants. Many contacts
are potentially phototoxic (toxic to plants) and can damage the
plant if absorbed.
• Role in protection: Repeated applications are needed to protect
new growth of the plant and to replace material that has been
washed off by rain or irrigation, or degraded by environmental
factors such as sunlight.
• Breadth of activity: Single-site fungicides are active against only
one point in one metabolic pathway in a pathogen .
• Mode of action. Fungicides kill fungi by damaging their cell
membranes, inactivating critical enzymes or proteins.
• Type of chemical: inorganic or organic. Chemically, organic
molecules are those that contain carbon atoms in their structure
whereas inorganic molecules do not.
Role of Fungicides in Disease Management
• In human medicines, most fungicides need to be
applied before disease occurs or at the first
appearance of symptoms to be effective.
• Fungicides can only protect new uninfected growth
from disease. Also, few fungicides are effective
against pathogens after they have infected a plant.
• . Fungicides can only protect new uninfected growth
from disease. Also, few fungicides are effective
against pathogens after they have infected a plant.
Why are Fungicides Needed
• To control a disease during the establishment and
development of a crop.
• To increase productivity of a crop and to reduce
• To improve the storage life and quality of harvested
plants and produce.
• Soluble in water.
• Contain only a small subset of the
minerals and nutrients .
• Not support soil biology .
• Produce from non renewable resources.
• Nutrient-deficiency of soil.
• Maintained soils have high acidity.
• Contamination of groundwater.
• Effect on nervous system functions in mice,
as well as influence on children’s and fetus's
developing neurological, endocrine and immune
• Cause of acid rain.
• The increase in the water-soluble nitrates
creates an influx of plant-life, which eats up
oxygen and starves out fish
Effect on soil
• you apply chemical fertilizers for long period
but oppositely beneficial insects will decline
leading to the loss of pest control.
• long-term resistance the ecosystem has of
pesticide which results in the lost of beneficial
organisms, earthworm, micro-organism, and
other species .
• Phosphorus is the second most abundant
nutrient in life.
• Nitrogen helps plants turn green by helping
plants create chlorophyll.
• Iron protects roots and preventing the
formation of phenol compounds.
• Plants use potassium to create sugars,
starches and carbohydrates.
Reaction with Ammonia
• Ammonium nitrate reacts with metal
hydroxides, releasing ammonia and forming
alkali metal nitrate:
NH4NO3 + NaOH → NH3 + H2O + NaNO3
NH4NO3 + KOH → NH3 + H2O + KNO3
IMPACTS Of SOIL POLLUTION,
PESTICIDES & AGROCHEMICALS
IMPACTS ON SOIL POLLUTION
The pesticides used in agriculture have chemicals that last long
in the environment. In addition to killing the pests, they also
effect some beneficial organisms like the earthworm in the soil.
Organisms like earthworm are vital to the decomposition of
materials and formation of soil.
• Acid Rains
The acid rains can change the pH of the soil making it unsuitable
The household and other city garbage lies scattered in the soil
in the absence of a proper disposal system. Materials like
polythene can block the passage of water into the soil and
affect its water-holding capacity.
• Radioactive Substances
Improper disposal of nuclear wastes can cause radioactive
substances to remain in the soil for a long time. These
substances cause mutations.
• Night Soil
Human excreta mixed with soil is called night soil. Open latrines
in the villages and some parts of cities are the source of this
pollution. These contain disease-causing germs which can spread
the disease. It is estimated that millions of children worldwide
die before they reach the age of five due to lack of sanitary
IMPACTS OF PESTICIDES
• PESTICIDE POISONING:
About one million pesticide poisonings occur globally every year,
resulting in 20,000 fatalities. About one-half of the human
poisonings occur in poorer, less-developed countries, even
though these places account for only 20% of the world's use of
Pesticides can contaminate unintended land and water when they
are sprayed aerially or allowed to run off fields, or when they
escape from production sites and storage tanks or are
• EFFECT OF DDT:
Environmental damage caused by pesticides have been associated
with the use of relatively persistent chemicals, such as DDT.
Most modern usage of pesticides involves chemicals that are
less persistent than DDT and related chlorinated hydrocarbons.
• EFFECT OF TOXICITY ON HUMANS:
Pesticides causing extensive toxicity to humans. The most
famous case occurred at Bhopal, India, in 1984, in the vicinity of
a factory that was manufacturing an agricultural insecticide. In
that case, there was an accidental release of about 45 tons (40
tonnes) of deadly methyl isocyanate vapor to the atmosphere.
This agrochemical-related emission caused the deaths of about
3,000 people, and more than 20,000 others were seriously
IMPACTS OF AGROCHEMICALS
• Extensive use of fertilizers: