A pesticide is any substance used to kill, repel, or control certain forms of plant or animal life that are considered to be pests. Pesticides include herbicides for destroying weeds and other unwanted vegetation, insecticides for controlling a wide variety of insects, fungicides used to prevent the growth of molds and mildew, disinfectants for preventing the spread of bacteria, and compounds used to control mice and rats. Because of the widespread use of agricultural chemicals in food production, people are exposed to low levels of pesticide residues through their diets. Scientists do not yet have a clear understanding of the health effects of these pesticide residues. The Agricultural Health Study, an ongoing study of pesticide exposures in farm families, also posts results online. Other evidence suggests that children are particularly susceptible to adverse effects from exposure to pesticides, including neurodevelopmental effects. People may also be exposed to pesticides used in a variety of settings including homes, schools, hospitals, and workplaces.
2. Topic: PESTICIDE POLLUTANTS
Name Of Scholar: FAROOQUE AHMED JANJHI
Assigned by: Prof: Dr. AAMNA BALOUCH
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NATIONAL CENTER OF EXCELLENCE IN
ANALYTICAL CHEMISTRY
UNIVERSITY OF SINDH JAMSHORO
4. PESTICIDES
Pesticides are chemical compounds that are
used to kill pests, including insects, rodents,
fungi and unwanted plants (weeds).
Pesticides are used in public health to kill
vectors of disease, such as mosquitoes, and in
agriculture, to kill pests that damage crops.
The term pesticide also treated as synonymous
with plant protection product.
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5. COMPOSITION OF PESTICIDES
Pesticide includes two types of ingredients
Active ingredients: These are used to kill, control or repel the pest.
Other ingredients: These are used to attract the pest, spreading the active
ingredient arounds
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6. CLASSIFICATION OF PESTICIDE
Its based on targeted organism;
PESTICIDES
Herbicides
Nematicides
Rodenticides
MolluscicideInsecticide
Algaecides
Fungicides
Piscicides Bactericides
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7. HERBICIDES
Herbicides, also commonly known as weed killers, are chemical
substances used to control unwanted plants. Selective herbicides
control specific weed species, while leaving the
desired crop relatively unharmed, while non-selective
herbicides (sometimes called total weed killers in commercial
products) can be used to clear waste ground, industrial and
construction sites, railways and railway embankments as they kill
all plant materials with which they come into contact.
e.g. Borax, Nitrofen.
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8. INSECTICIDE
Insecticides are substances used to kill insects. They include
ovicides and larvicides used against insect eggs and larvae,
respectively.
Insecticides are used in agriculture, medicine, industry and
by consumers. Insecticides are claimed to be a major factor
behind the increase in the 20th-century's agricultural
productivity. Nearly all insecticides have the potential to
significantly alter ecosystems; many are toxic to humans
and/or animals; some become concentrated as they spread
along the food chain.
e.g. DDT, BHC.
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9. RODENTICIDE
• Rodenticides are pesticides that kill rodents. Rodents include
not only rats and mice, but also squirrels, woodchucks,
chipmunks, porcupines, nutria, and beavers. Although rodents
play important roles in nature, they may sometimes require
control. They can damage crops, violate housing codes,
transmit disease, and in some cases cause ecological damage.
• e.g. Warfarin, Zinc phosphide.
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10. NEMATICIDE
• A nematicide is a type of chemical pesticide used
to kill plant-parasitic nematodes. Nematicides have
tended to be broad-spectrum toxicants possessing
high volatility or other properties promoting
migration through the soil.
• e.g. DBCP, Phorate
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11. MOLLUSICIDE
• Molluscicides, also known as snail baits and snail pellets,
are pesticides against molluscs, which are usually used in
agriculture or gardening, in order to control gastropod pests
specifically slugs and snails which damage crops or other
valued plants by feeding on them.
• e.g.: Sodium pentachloride phenate
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12. FUNGICIDE
• Fungicides are biocidal chemical compounds or
biological organisms used to kill parasitic fungi or
their spores. A fungistatic inhibits their growth. Fungi
can cause serious damage in agriculture, resulting in
critical losses of yield, quality, and profit. Fungicides
are used both in agriculture and to fight fungal
infections in animals.
• e.g. Bordeaux mixture
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13. BACTERICIDE
• A bactericide or bacteriocide, sometimes
abbreviated Bcidal, is a substance that kills
bacteria. Bactericides are disinfectants,
antiseptics, or antibiotics.
• e.g. Dichlorophen,Oxolinic acid
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14. ALGICIDE
• Algaecide or algicide is a biocide used for
killing and preventing the growth of algae.
• e.g. Copper sulphate, Endothal
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15. PISCICIDES
• A piscicide is a chemical substance which is poisonous
to fish. The primary use for piscicides is to eliminate a
dominant species of fish in a body of water, as the first
step in attempting to populate the body of water with a
different fish.
• e.g. Trifluoro methyl nitrophenol(TFM)
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16. WHAT IS POLLUTANT?
A pollutant is a substance 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.
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17. WHY PESTICIDES CAN BE HARMFUL
Pesticides contain ingredients such as oxygen, chlorine, sulfur, phosphorus,
nitrogen, and bromine as well as heavy metals such as arsenic, copper
sulfates, lead, and mercury. Pesticides, being toxic chemicals, can interfere
with the environment and cause harms in several ways.
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18. HOW DOES IT POLLUTE THE ENVIRONMENT?
This normally occurs when heavy wind or rain falls on the aforementioned
lands. The spreading of the pesticides into unintended areas, coming in
contact with natural resources such clean air, water, land, plants, and
animals, there by contaminating or harming them.
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19. WHAT HAPPENS AFTER CONTAMINATION?19
After contamination of pesticide can cause wide range of human health hazards,
ranging from short-term to long-term impacts such as
headaches
Cancer
Endocrine disruption.
Blood disorders
Kidney & liver problems
Reproductive problems
Breathing problems
Vomiting
Nausea
Skin irritation
20. DEGRADATION PROCESS OF PESTICIDES
There are Four major process of degradation of pesticides;
Microbial breakdown: It’s the breakdown of pesticides by microorganism
such as fungi and bacteria.
Chemical breakdown: It’s the breakdown of pesticides by chemical
reactions in soils.
Photodegradation or photolysis: It’s the breakdown of pesticides by
sunlight.
Hydrolysis: it’s the breakdown of pesticides by water into smaller ones.
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23. AIR POLLUTION BY PESTICIDE23
• Pesticides can spread by volatilization and may be blown by
winds into nearby areas.
• Following factors affect to the spreading of pesticide in the air
Weather conditions
Temperature
Relative humidity
24. CONT:24
Ground spraying produces less spread than aerial spraying.
To minimize this air pollution farmers can establish a buffer zone around
their crop fields.
Such windbreaks are legally required in the Netherlands.
plants such as evergreen trees to serve as windbreaks and absorb the
pesticides.
It prevent drift in to other areas.
25. WATER POLLUTION25
There are some major routes through which pesticides reach the water, like
Soil eroding, As a water runoff, Hydrolysis of pesticides
After contaminate the water it makes lot of problems
Reduce the quality of drinking water.
Insecticides are typically more toxic to aquatic life than herbicides and
fungicides.
Ex. Rice cultivation – it may be leach through the soil.
26. SOIL POLLUTION26
The use of pesticides decreases the general biodiversity in the soil.
Also affect to the soil micro-organisms & decrease the soil fertility.
Effect on growth of the plants.
Residual effect of the pesticide in the soil.
Enter to the food chain & bio magnification.
27. PESTICIDES EFFECT ON PLANTS
Root nodule formation in plants saves the world economy $10 billion in
synthetic nitrogen fertilizer every year.
specially pentachlorophenol interfere with legume rhizobium chemical.
Reduction of this symbiotic chemical results in reduced nitrogen fixation.
Pesticides can kill bees and decline the pollinators.
US farmers lose at least $200 million a year from reduced crop pollination
because pesticides applied to fields.
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28. PESTICIDES EFFECTS ON ANIMALS
Pesticides can eliminate some animals' essential food sources.
Residues can travel up the food chain.
Example: Earthworms digest organic matter and increase nutrient content in
the top layer of soil. Pesticides have harmful effects on growth and
reproduction on earthworms.
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29. PESTICIDES EFFECTS ON BIRDS
The US estimates that 72 million birds are killed by pesticides in the
United States each year.
DDT-induced egg shell thinning has especially affected European and
North American bird populations.
some types of fungicides slightly toxic to birds and mammals, but may kill
earthworms, which can in turn reduce populations of the birds.
The paraquat, when sprayed onto bird eggs, causes growth abnormalities
in embryos and reduces the number of chicks that hatch successfully
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30. RESISTANCE DEVELOPMENT30
When pesticide use long period of time, some pest
become resistance to the pesticide.
Because of resistance development pest can not be
control.
Farmer have to increase the concentration or change the
pesticide.
31. GREEN METHOD FOR CONTROLLING PESTICIDE
POLLUTANT
It include the use of living beneficial organisms, called natural enemies to
control pests.
Biological control is an important part of any integrated pest management
programme. All insect and mites have some natural enemies. Managing
these enemies can effectively control many pest.
There are three component of biological control- Importation,
Conservation, Augmentation
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32. BIO-PESTICIDES
These are most effective, important and commercially viable because
these are inexpensive, cause no pollution and no threat to human health.
It include naturally available agents in nature e.g.-
Bacteria-Bacillus thuringiensis, Fungi-Metarhizium, Beauveria.
It also includes the use of natural extracts obtained from plants and
microbes e.g. Azadiractin from neem, Nicotine from tobacco.
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33. BIOMAGNIFICATIONS
It’s the increasing of concentration of substance, such as a toxic
chemical in the tissues of tolerant organism at successively
higher level in a food chain.
Biomagnification also called bio amplification or biological
magnification.
This is danger expose to human because they are also in top of
the food chains.
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35. CONCLUSION
• The pesticides are the chemical compounds that can kill pest, weeds etc.
• EPA recommended value of pesticides is beneficial for our economic
growth but above this value can cause environmental pollution..
• Green methods are the key replacement for the pesticides pollutant.
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36. ACKNOWLEDGEMENT
First of all we are thankful to Almighty ALLAH for his great blessing.
We are also thankful to Prof: Dr. Amana Baloch to give us such an
opportunity.
We are also thankful to our fellows and friends, who encouraged as well as
support us.
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