Safe use of pesticides

Effect of pesticide on Environment with special reference to human health. its poisoning symptoms and antidotes.

1. Safe use of Pesticides
Dr. Subhomay Sinha, W.B.A.S. (Admn.)
Asst. Dir. of Agriculture, Training, MSD. 1

2. DEFINITION OF A PESTICIDE


A pesticide is any material (natural, organic, or synthetic) used to
control, prevent, kill, suppress, or repel pests.

"Pesticide" is a broad term that includes insecticides (insect
killers), herbicides (weed or plant killers), fungicides (fungus
killers), rodenticides (rodent killers), growth regulators, and other
materials like miticides, which are used for mite control, or
products that kill snails and slugs (molluscicides).
When to apply Pesticide ???????
Only when pest population exceeds the Economic Threshold Limit (ETL)
2

3. Pesticides Classified by Target Organism
Term Target Term Target
1. Algaecide Algae 2. Avicide Birds
3. Bactericide Bacteria 4. Defoliant Crop Foliage
4. Desiccant Crop Plants 5. Fungicide Fungi
6. Herbicide Plants (weeds) 7. Insecticide Insects
8. Miticide Mites 9. Molluscicide Molluscs
10. Nematicide Nematodes 11. Plant
Growth Reg.
Crop Plants
12. Rodenticide Rodents 13. Piscicide Fish
14. Lampricide Lamprey 15. Wood
Preservative
Wood
Destroying
Pests 3

4. 4

5. 5

6. Effect of Pesticides on Humans
Insects, rodents, and humans have similar
nervous, circulatory, and respiratory systems,
so pesticides can affect human being too!



Health effects - short- or long-term
Physical and chemical risks - explosive or
combustible
6

7. Mode of Action of Pesticides, Examples ……
Broad Spectrum -- Kills broad range of pests, usually refers to
insecticides, fungicides, and bactericides.
Contact Poison -- Kills by contacting with pest.
Systemic Poison -- Absorbed and translocated throughout the plant to
provide protection.
Disinfectant (Eradicant) -- Effective against pathogen that has already
infected the crop.
Germination Inhibitor -- Inhibits germination of weed seeds, fungus
spores, bacterial spores.
Nonselective -- Kills broad range of pests and/or crop plants, usually
used in reference to herbicides.
Nerve Poison -- Interferes with nervous system function.
Stomach Poison -- Kills after ingestion by an animal.
Protectants -- Protects crop if applied before pathogens infect the crop.
Repellents -- Repels pest from crop or interferes with pest’s ability to
locate crop.

7

8. Insecticides usually are classified in two groups,
first being contact insecticides and the second
being systemic insecticides.
Systemic insecticides becomes incorporated
throughout the whole plant usually in a protein
form that is somewhat not toxic to humans &
animals, but when the targeted insect feeds on this
plant, they ingest the toxin and die.
Contact insecticides kill the insects upon their
contact with the plant that is sprayed with the
insecticide, hence comes the name Contact
insecticide. The chemical is absorbed by insect
through direct contact. They can be organic,
inorganic, or natural insecticides which leave behind
a toxic residue.
8

9. Insecticides
Plant / animal
origin
Botanical
insecticides
Eg.
Azadirachtins,
nicotines,
Bio -
insecticides
Eg . Bacillus,
Inorganic
Oils / minerals
Eg. Arsenics,
petrolium oils.

Organic
Synthetic
Eg organochlorine
Organophosphate
Carbamates, synthetic
pyrethroids, neo -
nicotinoids
Naturally
occurring
eg Spinosad
Avermectin
Classification of insecticides on the basis of its CHEMICAL NATURE
9

10. Insecticides
Acts on
Nervous
system
Synaptic
transmission
inhibitor
Acetylcholine
esterase
inhibitor
Blocking
of Na
channel
Acts on
Respiration
System
Rotenones
Insect
growth
regulators

Chitin
synthesis
inhibitor

Juvenile
hormone
mimics
Synergistic
PBO
Classification of insecticides on the basis of its MODE OF ACTION
10

11. Stomach Poison enter an insect’s body through
mouth & digestive tract and kills by destroying
the midgut (stomach) of the larvae.
Stomach Poison
Generally enter the insect body or plant by
exposure to water, some treated surface
(leaves) or an aerosol (insecticidal fog).

Act upon the nerve and respiratory centers
of arthropods.


Conact Poison
11

12. Volatile compounds that enter the bodies of
insects in a gaseous phase.

Used in warehouses for controlling of stored
grain pests.
Fumigants
Aerosol contains an insecticide solution and a propellant
material in a container under pressure.

When the button is pressed the pressure forces the mixture
of insecticide and propellant up a dip tube and out trough
the valve to produce the spray.
Aerosol
12

13. Handling of Pesticides
13

14. While Purchasing

Purchase Pesticides /bio-pesticides
only from Registered pesticide
dealers having valid License.

Purchase only just required quantity
of pesticides for single operation in a
specified area.

See approved labels on the
containers/packets of pesticides.

See Batch No., Registration Number,
Date of Manufacture/ Expiry on the
labels.

Purchase pesticides well packed in
containers. Never purchase loose /
from open container.
DO DO NOT
While Purchasing

Do not purchase pesticides
from foot path dealers or from
un-licenced person.

Do not purchase pesticide in
bulk for whole season.

Do not purchase pesticides
without approved label on the
containers.

Never purchase expired
pesticide, or do not have batch
no. / smuglled from other
countries.

Do not purchase pesticides
whose containers are
leaking/loose/ unsealed. 14

15. During Storage

Store the pesticides away from house
premises.

Keep pesticides in original
containers.

Pesticides/weedicides must be
stored separately and where
pesticides have been stored, area
should be marked with warning
signs.

Pesticides be stored away from the
reach of the children and live stocks.

Storage place should be well
protected from direct sunlight and
rain
DO DO NOT
During Storage

Never store pesticide in house
premises.

Never transfer pesticides from
original to another containers.

Do not store insecticides with
weedicides.

Do not allow children to enter
the storage place.

Pesticides should not be
exposed to sunlight or rain
water.

15

16. While handling

Keep pesticides separate during
transportation.

Bulk pesticides should be carried
tactfully to the site of application.
DO DO NOT
While handling

Never carry / transport
pesticides along with food /
fodder / other eatable articles.

Never carry bulk pesticides on
head, shoulder or on the back.
Selection of Equipment

֎Select right kind of equipment.

֎Select right sized nozzles.

֎Use separate sprayer for
insecticides and weedicides.
Selection of Equipment.

Do not use leaky or defective
equipment and defective / non-
recommended nozzles.

Do not blow / clean clogged
nozzles with mouth. Instead use
tooth brush tied with sprayer.

Never use same sprayer for both
weedicides and insecticides.
16

17. ֎Always use clean water.

֎Use protective clothing viz., hand gloves, face masks, cap, apron, full
trouser, etc. to cover whole body. Always protect your nose, eyes,
ears, hands, etc. from spill of spray solution.

֎Read instructions on pesticide container label carefully before use.

֎Prepare the solution as per requirement.

֎Granular pesticides should be used as such.

֎Avoid spilling of pesticides solutions while filling the spray tank.

֎Always use recommended dosage of pesticide.

֎No activities should be carried out which may affect your health.
Precaution while preparing spray solution / Tank mixture : Dos.
17

18. Do not use muddy or stagnant water.

Never prepare spray solution without wearing protective
clothings.

Do not allow the pesticide / its solution to fall on any body parts.

Never avoid reading instructions on container’s label for use.

Never use left out spray solution after 24 hours of its preparation.

Do not mix granules with water.

Do not smell the spray tank.

Do not use overdose which may affect plant health and
environment.

Do not eat, drink, smoke or chew during whole operation of
pesticides.
Precaution while preparing spray solution / Tank mixture : Do Not.
18

19. ►Apply only recommended dose and dilution.

►Spray operation should be conducted on cool and calm day.

►Spray operation should be conducted on sunny day in general.

►Use recommended sprayer for each spray.

►Spray operation should be conducted in the wind direction.

►After spray operation, sprayer and buckets should be washed
with clean water using detergent /soap.

►Avoid the entry of animals / workers in the field immediately after
spray.
Precaution during Pesticide application: Dos.
19

20. ◙Never apply over-dose and high concentrations than
recommended.

◙Do not spray on hot sunny day or strong windy conditions.

◙Do not spray just before rains and immediately after the rains.

◙Emulsifiable concentrate formulations should not be used for
spraying with battery operated ULV sprayer.

◙Do not spray against wind direction.

◙Containers and buckets used for mixing pesticides should never
be used for domestic purpose even after thorough washing.

◙Never enter in the treated field immediate after spray without
bearing protective clothing.
Precaution during Pesticide application: Do Not.
20

21. DO DO NOT
After Spray Operation

Left over spray solution should
not be drained in or near ponds
or water lines etc.

Empty containers of pesticides
should not be re-used for
storing other articles.

Never eat/smoke before
washing clothes and taking
bath.

Do not take the risk by not
showing the poisoning
symptoms to doctor as it may
endanger the life of the patient.
After Spray Operation

Left over spray solutions should be
disposed off at safer place viz.
barren isolated area.

The used /empty containers should
be crushed with stone /stick and
buried deep in soil away from water
sources.

Wash hands and face with clean
water and soap before eating
/smoking.

On observing poisoning symptoms
give the first aid and show the
patient to doctor. Also show the
empty container to doctor.
21

22. Following information appears on pesticide labels:

Brand name
This is the most identifiable name for the product.
Common name / Technical name
Chemicals with complex scientific names are often given a common name that does not vary between
companies.
Ingredients
Active ingredients are listed by name and percent of total weight. Inert ingredients are listed as
percent of total weight. Certain highly toxic, inert ingredients must be presented by name as well.
Formulation
Identifies if the pesticide is in liquid, wettable powder, emulsifiable concentration, dust or other
formulation. Different types of formulations require different methods of handling.
"Keep out of reach of children" and degree
This statement must appear on the front label.
Net contents
The quantity of product in the container is expressed on the label in ounces, liters, pounds or other
units.
Directions for use
Labels contain detailed descriptions of how to use the product properly within its legal requirements
for the best results.
Registration and establishment numbers
Every pesticide product label must contain these numbers
Name and address of manufacturer or distributor
This information is included on pesticide labels to allow consumers to contact the company for more
information on the product.
22

23. ֎Exposure to pesticides for human being can occur through ingestion,
inhalation or skin absorption.

֎Physical responses to pesticide exposure depend on the type of
pesticide, its LD
50 value, amount of exposure, the age and overall
physical condition of the victim.

֎Children are far more susceptible to harm from exposure to
pesticides than adults. Because of their lower body weight,
exposure in children may result in more toxins per Kg body weight.

֎Children are also especially sensitive to the neurotoxins often found
in pesticides, because children's immune systems, organs, brains
and nervous systems are still developing.
Harmful effect of Pesticides on Human Being
23

24. Effect of Pesticides on Environment.


The environmental dangers posed by a pesticide depend on the
following factors :

Amount of time it takes the pesticide to break down.

the substances it breaks down into,

its ability to be stored in body tissues,

its toxicity to different organisms.

the amount of exposure.

The impact of pesticides is present upon our entire planet. A thin
residue of pesticides is found in living tissues, soil, air and water
supplies around the world.
24

25. Level of Toxicity as appears on pesticide containers
25

26. HAZARD = Toxicity x Exposure
Risk, the
potential for
injury
The capacity of
a pesticide to
cause injury
The risk of a
pesticide
contacting or
entering the
body
26

27. Hazard
•Higher toxicity = greater hazard
•Lower toxicity = less hazard

•Higher exposure = greater hazard
•Lower exposure = less hazard
27

28. How to Reduce Hazards
By using least toxic pesticides to reduce Toxicity

By wearing personal protective equipment
to minimize exposure
HAZARD = Toxicity x Exposure
28

29. Pesticides can enter our body in three ways:

Orally, through the mouth.

By inhaling, through the lungs.

Dermally, through the skin or eyes. This is the most common
way applicators come into contact with pesticides.
29

30. 30

31. Different parts of the body vary in their ability to
absorb pesticides.
Forehead 36%
Back of Hand 21%
Scalp 32%
Forearm 9%
Ear Canal 40%
Palm 12%
Ball of Foot 13%
Abdomen 18%
Genital Area 100%
Percent Dose
Absorbed
Chemical -parathion
Armpit 64%
31

32. Greater Dermal Absorption
Warm, Moist Areas: Groin, Armpits, Head, Neck
Cuts, Abrasions, And Rashes

Type of Pesticide Formulations Affect Absorption
Most
Absorbed
Least
Absorbed
32

33. Protective Clothing and Equipment for pesticide application
Avoid using cotton gloves or
lightweight dust masks
that may absorb the spray and
increase contact with skin.
Personal Protective
Equipment

•Minimum Requirement:
–rubber gloves,
–eye protection,
–long-sleeved shirt,
–long pants,
–mask,
–closed shoes
33

34. Acute poisoning from pesticides is an immediate reaction that occurs
soon after exposure. Symptoms can include skin irritation, dizziness,
headache, confusion, shortness of breath, respiratory irritation,
nausea, cramping, coma and death.
Type of Pesticide Poisoning
Acute
Poisoning
Chronic
Poisoning
Chronic poisoning can result from repeated exposure to a pesticide
over a long period of time. Symptoms can be similar to acute
poisoning, but because symptoms may not appear until long after
exposure, it is more difficult to isolate the cause.
34

35. Poisoning Effects of Pesticide
Contact
Systemic
Allergic
35

36. Contact Effects
Skin irritation (dermatitis):
Itching, Redness, Rashes,
Blisters, Burns
Eyes: Swelling, Stinging, Burning
Nose, mouth, throat irritation
Typical of herbicides, fungicides and other products
Contact injury to the skin
is the most common form of
pesticide poisoning!
36

37. Systemic Effects
From pesticides to target animals

Insecticides: nervous system
Rodenticides: circulatory system

Insecticide symptoms: nausea, vomiting,
diarrhea, headache, dizziness, weakness,
excessive sweating, tearing, chills, thirst, chest
pain, breathing difficulty, body aches & cramps
37

38. Allergic Effects of Pesticides
Contact or Systemic
Dermatitis, blisters, hives
Life-threatening shock
Red or itchy eyes
Respiratory discomfort, asthma

38

39. Routes of Entry: Lungs
( Through inhalation)
Inhalation exposure can occur:
• When using
Wettable powders
Dusts
Gases, vapors
Sprays
• While mixing and loading
• During applications
39

40. Routes of Entry: Eyes
Eyes are able to
absorb surprisingly
large amounts of
chemical
40

41. Possible Harmful Effects
from Pesticides
Acute effects
Chronic effects
Delayed effects
41

42. Acute effects .…
Occur from a single exposure to pesticide.
Develop within 24 hrs of exposure.
Any effect is measured.
Toxicity usually expressed as LD
50 or LC
50 .
42

43. Chronic Effects
Birth defects
Toxicity to a fetus
Production of tumors
Genetic changes
Blood disorders
Nerve disorders
Reproductive effects
Low dose exposures over an extended
period of time
43

44. Delayed Effects
For example, organophosphates
and carbamate INSECTICIDES…
After 24 hours
After repeated exposures
44

45. MODE OF ACTION of Insecticides
45

46. LD
50 and LC
50
LD
50 = the dose of a substance that kills 50% of a
population of test animals
It is measured in milligrams of toxicant per kilogram of body
weight (mg/kg).
96 dead


12 dead
Dose: 100 mg/kg 10 mg/kg 1 mg/kg
50 dead
LC
50 = concentration of a substance in air or water that
kills 50% of a test population, measured in parts per million
(ppm).
Total number of Test Animals : 100
Dose (Mg / Kg)
46

47. Over-exposure may decrease
available cholinesterase nerve
enzyme
Cholinesterase is the nervous system
“off switch”. If inhibited, nerves
continuously fire
Results over-stimulating of muscles,
glands, and organs
Organophosphates and carbamate insecticides
inhibit cholinesterase enzyme
47

48. Effect of Pesticides on human reproduction and birth.
48

49. Kasargod Endosulfan tragedy
Aerial spraying of Endosulfan since 1976 in cashew plantations spread over
4500 hectares three times in a year around 15 villages in Kasaragod
district of Kerala.
Long term exposure results this !!!
49

50. Fate of applied
pesticides on
plant
50

51. 51

52. 52

53. Loss of species diversity among
the food chains and food webs.

Effects on pollinators.

Effects on nutrient cycling in
ecosystem.

Effects on soil erosion,
structure and fertility.

Effects on water quality.

Effects on human beings.

Effects on birds.

Contaminates the food.
53

54. 54

55. Reaction of
pesticides with
Sunlight.
55

56. Reaction of
pesticides with
water
56

57. Reaction of
pesticides with
water
57

58. Bacteria and fungi can break down
chemicals, creating biodegradation
products.
Microorganisms (bacteria and fungi) use
the pesticide as an energy source for
growth.
58

59. Plant / Animal Metabolism of Pesticides
Plants and animals can change
chemicals into forms that dissolve
better in water (metabolites). This
makes removal from the body
easier.
Sorption with soil particle
Chemicals that stick
tightly to soil particles
can become inaccessible
59

60. A half-life is the time it takes for a certain amount of a pesticide to be
reduced by half.

This occurs as it dissipates or breaks down in the environment.

In general, a pesticide will break down to 50% of the original amount
after a single half-life. After two half-lives, 25% will remain. About 12%
will remain after three half-lives. This continues until the amount
remaining is nearly zero.
What is a half - life of a pesticide ?
60

61. Pesticide dissipation in Environment
61

62. 62

63. 63

64. Transformation of pesticides in Environment
64

65. The accumulation of more toxin in the bodies of organisms as move from
producers to primary consumers and then secondary consumers etc.

It occurs when a chemical becomes more and more concentrated as you
move up a food chain
65

66. SYMPTOMS OF PESTICIDE POISONING
&
TREATMENTS
66

67. Symptoms of Pesticide poisoning and First Aid there off.
–Dizziness
–Headache,
blurred vision
–Sweating too
much
–Stomach
cramps,
vomiting
–Eye irritation
–Skin rashes
–Trouble
breathing
–Chest pains
67

68. Rodenticides Symptoms are presence of red blood cells in urine
and passage of blood through anus.
Symptoms of Rodenticide poisoning
68

69. Safety – First Aid when pesticides is in Eye / Skin
•If pesticide is in eyes, rinse
immediately with clean water for
about 15 minutes.
•If pesticide gets on clothing or skin
take clothes off immediately and
wash skin with soap and water.
•The faster you act, the less likely
harm will occur.
69

70. Safety – First Aid, when pesticide is inhaled
•What should one do if pesticides are
inhaled?
–First leave the contaminated area.
–Loosen clothing for better breathing.
–Give cardio-pulmonary resuscitation (CPR) if
breathing has stopped.
–Try to calm down exposed person.
–Get immediate medical care.
70

71. 71

72. Safety – First Aid
What should you do if pesticide is
swallowed?


–Follow label’s instructions.
–Drink 1 liter of milk or water if person is conscious. If the pesticide
is not corrosive or petroleum based, induce vomiting.
– Get immediate medical care.
– But, never induce vomiting if the pesticide is corrosive in nature
(strong acid / alkali) or a petrolium based product / Emulsifiable
concentrate product.
–Never induce vomiting if the patient is in un-concious or is having
convulsion.
It is very important that the victim get to the hospital
without delay
72

73. Symptoms from Organophosphate
and Carbamate Insecticide
Exposure
Mild: fatigue, headache, giddiness, sweating, tearing, dizziness
or blurred vision, cramps, nausea, vomiting, diarrhea
Moderate: numbness, changes in heart rate, general muscle
weakness, difficulty breathing and walking, pinpoint pupils,
excessive salivation
Severe: convulsions and coma.
73

74. Antidotes for OP and Carbamate Poisoning
Organophosphates :
Atropine sulfate : To block the muscarinic receptors
until the organophosphate is metabolized away from the body.
Protopam Chloride (2-PAM): These are used
to restore neuromuscular transmission.

Carbamates
Atropine sulfate ONLY. 2- PAM is in-effective for
Carbamate poisoning.

Injected i.v. slowly in a dose of 1 - 2 g. Doses may be
repeated according to need. Use of oximes (2 – PAM)
in OP poisoning is secondary to that of Atropine.

Atropine can be poisonous if misused. It
should be given only under a doctor's
directions.
74

75. Antidotes for Chlorinated Hydrocarbon Pesticide poisoning
֎Barbiturates for convulsions or restlessness.

֎Calcium Gluconate given intravenously.

֎Do Not Use epinephrine (adrenalin) for this type of poisoning.
75

76. BAL (Dimercaprol) is specific for arsenic poison.
Inject intramuscularly.
76

77. Antidotes for Anticoagulants like Warfarin
Vitamin K orally, intramuscularly, or intravenously.

Vitamin C useful adjunct.
Antidotes for Bromides and Carboxides like Methyl Bromide
BAL (Dimercaprol) may be given before symptoms appear.
Barbiturates for convulsions.
77

78. Antidote for Organochlorine insecticide is
Diazepam. Intra-veineous application of 10 mL
of Diazopam is recommended for
Organochlorine poisoning.
Antidotes for Organochlorines
Antidote for Pyrethroids is used of
pentabarbitone in any vein at the rate of
0.7 g per day until poisoning has been
cured.
Antidote for Pyrethroids
78

79. In Case of Cartap hydrochloride, “Dimercaprol” can be used as
antidote at the rate of 3-4 mg per Kilogram of body weight in intra
muscles injection after every four hours for a period of two days
and after that 2 times a day for next ten days, if necessary.
Antidote for Cartap hydrochloride
79

80. Antidote for Carbendazim first gives test dose of ATROPINE @ 2-4 mg as
i.v. If no response has been notice against this dose, then repeat this dose
after every 10 minutes.
Antidotes for Fungicides
Antidote for Carbendazim
Antidote for Streptocycline is Injection of
CORTISONE. Adrenalin and Antihistamine is
given for intense degree of poisoning.
Antidote for Streptocycline
Antidote for Copper Oxychloride is DIMERCAPROL @ 3-4 mg per kilogram
of body weight. At early stage 3 ml is injected deep between muscles for
two days and then double amount of dose for next ten days.
Antidote for Copper Oxychloride
80

81. Antidotes for Fungicides
Antidote for fungicide belonging to Methoxy Ethyl group is usage of 1-4
gram SODIUM CITRATE after every 4 hours for speedy recovery.
Antidote for Mancozeb is usage of 0.2 gram of VITAMIN C in veins per
minute as i.v. injection.
In case of Triadimifon no specific Antidote is available. Only empty stomach
of toxic substances with the help of Sodium bicarbonate is effective
Toxicity of Dinocap can easily covered, but for this purpose no specific
chemical is available as Antidote. firstly make empty stomach from toxic
substances then give 15 gram of SODIUM SULPHATE in 0.5 liter water.
if Captan is consumed, than vomiting should be done by given of a spoon of
salt in Hot Water.
81

82. Antidotes for Herbicides
Glyphosate toxicity cause skin allergies, eyes irritation, respiratory problems
and can even cause death. In case of Glyphosate ingestion, immediately
consume milk or some water by patient, followed by hospitalization.
Isoproturon toxicity is cure by washing eyes and skin with soap and water.
Paraquat toxicity cause lung functioning disorder, respiratory problems and
even death. To cure the patient vomiting is induce so that poison is removed
for stomach with the help of 30% water suspension in sodium sulphate.
82