4. WHAT IS PESTICIDE?
Pesticides are designed to kill or harm pests.
But pesticides can also harm or kill people.
• Insecticide
• Herbicide
• Fungicide
• Rodenticide
6. WHAT IS PESTICIDE HAZARD?
• Hazard = Exposure x Toxicity
• Exposure
– How pesticides enter the body
• Toxicity
– Potential of a chemical to be poisonous
– LD50 (Lethal Dose Fifty measured as mg/kg body weight)
• The amount of a pesticide that has killed half of the animals in a laboratory test.
• The smaller the LD50 value, the less chemical required to kill half of the test animals.
• So, a pesticide with a dermal LD50 of 25 (rabbit) is more poisonous than a pesticide with a dermal LD50
of 2000 (rabbit).
7. PESTICIDE EXPOSURE- COMMON ROUTES
• Dermal – Skin
– Hands
– Arms
– Face & Head
– Eyes
• Oral – mouth & gasterointestinal tract
• Inhalation – nose & lungs
• For humans – dermal is the most significant
route of exposure
12. SAFETY EQUIPMENTS FOR
INHALATION & EYES EXPOSURE
INHALATION
Face Masks
Nasal Filters
Gas Masks
EYES PROTECTIN
• Goggles
• Face Shields
• Safety Glasses
• But never wear
contacts when
spraying pesticides
14. INTERNATIONAL OBLIGATIONS
• International food trade has grown exponentially to
a 200 billion dollar a year with billions of tons of
food produced, marketed and transported.
• The CODEX ALIMENTARIUS or "food code" was
established by FAO in 1963 to develop harmonized
international food standards, which protect
consumer health and promote fair practices in food
trade.
• Codex members cover 99% of the world's population
including Pakistan (1970).
• Codex food safety standards are referred in WTO's
agreement on sanitary and phytosanitary measures
(SPS Agreement) to settle trade disputes.
15. WHAT IS PESTICIDE RESIDUE?
• Residue is the presence of pesticide on treated
surfaces, in or on food after a period of time.
• A residue results when a pesticide is
deliberately applied to a food producing plant.
• Residues are measured as mg/kg of food.
• Residues can be harmful if people, animals and
wildlife are exposed.
• Residues are important in order to achieve pest
control.
• The longer the pesticide exists, the greater the
chances for exposure by the targeted pest.
16. WHAT IS THE MAXIMUM RESIDUE LEVEL OF A
PESTICIDE THAT IS ALLOWED ON FOOD?
• A tolerance is the maximum amount of a specific
pesticide or its break down products that is
allowed to remain in or on foods.
• The tolerance is not an estimate of the residue
amount that is common or typical for a food.
• Residue levels found in food are usually below the
tolerance levels.
• Tolerances for a given pesticide may vary for
different crops.
17. WHEN CAN PESTICIDE RESIDUES
CAUSE HARM?
• When pesticides are used by farmers to control the growth
of weeds, or prevent crop damage by insects, rodents and
molds.
• When pesticides are used on food crops after harvest to
prolong their storage life.
• When pesticides are used on animal farms to control insect
pests.
• Some pesticides, even though no longer used, persist and
remain in the environment. Residues of these pesticides
are sometimes found on food grown on contaminated soil,
or in the fish that live in contaminated waters.
18. WHEN CAN PESTICIDE RESIDUES
CAUSE HARM?
• When crops accumulate pesticides from the soil.
• When growers spray crops that the pesticide isn’t
intended for.
• When the applicator applies too much pesticide.
• When the applicator applies pesticide too close to
the harvest period.
• When pesticide drift occurs from nearby fields.
• During postharvest if residue is left on produce.
• Not following the pesticide label’s instructions when
spraying.
19. WHEN CAN PESTICIDE RESIDUES
CAUSE HARM?
• Pesticide residue leftover from a previous crop
site.
• Building up of pesticide residue over a time of
repeated applications.
• Pesticides can accumulate in soil, groundwater,
lakes/ponds and sometimes animals/plants.
• Some pesticides break down into a more toxic
form before continuing breakdown or combining
with elements in the soil.
20. HOW TO AVOID HAZARDOUS RESIDUES?
• Comply with label’s instructions and refrain
from off-label use of pesticides.
• Take care of Pre-Harvest Interval (PHI) of
pesticides before spraying.
• Use bio-pesticides on crops as they are
mostly exempted from residue limits on fresh
and processed foods around the world.
• Apply pesticides during dormant or fallow
periods when possible to avoid residue on
produce.
• Fill pesticide tanks carefully to prevent
siphoning back into wells.
• Calibrate sprayers such that correct amounts
of pesticides are sprayed on the correct area
size. Don’t over apply.
21. GOOD AGRICULTURAL PRACTICES
• Don’t spray on days that the weather allows high
pesticide drift (warm + windy).
• Choose pesticides that breakdown rapidly.
• Observe safety intervals of all chemicals.
• Use recommended doses.
• Avoid spray of pesticides at higher doses than
recommendation.
• Keep commodity transport vehicles clean and not
contaminated with chemicals.
• Store pesticides on the farm far from grain and seed
storage to avoid leakage.
• Separate pesticides/fertilizers, oils or other fluids from
grain and seed storage.
24. ENVIRONMENTAL EFFECTS OF
FOOD PRODUCTION
• BIODIVERSITY LOSS
– Loss and degradation of habitat from clearing grasslands and
forests and draining wetland
– Invasive species out competing natives
– Killing of wild predators to protect livestock
– Loss of genetic diversity from replacing thousands of wild crop
strains with a few monoculture strains
• SOIL DEGRADATION
– Erosion
– Loss of fertility
– Salinization from irrigation
– Desertification
25. ENVIRONMENTAL EFFECTS OF FOOD
PRODUCTION
• AIR POLLUTION
– Greenhouse gas emissions from fossil fuel use
– Other air pollutants from fossil fuel use
– Pesticide drift from spraying
– Dust / airborne particulates
– Weather alteration from large scale clearing
• WATER POLLUTION
– Aquifer depletion
– Water diversions
– Increased runoff and flooding from land cleared
to grow crops
26. ENVIRONMENTAL EFFECTS OF FOOD
PRODUCTION
HUMAN HEALTH
– Nitrates in drinking water
– Pesticides residues in drinking water, food & air
– Contamination of drinking and swimming water
with disease organisms from livestock wastes
– Bacterial contamination of meat
– Farm worker exposure & working conditions
27. HOW PESTICIDES IMPACT THE
ENVIRONMENT?
• Chemical characteristics of pesticides
• Degradation methods
• Pesticide movements during and after
application
• Mismanagement of pesticide waste – Excess
solution & containers
• Special environmental considerations
28. PESTICIDE CHARACTERISTICS
SOLUBILITY
– Water-soluble pesticides move with surface water or carried downward in soil profile
– Water-insoluble pesticides don’t move readily with surface or subsurface waters
ADSORPTION
– Pesticides that are oil-soluble or oil-loving tend to adsorb or bind to soil particles.
– Clay and organic soils have many binding sites and adsorb a lot of pesticide.
– Pesticide adsorbed or bound to the soil don’t move freely with the soil water and water
contamination concerns are greatly reduced.
PERSISTENCE
– Persistence is the measure of how long a pesticide remains active before it degrades.
– Persistent pesticides also pose concerns for illegal residues on rotational crops that can
pick up the chemical
VOLATILITY
– A chemical changes from a liquid or solid state into a gas or vapor and can move off-target
with the air flow
– It depends upon increase in temperature, wind speed and low humidity levels
29. PESTICIDE DEGRADATION
• MICROBIAL
– Microbes like bacteria and fungi feed on
pesticides and break them down
– Soils that are warm, have adequate
moisture, favorable pH, good mix of
oxygen, sufficient fertility and with
pesticide adsorbed onto the soil, have
increased degradation
• CHEMICAL
– Hydrolysis causes chemicals to break
down in soil
– Soil properties and conditions affect
chemical reactions.
• PHOTODEGRADATION
– The sun can cause chemical degradation
30. PESTICIDE MOVEMENT
• BY AIR
– Vapor, particle, spray drift
• BY WATER
– Surface runoff
– Movement through soil
• BY OTHER OBJECTS
– Residues on plants and animals
31. FACTORS THAT INFLUENCE DRIFT
• Applicator attitude
• Droplet Size
• Viscosity of spray
– a liquid’s resistance to flow
• Weather conditions
32. APPLICATOR ATTITUDE
–Assess what sensitive sites are near the
application area
–Assess weather conditions: air stability,
wind direction and speed
–Set up equipment with appropriate boom
height, nozzles, and pressure
–Make decision to spray or not to spray
33. DROPLET SIZE
• The Larger the Spray Droplet Size
The Less Distance the Droplet Drifts
34. WEATHER CONDITIONS
Read the Wind direction and
speed
0-3 mph: Could be very
stable with airflow, just
not sure which direction
the air is moving
3-7 mph: Manage for off-
target movement
downwind
>7 mph: Carries more
material off-target
35. PESTICIDE MOVEMENT IN WATER
• Pesticides can move
into water from an
identifiable occurrence
or from general
contamination.
– Point Source
• identifiable source
– Non-point Source
• wide area contamination
Maintain an
Air Gap
36. RUNOFF IS DEPENDENT ON
• Soil moisture
• Amount and timing
of irrigation/rainfall
• Pesticide
characteristics
• Grade or slope of
the area
• Soil texture
• Vegetation
37. LEACHING
Geology – how permeable is
the soil?
Soil texture and structure
Sandy: fast percolation, few
binding sites
Silt, clay or organic matter:
slower percolations and
many binding sites
Depth to groundwater:
shallow water tables pose a
concern
Amount and timing of
rainfall or irrigation
38. LEACHING/RUNOFF & GROUNDWATER
High Annual
Precipitation
Cool Soil
Temperature
Shallow
Groundwater
Sandy or
Gravely Soil
Soluble
Pesticide
Concern for leaching
or the site is
vulnerable
select a product
that does not pose
a concern
Little or no concern for
leaching
product selection is not a
concern
39. SPECIAL ENVIRONMENTAL CONCERNS
• Protect sensitive areas
• Protect non-target organisms
– Pollinators, beneficial
– Fish, livestock, and wildlife
– Protect endangered and threatened species
40. PROTECT SENSITIVE AREAS
• Schools, playgrounds,
parks, hospitals
• Wildlife refuges, bee hives
• Yards, gardens, crop fields
• Indoors: homes, offices,
stores, clinics,
restaurants, factories,
animal facilities
• Endangered/threatened
species and their habitats
41. PROTECT NON-TARGET ORGANISMS
• Plants
• Bees, other
pollinators
• Other beneficial
insects
• Fish and other
wildlife
• Humans
Hover fly
H. Riedl
Jerry Stein, Nev. DOW
Virgin River Chub
42. PESTICIDE WASTE MANAGEMENT
• Use Integrated Pest Management
practices to avoid unnecessary
pesticide use.
• Purchase only the amount needed to
reduce the need to store extra
materials.
• Store all pesticides in a well ventilated,
dry, and safe areas free from accidental
mechanical contact and temperature
extremes.
• Make sure all containers are labeled.
43. MANAGEMENT OF EMPTY
CONTAINERS
• Rinsing plastic, glass, and metal containers
– Pressure- or triple-rinse all empty containers
before they can be recycled, disposed, or
reconditioned
– Containers that have been properly rinsed pose
less hazard to people and the environment than
unrinsed containers.
– Rinsing at the time of use allows the rinse water to
be added into the spray tank.
– Properly rinsed pesticide containers should be
stored separate from regular pesticide storage
areas
– Unrinsed containers are not placed with properly
rinsed containers.
– Empty unrinsed pesticide containers must be
capped, stored upright in a secure (locked) areas,
and placed on an impervious surface
44. PROCEDURE OF RINSING EMPTY
CONTAINERS
• Pressure Rinsing
– Empty the container into spray tank. Once flow
is down to a drip, allow the container to drain
for an additional 30 seconds.
– A special nozzle is attached to the end of a
hose to force the remaining pesticide from the
container
• Triple Rinsing
– Empty the container into spray tank. Once flow
is down to a drip, allow the container to drain
for an additional 30 seconds
– Fill the empty container one-fourth full of
water. Replace the cap on the container. Shake
the container about twice per second for 30
seconds.
– Drain rinse water into spray tank.
– Repeat the process thrice.
45. RECYCLE CONTAINERS
• Properly rinsed containers may be recycled.
• Large pesticide drums may be returned to the
manufacturer or to drum reconditioners.
• Plastic pesticide containers should not be recycled
with household plastic recycling programs.
• Pesticide containers should only be recycled through
programs designed for pesticide containers.
46. SAFELY LANDFILL PROPERLY RINSED
CONTAINERS
• If not recycled, the rinsed
containers may be buried at an
approved landfill.
• Under no circumstances should
rinsed containers be carelessly
discarded.
• Keep properly rinsed empty
containers in your pesticide
storage area until you recycle or
dispose of them at an approved
landfill.
47. PAPER AND OTHER CONTAINERS
• Before disposing of paper, plastic, and
composite pesticide bags, make sure they are
completely empty.
• Thoroughly empty the contents into
application equipment.
• Then dispose of the bag at an approved
landfill.
• Do not attempt to rinse.
• Read the label for instructions.
48. HOW TO DISPOSE OF PESTICIDE
CONTAINERS?
S# Container Disposal Method
1 Plastic Jugs Recycle or landfill
2 Metal Recycle or landfill
3 Plastic bags Landfill
4 Paper bags Landfill
5 Aerosol Landfill
6 Mini-bulk Check with the dealer
49. WHAT ARE EXCESS PESTICIDE
MIXTURES?
• Leftover solutions after spraying is done.
• Water used to wash the outside or rinse the inside of
the sprayer.
• Spray left in the boom or hoses.
• Solutions from a spraying job interrupted by weather or
equipment breakdown.
• Small quantities of material spilled during mixing.
50. DISPOSAL OF EXCESS PESTICIDE
MIXTURES
• Excess pesticide mixtures should be collected and used again.
• They can be used on a crop or other site listed on the label or
stored for mixing future solutions of the same pesticide.
• Clean equipment on an asphalt or cement pad equipped with an
aboveground tank to hold runoff.
• Diluting the pesticide will not solve the hazardous waste
problem. In fact, it can make it worse. Ten liters of hazardous
waste diluted with 90 liters of water creates 100 liters of
hazardous waste. Likewise, mixing hazardous waste with
nonhazardous waste makes the whole mixture hazardous.
Again, pesticides that are water-soluble tend to leach through the soil. The contaminated soil water may move horizontally to nearby roots or it may move vertically through the soil profile down to the groundwater. Pesticides that tend to leach are those that are highly water-soluble, don’t readily adsorb onto soil particles, and don’t degrade quickly.
Dependent on:
Geology – how permeable is the soil?
Soil texture and structure
Sandy: fast percolation, few binding sites
Silt, clay or organic matter: slower percolations and many binding sites
Depth to groundwater: shallow water tables pose a concern
Amount and timing of rainfall or irrigation
