Pesticide Hazard Assessment Pest And Pesticide Survey & Surveillance, Field Monitoring and Sampling Bioassay

1. PRESENTATION ON:
PESTICIDE HAZARD ASSESSMENT
PEST AND PESTICIDE SURVEY AND SURVELLIANCE
FIELD MONITORING, SAMPLING AND BIOASSAY
Presenters:
Purushottam Dhodary (29)
Rahul KC (30)
Ashmita Khanal (31)
Ram Dhan Tharu (32)
Renu Ojha (33)
Sabina Tiwari (34)
Sachin Bhattarai (35)

2. PESTICIDES HAZARD
ASSESSMENT

3. • Pest : Organisms dangerous to cultivated plants
and animals. (insects, fungi, herbs, nematodes
etc.)
• Pesticides: Any substance used for killing pests.

4. • Insects, rodents, and humans have similar nervous,
circulatory, and respiratory systems, so pesticides can
affect people too!
• Health effects -short-or long-term
• Physical and chemical risks -explosive and
combustible

5. 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

6. HAZARD
•Lower toxicity = Less hazard
•Higher exposure = Greater hazard
•Lower exposure = Less hazard

7. HAZARD ASSESSMENT ?
• New pesticides must be evaluated before they
can enter the market.
• Existing pesticides must be re-evaluated
periodically to ensure that they continue to meet
the appropriate safety standard.

8. • Ecological risk assessment
• Human health risk assessment
• Assessing pesticide cumulative risk
• Models, databases, and guidelines

9. ECOLOGICAL RISK ASSESSMENT
• Planning and scoping process
Phase 1 - problem formulation
information is gathered to determine what plants and animals
are at risk and need to be protected.
Phase 2 - analysis
This is the determination of what plants and animals are
exposed and to what degree they are exposed, and whether or
not that level of exposure is likely to cause harmful ecological
effects.

10. Phase 3 - risk characterization
Risk characterization includes two major components: risk
estimation and risk description. "risk estimation" combines
exposure profiles (i.e., the findings of exposure
characterization) and effects from exposure. "risk
description" provides information important for interpreting
the risk results and identifies a level for harmful effects on
the plants and animals of concern.

11. HUMAN HEALTH RISK ASSESSMENT
A human health risk assessment is the process to
estimate the nature and probability of adverse health
effects in humans who may be exposed to chemicals in
contaminated environmental media, now or in the future.
human health risk assessments address questions such
as:

12. • What types of health problems are caused by
pesticides in the environment?
• What is the chance that people will experience
problems when exposed to different levels of
pesticides?
• Is there a low level below which some chemicals
don’t pose a human health risk?
• What pesticides are people exposed to and for how
long?

13. ASSESSING PESTICIDE CUMULATIVE RISK
This new assessment is called a cumulative risk
assessment and is designed to evaluate the risk of a
common toxic effect associated with concurrent exposure
by all relevant pathways and routes of exposure to a
group of chemicals that share a common mechanism of
toxicity.

14. MODELS, DATABASES, AND GUIDELINES
• The risk assessment process depends on having
appropriate data and using well tested models

15. HEALTH IMPACTS
Chronic impacts
• Increased risk of cancer
• Neurological impairment
• Developmental effects
• Reproductive effects
• Organ damage
• Intrusion with the human hormone system

16. Acute Impacts:
Eyes : tearing , irritation, conjunctivitis
Skin: rash ,blistering, burns, sweating ,contact
dermatitis, jaundice
Nervous system: headache dizziness, mood
disturbances, depression, stupor, muscle twitching, lack
of coordination, seizures, paralysis, loss of
consciousness, coma
Respiratory system :throat pain, rhinorrhoea, cough,
pulmonary oedema, difficult in breathing, respiratory
failure
Cardiovascular system: cardiac arrhythmias

17. PEST SURVEY
• Survey is a sampling or partial collection of facts,
figures or opinions taken and used to approximate or
indicate what a complete collection and analysis
might reveal.
• Pest survey activities involve sampling of plants for
various insects and pest, trapping and identifying
insects, and estimating insects populations.
• It is conducted to study the abundance of a pest
species.

18. TYPES OF SURVEY
Roving survey
• Assessment of pest population /damage from
randomly selected spots representing larger area.
• Larger area surveyed in short period
• Provides information on pest level over large area

19. Fixed plot survey
Assessment of pest population /damage from a
fixed plot selected in a field. The data on pest
population/damage recorded periodic from
sowing till harvest.

20. PEST SURVEILLANCE
• Pest surveillance refers to the constant watch on the
population dynamics of pests, its incidence and
damage on each crop at fixed intervals to forewarn the
farmers to take up timely crop protection measures
• Pest surveillance is necessary for exotics pest
eradication, market access, improved pest
management, pest status information

21. Basic components of pest
surveillance
Determination of-
• The level of incidence of the pest species
• The loss caused by the incidence
• The economics benefits, the control will provide

22. Objectives of pest surveillance
• To know existing and new pest species
• To assess pest population and damage at different
growth stage of crop
• To study the influence of weather parameters on pest
• To study changing pest status
• To assess natural enemies and their influence on pests
• To assess effects of new cropping pattern and varieties
on pest

23. PEST MONITORING
• Process of regularly observing measuring and recording conditions within a given area.
• Is an essential tool for pest management programs.
• Information gathered during monitoring includes:
Pest populations and infestation levels
Weather
Crop development and soil conditions
Population of both beneficial organisms

24. OBJECTIVES OF PEST MONITORING
• Predict and evaluate potential key pest problems and non-target effects
• Provides info for choosing and timing appropriate control actions
• Evaluates effectiveness of management practices
• Establishes a pest history for the specified area

25. BENEFITS OF MONITORING
• Greater awareness of pest activity, including changes in pest
populations.
• Up-to-date information on the health of your plants.
• Data that can be used to compare pest outbreaks from season to
season.
• Early detection of pest problems, resulting in the availability of
more management options.

26. SAMPLING TECHNIQUES
• Sampling technique is important to ensure a representative portion of the
crop has been monitored since pest activity is often patchy.
• Sampling parameters(e.g. number of samples per padlock and number of
leaves per sample) helps sampling consistency. sampling technique
includes:-
• Sample size
• Sample number
• Depend on crop type
• Crop age
• Padlock size

27. SAMPLING TYPES
1. ABSOLUTE SAMPLING-
• To count all the pests occurring in a plot
• Pests per spatial area
• Direct observation/count of pests: easier with static organisms
• Total census of pests within a given area
2. RELATIVE SAMPLING-
• To measure pest in terms of some values which can be compared over time and space e.g.
light trap catch, pheromone trap
• Pests per sampling effort i.e. sweeps with a sweep net
• Insects/spores per passive or active trap
• Partial census: sampling method is not 100% fool proof
• Relative measures can be transformed in to absolute measures
• This is often the basis for pest management thresholds

28. SAMPLING METHODS
BETA SHEET:-
Main tool used to sample row crops for pests and beneficial insects.
Beta sheets are particularly effective or sampling caterpillars, bugs, aphids
and mites.
A standard beat sheet is made from yellow or white taroaulin material with
heavy dowel on each end.
Beta sheets are generally between 1.3-1.5 m wide by 1.5-2.0 m deep (the
larger dimension are preferred for taller crops). the extra width on each side
catches insects thrown out sideways when sampling and the sheets depth
allow it to be draped over the adjacent plant row. this prevents insect being
escape through this row.
Other various sampling techniques can be used to quantify pest
populations in the field, they are:-

29. • In situ counts- visual observation on number of insects on plant canopy(either entire plot or randomly
selected plot)
• Knock down- collecting insect from an area by removing from crop and (sudden trap)counting
• Suction sampling- it is quick and relatively easy way to sample for mirids. its main drawback are
unacceptably low sampling efficiency, a propensity to suck up flowers and bees, noisy operation, high
purchase cost of the suction machine.
• Netting- use of sweep net for hoppers
• Narcotized collection- quick moving insects anaesthetised and counting
• Trapping- used to sample mobile insects. left out in the field for a period of time, then the number of
insects is counted.
• Pan trap: blue pan traps for aphids
• Pheromone trap: species specific
• Sticky trap: sucking insect
• Bait trap: Shoot fly and other flies
• Emergence trap: for soil insects
• Light traps – moths, mosquitoes, beetles

30. • STAGES OF SAMPLING
Usually most injurious stage counted but depends on the type of crop,
insects, history of insects, influences of biotic and abiotic factors on pest
population and insect nature of a damage.
• SAMPLE SIZE
Sample size differ with nature of pest and crop but large sample size gives
accurate result.
Sample size will depend on crop type, age and padlock size, and is often in
between the ideal number and location of samples and what is practically
possible.
Sample size should be enough to provide good field representation or
coverage

31. DECISION MAKING
• Decision regarding when to start control measure
depends on the population or damage assessed from
the crop.
• The pest population is compared to economic
threshold level and economic injury level.
• When pest level crosses ETL, control measure has to
be taken to prevent pest from ETL.

32. BIOASSAY
• A bioassay involves use of a biological organism to test for chemical toxicity.
• It involves the use of live animal or plant(in vivo) or tissue or cell(in vitro)to
determine the biological activity of the substance, such as a hormone or drugs.
• Bioassay are typically conducted to measure the effects of a substance on a
living organism, such as a hormone or drug.
PROPERTIES OF GOOD BIOASSAY:-
• Reproducibility (the “litmus test” of science)
• Results easily observed and measured
• Relatively low cost
• Preferably of short duration (less opportunity for confounding factors); more
replication
• Linear dose-response

33. PURPOSE OF BIOASSAY
• Measurements of the pharmacological activity of new or chemically
undefined substances.
• Investigation of the function of endogenous mediators.
• Determination of the side-effect profile, including the degree of the drug
toxicity.
• Measurement of the concentration of known substances(alternatives to
the use of the whole animals have made this use obsolete).
• Assessing the amount of pollutants being released by a particular source,
such as wastewater or urban runoff.
• Determining the specificity of certain enzymes to certain substrates.

34. THANK YOU VERY MUCH