7/29/2019 Russell Reza
1/98
A Project Review Work
OnPesticide Pollution and Management
InAgriculture
A PROJECT REPORTSUBMITTED IN PARTIAL FULFILLMENT FOR THE REQUIREMENTS
OF THE DEGREE OF BACHELOR OF SCIENCE
INENVIRONMENTAL SCIENCE
SUBMITTED BYROLL NO. ENV- 010375
REGISTRATION NO. # 344SESSION -2000-2001
DEPARTMENT OF ENVIRONMENTAL SCIENCEJAHANGIRNAGAR UNIVERSITY, SAVAR, DHAKA
7/29/2019 Russell Reza
2/98
Dedicated
to
My Family
7/29/2019 Russell Reza
3/98
Acknowledgement
I am grateful to almighty Allah who has endued me to complete the project.
I express my heart-felt gratitude to Dr. Md. Khabir Uddin, Associate
Professor, Dept. of Environmental Science, Jahangirnagar University, Savar,
Dhaka to commit me the lively supervising guidelines in research project
during preparation of the report.
I also utter my gratefulness to Dr. Md. Mazibur Rahman , Principal Scientific
Officer, Institute of Food and Radiation Biology (IFRB), Bangladesh Atomic
Energy Commission, Savar, Dhaka) for providing valuable suggestions during
preparation of the report.
Finally, I disclose a special thanks to my beloved parents, sisters and my
friends for their encouraging and spiritual support throughout the time.
The Author
June 6, 2006
7/29/2019 Russell Reza
4/98
List of Contents
AbstractixAbbreviationsx
1.INTRODUCTION1Pesticides, an important issue for Bangladesh.Objectives of the report
2. METHODOLOGY.3
3.ABOUT PESTICIDES
3.1. Definition..4 3.2. Historical Time Line for Pest Control .......................43.3. Sectors of Pesticide Use in Bangladesh..63.4. General Characteristics of Pesticides.7
3.5. Formulation of Pesticide.113.6. Classification of Pesticide .12
3.7. Natural products pesticide ..163.8. Pesticide Toxicity..173.9 Overview of mostly used pesticides.18
Chlordane
DDT(dichlorodiphenyltrichloroethane)Aldrin / Dieldrin
EndrinHeptachlorMirex
Toxaphane
4.PESTICIDE CIRCULATION IN THE ENVIRONMENT4.1 Pesticide Circulation25
4.2 Physicochemical Properties of Pesticides in Relation with the Environment4.3 Fates of pesticides.28
4.3.1. Enter of the pesticides..284.3.2. Pesticide in the water body294.3.3.Behavior of pesticides.30
4.4 Effect of pesticides
4.4.1. Pesticidal toxicity in air33
4.4.2. Pesticidal toxicityin soil.334.4.3. Toxicity of pesticides to fish.34
4.4.4. Pesticidal toxicity to birds 34
4.45. Effects of pesticides on biota.35
4.4.6. Effect of pesticideson human.35
5. MANAGEMENT PRACTICES5.1 management practices38
5.2 pest management..405.3 Pesticide management practices..425.4 Reducing risk through use of engineering controls.46
7/29/2019 Russell Reza
5/98
6. TREATMENT METHODS6.1. Traditional Disposal Methods 50
6.2. Modern Innovation Non-Combustion Destruction Methods..52
6.3. Biological Treatments6.3.1.BIOREMEDIATION54
6.3.2Phytoremediation / Phytotechnology.58
7. REGULATIONS IN BANGLADESH
7.1 Acts and regulation In Bangladesh..637.1.1. The Pesticide Ordinance, 1971 637.1.2 The Pesticide Rules, 1985..64
7.1.3. Quality control 657.2. Convention on pesticides ..667.3. Pesticide management in Bangladesh..71
7.3.1 The action plan for pesticides..73
8. RECOMMENDATIONS AND CONCLUTIONS74
Reference:.76
7/29/2019 Russell Reza
6/98
List of table used in the report
Table no Topics Page no
Table-1 a listing of developments relating to pest control andpesticides
5
Table-2 Pesticides use in Bangladesh in M. tons 7
Table-3 Partition coefficients (PC) for selected pesticides(generic name only)
9
Table-4 Grouping of pesticides based on persistence in soils 11
Table-5 Chemical or Physical Property of pesticide 11
Table-6 Formation of pesticide 12
Table-7 the mode of action of most of pesticides 13
Table-8 Types of Pesticides, Target Pests and Nature of UserBenefits from Pest Control usage
14
Table-9 Synthetic organic pesticides 16
Table-10 USEPA Pesticide Health Advisory Level 17
Table-11 Important physicochemical properties of pesticides 27
Table-12 Toxicity of pesticides to fish 34
Table-13 Toxicity of pesticides 36
Table-14 A list of common health problems related toPesticides exposure in human
37
Table-15 Traditional Pesticides Disposal Methods 50
Table16 Selection of modern pesticide destruction
technologies
52
Table-17 Phytoremediation for elimination of pesticide 59
Table-18 status of different Pops pesticides in Bangladesh 71
7/29/2019 Russell Reza
7/98
List of figure used in the report
Figure no Topics Page no
Figure -1 Structural formula of Chlordane 18
Figure -2 Structural formula of DDT and DDE 19
Figure -3 Structural formula of Dieldrin and Aldrin 20
Figure -4 Structural formula of Endrin 21
Figure -5 Structural formula of Heptachlor 22
Figure -6 Structural formula of Mirex 23
Figure -7 Structural formula of Toxaphane 24
Figure -8 Pesticide circulation in the environment 25
Figure -9 Fate and route of pesticides in the environment 28
Figure -10 Pesticides loss in water 29
Figure -11 Behavior and fate of pesticides in soil, water, & air 31
Figure -12 Biological transfer of pesticides 32
Figure -13 Co-metabolic process diagram of Bio-remediation 55
Figure -14 Air sparging process diagram 56
Figure -15 Typical composting method 57
Figure -16 Mechanisms for organo-hlorine pesticidesphytoremediation
61
No Annex Page no
1. Annex-I 12. Annex-II 2
3. Annex-III 3
4. Annex-IV 5
5. Annex-V 6
Glossary
7/29/2019 Russell Reza
8/98
Abstract
The report was put on to find about overviews of pesticides used in
Bangladesh and their circulation in the environment and their toxic effects tohuman being as well as on to the environment. Pesticides are chemical
compounds or mixture of substances with diverse chemical nature andbiological activity. They are specially designed and manufactured for their useto prevent, destroy, repel, attract, sterile, stupefy or mitigate any undesired
life declared to be the pest. They are ubiquitous chemicals in theenvironment. They can be transported over long distances in the atmosphere,resulting in widespread distribution across the earth, including regions where
they have never been used. They are organic compounds of anthropogenicorigin that resist degradation and accumulate in the food chain. Pesticidescan pose a threat to human and the environment. The main concerns of
pesticides have been reviewed in this report with their pathways and fates inthe environment, persistence and bioaccumulation.The purpose of the project was also to review on possible managementpractices including pest management, IPM, Sustainable Pest Control, that can
be effective.Here, it is also to review on available treatment technologies. Both
traditional and innovative non-combustion destruction technologies fortreatment of Pesticides. Potential biological methods for treatment of POPshave been explored. Different bioremediation methods with their applicabilityhave been discussed.
Finally, the pesticide act and regulations are discussed and their obligation
and limitation are also found out.
7/29/2019 Russell Reza
9/98
Abbreviations used in the report
AC Adsorption Co-efficient
AChE Acetyl Cholinesterase
ADI Acceptable Daily IntakeATSDR Agency For Toxic substance and Disease Registry
bw Body Weight
BMP Best Management Practices
DDD dichlorodiphenyldichloroethane
DDE dichlorodiphenyldichloroethylene
DDT dichlorodiphenyltrichloroethane (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane)
DE Destruction Efficiency
DRE Destruction And Removal Efficiency
DOE Department Of Environment
EPA Environmental Protection Agency
EXTOXNET Extension Toxicology Networks
FRTR Federal Remediation Technologies Roundtable
FAO Food and Agriculture Organization
of the United Nations
GOB Government Of Bangladesh
HAL Health Advisory Level
HCB Hexachlorobenzene
HPP Hydropower plant
IPM Integrated Pest Management
Koc Organic carbon partition Co-effientOctaneKow Octane/ Water partition co-efficients
LD50 Lethal Dose
LC50 LethL concentration
OCP Organochlorine Pesticide
OC Organi Chlorine
OPP Organophosphorus Pesticide
PC Partition co-efficient
PCBs Polychlorinated biphenyls
POPs Persistent Organic Pollutants
PP Plant Protection
PPM Part Per MillionPPW Plant Protection Wing
R&D Research and Development
SPC Sustainable Pest Control
SRPP State Regional Power Plant
TCB Tri-chloro-biphenyls
TEQ Toxic Equivalent
WHO World Health Organization
7/29/2019 Russell Reza
10/98
CHAPTER ONE
INTRODUCTION
Man struggles to obtain adequate supplies of food (and fiber) against all the
elements, including pests of various sorts which reduce the quantity and
quality of output, by physical damage, disease, etc. Through the ages, it
seems, increasingly, that people find a need to minimize the existence and/or
damage of pests, with the use of pesticide chemicals and by other means
noted above. Some of the factors that lead to increased need for pest control
are: development of succulent crops attractive to pests, e.g.
high sugar content of fruits;
large acreage/mass production of monoculture crops which facilitates
pest development ;
widespread incursion of people into new areas occupied by pests not
formerly interacting with man;
use/development of plants/animals susceptible to pest damage;
mobility of people and commerce leading to importation of pests
without natural controls; expectations of people that there should be a minimum of interference
from pests; and
adaptation of pests to chemical and other control measures.
Pests and disease cause a 20-40% loss of world wide crop production. These
may occur at all stages of the food chain: during harvesting, drying, storage,
processing, and retailing. Pesticide reduces attack by pests, disease, and
weeds, contribute higher yields, increased quality and higher economic
returns. The use of pesticide is one of the most important contributors to
increased agricultural production since 1940s.
Pesticide in Bangladesh
Pesticides have intrinsically inserted itself into the threads of everyday
agricultural life in Bangladesh. This is a legacy of chemical pesticides and
7/29/2019 Russell Reza
11/98
insecticides use that has existed in the country since the introduction of
modern agriculture in the mid-1960s.
Without knowing the proper use of equipments and pesticide handling and
disposal procedure, illiterate poor farmers and their family are directly
exposing themselves to the risk of pesticide poisoning.
Bangladesh is one of the signatory parties and requires taking actions to
generate general awareness of harmful consequences of POPs to reduce their
releases and their ultimate elimination. For sustainable agriculture practice
and environment, its our own concern to phase out the POPs pesticides and
industrial chemicals.
The objective of this work specifies the following points:
1. To import knowledge to the people about the environmental pollution
of pesticides ,
2. To find about overviews of pesticides used in Bangladesh and their
circulation in the environment and their toxic effects on it.
3. To create mass awareness about the effects of harmful pesticides
4. To identify the pathway of reducing toxic effect he total concentration
from different agricultural soil
5. To attain government attention on this problem to make necessary
policies
Finally, it is emphasized that possible remediation and management
techniques that can be effective and suitable for a country heavily burdened
by contaminants used by man consciously or unconsciously.
7/29/2019 Russell Reza
12/98
CHAPTER TWO
METHODOLOGY
The project is emphasized on literature reviews and collection of existing
information on research do on historical background, general properties, and
circulation in the environment, health risk assessment, and potential
destruction technologies for the treatment of Pesticides.
The key information of historical review, properties are designed from the
information of Natural Resources Cornell Cooperation Extension available in
various web sites.
The health effects and exposure scenario of the Pesticides were primarily
collected from the World Health Organizations various reports, guidelines and
fact sheets.
The circulation of pesticides and their effects on the environment was
discussed from Pesticide Management by Dr. S.K. Agarwal.
The Status reports of Pesticides in Bangladesh were collected from the
National Implementation Plan (NIP) for Management of Persistent Organic
Pollutants (POPs) Bangladesh, under the Stockholm Convention and reports
published by Bangladesh Atomic Energy Commission.
The information on the management and remediation techniques was
primarily collected from the United States Environmental Protection Agency
(USEPA) website.
Additional information on Pesticides came from a variety of sources, including
the websites of organizations such as www.safepesticideuse.com,
www.nedcc.org, United Nations Environmental Program (UNEP), and various
conference reports and science journals.
7/29/2019 Russell Reza
13/98
CHAPTER THREE
ABOUT PESTICIDES
3.1 Pesticides
Pesticides are chemical compounds or mixture of substances with diverse
chemical nature and biological activity. They are specially designed and
manufactured for their use to prevent, destroy , repel, attract, sterile, stupefy
or mitigate any undesired life declared to be the pest .It is difficult to image
of modern pest control and agricultural programmes without some forms of
chemical control. The United States Federal Environmental Pesticide Control
Act has defined pesticide as
(1)Any substance or substance or mixture of substances intended for
preventing , destroying , repelling, or mitigating any pest insect,
rodents, nematode, fungus, weed, other form of terrestrial or aquatic
plants , animals , viruses, declares to be a pest, (1)
(2)Any substance or mixture of substances intended for use as a plant
regulator, defoliant or desiccant
3.2 Historical Time Line for Pest Control
There is information to suggest that certain types of pest control products
were used in Roman times, but the use of synthetics began in the 1930s and
became more widespread after the end of World War II. In recent years,
chemical pesticides have become the most important consciously-applied
form of pest management.
The "first generation" pesticides were largely highly toxic compounds, i.e.
arsenic and hydrogen cyanide.
The "second generation" pesticides largely included synthetic organic
compounds. A listing of developments relating to pest control and pesticides
is presented in the following table:
7/29/2019 Russell Reza
14/98
Table 1: a listing of developments relating to pest control and
pesticides
YEAR REMARKS REFERENCE
12000BC First records of insects in human society Jones, p. 309
2500 BC Ancient Sumarians use sulfur to control mites Jones, p. 321
1000 BC Homer refers to the use of sulfur compounds Shepard, p. 4
324 BC Chinese use ants in citrus groves to control
caterpillars
Shepard, p. 4
1300 Marco Polo writes of the use of mineral oil
against mange in camels
Shepard, p. 4
1669 Earliest use of arsenic as insecticide Shepard, p. 4
1763 Ground tobacco recommended in France to kill
phids
Mrak, p. 44
18th
century
Petroleum, kerosene, creosote and turpentine
introduced as insecticides
Frear, p. 120
1787 Soap mentioned as insecticide and turpentine
emulsion recommended to kill/repel insects
Shepard, p. 4
1809 Nicotine discovered in France to kill aphids Mrak, p. 44
1848 Rotenone used as insecticide Mrak, p. 45
1867 the dye Paris Green killed insects Shepard, p. 4
1860's Paris Green (arsenical) used to control Colo. Shepard, p. 6
1873 DDT first made in a laboratory Ordish, p. 152
1882 Bordeaux mixture discovered to control plant
diseases
Shepard, p. 5
1892 Lead arsenate discovered as control for gypsy
moth
Perkins, p.5
1893 Lead arsenate found to be effective Perkins, pp. 5-6
1928 Ethylene oxide patented as insect fumigant Shepard, p. 6
1932 Methyl bromide first used as fumigant Shepard, p. 6
1932/39 discovery of DDT Compound Perkins,p. 10
1942/45 DDT made available for use Perkins, p. 20
1946 Organic phosphate insecticides Shepard,p. 6
7/29/2019 Russell Reza
15/98
1979 First of synthetic pyrethroids registered as
insecticides (fenvalerate and permethrin)
1994 Registration of imidacloprid as first of nicotinoid
insecticides
1997 Fipronil registered as systemic insecticide of fip
role type
2000 More effective pesticides
2003 Eco-friendly pesticides
2005 Pesticides from neem Agarwal, p-29
3.3 Sectors of Pesticide Use in Bangladesh
Agriculture is the main occupation of the people employing about 63% of the
54.6 million labor forces, which directly contribute around 46% of the GDP
(Gross Development per capita). Bangladesh has got one of the most fertile
lands but due to paucity of capital and lack of knowledge of new inputs and
techniques its yield per acre is one of the lowest in the world. Rice, wheat,
jute, sugarcane, tobacco, oilseeds, pulses and potatoes are the principal
crops. Bangladesh is marginally deficit in food grains. All out efforts are being
made by the government and the people to increase the production of food
grains and diversify agriculture output. From 1960 onward, the official
strategy of successive governments was intensification of agriculture. It was
to be carried out with the help of High Yield Varieties (HYV) of rice and
wheat. To grow HYV requires three principal inputs: irrigation facility,
chemical fertilizer and pesticides With the advent of industrialization and
urbanization, industries dealing with the production, packaging and transport
of fertilizer, petrochemical products, cement, textile, leather and mining were
set up. Improper chemical use, handling and indiscriminate disposal of
chemical wastes thus became a hazard introduced to health and
environment.
7/29/2019 Russell Reza
16/98
Table 2: Pesticides use in Bangladesh in M. tons
Type of
pesticide
No of
brand
s
Consumptio
n
20000
Consumption
2001
Consumption
2002
Consumption
2003
Insecticides 239 13,785 12,301 13,984 13,736
Fungicides 51 1,430 2,148 2,419 2,941
Herbicides 38 271 838 964 1,364,
Miticides 28 26, 19 27 32
Rodenticides 10 122 70 37 19
Total 366 15,634 15,376 17,395 18,092
Source : Bangladesh Crop Protection Association, 2003
In Bangladesh, pesticides are imported. Some agro- chemical industries
formulate and re-pack pesticides. There are numerous pesticide products that
are formulated by local unauthorized companies and these are mostly
adulterated with toxic pesticides like DDT.
3.4 General Characteristics of Pesticides
The pesticide has the various properties including degradation, adsorption,
solubility, volatility and Persistence.
Degradation
Most pesticides are organic compounds which degrade under typical
environmental conditions. There are three types of degradation process,
including -
Microbial degradation
Chemical degradation and
Photo degradation.
Microbial degradation. Soils and plants hold populations of
microorganisms which derive energy from the degradation of organic
7/29/2019 Russell Reza
17/98
compounds such as pesticides. Two important processes are
distinguished mineralization, in which the compound is completely
degraded to carbon dioxide (CO2), and co-metabolization, in which the
chemical is transformed into other chemical compounds.
Chemical reactions. Pesticides may react with air, water, and other
chemicals in soil and plants through oxidation, reduction, and
hydrolysis.
Photochemical reactions or decomposition through exposure to
sunlight.
Factors of degradation
The following factors are involved in degradation process:
Chemical structure. Some types of chemical compounds are more
easily degraded through chemical or microbial reactions than others.
Soil type. Soil properties affect pesticide degradation in many ways.
In general, the higher the organic matter content and moisture-holding
capacity of the soil, the higher the rate of pesticide degradation in that
soil. Temperature. The rates of microbial and chemical reactions increase
with temperature, so pesticide degradation occurs faster as the soil
and air become warmer.
Soil water content. Microbial and chemical reactions are favored by
moist soil conditions, so degradation occurs fastest when soils are not
too dry.
Position in the soil. The upper layers of the soil profile are chemically
and biologically most reactive.
Adsorption
Soil organic matter and, to a lesser extent, clay particles can bind pesticides.
Pesticides which are strongly adsorbed to soil are not carried downward
through the soil profile with percolating water.
7/29/2019 Russell Reza
18/98
a) Partition coefficient (PC).
The PC value is defined as the ratio of pesticide concentration in the
adsorbed-state (that is, bound to soil particles) and the solution-phase (that
is, dissolved in the soil-water). The partition coefficient makes it possible to
put a value on a particular pesticide's chance of being lost via runoff or
leaching in a specific soil, via the formula:
K = (PC) (%OM) (0.0058)
Where K is an index for sorption of a given pesticide on a particular soil, %
OM is the percent of organic matter in the soil,
Table 3 Partition coefficients (PC) for selected pesticides
Pesticide PC Pesticide PC
Aldicarb 10 Carbaryl 229
Chloramben 13 Methyl 7,079
Simazine 158 Trietazine 549
Atrazine 172 Malathion 1,778
DDT 243,000 Parathion 7,161
b) Adsorption coefficient:
A pesticide's tendency to be adsorbed by soil is expressed by its adsorption
coefficient:
K (oc) = conc. adsorbed/ conc. dissolved/% organic carbon in soil
High K(oc) values indicate a tendency for the chemical to be adsorbed by soil
particles rather than remain in the soil solution.
Since pesticides bond mainly to soil organic carbon, the division by the
percentage organic carbon in soil makes the adsorption coefficient a
pesticide-specific property, independent of soil type.
7/29/2019 Russell Reza
19/98
Solubility
The tendency of a chemical to dissolve in water is expressed by its solubility.
Pesticides with solubility below the threshold value of 30 mg/l are considered
to have relatively low potentials for leaching. Pesticides with solubility values
higher than 30 mg/l may have a high leaching potential if the degradation
rate and the soil adsorption coefficient are low.
Volatility
The potential for a pesticide to volatilize, or become a gas, is expressed by its
Henry's Law Constant:
H = vapor pressure/solubility
A high value for this constant indicates a tendency for the pesticide to
volatilize and be lost to the atmosphere.
Gaseous losses can be reduced through soil incorporation. Although exchange
of soil air with the atmosphere does take place, the rate is so slow that
volatilization losses of incorporated pesticides are very low.
Persistence
Persistence defines the "lasting-power" of a pesticide. Most pesticides break
down or "degrade" over time as a result of several chemical and micro-
biological reactions in soils. Sunlight breaks down some pesticides. Generally,
chemical pathways result in only partial deactivation of pesticides, whereas
soil microorganisms can completely break down many pesticides to carbon
dioxide, water and other inorganic constituents.
Degradation time is measured in "half-life." Each half-life unit measures the
amount of time it takes for one-half the original amount of a pesticide in soil
to be deactivated.
7/29/2019 Russell Reza
20/98
Table 4: Grouping of pesticides based on persistence in soils
Non-persistent
(half-life less than
30 days)
Moderately Persistent
( half-life greater
than 30 days,
less than 100)
Persistent (half life
greater than100
days)
Aldicarb Aldrin Bromacil
Atrazine Chlordane
Methyl parathion Heptachlor l Lindane
Parathion
Malathion Diazinon Picloram
Endrin
Table -5 Chemical or Physical Property of pesticide
Chemical or Physical Property Threshold Value
Water solubility greater than 30 ppm
Henry's Law Constant less than lO-2 atm - m-3 mol
Kd less than 5, usually less than 1 or 2
Koc less than 300 to 500
Hydrolysis half-life more than 25 weeks
Photolysis half-life more than 1 week
Source: U.S. Environmental Protection Agency, 1986,
3.5 Formulation of Pesticide
Pesticide products contain a number of constituents, including the active
ingredient that kills or controls the target organism as well as a number of
additives. These additives include solvents, sufficient liquid or solid carriers,
softeners and additives.
7/29/2019 Russell Reza
21/98
Table: 6. Formation of pesticide
No Formation nature of application
1. Aqueous
Concentration
A concentrate solution of the active ingredient, or
Ingredients, in water.
2. Emulsifiable
Concentration
A homogeneous liquid formulation that forms an
emulsion on mixing with water.
3. Suspension
Concentration
A stable suspension of finely ground active ingredient in
water intended for dilution before use.
4 Water Soluble
Powder
A powder formulation which forms a true solution of the
active ingredient, when dissolved in water.
5. Wettable
Powder
A powder formulation that is dispersible in water to
form a suspension.
6. Water
Dispersible
Powder
Similar to wettable powder, but involving a more
advanced formulation.
7. Granules Granules or pellets which contain, or are coated with,
the active ingredient or ingredients
8. Dusts A fine powder formulation used for specific applications.
Source: Agricultural pollution by Merrington.
3.6 Classification of Pesticide
The pesticide can be classified in three different ways taking into account
three different criteria viz, mode of entry, mode of action and their chemical
nature.
a) Classification based on mode of entry
i) Stomach poisons: those pesticides which enter the body of the target
organism through its food are termed as stomach poison. They reach the
stomach and kill the organism .Stomach pesticides are very effective against
insect pests and rodents.
7/29/2019 Russell Reza
22/98
ii) Contact poisons: Contact pesticides are those ones which enter the body
of the organism by penetrating through their cuticle or through spiracles. The
pest may absorb the pesticide while walking on the treated parts, while flying
through a mist or fine droplets or when they are hit directly during spraying
or dusting of the pesticides.
iii) Fumigants: are those pesticides which enter in gaseous state into the
body of the organism through the spiracles, trachea and nose. They are most
effective in closed spaces and as such are widely used for controlling the
stored grain pests.
b) Classification based on mode of action
The mode of action of pesticides is given below in the following figure:
Table: 7. the mode of action of most of pesticides
Source: Agricultural pollution by Merrington.
No Mode of
action
description
1 Poison Ingested by the pest organism before releasing toxins
into its stomach.
2 Contact Applied directly to the pest organism Penetration its
Surface and producing a localized toxic effect they
remain active for few days at most.
3 Residual Act in the same way as contact pesticide, but do not
need to be applied directly to the pest organism since
they remain active for long period.
4 Translocated Active ingredient is mobilized within the pest organismand a more effective toxic effect upon it.
5 Systemic Active ingredient is mobilized within the crop or animal
being protected and is then transferred to the target
pest.
7/29/2019 Russell Reza
23/98
Physical poisons: Which kill the pest by exerting physical effect? Heavy oils
and tar oil kill the insects, birds and fishes through asphyxiation i.e. exclusion
of air. Inert dust cause abrasion of cuticle or absorb moisture from the body
of the organism.
Protoplasmic poisons the toxicants which kill the organism by destruction
of the cellular protoplasm of the mid gut epithelium.
Respiratory poisons blocks the cellular respiration and render the
respiratory enzymes inactive.
Nerve poisons affect the nervous system and render the organism to
behave abnormally, leading to death. The toxicant gets dissolved in tissue
lipoids and inhabits the production of acetyl cholinesterase enzyme insects
and mammals.
c) Classification based on chemical nature
This classification system segregates pesticides into either the inorganic
compounds having pesticidal property, or organic compounds having
pesticidal property.
Table 8 Types of Pesticides, Target Pests and Nature of User Benefits
from Pest Control usage.
No Pesticide
type
Target pest User benefits from pest control
1. Acaricides/
miticides
Mites Stop pests sucking juices from
plants or liquids from animals
2. Algaecides Algae, marine
plants,
Kill algae in desired locations
3. Avicides Birds Avoid nuisance and physical
damage of birds
7/29/2019 Russell Reza
24/98
4. Defoliants &
desiccants
Plants Removal of leaves/foliage of plants
or completely kills plant
immediately, to facilitate harvest
5. Bactericides Bacteria Kill bacteria in desired locations
6. Disinfectants viruses Kill/eliminate microbes from target
area, e.g., disinfection,
sanitization
7. Fumigants Nematodes, insects,
fungi, , etc
Kill undesired species from soil,
commodities or space
8. Fungicides Fungi Kill fungi causing plant diseases,
nuisance
9. Herbicides Undesired plants
(weeds)
Elimination of visual or other
nuisance of weeds
10. Insecticides/ Insects Eliminate nuisance/disease threats
to humans and animals
contamination
11. Moluscicides Invertebrates, e.g.,
snails, slugs
Eliminate nuisance or economic
damage of invertebrates12. Piscicides Fishes Removal of undesired fish from
target waters
13. Plant growth
regulators
Plants/fruits/seeds Control growth/development of
plant to obtain desired effect, e.g.,
ripening, storage life, etc.
14. Repellents Various insect and
other animal forms
Dissuades/deters animal from
being on protected object or in
protected area.
15. Rodenticides Rodents Eliminate nuisance and disease to
humans and damage to
Commodities
16. Silvicides Woody plants/
weeds in forestry
Eliminate damage to by undesired
species of trees
7/29/2019 Russell Reza
25/98
Synthetic organic pesticides dominate the field of pest control. A rigid
classification of these compounds is difficult. They broadly include following
groups:
Table: 9. Synthetic organic pesticides
No pesticide Chemicals
1. Organo-
chlorine
BHC, DDT, Methoxychlor, Aldrien, Dieldrin,
Heptachlor, Chlordane, Endosulfan etc
2. Organo-
phosphorous
Malathion, Parathion, Phorate, DDVP, Phenthoate,
Diazinon, etc.
3. Carbamate Carbaryl, Aldiucarb, etc.
4. Herbicide 2,4-D,2,4,5-T, Paraquate, Diquat, Trizolcs ,etc
5. Botanical Pyrethrins, Nicotine, Rotenoids.
6. Fungicide Organo-mercury and tin compounds
7. Rodenticides Thallium sulfate , arsenic , zinc phophide, warafin
8. Fumigants Hydrogen cyanide, fomaladehyde,
9. Mulluscicides Metaldehyde, Carbamate, Copper sulfate, etc
10. Nematocides methyl-isothio-cyanide, carbamates, organo-
phosphorus compounds.
3.7 Natural products pesticide
There are ample evidence to show that the plant kingdom is a vast store-
house of chemical substance manufactured and used by plants in their own
defense from attack by insects, bacteria, fungi, and viruses. Several
significant groups of pesticide are obtained from plants. These include
i) Nicotine
ii) Rotenone
iii) Pyrethrins
Nicotine is isolated from at least 18 species of tobacco among which
Nicotinetobacum and N. rustica are most common. Nicotine does not
7/29/2019 Russell Reza
26/98
leave any harmful residue on applied surfaces. It is highly toxic to
mammals.
Rotenone is isolated from Derris elliptica and D. malacensis. It is
photo-and thermo-stable. It is highly toxic to fishes. Its active
ingredient is nicoulene
Pyrethrum is prepared from the flowers of Chysanthemum
cinereraefolium and C. coccineum. The active ingradients of pyrethrum
are four esters
i) pyrethrin I
ii) pyrethrin II
iii) Cinerin Iiv) Cinerin II
It is viscous liquid insoluble in water but soluble in organic solvents. it is
highly unstable in light, moisture and air. It has powerful contact action with
rapid knock down. Synthetic analogs of the pyrethrins are pyrethroids
including allethrin and fenvalerate.
3.8. Pesticide Toxicity
The U.S. Environmental Protection Agency has issued guidelines for lifetime
health advisory levels (HAL's) for commonly used pesticides, expressed in
concentrations of micrograms per liter. It is equivalent to parts per billion
(ppb). For example, alachlor has a HAL of 0.4 ppb and carbofuran has one of
40 ppb.
Table 10 USEPA Pesticide Health Advisory Levels
Name HAL(ug/l) Name HAL(ug/1)
Carbaryl 700 Endrin 0.3
Chlordane 0.03 Methoxychlor 400
Dieldrin 0.002 2,4-D 70
Aldicarb 10 Atrazine 3
Source: U.S. Environmental Protection Agency
7/29/2019 Russell Reza
27/98
3.9. Important and widely used pesticides are discussed below:
3.9.1.CHLORDANE
Chemical Characteristics:
Chlordane is a broad-spectrum organochlorine insecticide known for its
toxic effects and its capacity to persist and bioaccumulate in the
environment.
The chemical builds up in the fatty tissues of fish, birds, and mammals.
Production and Use:
Introduced in 1945, chlordane was used in the greatest quantities as a soil
insecticide for controlling termites.
It has been used as a pesticide on corn, citrus, and other crops. I
Chlordane has been used also on livestock; on home lawns and gardens
and underground around the foundation of buildings to control termites.
The structural formula of CHLORDANE IS shown below in Fig. 1
Fig.1 Structural formula of Chlordane
Exposure and Effects:
Exposure to chlordane may occur through several routes, including
consumption of contaminated meats, fish, shellfish, root crops, and other
foods;
7/29/2019 Russell Reza
28/98
Chlordane has been linked to liver and blood disorders, severe neurological
effects, and damage to the endocrine and reproductive systems.
3.9.2.DDT(dichlorodiphenyltrichloroethane)
Chemical Characteristics:
DDT is an organochlorine compound that persists in the environment
and bioaccumulates in human and animal tissue.
DDT was recognized as an effective insecticide in the 1930s.
The structural formula of DDT and DDE is shown below in Fig. 2.
Fig. 2 Structural formula ofp,p-DDT, C14H9Cl5 & p,p-DDE, C14H8Cl4
Production and Use:
The World Health Organization (WHO) estimates that approximately
two dozen countries use DDT for controlling malaria.
More than 80 countries have banned or restricted use of DDT.
Exposure and Effects:
Exposure results from consuming contaminated food, and from contact
in homes that have been sprayed with DDT for malaria control.
DDE, a breakdown product of DDT, has contributed to eggshell
thinning in predatory birds.
7/29/2019 Russell Reza
29/98
3.9.3. Aldrin/Dieldrin
Chemical Characteristics:
They are synthetic organochlorine insecticides with similar chemical
structures.
Aldrin quickly breaks down to dieldrin in the environment.
The structural formula of Dieldrin & Aldrin is shown in Fig. 3.
(a) (b)
Fig. 3 Structural formula of (a) Dieldrin & (b) Aldrin (CAS No.: 309-00- )
Production and Use:
Since the 1950s, aldrin and dieldrin have been widely used as
agricultural insecticides, veterinary agents, termiticides, and vector
control agents.
Aldrin has been used as a soil insecticide to control root worms,
beetles, and termites.
Dieldrin has been used for control of disease vectors such as
mosquitoes and tsetse flies, for veterinary purposes as a sheep dip,
and for the treatment of wood and the mothproofing of woolen
products.
Exposure and Effects:
Animals and people may be exposed via consumption of fish, seafood,
dairy products, fatty meats, and root crops grown in contaminated soil
or water.
7/29/2019 Russell Reza
30/98
It demonstrates very high acute toxicity to aquatic organisms such as
fishes, crustaceans, and amphibians.
3.9.4.ENDRIN
Chemical Characteristics:
Endrin is a persistent, acutely toxic organochlorine insecticide used
mainly on field crops.
It does not easily dissolve in water.
The structural formula of Endrin & Heptachlor is shown in Fig. 4.
Cl
Cl
Cl
Cl
CH Cl2O
Fig. 4 Structural formula of Endrin
Production and Use:
Introduced in 1951, endrin has been used as a pesticide to controlbirds on buildings and insects and rodents in fields and orchards.
Endrin is applied in the production of cotton, maize, sugarcane, grains,apples, and ornamentals.
Exposure and Effects:
Human exposure takes place primarily through consumption ofcontaminated food and water, or in occupational settings.
Exposure to endrin can cause endocrine effects, liver damage, anddisorders of the nervous system.
7/29/2019 Russell Reza
31/98
3.9.5. Heptachlor
Chemical Characteristics:
Heptachlor is characterized by its toxicity, environmental persistence,
and ability to bioaccumulation in the fat of living organisms.
It has a half life of up to two years in soils
The Structural formula of Heptachlor is given below:
.
Fig. 5 Structural formula of Heptachlor (CAS: 76-44-8)
Production and Use:
Heptachlor is primarily used to kill soil insects and termites. It has also
been used against cotton insects, grasshoppers, some crop pests, and
to combat malaria.
Heptachlor is now banned in many countries throughout the world.
Heptachlor is also used to protect underground cable boxes from fire
ants.
Exposure and Effects:
Contaminated food is probably the major exposure route for most
species including humans.
Inhalation may be an exposure route, particularly in homes treated for
termites.
Drinking contaminated water or dermal contact can also result in
exposure.
7/29/2019 Russell Reza
32/98
3.9.6. Mirex
Chemical Characteristics:
Mirex is considered to be one of the most stable and persistent
pesticides in soil, sediment, and water, with a half life in soil of up to
10 years.
It does not dissolve easily in water, but sticks to soil and sediment
particles such that it is not likely to travel far through the soil and into
underground water.
The structural formula of Mirex is shown in Fig. 5.
Fig 6 Structural formula of Mirex
Production and Use:
Mirex was formerly used as an insecticide to kill ants. It has been used
to combat fire ants, leaf cutters, harvester termites, Western harvester
ants, and mealybug of pineapple.
Mirex also had extensive use as a fire retardant in plastics, rubber,
paint, paper, and electrical goods.
Exposure and Effects:
Most exposures occur thorough eating contaminated food, particularly
fish and other animals living near contaminated sites.
Exposure can also arise through inhalation.
7/29/2019 Russell Reza
33/98
3.9.7. Toxaphene
Chemical Characteristics:
Toxaphene is an insecticide containing more than 670 chemicals.
Toxaphene is characterized by its toxicity, persistence, and ability to
bioaccumulate in animals and travel long distances.
It does not dissolve well in water, so it is likely to be found in air, soil,
or sediment at the bottom of lakes or streams.
The Structural formula of Toxaphane is given below:
Fig- 6 Structural formula of Toxaphane
Production and Use:
Toxaphene was one of the worlds most widely used pesticides in the
1970s.
Toxaphene was used to control insect pests on cotton, cereal grains,
fruits, nuts, and vegetables.
Exposure and Effects:
Exposure may result from eating contaminated animals, particularly
fish and shellfish, drinking water from contaminated wells,
At high exposures, toxaphene has been associated with kidney and
liver damage, central nervous system effects, possible immune system
suppression, and cancer.
Acute exposure to toxaphene is typically lethal to mammals, birds, and
aquatic species.
7/29/2019 Russell Reza
34/98
CHAPTER FOUR
PESTICIDE CIRCULATION IN THE ENVIRONMENT
There are basically two ways properly-applied pesticides may reach surface
and underground waters -- through runoff and leaching into the atmosphere.
4.1 Pesticide circulation:
Occurrence of pesticide residues in edible parts of plants is significant in
terms of human exposure, while pesticides released into the atmosphere
have an impact on air quality and create problems when agricultural workers
enter the treated areas.
Fig. 7 Pesticide circulations in the environment
7/29/2019 Russell Reza
35/98
Once applied to cropland, a number of things may happen to a pesticide. It
may be taken up by plants or ingested by animals, insects, worms, or
microorganisms in the soil. It may move downward in the soil and either
adheres to particles or dissolve. The pesticide may vaporize and enter the
atmosphere, or break down via microbial and chemical pathways into other,
less toxic compounds. Pesticides may be leached out of the root zone by rain
or irrigation water.
4.2 Physicochemical properties of pesticides in relation with the
environment
The physical and chemical properties of a chemical substance determine their
fate and behavior in the environment. Chemical substances emitted in the
environment are distributed/trans-located in their compartments and/or
transformed due to inextricable network of interaction of their
physicochemical properties with a variety of environmental parameters.
ENVIRONMENTAL PARAMETERS
1. General: Geography and climate/meteorology (latitude, altitude, sunlight
intensity, rainfall, wind, temperature, humidity, etc.)
2. Air: Chemical composition (presence of contaminants), suspended
particles, aerosols
3. Water: PH, suspended materials, soluble inorganics and organics, biota.
4. Soil and sediment:
Clay mineral, cation exchange capacity (Al,Mg, Cu, etc.)
Organic matter content Redox potential
Biota (terrestrial invertebrates, including soil insects and earthworms,.)
PH
Source: Miyamoto 1996
7/29/2019 Russell Reza
36/98
A list of physical characteristics of some Pesticides is given in Table 11.
TABLE 11 IMPORTANT PHYSICOCHEMICAL PROPERTIES OF 9 CHLORIANTED
PESTICIDES
Pesticides Molecular
formula
Molecular
weight
Density
g/L
Aqueous
solubility
mg/L
Log
Kow
Persistence
T1/2
Aldrin C12H8Cl6 364.93 1.6 0.017 6.5 20days-1 yr
Chlordane C10H6Cl8 409.78 1.6 0.056 6 4 yrs
DDT C14H9Cl5 354.49 1.55 0.0055 6.19 2-16 yrs
Dieldrin C12H8Cl6O 380.92 1.7 0.2 5.48 2-15 yrs
Endrin C12H8Cl6O 380.92 1.72 0.26 5.2 Up to 12 yrs
Heptachlor C10H5Cl7 373.32 1.58 1.8 5.47-
6.10
0.4-2 yrs
Hexachloro
Benzene
(HCB)
C6Cl6
284.81 2.044 0.005 5.73 2.7-7.5 yrs
Mirex C10Cl12 545.55 1.8 0.085 7.18 Up to 10 yrs
Toxaphane C10H10Cl8 414 1.66 0.55 5.78-
6.79
1-14 yrs
Source: ASTDR, ETOXNET
7/29/2019 Russell Reza
37/98
4.3 Fates of pesticides
4.3.1 Enter of the pesticides:
Pesticide enter the environment through spillage or drifts at the time of pesticide
application or because of their volatility or through wastes of human, animal,
plant and industrial processes After a pesticide is applied to a field, it may meet
a variety of fates.
Fig. 8 fate and route of pesticides in the environment
Some may be lost to the atmosphere through volatilization, carried away to
surface waters by runoff and erosion, or broken down in the sunlight by
photolysis. Pesticides which have entered into soil may be taken up by plants
(and subsequently removed), degraded into other chemical forms, or leached
downward, possibly to groundwater. The remainder is retained in the soil and
continues to be available for plant uptake, degradation, or leaching.
7/29/2019 Russell Reza
38/98
4.3.2. Pesticide in the water body:
If a pesticide is not readily degraded and moves freely with water percolating
downward through the soil, it may reach groundwater. If, however, the
pesticide is either insoluble or tightly bound to soil particles, then it is more
likely to be retained in the upper soil layers and small amounts may be lost to
surface waters through runoff or erosion.
Pesticides are lost to water resources through surface loss (runoff and
erosion) to streams, lakes, and estuaries, and leaching through the soil to
groundwater.
Surface Loss of Pesticides
If pesticides are applied to the soil surface without incorporation, they are
susceptible to loss through runoff and erosion during high- intensity rainfall
events. Surface losses will likely result in contamination of streams, lakes,
and estuaries. The potential for surface loss depends on pesticide properties,
soil type, and the length of time after application. Pesticides that attach easily
to soil particles or are very insoluble tend to remain close to the soil surface.
Fig. 9 Pesticide loss in water system
7/29/2019 Russell Reza
39/98
Rainfall and Soil Water
Water flow is the most important transport mechanism for pesticides. Water
is added to the soil through precipitation or irrigation, which either infiltrates
into the soil or runs off the soil surface.
The fraction of water that infiltrates compared to the fraction that runs off
depends largely on the intensity of precipitation and the infiltration capacity
of the soil. For example, if rainfall rates are high and the soil is a compacted
clay loam, little water will enter the soil and most will be lost through runoff.
This is especially the case when the soil is near saturation and therefore has
a low capacity for absorbing additional water from precipitation.
Pesticide Leaching and Groundwater
Groundwater originates as recharge, the water that percolates downward
through soil to the depth at which all soil pores are saturated. Depending on
local geology and groundwater flow characteristics, water in any given well
may be recharged from the land directly adjacent to the well or from areas
miles away. Shallow wells typically are recharged by water originating from
adjacent land.
Dilution:
The toxic effect of a pesticide on humans and animals is directly related to its
concentration. Dilution plays an important role in maintaining pesticide
concentrations below health standards. Dilution may occur both over space
and time. In regions where agriculture coexists with other land uses (e.g.
forestry), recharge and runoff are diluted with waters from adjacent lands.
4.3.3. Behavior of pesticides
Pesticides accumulate in various organisms and transfer from one trophic
level to upper trophic level. The concentration of pesticides increase through
the trophic levels and cause various harmful effect on organisms.
7/29/2019 Russell Reza
40/98
Bio-concentration of pesticides
Bio-concentration of pesticides in food chains or webs is governed essentially
by the molecular recalcitrance of the compound concerned and by physico-
chemical and metabolic transformations under different ecological conditions.
Development in plant protection is concerned increasingly with pesticides of
high specificity and low persistence.
Fig. 10 Behavior and fate of pesticides in soil, water, & air.
Biotransformation of pesticides
The metabolic reaction which occur and higher plants wherein pesticides are
bio-transformed are microsomal transformations and non-microsomal
transformation.
7/29/2019 Russell Reza
41/98
Bio-concentration of pesticides
The accumulation of pesticides in various biological systems is called
bioaccumulation. The pesticides enter a biological system mainly by three
routes:
aerial,
terrestrial, and
Aquatic.
Although the actual relationship of these routes is very complicated yet an
attempt has been made to present the details in a simplified manner.
I II III
(Arial) (Terrestrial) (Aquatic)
Air Soil Water
Terrestrial Soil invertebrates planktons
Plants Aquatic Animals
Herbivorous Terrestrial Fish eating
Animals Vertebrates birds
Carnivorous animals
Fig: 11: Biological transfer of pesticides
7/29/2019 Russell Reza
42/98
The rate of accumulation of pesticides is higher through aquatic route than
through aerial and terrestrial routes. The cause of higher accumulation is
aquatic environment is attributed to the chemical nature of the pesticide,
which have higher lipo-solubility and lower water solubility. When the
pesticide enters the aquatic environment, its movement is facilitated by
water. It is then picked up by organic-lipid containing particles which remain
suspended in water. From this stage, the particles enter the food chain and
get accumulated in the biomass.
4.4. Effect of pesticides
4.4.1 Pesticidal toxicity in air
The pesticidal pollution of air occur through volatilization of pesticides where
filling, loading, mixing and spraying operations are performed and sometimes
through drift and wind erosion of soil particles with absorbed residues.
Measurements of concentration of air borne organochlorine pesticides in the
ambient air has been made in areas both near to and remote from where
these chemicals have been used in agriculture. These measurements have
shown that their concentration depends heavily on meteorological conditions,
proximity of the site of application, and time elapsed since application. Air
may be an important vehicle for the transport of DDT on a global scale.
4.4.2. Pesticidal contamination in soil
Soil pollution by pesticides results in various ways, namely direct mixing of
pesticides in soil for pest control, runoff of pesticides during and after
application , fall out after crop spraying, particle settling over the ground,
contaminated plant parts getting ploughed up in the soil. Soil pollution
assumes a major concern in contaminating the crop grown, affecting soil pH
and microbial population, thus affecting soil fertility.
7/29/2019 Russell Reza
43/98
4.4.3 Toxicity of pesticide to fish
Toxicity of pesticides to fishes has been established by Duodoroff and
Tarzwell (1954), James (1965), Mathur(1969), and Gautam et al (1979).
Toxicity of certain pesticides to fishes has been shown in Table 12.
Table 12: Toxicity of pesticides to fish
Pesticides Toxic concentration(ppm)
Aldrin 0.02
Chlorodane 1.0 (sunfish)
Dielrin .0025 (trout)Endrin .003 (bass)
Toxaphene 1.0
Source : Pollution Management by Agarwaal
According to Gautam et al (1979) DDT was found to be toxic to Channa
punctata. They found that mortality rate of the fishes was maximum in the
younger fishes and gradually decreased in the older fishes from 60 to 250
minutes. The initial mortality might be due to the high susceptibility of the
fish.
4.4.4 Pesticidal toxicity to birds
The effects of non-lethal concentrations pesticides are subtle and do not
cause mortality. However, pesticides do interfere with growth, egg
production, egg size, shell thickness, hatchability, fertility etc., ultimately
resulting in reduction in their population (ITRC, 1975).
The inhibitory response of the acetyl cholinesterase (AChE) of some birds in
response to pesticide application indicate that, it was dose dependent, and
showed the circulating insecticidal contamination levels.
7/29/2019 Russell Reza
44/98
4.4.5. Effects of pesticides on biota
The most obvious effects in this respect are a consequence of the many
deleterious effects either directly or indirectly on the target as well as on the
non-target system. These effects include:
disturbance in equilibrium existing between insect, pests and their
parasites,
increased disease susceptibility,
bioaccumulation,
development of pest tolerance,
disturbance in reproductive physiology,
behavior abnormalities in birds and insects,
effects on population of birds, wild life, fishes and seed production,
effects on finally
Contamination of food and human bodies.
4.4.6. Effects of pesticide on human
Pesticide Poisoning
A particular pesticide can have
1. acute toxic effects,
2. Chronic toxic effects or both.
Acute toxicity occurs when a person is exposed to a single, large dose of
poison. Symptoms usually appear immediately, although they may be delayed a
day or two. The severity of the symptoms depends on
how toxic the particular poison is and
The length of exposure.
Chronic toxicity occurs when a person is exposed to repeated small doses of a
toxic material over a long period of time. Potential chronic effects include cancer,
birth defects, and damage to organs such as the liver.
7/29/2019 Russell Reza
45/98
Table 13: Toxicity of pesticides.
Category Signal word
required onthe label
LD50 LC50
Oral Dermal Inhalation
Approximate oral
dose that can killan average
person
I. Highly toxic DANGER 050 0200 00.2 A few drops to 1
tsp.
(or a few drops
on the skin)
POISON! skull and
crossbones
(Not used to indicate skin and eye irritation
effects)
II.
Moderately
toxic
WARNING! 50500 200
2,000
0.22 More than 1 tsp.
to 1 oz.
III. Slightly
toxic
CAUTION! 500
5,000
2,000
20,000
220 More than 1 oz. to
1 pt. or 1 lb.
IV. Relatively
nontoxic
CAUTION! 5,000+ 20,000+ 20+ More than 1 pt. or
1 lb.
Source: EPA
Toxicological Aspects
Pesticides are highly toxic; their toxicity may range from acute toxicity,
such as death at extreme limit in humans (including aborted fetuses) and
wildlife following the exposure of pure substance accidentally. Pesticides have
the potential to injure human health including adverse health effects, such as
birth defects, damage to immune and respiratory systems, and critical
organs.
7/29/2019 Russell Reza
46/98
Table 14. A list of common health problems related to Pesticides
exposure in human
HEALTH CONCERN DESCRIPTION
CANCER There are over a hundred different types of cancer, but
the incidence of potentially hormone-stimulated cancers,
such as breast, testicular and prostate cancers.
Birth Defects Physical defects or malformations occur during embryo
development resulting in deformed offspring.
Reproductive
Damage
Reduced fertility due to reduced quality and/or quantity
of eggs and/or sperm.Prenatal exposures can affect
reproductive organ development and sexual
development, i.e., endocrine disruption,
Developmental
and Behavioral
Effects
CONTAMINANTS AFFECT THE DEVELOPMENT AND FUNCTION OF THE
CENTRAL NERVOUS SYSTEM, LEADING TO DEVELOPMENTAL AND
BEHAVIORAL PROBLEMS.
Damage to the
Immune System
Exposure can reduce the bodys ability to protect against
and fight disease.
Effects on the
Respiratory and
Circulatory
System
There are direct effects on the lung, heart and blood
vessels, lung volume and airways (e.g., asthma).
Source: Ohanjanyan 1999
7/29/2019 Russell Reza
47/98
CHAPTER FIVE
MANAGEMENT PRACTICES
There are various procedure for pesticide pollution management, including
management practices, pest control, and finally pesticide management
practices.
5.1 management practices
The key to reducing the potential for pesticide contamination of water
resources is the use of planned pest management. This may include avoiding
unnecessary pesticide applications, use of targeted and economical
applications, and use of cultural or biological practices that substitute for or
complement pesticide use. In addition, pesticide selection and crop
management should be carried out according to the site-specific needs for
reduction of water contamination. The management plan requires evaluation
of the nature of the water quality problem through consideration of the
relative priorities for protection of various surface and groundwater
resources, and the vulnerability of these water resources to contamination by
pesticides.
Soil and Crop Management
Pest infestations can be minimized by using soil and crop management
practices which provide for vigorous plant growth. These practices include:
appropriate seedbed preparation and planting,
optimization of timing of crop planting and harvesting,
maintenance of optimum soil nutrient and pH levels,
use of appropriate crop rotations,
use of good water management practices (drainage and irrigation), as
appropriate,
avoidance or alleviation of soil compaction, and
Use of soil and water conservation practices that reduce surface loss or
leaching.
7/29/2019 Russell Reza
48/98
Irrigation
Irrigation of crops and water of lawns may increase the potential for
movement of pesticides to groundwater or surface water. Pesticides located
at the soil surface may be carried to streams and lakes with this runoff water.
Excessive irrigation rates also may increase the potential for leaching of
pesticides to groundwater. If more water is supplied than is required to
recharge the water storage capacity in the root zone,
Drainage
Subsurface drainage may increase pesticide contamination of streams and
lakes by diverting water flow from groundwater to surface water and
providing a shortcut for drainage water. However, it also provides for a
superior plant growth environment and therefore insures more vigorous plant
growth and higher resistance to pests.
Best Management Practices
Pesticide management on the farmstead plays a key role in groundwater
contamination. Appropriate pesticide handling practices that help protect the
well should always be used whether pesticide contamination is documented
or not.
The important points of BMP are given below:
1. Prevent spillage and back-siphoning from spray equipment into the
well by preventing overflow and maintaining an air gap between the
filling hose and the water level in the tank.
2. Maintain as much distance as possible from the well and the pesticide
mixing and loading site.
3. Mix, load, and rinse pesticides over an impermeable surface that is
designed to drain to sealed catchments, whenever possible.
4. Rinse chemical containers thoroughly using the triple rinse method or a
pressure rinser.
5. Recycle pesticide containers and avoid the need to locate anacceptable landfill site.
7/29/2019 Russell Reza
49/98
6. Dispose of unused pesticides that have been banned or are no longer
wanted to reduce the overall contamination potential from the
farmstead.
7. Store pesticides in a secure, properly ventilated location where product
usefulness can be maintained with minimal risk to people, animals, and
the environment.
8. Attend to all pesticide spills immediately.
9. Attend to all back-siphoning incidents immediately.
10.Clean the pesticide sprayer properly. In the farmyard, clean over an
impermeable surface.
11.Use closed-handling systems for mixing pesticides where practical.
12.Locate and construct new wells according to codes that are intended to
avoid contamination.
13.Decommission or plug old wells, if not intended for future use.
5.2 Pest management
Pest management is an effective method for pest control. It damages the
infected pest and reduces the amount of pesticide use. There are many
methods for pest control, including integrated pest management and
sustainable pest control.
Integrated pest management
"Integrated Pest Management is the coordinated use of pest and
environmental information along with available pest control methods,
including cultural, biological, genetic and chemical methods, to prevent
unacceptable levels of pest damage by the most economical means,
and with the least possible hazard to people, property, and the
environment.
(Integrated Pest Management Forum. 2002. American Farmland Trust )
7/29/2019 Russell Reza
50/98
Objectives of integrated pest Management
The New York State IPM programme operates under five
to minimize crop losses caused by insects, weeds, and plant diseases,
to optimize the use of cultural management techniques, biological pest
controls, and resistant varieties,
to maximize the effectiveness of pesticide use,
to reduce pest management costs, and
to minimize the development of pesticide resistance.
Most groundwater contamination problems are associated with application of
pesticides to control soil-dwelling pests such as nematodes, weeds,
pathogens, and insects.
Key components of integrated pest management
Successful integrated pest management usually has several key components.
1. Knowledge. Understanding the biology and ecology of the pest, and
the crop (or livestock) is essential. Information about interactions
within agricultural ecosystems is also important. IPM draws on the
fundamental knowledge of plant and insect biology accumulated by
biologists.
2. Monitoring. Farmers can use relatively simple techniques to keep
track of what pests are where. This information, combined with
knowledge of pest life cycles, can enable farmers to implement control
measures at the most effective times.
3. Economic threshold. This takes into account the revenue losses
resulting from pest damage and the costs of treatment to prevent the
damage. Below the economic threshold, the presence of the pest is
tolerated. Only when pest numbers increase above the threshold does
the farmer take action.
4. Adaptability. Farmers must keep informed about what is happening in
their paddocks so that they can adapt their strategies to changing
circumstances. Research scientists, too, must aim to keep at least one
7/29/2019 Russell Reza
51/98
step ahead of the pest, which is also undoubtedly changing and
adapting over time.
Sustainable Pest Control
The immense social and economic costs of relying on chemical pesticide s
have slowly begun to be recognized. A banding the idea that pests can or
should totally be eradicated , many no longer believe that chemical
treatments exists, or can be developed , that will allow safe and profitable
large scale, pest free monoculture.
These are, in fact, superior to chemical based pest control for four reasons:
1. It is scientifically more advanced.
2. It is less costly and maximizes profits.
3. It is better for small scale traditional producers.
4. It can assure environmental and human safety.
Thus, sustainable pest control is ecologically sound, economically viable,
socially just and humane.
5.3 Pesticide management practices
Pesticides management practices are important procedure to reduce the
pollution of pesticide as well as their harmful effect. Appropriate application
methods, following using procedures, proper storage system and also the
disposal of pesticide contamination reduce the pesticide contamination.
Management practices
The evaluation of soil-pesticide interactions can be used to reduce the
pollution potential of pesticides.
7/29/2019 Russell Reza
52/98
First, the most effective pest control method should be selected based
on Cornell recommendations. In cases in which various chemicals can
economically be applied to remedy an infestation, the pesticide with
the least environmental impact should be selected. This includes the
evaluation of the site-specific leaching and surface loss potentials
(Supplements A, B, and C).
In addition, the chemical's toxicity to human and aquatic life and the
importance of the affected water bodies as drinking water supplies or
natural habitats need to be considered.
Pesticides should be applied when they are most effective, which is
influenced by temperature and moisture conditions. Pests under
dormant or stressed conditions may be less susceptible to pesticide
treatment.
Pesticide efficacy can also be reduced by continuous use of pesticides
of similar chemistry, which can cause pesticide resistance.
Pesticide applications should be avoided under adverse weather
conditions.
Finally, pollution from pesticides can be reduced by proper operation,
safety, and maintenance practices.
Rules for Using Pesticides
We should do to
Use the proper pesticide at the proper time to manage a pest.
Measure the material accurately. Over dosage seldom kills more insects,
diseases, or weeds and, in fact, may harm non target plants, animals, or
people.
Measure and mix the materials in a well-ventilated area.
Wear rubber gloves when handling pesticides. When applying the
materials, wear long pants, long sleeves, gloves, shoes or boots (not
sandals), and a wide-brimmed hat to protect your neck.
When spraying pesticides outside, remove or cover food and water
containers used by pets. Do not contaminate fish ponds or streams.
Never spray when children or pets are nearby.
7/29/2019 Russell Reza
53/98
Use a sprayer separate from that used for insecticide or fungicide
applications for applying herbicides to avoid accidentally injuring sensitive
plants with herbicide residue.
Do not leave mothballs where children can get them; mothballs resemble
candy.
Cleanliness
We need to follow the following guidelines
Never smoke, drink, or chew gum or tobacco while handling pesticides.
Avoid inhaling sprays, dusts, or vapors.
Have soap, water, and a towel available. If we spill concentrated pesticide
on ourself, wipe it off immediately and then wash thoroughly with soap
and water.
Launder clothes worn when applying pesticides separate from the rest of
your laundry. Afterward, clean the washing machine by running an empty
cycle with hot water and detergent.
Storage
To keep pesticide in safe, we should obey the rules including:
To avoid long-term storage, purchase only what you will use within the
season.
Store pesticides and pesticide equipment in a locked cabinet or room. A
cool, dry, well-ventilated storage area is best.
Post a sign, KEEP OUTPESTICIDE STORAGE, on the cabinet or door to
the room in which pesticides are stored.
Never store pesticides with or near food, medicine, or cleaning supplies.
Do not store herbicides with other pesticides because the vapors from the
herbicides may be absorbed by other pesticides.
7/29/2019 Russell Reza
54/98
Management of pesticide Container
Finally, after use of pesticide the remaining amount and the keeping
container is necessarily managed to reduce pesticide pollution. We should
keep attention in the following steps:
Minimizing Concentrated and Persistent Pesticide Residues
We can minimize pesticide residues by:
Purchasing no more pesticide than can be used in one season;
Measuring, mixing and loading only enough pesticide spray to do the
job;
Applying all the pesticide spray mixture onto the target area as
directed by the label; and
Select the most benign, immobile product to do the job.
Managing Pesticide Residues at the Point of Application
We should follow the following procedures for managing these materials at
the point of application:
Washing the exterior of application equipment at a designated cleanup
area so that the wastewater does not enter groundwater, surface
water, wells, storm drains, drainage ditches, streams, creeks, lakes or
rivers.
Managing small quantities (one gallon or ten pounds) of biodegradable
pesticide-containing residues,
Alternating the land used for such residue management and lightly
cultivating the soil should speed up the biological breakdown of the
residues
A pesticide active ingredient that must be disposed may be managed
at pesticide waste collection programs.
7/29/2019 Russell Reza
55/98
Managing Empty Pesticide Containers
By carefully decontaminating empty pesticide containers, we can eliminate
having to dispose of the containers. At the time of emptying, decontaminate
rigid containers, such as plastic pails or drums, metal pails or drums, and
fiber containers by:
Pressure or multiple rinsing (multiple rinse at least three times or as
often as necessary to clean the container)
Visually verifying that the residues have been removed from the inside
and outside of the container
Drying the containers interior surfaces before crushing
Decontaminated metal and plastic containers should be recycled.
If containers are to be discarded, contaminated containers must be
disposed of as hazardous waste.
5.4 Reducing risk through use of engineering controls
Because handling and applying pesticides is risky business, keeping pesticide
exposure to a minimum should be a chief concern of any pesticide applicator.
To reduce the risks associated with handling and applying pesticides, devices
known as engineering controls can be used that help to reduce or practically
eliminate exposure to toxic chemicals.
Loading the Sprayer
Closed Transfer Systems - Closed transfer systems allow concentrated
pesticide to be moved from the original shipping container to the sprayer mix
tank with minimal or no applicator contact. Many systems provide a method
to measure the concentrated pesticide. Some systems also include a
container rinsing system. Currently available closed transfer systems use a
probe inserted into the pesticide container, a connector on the container that
mates to a similar connector on the application equipment, or a vacuum-type
(venturi) system that uses flowing water to transfer the chemical from the
container.
7/29/2019 Russell Reza
56/98
Induction Bowls - Induction bowls are metal, plastic or fiberglass hoppers
attached to the side of the sprayer or the nurse tank that allow pesticides to
be added to the mix tank without the applicator climbing onto the spray rig.
Pesticides are poured into the bowl and water is added to flush out the bowl
and carry the pesticide to the spray tank. Often a rinse nozzle is mounted
inside the bowl for rinsing out empty pesticide containers.
Direct Pesticide Injection System - Direct pesticide injection systems
allow pesticides to be mixed directly with water in the sprayer plumbing
system rather than in the main spray tank. The pesticide is pumped from its
container and mixed with the water either in a manifold or at the main water
pump. Only clean water is held in the main tank of the sprayer. An electroniccontroller and up to four pumps adjust the amount of concentrated pesticide
that is injected into the water stream, allowing for variable application rates.
Container Rinse System - Container rinse systems consist of a rinse nozzle
and a catch bowl that traps the container washings (rinsate). The empty
container is placed over the rinse nozzle and a jet of water cleans the inside
of the container.
Reducing Contamination at the Boom
Boom Folding/Extending - Manually folding booms can be a major source
of operator contamination because the boom can be covered with pesticide
from drift or dripping nozzles. Consider the use of hydraulic or mechanical
folding methods. Diaphragm Check Valves - Typically, when a sprayer is shutoff and as the system pressure drops, any liquid remaining in the boom
piping drips from the nozzles, possibly dripping onto the boom or even the
operator.
Multiple Nozzle Bodies - Contamination can occur when operators change
or unclog nozzles during an application. Multiple nozzle bodies (or turret
nozzles) allow operators to switch between nozzles with a turn of the nozzle
body rather than having to unscrew or undo a threaded or a bayonet fitting.
7/29/2019 Russell Reza
57/98
Hand Wash Water Supply - Providing adequate wash water is essential
(and often required). A simple container with a hand-operated valve can be
mounted on the side of the sprayer to provide clean water for hand washing
and personal hygiene.
Drift and Contaminated Clothing in Cabs
Cab Filtration Using Carbon Filters - Carbon filtration systems are used to
remove pesticide odor and pesticide-laden mist from fresh air used in a
tractor or self-propelled sprayer cab. Carbon filtration systems are often a
standard feature on self-propelled sprayers. Now many factory installed
tractor cabs offer optional filtration systems. In 1998, the American Society
of Agricultural Engineers (ASAE) adopted testing standards for operator cabs
used in pesticide application. Cabs certified under this standard meet the
requirements for enclosed cabs contained in the Worker Protection Standard.
Protective Clothing Lockers - To prevent contamination of the tractor or
sprayer cab interior, protective clothing should be removed before entering
the cab. A few sprayer companies offer a simple compartment (or locker)
mounted to the side or front of the sprayer where protective clothing can bestored. Alternatively a locker can be fitted to the mixer wagon.
Controlling Drift
Low-Drift Nozzles - Low-drift nozzles create larger-size droplets than i-
conventional nozzles. The larger droplet sizes are less prone to drift, reducing
environmental and operator contamination.
Air Induction (Twin Fluid) Nozzles - These nozzles allow air to mix with
the spray liquid, creating large, air-filled droplets that have virtually no fine,
drift-prone droplets. The droplets explode when they contact their target and
offer similar coverage to droplets from conventional, finer-spray nozzles.
Cleaning the Sprayer
Tank Rinse Systems - Tank rinse systems consist of a clean water supply
tank mounted to the sprayer and one or more rotating discs or nozzles
7/29/2019 Russell Reza
58/98
mounted inside the main sprayer tank. Water is pumped from the clean water
tank to the rinse nozzles, which spray water around the inside of the spray
tank. These systems are designed for in-field rinsing of the sprayer so that
the tank washings can be applied to the field at label rates.
Checking the sprayer
Surveys have shown that many farmers are using inaccurate sprayers; faulty
sprayers contribute to increased drift levels and waste money through
inefficiency and overuse of chemicals. Sprayers must be regularly checked to
ensure that proper maintenance has been carried out and that no
outstanding repairs need to be done. Before attempting any work on a
machine make sure that it is fully supported on stands and that all necessary
protective clothing is on.
Fitting the sprayer to the tractor
The selected tractor must always be powerful enough to operate the sprayer
efficiently under the working conditions that will be encountered. All its
external services - hydraulic, electrical and pneumatic - must be clean and in
working order. Tractors fitted with cabs must have efficient air filtration
systems. All protective guards must be in place. Trailed sprayers are often
close-coupled to the tractor,
Checking the operation of the sprayer
Parts fill the tank with clean water and move the sprayer to outcropped waste
ground. Remove the nozzles. Engage the PTO and gently turn the shaft,
increasing speed slowly to operating revs. Test the on/off and pressure relief
valves, and check the agitation system. Flush through the spray lines, then
switch off the tractor. Refit the nozzles and check the liquid system again for
leaks.
7/29/2019 Russell Reza
59/98
CHAPTER SIX
TREATMENT METHODS
We can categorize treatment methods as-
Traditional disposal methods
Modern innovative non-combustion destruction methods
Potential innovative biological methods
6.1. Traditional Disposal Methods
Among the traditional disposal methods storage, landfill and deep well
injection are done frequently as methods of containment. A list of traditional
Pesticides stockpile disposal methods are mentioned with their concerns in
Table 15.
Table 15 Traditional Pesticides Disposal Methods
Technology Comments
Storage Concerns: Spills, leaks & volatilization of Pesticides from
storage are problematic both in tropical and temperate
climates despite the use of the best available preventive
measures.
Landfill Cap Process: This is a method of containment.
Landfill Caps: The design of landfill caps depends on the
intended functions of the system. The most critical components
of a landfill cap are the barrier layer and the drainage layer.
Concerns: Constituents in buried wastes can and do escape
into the surrounding environment, primarily through leaching
into groundwater and volatilizing into the air.
7/29/2019 Russell Reza
60/98
Deep well
injection
Concerns: "Unsuitable because of the environmental risk and
lack of control" (FAO 1996). Chemicals often releases from
deep wells.
Little is known about the long-term chemical behavior of
chemicals that have been injected down deep wells- potential
reactions between hazardous waste and underground rocks or
the effects such reactions might have on migration and
toxicity.
Cement
kilns
Process: The main processes employed in making cement
clinker can be classified as either "wet" or "dry" depending on
the method used to prepare the kiln feed.
Destruction efficiency1: The highly alkaline conditions in a
cement kiln are ideal for decomposing chlorinated organic
waste.
Concern: Dioxin emissions from cement kilns burning
hazardous wastes are significantly higher than non-waste
burning facilities. Dioxins have been detected in solid residues.
High
temperature
incineration
Process: This has been one of the most applied remediation
technologies. It is a high temperature (870 co to 1200 oC)
destructive ex situ treatment of polluted soil; the waste and/or
contaminated soil are fed into the incinerator,
Incinerator design: Most incinerator designs are fitted with
rotary kilns, combustion chambers equipped with an
afterburner, a quench tower and an air pollution control
system.
Efficiency: Destruction & removal efficiencies2 of more than
99.99% are feasible.Concerns: pesticide released in stack
gases and solid residues.
7/29/2019 Russell Reza
61/98
1 Destruction Efficiency (DE) is the overall destruction of an hazardous
compound is calculated on the basis of total weight of the same into the
process, minus the sum of the compound found in all products, by-products,
and environmental releases, divided by the compound input. (DE is reported
as a percentage).
2Destruction and removal efficiency (DRE) is intended as the efficiency in
destruction andremoval from a main stream, generally the flue gases. It is
calculated similarly to DE, but as it is referred only to one stream may be
useful to evaluate cleaning equipment, while may be misleading for a whole
process evaluation. DRE is defined by
DRE= (Win Wout) x 100/ Win, Where, Win= mass of POPs feed to the
incinerator per unit of time, Wout= mass of POPs exhausted at the stack per
unit time.
(Source: IPEN 2001, Rahuman et al. 2000)
6.2. Modern Innovation Non-Combustion Destruction Methods
There are various non-combustion technologies on the process of
commercialization (Rahuman et al 2000, STAP/GEF 2004, USEPA 2005),
which are listed with a brief description in Table 16.
TABLE 16.SELECTION OF MODERN PESTICIDES DESTRUCTION TECHNOLOGIES
Technology Process Description
Gas-phase
chemical
reduction
(GPCR)
Process: In the first stage, contaminated soil is heated in a
thermal reduction batch processor in the absence of oxygen
to temperatures around 600oC. The treated soil is non-
hazardous and is allowed to cool prior to its disposal on or
off site. In the second stage, the desorbed gaseous-phase
contaminants pass to a GPCR reactor, where they react
with introduced hydrogen gas at temperatures ranging from
850 to 900oC.(Kummling 2001).
7/29/2019 Russell Reza
62/98
Efficacy: Demonstrated high destruction efficiencies for
PCBs, dioxins/furans, HCB, DDT.
Applicability: All Pesticides
Emissions: All emissions and residues are captured for
assay and reprocessing if needed.
Electro-
chemical
oxidation
Process: An electrochemical cell is used to generate
oxidizing species at the anode in an acid solution, typically
nitric acid. These oxidizers and the acid then attack any
organic compounds, converting most of them to carbon
dioxide, water and inorganic ions at low temperature (< 80
C) and atmospheric pressure.
Efficacy: Both technologies have demonstrated high
destruction efficiencies.
Applicability: all Pesticides.
Emissions: All emissions and residues can be captured for
assay and reprocessing.
Concerns: Limited detailed information about residues and
process wastes.
Supercritical
water
oxidation
Process: At temperatures and pressures above the critical
point of water (374C and 22.1 MPa) all dissolve freely and
are treated with an oxidizing agent (e.g. oxygen or
hydrogen peroxide) to produce carbon dioxide, water andhydrochloric acid.
Efficacy: high destruction efficiency (99.99%)
Applicability: all
Emissions: All emissions and residues may be captured for
assay and
Top Related