Russell Reza

7/29/2019 Russell Reza

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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


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Dedicated

to

My Family


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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


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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


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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


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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


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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


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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.


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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


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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


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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.


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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.


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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:


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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


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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.


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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


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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.


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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.


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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.


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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.


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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.


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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.


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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


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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


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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


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


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;


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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)


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 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.


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3.9.3. Aldrin/Dieldrin


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.


Animals and people may be exposed via consumption of fish, seafood,

dairy products, fatty meats, and root crops grown in contaminated soil

or water.


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It demonstrates very high acute toxicity to aquatic organisms such as

fishes, crustaceans, and amphibians.

3.9.4.ENDRIN


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.


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.


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3.9.5. Heptachlor


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.


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.


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3.9.6. Mirex


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.


Most exposures occur thorough eating contaminated food, particularly

fish and other animals living near contaminated sites.

Exposure can also arise through inhalation.


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3.9.7. Toxaphene


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 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.


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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


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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


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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


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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.


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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


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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.


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.


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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


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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.


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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.


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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.


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.


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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


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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.


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.


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 )


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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


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.


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.


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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.


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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.


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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.


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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.


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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


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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.


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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.


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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.


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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).


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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

Documents

Russell Reza