BYprr.hec.gov.pk/jspui/bitstream/123456789/7170/1/Thesis Adeel Mah… · Muhammad Usman Khan, Naeem...

Spatial distribution and screening-level risk assessment of

persistent organic pollutants in the cereal crops and

environmental compartments along upstream tributaries of

the River Chenab, Pakistan

BY

ADEEL MAHMOOD

DEPARTMENT OF PLANT SCIENCES

QUAID-I-AZAM UNIVERSITY

ISLAMABAD, PAKISAN

2015

Spatial distribution and screening-level risk assessment of

persistent organic pollutants in the cereal crops and

environmental compartments along upstream tributaries of

the River Chenab, Pakistan

This work is submitted as a dissertation in partial fulfillment for the award of

the degree of

Doctor of Philosophy

In

Environmental Biology

BY

ADEEL MAHMOOD

Department of Plant Sciences

Quaid-I-Azam University

Islamabad, Pakistan

2015

Dedicated to

My Family

M,ma & Abu G.

Brother

Sisters

Misbah Maqsood &

Aiysha Khalid

DECALARATION

The data presented in this thesis pertained to my original research work and have not been

previously submitted to this or any other university.

Adeel Mahmood

I

Acknowledgments

All worships and praises are only due to the Almighty Allah, The compassionate, The merciful,

Who gave us health, thoughts, strength and potential to achieve the recommended tasks. I owe my deepest

respect to Hazrat Muhammad (PBUH) who are forever the torch of guidance and light of knowledge for

mankind.

I would like to express my deepest gratitude and sincere thanks to Dr. Riffat Naseem Malik

(Research Supervisor), Associate Professor, Department of Environmental Sciences, Quaid-I-Azam

University, Islamabad, for her keen interest, providing her precious time and valuable insight for this

practicum. Special thanks are due, to Prof. Dr. Waseem Ahmad Dean, Faculty of Biological Sciences, ,

and Chairperson, Department of Plant Sciences, Quaid-I-Azam University, Islamabad for providing the

existing research facilities to conduct my research work.

Special thanks are due, to Prof. Dr. Gan Zhang, State Key Laboratory of Organic Geochemistry,

Guangzhou Institute of organic Geochemistry, Chinese Academy of Sciences for providing necessary

field and lab facilities regarding POPs residue analysis. I feel more pleasure in expressing my heartiest

gratitude for Dr. Jun Li, for his reliable suggestions, affectionate and encouraging behavior during my

stay at the CAS, China. Many thanks to Dr. Lucci, Dr. Chakra, Dr. Xu Ye, Dr. Yan Wang, Dr. Jerry,

Dr. Zheng Qian, Dr. Zhineng Cheng, Jenny and Dr. Junwen Li for their support, guidance and love

during laboratory work at CAS, China. I highly acknowledge Prof. Dr. Xiandong Li (Hong Kong,

Polytechnic University) for the support during sample transportation to CAS.

Special thanks to Mr. Irfan Ali Choudhary, Dr. Cheng and Dr. Qian for their support during

field and laboratory work. I have no words of appreciation for Prof. Dr. Rizwana Aleem Qureshi, Prof.

Dr. Mir Ajab Khan, Prof. Dr. Asghari Bano and Dr. Abdul Samad Mumtaz for their kind support

throughout my PhD studies. I also wish to thank Dr. Nadeem Ahmed and Ms. Zahra Sadeghi (Iran) for

their kind support during my PhD studies.

I have no word of appreciation for my sweet brother Dr. Aqeel Mahmood and sisters Andleeb

Mehmood, Rabia Mahmood and Memoona Mehmood for their moral/technical support throughout my

PhD studies. I can not forget the joyfull and relaxing company of my younger sister Amna Mahmood

and my beloved Misbah Maqsood and Aiysha Khalid.

I am thankful to my affectionate, sympathetic and respectable parents and uncle (Eng. Hassan

Mahmood Ch.). I must acknowledge the kind support, cooperation, encouragement, cordial prayer and

unlimited patience of my Father Khalid Mahmood Ch. who supported me financially and morally

throughout my life. My parents hands always raised in prayer for me. I pray for their long life. Allah

blesses them throughout their life Amin.

I never forget the kindness of Prof. Khani Zaman Siddique; I’m heartedly thankful for their

moral support and help in one way or the other.

My aknowledgements are due for Higher Education Commession, Pakistan for providing

financial and technical support through Indigenous Scholarship and IRSIP (International Research

Support Initiative Program).

At the end, I feel that my acknowledgments will be incomplete without expressing my warm

affiliations with my sweet and saline friends; Dr. Muhammad Younas Majeed, Dr. Syed Ali Mutajab

Akbar Eqani, Dr. Jabir Hussain Syed, Zeeshan Ali, Atif Kamal, Sofia Rasheed, Abida Bano, Muhammad Usman Khan, Naeem Akhtar Abbasi, Sumya Nazir, Sidra Waheed and Usman Ali for

their moral and technical support throughout the course of my research work. Finally, as customary, the

errors therein are mine alone.

Adeel Mahmood

II

Table of Contents

S. No. Title Page

No.

Acknowledgements I

Table of Contents II

List of Figures VI

List of Tables VII

List of Plates IX

List of Appendices X

List of Abbreviations XI

Abstract XIV

Chapter 1 General Introduction and Review of Literature 1

1.1. Introduction 1

1.1.1. Stockholm Convention on POPs and Regulatory Mechanism in Pakistan 3

1.2. Review of Literature 5

1.2.1. Organochlorines pesticides (OCPs) 5

1.2.2. Polychlorinated biphenyls (PCBs) 6

1.2.3. Polychlorinated naphthalene (PCNs) 7

1.2.4. Polybrominated diphenyl ethers (PBDEs) and Dechloran plus (DP) 8

1.3. Pesticides use in Pakistan 10

1.4. Problem Statement 11

1.5. Objectives 13

1.6. Structure of Thesis 13

Chapter 2 Materials and Methods 19

2.1. Study area 19

2.1.1. Sampling strategy 20

2.2. Field sampling 21

2.2.1. Air sampling 21

2.2.2. Surface soil sampling 26

2.2.3. Water sampling 27

2.2.4. Sediment sampling 27

2.2.5. Wheat and rice sampling 27

2.3. Experimental section 27

III

2.3.1. Extraction and cleanup procedure 27

2.3.2. Chromatographic analysis 28

2.3.2.1. Organochlorines pesticides (OCPs) 28

2.3.2.2. Polychlorinated biphenyls (PCB) 29

2.3.2.3. Polychlorinated naphthalene (PCN) 29

2.3.2.4. Polybrominated diphenyl ethers (PBDEs) and Dechloran plus (DP) 29

2.4. Quality control and quality assurance (QC/QA) 30

2.5. Statistical analysis 30

2.5.1. General statistical analysis 30

2.5.2. Health risk assessment 31

2.5.3. Hazard ratio 31

Chapter 3 Results and Discussions 35

Part 1 Levels, distributions and screening-levels risk assessment of

organochlorines pesticides (OCPs) in the cereal crops and environmental

compartments along two tributaries of River Chenab, Pakistan

36

3.1. Methodology 36

3.2. Results and Discussions 36

3.2.1. Levels of OCPs 36

3.2.1.1. Water 36

3.2.1.2. Sediment 37

3.2.1.3. Air 38

3.2.1.4. Soil 39

3.2.1.5. Cereal crops (rice and wheat) 39

3.2.2. Spatial distribution pattern and source apportionments of OCP 44

3.2.3. Dietary intake of OCP via consumption of cereal crops 50

3.2.4. Human health risk assessment 50

3.2.5. Risk assessment to ecological integrities 52

3.2.6. Conclusion 55

Part 2 Polychlorinated biphenyls (PCBs) in environmental compartments and

cereal crops along the two tributaries of River Chenab, Pakistan:

Concentrations, distribution and screening level risk assessment

56

IV

3.3. Methodology 56

3.4. Results and Discussions 56

3.4.1. Concentrations and profiles of congeners 56

3.4.1.1. Water 57


3.4.1.3. Air 58

3.4.1.4. Soil 58

3.4.1.5. Rice 59

3.4.1.6. Wheat 60

3.4.2. PCB homologues pattern 63

3.4.3. Potential sources and spatial distribution of PCB 64

3.4.4. Accumulation or transfer factor 69

3.4.5. Dioxin like PCB and toxicity equivalency (TEQ) fluxes 69

3.4.6. Human health risk assessment 70

3.4.7. Ecological risk assessment 71

3.4.8. Conclusions 75

Part 3 PCNs (polychlorinated napthalenes): dietary exposure via cereal crops,

distribution and screening-level risk assessment in wheat, rice, water,

sediment, soil and air along two tributaries of the River Chenab, Pakistan

76

3.5. Methodology 76

3.6. Results and discussions 76

3.6.1. PCN congeners and homologue profile 76

3.6.1.1. Water 76


3.6.1.3. Air 78

3.6.1.14. Soil 78

3.6.1.5. Cereal crops (wheat and rice) 79

3.6.2. Potential sources and spatial distribution 84

3.6.3. Potential toxic equivalency (TEQ) 88

3.6.4. Daily intake exposure of PCN to human 89


V


Part 4 Congener specific analysis, distribution pattern and screening-level risk

assessment of Polybrominated diphenyl ethers (PBDEs) and Dechloran

plus (DP) in the cereal crops and environmental compartments from two

tributaries of the River Chenab, Pakistan

92

3.7. Methodology 92

3.8. Results and discussion 92

3.8.1. Levels and congener specific analysis of PBDEs and DPs 92

3.8.1.1. Water 92


3.8.1.3. Air 94

3.8.1.4. Soil 95

3.8.1.5. Cereal crops (wheat and rice) 96

3.8.2. Source apportionment and spatial distribution pattern 99

3.8.3. Stereoisomer of DP 105

3.8.4. Dietary intake of PBDEs and DPs by human and risk assessment 105



Chapter 4 General Discussion, Conclusions and Recommendations 109

4.1. General Comments and Conclusions 109

4.1.1. OCPs 110

4.1.2. PCBs 111

4.1.3. PCNs 112

4.1.4. PBDEs and DP 112

4.2. Recommendations and Future Strategies 109

References 115

Appendices 148

VI

List of Figures

Fig. No. Title Page

No.

Fig. 2.1 Map showing location of the study area along with the population pressure 23

Fig. 2.2 The study area map, displaying the sampling strategy 24

Fig 2.3 Map showing the allocated zones and sampling locations along with the possible

pollution sources

25

Fig. 2.4 Schematic representation of passive air sampler 26

Fig. 3.1.1 Distribution patterns of OCPs (%) among different zones in all matrices 46

Fig. 3.1.2 Spatial distribution pattern of OCPs in sediment and water samples from each

site of the study area

47

Fig. 3.1.3 Spatial distributions of OCPs in air and soil 48

Fig. 3.1.4 Spatial distributions of OCPs in rice and wheat 49

Fig. 3.2.1 Distribution patterns of PCB homologs and aroclor mixture compositional

comparison among environmental compartments and cereal crops from each

zone

66

Fig. 3.2.2 Spatial distributions of PCBs in soil, air, rice and wheat 67

Fig 3.2.3 Spatial distributions of PCBs in sediment and water 68

Fig. 3.3.1 Spatial distributions of PCNs in air, soil, wheat and rice 86

Fig. 3.3.2 Spatial distributions of PCNs in sediment and water 87

Fig. 3.4.1 PBDEs and DPs level among investigated environmental compartments 101

Fig. 3.4.2 Levels and spatial distribution pattern of PBDEs and DPs in sediment and water

from each study site

102

Fig. 3.4.3 Levels and spatial distribution pattern of PBDEs and DPs in air and soil from

each study site

103

Fig. 3.4.4 Levels and spatial distribution pattern of PBDEs and DPs in wheat and rice from

each study site

104

VII

List of Tables

Table No. Title Page

No.

Table 1.1 (a) Contamination load of POPs (ng g-1

) in sediment and soil samples collected

from Pakistan

16

Table 1.1 (b) Contamination load of POPs (ng L-1

) in water samples collected from Pakistan 17

Table 1.1 (c) Contamination load of POPs (ng g-1) in biota samples collected from Pakistan 18

Table 2.1 Detail description of sampling sites along with the location and weather

information

22

Table 3.1.1 Descriptive statistics of OCPs in environmental compartments 41

Table 3.1.2 Comparison of DDTs and HCHs in Air (pg m-3

) and soil (ng g-1

) from the

current report with previously reported studies

42

Table 3.1.3 Descriptive statistics of OCPs in cereal crops (rice and wheat) 43

Table 3.1.4 Estimated daily intake of OCPs (ng kg-1

day-1

) via consumption of food stuff

for the present study and other countries

53

Table 3.1.5 Cancer benchmark concentrations (CBCs) and hazardous ratios in food crops

from Pakistan

54

Table 3.1.6 Comparison between OCPs isomers from sediment samples and guidelines

values (ng g-1

dw)

54

Table 3.2.1 Descriptive statistics of PCBs congeners in environmental compartments 61

Table 3.2.2 Descriptive statistics of PCBs congeners in rice and wheat 62

Figure 3.2.3 Spatial distributions of PCBs in sediment and water 73

Table 3.2.4 TEQ values of dioxin-like PCBs 74

Table 3.2.5 Health ratio (HR) and estimated daily intake (EDI) in rice and wheat by human

(pg/kg/day) using mean concentrations (pg g -1

) of ∑PCB and dioxin-like ∑non

and mono-ortho PCBs

75

Table 3.3.1 Descriptive statistics of PCNs in air, soil, sediments and water 80

Table 3.3.2 PCN levels reported from other parts of the world 82

VIII

Table 3.3.3 Descriptive statistics of PCNs in wheat and rice 83

Table 3.3.4 Estimated daily intake (EDI) in wheat and rice by human (ng kg-1

day-1

) using

mean concentrations (ng g -1

) of PCNs

91

Table 3.4.1 Basic descriptive statistical values of PBDEs and DPs in the environmental

compartments and cereal crops

98

Table 3.4.2 Estimated daily exposure (pg kg-1

day-1

) of PBDEs and DPs to human through

wheat and rice

107

IX

List of Plates

Plate No. Title Page

No.

Plate 1.1 Discharge of industrial effluents into Nullah Aik and Nullah Palkhu in

midstream zone

15

Plate 1.2 Wastewater irrigation system through pumps at Site 9 and 13 15

Plate 2.1 Diverted streams into small water distributaries over long distance for irrigation

purpose

32

Plate 2.2 Agricultural practice across Nullah Aik and Nullah Palkhu 32

Plate 2.3 Pictorial view of field activities during sampling trip 33

Plate 2.4 Pictorial view of experimental activities during PhD research work 34

X

List of Appendices

Appendix No. Title Page

No.

Appendix 3.1

Descriptive statistical values for OCPs concentration in the environmental

compatments and cereal crops from different zones of Nullah Aik and Palkhu,

tributaries of the River Chenab, Pakistan

148

Appendix 3.2

Descriptive statistics of PCBs congeners in the investigated matrixes from

different zones 151

Appendix

3.2.1

Figure: Cluster analysis based on the PCB concentrations from each sampling

site

155

Appendix 3.3

Descriptive statistics of physic-chemical properties and total organic content

of soil 156

Appendix 3.4

Descriptive statistics of PCNs in investigated matrix from different zones 157

Appendix 3.5

Source identification ratios for studied matrix from sampling sites 163

Appendix 3.6

TEQ values of dioxin-like PCNs 164

Appendix 3.7

TEQs for dioxin like PCNs in water and sediments

166

Appendix 3.8

Table: Basic descriptive statistical values of PBDEs and DPs in the

environmental compartments and cereal crops from different zones

167

XI

LIST OF ABBREVIATIONS

POPs Persistent Organic Pollutants

OCs Organochlorines

OCPs Organochlorine Pesticides

DP Dechloran plus

PCNs Polychlorinated naphthalens

PCBs Polychlorinated biphenyles

PBDEs Polybrominated diphenyl ethers

PAHs Polycyclic Aromatic Hydrocarbons

o, p-DDD ortho, para-Dichlorodiphenyldichloroethane

p, p-DDD para, para-Dichlorodiphenyldichloroethane

o, p-DDE ortho, para-Dichlorodiphenyltrichloroethane

p, p-DDE para, para-Dichlorodiphenyltrichloroethane

o, p-DDT ortho, para-Dichlorodiphenyltrichloromethane

p, p-DDT para, para-Dichlorodiphenyltrichloromethane

TC trans-Chlordane

CC cis-Chlordane

t-CHL total Chlordane

Endos Endosulfan

-HCH -hexachlorocyclohexane



PUF Polyurethane foam

PAS Passive air sampler

TCmX 2,4,5,6-tetrachloro-m-xylene

PCB-209 decachlorobiphenyl

ND not detected

MT Metric tons

GC-ECD Gas Chromatograph-Electron Capture Detector

GC/MSD Gas Chromatograph/Mass Selective Detector

XII

IDL instrumental detection limit

MDLs method detection limits

PCA/FA Principal Component Analysis/Factor Analysis

TDS Total Dissolved Solids

DCM Dichloromethane

USEPA United States Environmental Protection Agency

CCC The Criterion Continuous Concentration

CMC Criteria Maximum Concentration

ISQG Interim Sediment Quality Guidelines

PECs Probable Effect Concentrations

TECs Threshold Effect Concentrations

LEL Lowest Effect Level

SEL Sever Effect Level

CB-TECs Consensus Based Threshold Effect Concentrations

ERL Effect Range Low

ERM Effect Range Median

EU European Union

TDS Total Dissolved Solids

EC Electrical Conductivity

KPK Khyber Pakhtoonkhwa

CCME Canadian Council of Ministers of the Environment

MRL Minimal risk level

LOAEL Lowest observed adverse effect of level

EDI Estimated daily intake

HRs Hazard ratio

XIII

Conflict of Interests, Information on Funding Authority and Ethical Statement

The Higher Education Commission (HEC), Pakistan provided all the funding for this

study and there is no conflict of interests among all the authorities of this document. All the

experimental work was conducted at State Key Laboratory of Organic Geochemistry Guangzhou

(SKLOG), Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (CAS). The

student wish to thanks IRSIP (International Research Support Initiative Program, HEC Pakistan),

Chinese Academy of Sciences (No.KZCX2-YW-GJ02) and the Natural Science Foundation of

China (NSFC) for providing supporting funds for foreign visits (PhD research).

XIV

Abstract

Persistent organic pollutants (POPs) are major environmental concern throughout the

globe due to their persistent and bio-accumulative nature, long range transportation and adverse

effects on lives. This study has been aimed to report the first systematic data on POPs levels,

distribution pattern, probable sources and their risk assessment of environmental compartments

(air, soil, sediment and water) and cereal food crops (wheat and rice) along upstream feeding

tributaries of the River Chenab, Pakistan. Dietary exposure and potential risks to human health

were assessed through consumption of cereal food crops from the study area. Organochlorine

pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated napthalenes (PCNs),

polybrominated diphenylethers (PBDEs) and dechloran plus (DP) were analyzed in wheat, rice,

air, surface soil, sediment, and water samples.

Concentrations of ∑OCPs ranged from 123 to 635 (pg m-3

), 31 to 365, 2.72 to 36.6, 0.55

to 15.2, 17 to 224 (ng g-1

dw) and 8 to 76 (ng L-1

) for air, soil, rice, wheat, sediment and water

samples, respectively. DDTs and HCHs were the dominant over other investigated OCPs while

source apportionment analysis suggested the new input of DDTs and historic use of HCHs.

Estimated daily intake (EDI) of ∑OCPs through rice and wheat was found 39 and 40 ng kg-1

(body weight) day-1

, respectively. Hazard ratio (HRs) on the basis 95th

percentile concentrations

exceeded the integrity for most of the investigated OCPs in rice and wheat which indicated the

carcinogenic risk to human. ∑33PCB concentrations ranged between 0.15-2.22, 0.05-9.21, 0.70-

30.5, 0.80-60 (ng g-1

dw), 41-299 (pg m-3

), and 0.20-28 (ng L

-1) for wheat, rice, soil, sediment, air,

and water samples, respectively. Comparatively lower dioxins TEQs (toxicity equivalency) for

PCBs were calculated than the previously reported data. HRs allied to non-cancer for human was

found lower than integrity.

∑39PCN concentrations ranged between 0.02-0.21, 0.02-1.21, 24.6-233, 8.94-414 (ng g-1

dw), 1222-5052 (pg m-3

), and 178-489 (ng L-1

) for wheat, rice, soil, sediment, air, and water

samples, respectively. Dominancy of ∑PCNcom indicated the biomass burning as possible source.

Soil and sediment exhibited higher TEQ values for PCNs while in case of air, water, wheat and

rice TEQ concentrations were in accordance with the previously reported pattern from other

parts of the world. EDI for wheat and rice was calculated as 0.21 and 0.03 ng Kg-1

(body weight)

day-1

, respectively. Considerable human health risks were observed for PCNs intake through

cereal food crops. ∑PBDE levels in air, soil, wheat, rice, sediment and water ranged between

XV

0.59-7.80 (pg m-3

), 6.88-37.7, 0.30-1.43, 0.07-46.0, 0.35-88.1 (ng g-1

dw), and 0.48-73.4 (ng L-1

),

respectively. ∑DP concentrations calculated in air, soil, wheat, rice, sediment and water ranged

between 0.80-0.10 (pg m-3

), 0.17-2.61 ng g−1

, 0.90-0.49, 0.00-12.5, 0.10-12.5 (ng g-1

dw), and

0.01-4.58 (ng L-1

), respectively. EDI for wheat and rice ranged between 0.002-0.035 and 0.033-

0.680 pg kg-1

(body weight) day-1

. Ratio for fsyn reflected no usage of industrial mixture of DP

isomers in the study area. Human HRs for adults on the basis of EDI was lower than the

recommended minimal risk level (MRL) and lowest observed adverse effect of level (LOAEL).

Potential risks to ecological integrities deemed marginal at the present time, assessed on the basis

of the available toxicological data. The scarcity of available data on screening-level risk

assessment and dietary exposure of PCNs, PBDEs and DPs warrants auxiliary devotion in future,

to this group of contaminant.

Our results concluded a) abuse/misuse of off-label, illegal, banned adulterated pesticides

b) existence of obsolete pesticide dumping sites c) uncontrolled coal combustion and unchecked

disposal/dumping of industrial, solid and e-waste to open lands and rivulets. Findings of this

dissertation depicted that POPs contamination must be considered as an important environmental

issue due to their extensive use in industrial and agricultural sector. The current work may be an

approach/way onward for valued future studies for the sustainability of ecosystem and safety of

ecological integrities and human.

Keywords: POPs, Air, Cereal crops, Screening-level risk assessment, River Chenab, Pakistan

Chapter 1: General Introduction and Review of Literature

Page 1

Chapter 1

General Introduction and Review of Literature

1.1. Introduction

There has been an increasing emphasis in the last few decades on circumstance that human

and animal are concomitantly exposed to a variety of chemicals through foodstuff and the

environment. Toxicological effects and ecological behaviors of such chemicals are of global

concern because of their persistence, toxic and bio-accumulative properties to ecological

integrities, wildlife and human beings (Guo et al., 2008; Eqani et al., 2012). These chemicals

may have accumulative action that cause a minor or major chronic effect that would be

anticipated from knowledge about the single compound (Larsen et al., 2003). The exposure of

such chemicals may lead to the carcinogenic, reproductive, neurological, immunological effects

(Kalyoncu et al., 2009). Among such chemicals, consensus about persistent organic pollutants

(POPs) seems to be conferred, as these migrate/move in the ecological integrities.

There are thousands of POP chemicals, migrating to environment from certain series or

“families” of chemicals (as a case, about 209 different polychlorinated biphenyls hiving a wide

range difference in chlorination and substitution position), having long half lives in air, soil,

sediments and biota. POPs in soil, sediments and biota could have a half-life of decades and

many days in the air. POPs are lipophilic and hydrophobic chemicals which incline a strong

partition to solid, preferably organic matter. These partition strongly to lipids in living organisms

avoiding, entering the aqueous environment of cell and tend to store in fatty tissues. This

property of POPs confers its persistence in biota and may easily accumulate in food chain (Jones

and de Voogt, 1999). Notably, POPs have the tendency to transport the gaseous phase under

ambient temperature. Thus, they can volatilize from water, soil and vegetation into air and due to

their persistant nature, they do not undergo the breakdown reactions in atmosphere and, hence

transport to a wide range distance before being re-deposited. This cycle (volatilization and re-

deposited) continues and allow their presence in an area far from the source of POPs emission

(Jones and de Voogt, 1999).


Page 2

From source perspectives, POPs and associated organic pollutants may derive from two

broad categories. a) Produced intentionally for one or numerous commitments, b) produced as

unintentional/accidental byproduct in other processes (industrial) or by anthropogenic activities.

Furthermore, traces of POPs may instigate from natural processes (Breivik et al., 2004).

Intentionally produced chemicals, especially in the context of POPs, may be divided into many

subgroups. These POPs chemicals belongs to many families of chlorinated and brominated

aromatic, comprising PCBs (polychlorinated biphenyls), PCDD/Fs (polychlorinated dibenzo-p-

dioxins/furans), PBDEs (polybrominated diphenyl ethers), PCNs (polychlorinated naphthalenes)

and OCPs (organochlorines pesticides) including DDTs and its metabolites (toxaphene,

chlordane, etc.). Few POPs chemicals belong to the multiple sources; HCB (hexachlorobenzene)

is the one of them, which is produced deliberately as industrial chemical as well as unintentional

byproduct (Bailey, 2001). PCBs are another example of such chemicals that are produces by both

of the sources (Brown et al., 1995; Lohmann et al., 2000). Though, the relative significance of

by-product formation is ambiguous however an initial assessment accepts a little importance

with respect to the PCBs historical mass balance throughout the globe (Breivik et al., 2002). It is

important to note, that Stockholm Convention on Pops listed PCBs and HCBs as intentionally

produced POPs as well as unwanted by-products, and thus wants quantification and

identification of their sources and establishment of release inventories from un-intentional

production (Breivik et al., 2004).

POPs can bio-accumulate and magnify in the food chain, apprehension exist on their

impact on top predator species, including human. In recent years, concern about POPs

contamination is increasing, as many compounds/metabolites are identified as hormone disrupter

and may alter the functioning of reproductive and endocrine system in wildlife and humans.

These pollutants are able to stay in fatty tissues for many years causing chronic problems like

birth defects, reduced ability to cope diseases, stunted growth and permanent impairment of

brain function, cancer, learning disabilities, respiratory problems like asthma and behavioral,

neurological, immunological and reproductive discrepancies in animals and human well-beings

(Harrison et al., 1995). POPs are mistrusted carcinogen, endometriosis, increased incidence of

diabetes and neurobehavioral impairment with learning illness and mental weakness. Some

authors considered the POPs as potential risk factor of the human breast cancer (Safe, 1994; Ross

et al., 1995). Scientific finding on environmental impact studies have concerned POPs in


Page 3

reproductive and immune dysfunction, endocrine disruption, neurobehavioral disorder and

cancer (Kelce et al., 1995; Kavlock et al., 1996). In children and infants reduced immunity,

infection, neurobehavioral impairment, developmental abnormalities and tumor induction is the

result of POPs contamination. Children are more susceptible to pollutants at developing stages.

Developing cells are very sensitive to the environmental contaminants and easily affected by the

exposure of POPs. Brain is the greatest concern, because during infancy POPs exposed children

scored least on intelligence assessment (Bouwman, 2003). Therefore, cumulative actions of

POPs are addressed in the screening-level risk assessment processes.

Risk assessment is significant for appraising the efficacy of remedial routs and can be

used to set clean-up goals if suitable to implement. Lives standards are designed to ensure the

safety/protection for both terrestrial and aquatic organisms from the hazardous impact of acute

and chronic exposure to persistent chemicals. This criteria is based on toxicity level; and

standardized to protect living organisms from death, stunted growth, reproductive errors, and the

accumulation of hazardous/toxic chemicals in living tissues, and ultimately this may affect up to

the consumer level. Canadian Council of Ministers of the Environment (CCME, 1999), European

Union Directorate (EU, 1999), United State Environmental Protection Agency (USEPA, 2000),

Agency of Toxic Substances and Disease Registry (ASTDR, 2005), Florida Department of

Environment Conservation of America, and some published quality guidelines (Long et al.,

1995; Sun et al., 2010) developed the life criteria as numeric limits on the permissible amount of

chemicals (i.e. heavy metals, organochlorines, other toxic chemicals) that can present in both

aquatic and terrestrial lives.

1.1.1. Stockholm Convention on POPs and Regulatory Mechanism in Pakistan

The Stockholm Convention was held on 12, May 2001, as a results of negotiation started

on 1998 among 100 nations, which was implemented later in 2004. Pakistan became the

signatory member of this convention on 6, December 2001. The Stockholm Convention on POPs

requires all members to stop production and use of pesticides. Initially, twelve toxic chemicals

including, metabolites of organochlorines and PCBs were listed as POPs. Moreever, new nine

POPs were reviewed and listed in the 4th

meeting of Stockholm Convention held on May, 2009.

New listed POPs including industrial chemicals (hexa and heptabromodiphenyl ether,

perfluorooctane sulfonic acid, its salts, hexabromobiphenyl, pentabromodiphenyl ether and


Page 4

tetrabromodiphenyl ether, pentachlorobenzene and perfluorooctane sulfonyl fluoride) and some

byproducts (alpha and beta hexachlorocyclohexane and pentachlorobenzene). In 5th

meeting held

on May, 2011, perties of the conference signed and listed the technical endosulfan and its

isomers as new POP (UNEP, 2009). PBDEs and PCNs have been reviwed in 9th

meeting held on

October, 2013, to declare as POP. Manufacturing of PCB is banned after 6th

meeting and

signatory members are bound to reduce the usage and eliminate the existing stock. Use of DDTs

is constrained to vector control (control for mosquitoes), and is scheduled for eventual removal

as economical substitutes become available. Parties of Stockholm convension are also requied to

control the POPs souces and byproducts to minimize its emission/release. The Treaty also

includes to support developing countries in term of sound finanational as well as technical

support to succor them in employing the commetments with the Treaty.

Manufacturing, import and use of pesticides in Pakistan is regulated by the Agricultural

Pesticides Ordinance 1971, through the Agricultural Pesticide Rules, 1973. However, efforts to

highlight the threats of extensive pesticide usage in agriculture sector are appealing sensation at

global scale. At the same time, anxieties about the deterioration of universal environment are

changing the attitude of nations. The awareness about POPs on global scale brought many

changes in the attitude of Pakistan‟s government and became evident with the endorsement of

Pakistan Environmental Protection Ordinance of 1983 on December 31, 1983; instituted by The

Environmental Protection Council and The Pakistan Environmental Protection Agency (PEPA).

The Environmental Protection Council was established on February 13, 1984 and PEPA was

established on February 6, 1984. Pakistan Environmental Protection Act, 1997 was endorsed in

December 1997 “An Act to provide for the protection, conservation, rehabilitation and

improvement of the environment, for the prevention and control of pollution, and promotion of

sustainable development”. However it is advantageous to provide for the conservation,

protection, improvement and rehabilitation of the environment, prevention and control of

pollution, promotion of sustainable development and for matters connected therewith and

incidental thereto.


Page 5

1.2. Review of Literature

1.2.1. Organochlorines pesticides (OCPs)

Organochlorine pesticides (OCPs) are persistent and toxic chemicals which belong to the

persistent organic pollutants (POPs). They have ability for wide range transportation in the

environment (Park et al., 2011) and bio-accumulation in food crops and animal tissues via food

chain (Nakata et al., 2002). These contaminants are diversified in ecological integrities even in

the primeval ecosystem of polar ice caps (Zhang et al., 2008). Due to the high lipophilic nature

they can accumulate and tend to surpass in animal tissues, resulted in a number of health

problems (Mishra et al., 2005). A variety of carcinogenic, reproductive, neurological,

immunological and other adverse effects have been reported to linked with the exposure of

humans and other living organisms to these chemicals (Sharma et al., 2009; Eqani et al., 2013).

OCP compounds like DDT, HCH, endosulfan and heptachlore are still used for agricultural and

industrial purpose in the developing countries. These hazardous compounds enter into the

freshwater ecosystem through different sources like, domestic and metropolitan effluents,

industrial wastewater, agricultural runoff, atmospheric deposition and some other means (Syed et

al., 2013a; Zhou et al., 2005).

The Stockholm Convention was adopted in 2001 in response to the global concern on

POPs; production, usage and phase out of POPs containing commercial product was banned

(Ahad et al., 2010; Alamdar et al., 2014). Use of these chemicals is still practiced in Pakistan due

to their economic and tranquil availability in the market (Eqani et al., 2013). Despite of these,

Pakistan holds one of the world‟s largest stockpiles of obsolete pesticides, demolished OCPs

formulation factories and dumping sites in the vicinity of the populated cities (Syed et al., 2011).

Besides fastening miserable storage amenities, no legal policy for law enforcement against

illegal practice and proper dumping of banned/obsolete chemicals has been framed till today to

halt this practice (Ahad et al., 2010). Conversely, the obsolete pesticides dumping sites have

been documented as the secondary source for emission of POPs in a tropical environment which

facilitate the long range transportation (regional and global) (Zhang et al., 2009; Dvorska et al.,

2012).

Published reports on OCPs level and distributions in water, soil, sediment and fish

samples from Pakistan are limited (Ahad et al., 2010; Eqani et al., 2011; Eqani et al., 2012;

Eqani et al., 2013). Few specific reports have been published on OCPs contamination load in


Page 6

surface soil and sediments collected from outdated pesticide dumping stores and surrounded

environment (Jan et al., 2008; Ahad et al., 2010; Syed and Malik, 2011; Alamdar et al., 2014;

Syed et al., 2013b). Available reports on the levels of OPCs in air are only two from Pakistan

(Syed et al., 2013a; Alamdar et al., 2014).

1.2.2. Polychlorinated biphenyls (PCBs)

Polychlorinated biphenyls (PCBs) are synthetic chemicals which have been prepared

commercially for various applications (Wright and Welbourn, 2002). PCBs, a group of 209

congeners, are important for concern due to the magnification and bioaccumulation in the food

chain (Morrison et al., 2002). The ecological behavior and toxicological effects of

polychlorinated biphenyls (PCB) are of global concern because these compounds have

detrimental properties: persistence, toxicity and bio-accumulation, harmful to ecological

integrity, wildlife and humans (Guo et al., 2008; Eqani et al., 2012). Human exposure of PCB

may lead to severe effects such as carcinogenic, reproductive, neurological and immunological.

(Wang et al., 2008; Kalyoncu et al., 2009). Long run exposure may affect the liver functioning

and mutation in DNA leading to developmental defects and cancer. PCBs are considered as

„endocrine disrupting‟ chemicals and their exposure may cause thyroid hormone dis-functioning

by reducing serum concentration (Wei et al., 2008).

According to the World Health Organization (WHO), about 1.2 million metric tons of

PCBs were produced world-wide during 1929-1977 (WHO, 1983). Thus, the leakage of

transformer oil during repair, transportation and storage [auctions] of old transformers to

industries are the reasons of PCB contamination (Eqani et al., 2013). PCBs which are similar in

structure and properties to dioxins and furans are called dioxin-like PCBs. Four coplanar PCB

(co-PCBs: CB-77, -81, -126, -169) and eight mono-ortho-PCB (CB-105, -114, -118, -123, -156, -

157, -167, -189) share a common toxic mechanism similar to those of [like] seven

polychlorinated dibenzodioxins (PCDD) and ten polychlorinated dibenzofurans (PCDF) (Van

den Berg et al., 2005).

Industrial and urban areas donate the PCBs to aquatic environment, atmosphere and

ultimately to other environmental matrices from discharge of industrial wastewater to river

linked tributaries, unattended municipal and industrial waste dumping sites (Khawaja, 2003).

PCB congeners have a sturdy attraction with suspended matter particulates in aquatic


Page 7

environment and eventually, sink and accumulate in sediments (Eqani et al., 2012a; Malik et al.,

2011). Many studies have been recently conducted to assess the status of organochlorines (OCs)

in the environments of Pakistan (Syed & Malik, 2011; Eqani et al., 2011, 2012, 2013, Syed et

al., 2013a, b, c, Alamdar et al., 2014; Syed et al., 2014). However, from Pakistan only a few

reports are available on the PCB levels from the environmental compartments (Eqani et al.,

2012; Eqani et al., 2013; Syed et al., 2013c). However, as we know, so far no effort was made to

address the potential risk associated with [via] the consumption of food contaminated by PCBs.

1.2.3. Polychlorinated naphthalene (PCNs)

PCNs (polychlorinated napthalenes) have been identified about 170 years ago and their

commercial production have been started for about 100 years ago (Hayward, 1998), but the

understanding about the occurrence, sources, fate, formulation and impact on life and the

environment is still partial (Brack et al., 2003). PCNs gained aggressive anxiety in the

environmental chemistry, within the last decade (Paasivirta, 1998; Lerche et al., 2002), as these

are widespread environmental contaminants which have been detected from populated areas like

Chicago (Harner and Bidleman, 1997), as well as from remote areas, such as Arctic (Lee et al.,

2007). PCN has bioaccumulative, persistent and potentially toxic properties similar to

dioxin/furans and PCBs (Polychlorinated biphenyls) co-planer compounds. The toxic impacts of

PCNs mixtures are attributed predominantly to penta, hexa and hepta-chlorinated nepthalenes

(CNs), which exhibit dioxin like special effects on human and animal liver cell lines

(Blankenship et al., 2000; Villeneuve et al., 2000). Their properties are enough to meet the

persistent organic pollutants (POPs) criteria, and therefore, were targeted as the contenders of

POPs by United Nations Economic commission for Europe (UNECE) in 1998 (Lerche et al.,

2002) and United Nations Environment Program (UNEP). Recently, PCNs are under review by

Stockholm Convention as a contender of POPs (Wang et al., 2011). Global production of PCNs

has been estimated about 150,000 tons (Falandysz, 1998).

The historical application of a technical mixture as insulator and coolant for thermal

stability, combustion processes like metal refining and incineration, wood and coal burning, and

various PCB-associated applications may discharge PCN into the environment (Lee et al., 2007).

Commercial production of technical PCN mixture is under the title of Halowax (America) and

Nibren wax (Germany) for aroclor PCBs (polychlorinated biphenyls) like applications (Jarnberg


Page 8

et al., 1997). Various industrial processes are identified for PCNs emissions, which are also in

favor to PCDDs and PCDFs formation (Brack et al., 2003). Industrial units, including chloralkali

industry, waste incineration plants, magnesium production and copper smelting units are

responsible for PCN emission (Kannan et al., 1998). Global production of PCNs has been

estimated about 150,000 tons (Falandysz, 1998).

There is a scarcity in information on PCN usage and emission in South Asia. Lee et al.

(2007) launched a global monitoring program, but the region of South Asia was excluded. In

India and Pakistan, the industrial and agricultural sector contributes about 26.7% and 25.4%,

respectively, to the overall GDP (Xu et al., 2014). Coal combustion is a major source of PCN

emission; in India and Pakistan coal consumption rate is very high and India ranked third in the

world (Xu et al., 2014). PCN emission by those processes is transmitted even in the remote areas

due to the monsoon outbreaks and high temperature in South Asian countries. Though, PCN

have been banned since 1977, but still observed in air and soil (Jaward et al., 2004; Nadal et al.,

2007; Wyrzykowska et al., 2007; Mari et al., 2008; Wang et al., 2012 a, b; Hogarh et al., 2012).

The published data on PCN levels and distribution is scarce in South Asia, recently a report has

been published on PCN monitoring in atmosphere from India and Pakistan (Xu et al., 2014).

However, there is no published report available from Pakistan on distribution, screening level

risk assessment and bioaccumulation of PCN in environmental compartments and food crops.

1.2.4. Polybrominated diphenyl ethers (PBDEs) and Dechloran plus (DP)

Over the few past decades demand for flame retardants (FRs) have increased vividly due

to the growing usage of plastic and electronic components in homes and offices as well as in the

textile industry for the sake of safety standard. FRs have venomous effects on wildlife and

humans, and have been repeatedly reported from the environment (de Wit. 2002; Watanabe and

Sakai, 2003). Polybrominated diphenyl ethers (PBDEs), the members halogenated flame

retardants are bioaccumulative, persistent, potentially toxic and universal compounds in the

environment (Ismail et al., 2009; Malik et al., 2011). These compounds are used as additive

flame retardants in several industrial products such as electronic goods, polyurethane foam,

plastics, textiles and building materials, to avert the development of fire (Wilford et al., 2004;

Syed et al., 2013). Technical PBDE mixture includes three commercial products; penta-BDE,

octa-BDE and deca-BDE. Among these, penta-BDE and octa-BDE have been reported for severe


Page 9

effect on human health like neurotoxicology, carcinogenicity and endocrine disruption (Costa

and Giordano, 2007). PBDEs are more lipophilic, bioaccumulative, toxic and persistent in nature

due to their complex degradation by debromination and share these structural and

physiochemical traits with PCBs, DDTs and their metabolites (Stapleton et al., 2006). In

Canada, Europe, America and Japan these flame retardant compounds have been regulated, but

the commercial mixture of deca-BDE is most widely produced and still used in the rest of the

world (Malik et al., 2011). Such banned flame retardants are probable to be substituted by non-

regulated Dechloran Plus (DP).

DP (dechlorane plus) was introduced as the surplus of dechloranes, known as Mirex, in

the 1960s by the group of Hooker Chemicals (Hoh et al., 2006). Rather than the long commercial

history, DP have been found in the environment. DP is a flame retardant and highly chlorinated

that integrated in cables, electric wires and connectors coating (Qiu et al., 2007). Though it has

been used for decades, but still recently a little attention has been paid when DP was detected in

soil, sediments, fish and air of far-flung areas near the Great Lakes and in the bark of trees from

the US, which signified their potential for long distance transmission/transport (Hoh et al., 2006;

Tomy et al., 2007; Qui et al., 2007; Qiu and Hites, 2008; Sverko et al., 2008, 2010; Gauthier and

Letcher, 2009). Only a few studies on DP contamination in the environment and source

identification have been conducted in Asia till now. In China, DP in air (Ren et al., 2008; Ma et

al., 2009, 2011; Yu et al., 2011), aquatic species (Luo et al., 2009), soils (Wang et al., 2010a, b;

Yu et al., 2010; Ma et al., 2011) and human serum (Ren et al., 2009) has been detected.

FRs can enter into the food web via different environmental media and these media

receive FRs during their production, use, disposal and recycling processes as well as from

volatilization and leaching (Chen et al., 2007). The number of reported studies on levels,

distribution and transportation of PBDEs and DP in air and soil from China is increasing day by

day (Chen et al., 2006a,b; Chen et al., 2009; Zhang et al., 2009; Jiang et al., 2010; Wang et al.,

2011). However, the data on PBDEs and DP occurrence and distribution in food chain is scarce

throughout the world. In other Asian countries scarcity of data regarding to the occurrence of

flame retardants in environmental compartments is observed (Zhang et al., 2008). In Pakistan,

only one report has been published recently on levels and distribution of PBDEs and DP in air

and soil (Syed et al., 2013). However, there is no data available for risk assessment, levels and

distribution of PBDEs and DP in food stuff from Pakistan.


Page 10

1.3. Pesticides use in Pakistan

Chemical pesticides are used in Pakistan since centuries. However, the use of agro-

chemical pesticides has been started since 1954 with 254 MT (metric tons) formulations and its

consumption increased over 7000 tons/annum. Pesticides consumption increased to 16,226 MT

in 1976–77 and the graph jet every year, reached to a maximum of 20,648 MT in 1986-87

(Baloch, 1985), and further increased up to 78,132 tons per annum (Syed and Malik, 2011).

Khan et al. (2002) reported, that 100 times increase in pesticide use has been observed in

Pakistan during 1980-2002. Before 1971, peptides import and distribution was regulated by the

Plant Protection Department (DPP), Federal Government of Pakistan. The rules for agricultural

pesticides and the agricultural pesticides ordinance (APO) were publicized in 1971 and 1973.

APO standardized the import, sale, formulation, distribution, registration and regulation of

pesticides in Pakistan (Mazari, 2005). In 1980, the business of pesticides was reassigned to

private sector from the public sector with the agreement “the pesticides available in government

stock will not be imported until they are exhausted”. This brought a steady increase in the

pesticide consumption (about five-fold increase). During 1980 to 1992 pesticides consumption

was increased from 906 MT to 5519 MT, at the rate of 25% increase/year. Pesticide corporations

inspired the agriculturalists to practice the extra dose for crops, via media crusade. Increase in

sprayed area from 1.8 million hectare to 3.8 million hectare (18% increases in total agricultural

area) was observer and higher concentration of pesticides in different crops were found (Tariq,

2005). It is not surprising that insecticides are the most used pesticides in Pakistan (74%)

followed by herbicides (14%), fungicides (9%), acaricides (2%) and fumigants (1%). Almost

69% of total pesticides in Pakistan are applied on the cotton crop; rest of pesticides are used for

others; like maize, wheat, rice, etc. (Economic Survey of Pakistan 2005-2006). At present, about

108 kinds of insecticides, 39 kinds of weedicides,30 kinds of fungicides, six different kinds of

rodenticides and five kinds of acaricides are being practiced in th country (PPSGDP, 2002).

During the last two decades, pesticides usage in Pakistan has increased by 1169% and number of

sprays have reached to 10/crop that is drastic hazard to human health (Technical Bulletin, 2000).

The results of previously published studies for biota and environmental compartments from

different area of Pakistan are summarized in Table 1.1. (a, b,c).


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1.4. Problem Statement

Pakistan is among those few countries, which have been struggling to develop its

industrial as well as the agricultural sector. Rapid urbanization and undiscerning industrialization

have created numerous environmental issues relating to the ecological integrities. About 80% of

the industrial growth is restricted to major cities like Karachi, Lahore, Hyderabad, Multan,

Faisalabad, Gujranwala, Sialkot, Rawalpindi, Peshawar and Kasur (Aftab et al., 2000). Besides

of this, rural areas have agricultural lands which are under catholic use of pesticides and

fertilizers that marks the way to rivulets and rivers via surface runoff along with the uptake by

plants. About 1% of the total land cover area is occupied by the urban settlements; contributing

48% of GNP (Gross National Productivity) and about 80%of industrial business (Khan, 1996).

Urban centers of Pakistan are growing briskly, and putting a stress on natural resources.

Untreated urban and industrial effluents and wastewater continuously discharge into the rivulets

and rivers, due to which the water quality of riverine ecosystem is promptly getting deteriorated.

Pakistan is facing water scarcity due to the high population pressure (World Bank, 2005), and

water shortage is estimated over 40 MAF (million acre feet) that will increase over 151 MAF by

year 2025 (Mirjat and Chandio, 2001). Industrialization and rapid urbanization has resulted large

amount of wastewater which is used as a valued source of irrigation in urban and sub-urban

areas. Although this may provide economic benefits to support livelihood, especially poor

farmers, but significantly deteriorate quality and ecological integrity of water bodies (Marshall et

al., 2007). Continuous irrigation of the soil with contaminated water; reduce capacity of soil to

retain toxic chemicals, which percolate into the ground water and also soil minerals that are

available for plant uptake (Chary et al., 2008).

In this study catchment area (an important agricultural belt) along two upstream feeding

tributaries of the River Chenab namely Aik and Palkhu streams [stream locally called [as]

Nullah], located in Sialkot and Gujranwala districts, Punjab Province, Pakistan was given prime

importance. Gujranwala and Sialkot are the 7th

and 9th

, respectively, largest cities situated in the

north east of Punjab Province, Pakistan (Ghani, 2000). These cities are in the grip of pollution

problem since last three decades, which are posing threat to the environment, triggered by

industrial sector (Mehdi, 2005). According to an estimate a total of 3,229 industrial units,

including, 264 tanneries and 220 surgical instruments producing factories, 120 chemical and

electroplating units, transformer repairing units, rubber industries have been reported, working in


Page 12

the vicinity of the study area (Anonymous, 2006; Khan and Mahmood, 2007). According to an

estimate, Sialkot city generates 1503 gallons/day of wastewater that is directly discharged into

Nullah Aik and Palkhu (Randhawa, 2002). A total of 52 million liters per day of wastewater

along with 1.1 million tanneries, chemical, surgical, electroplating, the transformer repairing

workshop generated waste is discharged into Ail and Palkhu tributaries (Plate 1.1), which

influence the biological, physical and chemical characteristics of these streams (EM Research

Organization, 2002; Anonymous, 2006). Few stockpiles of organochlorine pesticides holding

thousands kilogram of pesticides, are located in the catchment area of Nullah Aik and Plkhu

(Malik et al., 2011).

Nullah Aik and Palkhu, the most important surface water resources in the study area are

more vulnerable to venomous effects of toxic chemicals in industrial and municipal effluents

without proper treatment. In the past, these Nullahs were used a resource of domestic, irrigation

as well as drinking water (Qadir et al., 2008). However, at present no wastewater treatment plant

has been established to treat the industrial effluents and sewage before draining into Nullah Aik

and Nullah Palkhu and ultimately, these river tributaries are gradually turning into municipal and

industrial drains. Catchment area along Nullah Aik and Palkhu is facing the population pressure

of 2.5 million people. This area is an important agricultural belt of Sialkot and Gujranwala

districts, famous all over the country for rice and wheat production. Wheat and rice cultivated in

the catchment area of Nullah Aik and Nullah Palkhu are irrigated by the wastewater pumped

from tributaries of the River Chenab. Along the banks of these streams, hundreds of pumps are

used to suck the polluted wastewater and used for irrigation to the long distanced cropland (Plate.

1.2). Wheat (Triticum aestivum L.) and rice (Oryza sativa L.) are consumed as food at large scale

in the study area and also traded to the other parts of the country due to their best quality and

palatable values. People, who consume food crops cultivated in the study area, may be highly

vulnerable to the toxic effects of pollutants. Notwithstanding with agricultural importance of this

area, Nullah Aik and Nullah Palkhu, upstream feeding tributaries of the River Chenab, Pakistan

have never been studied in detail for the screening level risk assessment, occurrence and

distribution of persistent organic pollutants like OCPs, PCBs, PCNs, PBDEs and DP. Keeping

in view the environmental problems and health hazards to ecological integrity and human, this

research project was designed to presents for the first time levels of the aforesaid compounds and


Page 13

discriminates spatial trends of distribution, source apportionments, risk assessment, long-

distance/range transportation and environmental re-cycling.

1.5. Objectives

This study has been conducted on following main objectives

To assess the spatial distribution trends, sources and contamination load of POPs in the

cereal crops and environmental compartments

To evaluate the occurrence, finger printing and source apportionment of POPs in the

cereal crops and environmental compartments

To investigate risk assessment and dietary exposure of POPs through cereal crops

To develop a baseline data for investigated POPs in the cereal crops and environmental

compartments of Pakistan

1.6.Structure of Thesis

This research thesis is divided into four chapters; each of them is focusing on the specific

objectives in details.

Chapter 1 describes the general introduction of POPs, regulatory mechanism of POPs, status of

POPs in Pakistan, review of literature and discuss problem of the statement.

Chapter 2 describes the details of the study area, research and sampling strategies and analytical

approaches to extract and analyze the targeted POPs (OCPs, PCBs, PCNs, PBDEs and DP) from

environmental compartments and cereal food crops. This chapter also provides the details of

statistical analysis and indices to see the actual picture of contaminants in order to the

environment and human health.

Chapter 3 provides the discussion on results obtained and further consisted of four parts:

Part 1 presents the levels, distributions and screening-levels risk assessment of organochlorines

pesticides (OCPs) in the cereal crops and environmental compartments along two tributaries of

River Chenab, Pakistan.

Part 2 highlights polychlorinated biphenyls (PCBs) in environmental compartments and cereal

crops along the two tributaries of River Chenab, Pakistan: Concentrations, distribution and

screening level risk assessment.


Page 14

Part 3 explains the PCNs (polychlorinated napthalenes): dietary exposure via cereal crops,

distribution and screening-level risk assessment in wheat, rice, water, sediment, soil and air

along two tributaries of the River Chenab, Pakistan.

Part 4 describes congener specific analysis, distribution pattern and screening-levels risk

assessment of polybrominated diphenyl ethers (PBDEs) and dechloran plus (DP) in the cereal

crops and environmental compartments from two tributaries of the River Chenab, Pakistan.

Chapter 4 concludes the findings of the research with general discussion on whole thesis along

with the recommendations and future prospective.


Page 15

Plate 1.1: Discharge of industrial effluents into Nullah Aik and Nullah Palkhu in midstream zone

Plate 1.2: Wastewater irrigation system through pumps at Site 9 and 13


Page 16

Table 1.1 (a): Contamination load of POPs (ng g-1

) in sediment and soil samples collected from Pakistan

Sampling stations ΣHCHs ΣDDTs PCBs PBDEs & DP PCNs References

Coastal area, Karachi

(Sediments) 1.1-3.5 2.7-9.2 -- -- --

Bano and Siddique,

1991

Cropland Soils -- 0-2.0 -- -- -- Jabbar et al., 1993

Degh Nullah, Lahore

(Sediments) Traces 62-2041 Traces -- -- Tehseen et al., 1994

Haleji Lake Thatta, Sindh

(Sediments) -- 0-6.5 Traces -- -- Sanpera et al., 2002

Taunsa barrage (Sediments) -- -- 0.3-0.9 -- -- Sanpera et al., 2003

Rawal Lake, Islamabad

(Sediments) 0-19.5 0-42.2 -- -- -- Malik et al., 2011

River Chenab (Sediments) 0-9.2 0-17.7 -- -- -- Malik et al., 2011

River Ravi (Sediments) 0-8.3 0-24 -- -- -- Malik et al., 2011

Kala Shah Kaku (Soil) 0-119 0-206 -- -- -- Syed and Malik, 2011

River Chenab (Sediments) 2.06-18.15 7.6-60 9.33-144 -- Eqani et al., 2011,

2012a

Gujrat (Indoor dust) 0.4-26.5 1.8-975 0.3-6.10 BDE-209: 2-1465 -- Ali et al., 2012

Selected districts, Punjab

(Soil) 7.8 40 7-45 40 -- Syed et al., 2013 a, b, c

Selected districts, Punjab

(Sediments) -- -- -- 640 --- Syed et al., 2013d

Hyderabad City, Sindh

(Soil) 43-4090 77-212200 -- -- -- Alamdar et al., 2013


Page 17

Table 1.1 (b): Contamination load of POPs (ng L-1

) in water samples collected from Pakistan


Karachi, River Surface

water Traces -- -- -- --

Parveen and Masud,

1988

Faisalabad, Shallow

ground water -- -- -- -- -- Jabbar et al., 1993

Multan, Ground water 0-0.11 -- -- -- Ahad et al., 2010

Punjab districts, Ground

water -- 0-0.86 -- -- -- Asi et al., 2008

Nowshera, Surface and

ground water -- 70-400 -- -- -- Jan et al., 2008

Obsolete Pesticides site,

Surface and ground

water

0.125

0.05

--

--

-- Ahad et al., 2010

Rawal Lake, Islamabad,

Surface water -- 1.6 -- -- -- Iram et al., 2009

River Chenab, Water 3.0-330 0.55-580 7.7-110 ---- -- Eqani et al., 2012b


Page 18

Table 1.1 (c): Contamination load of POPs (ng g-1

) in biota samples collected from Pakistan


River Ravi Heronry, Cattle

egrets 344±9

73.4±27.4 -- -- -- Malik et al., 2011

River Chenab Heronry,

Cattle egrets 239±84

60.7±34 -- -- -- Malik et al., 2011

Rawal Lake, Heronry,

Islamabad, Cattle egrets 115±19 73.1±29 -- -- -- Malik et al., 2011

Punjab, Little egret -- -- -- PBDE: 2.41

(median) -- Malik et al., 2011b

Punjab, Cattle egret -- -- -- PBDE: 2.41

(median) -- Malik et al., 2011b

Haleji Lake, Little egret 170.5 (G.M) 728.3 (G.M) 1.4 (G.M) --

-- Sanapera et al., 2003

Taunsa Barrage, Little egret 85.4(G.M) 2943.4 (G.M) 100.4 (G.M) -- -- Sanapera et al., 2003

Ghas Bandar, Karachi,

Little egret 44.7 (G.M) 4203.4 (G.M) 4203.8(G.M) -- -- Sanapera et al., 2003

Chapter 2: Materials and Methods

Page 19

Chapter 2

Materials and Methods

2.1. Study area

The study area lies in the Punjab Province which is the most populated province of

Pakistan having about 56% of the total population of the country. Punjab, the second largest

province of Pakistan, covers an area of 205,344 km2

and situated at the northwestern geological

Indian plate in South Asia. Gujranwala and Sialkot are the 7th

and 9th

largest cities, located in the

north-east of Punjab Province, Pakistan (Ghani, 2000). The current research was conducted

along Aik and Palkhu Nullahs (stream; locally called [as] Nullah), two upstream feeding

tributaries of the River Chenab, which pass from district Sialkot and Gujranwala (Fig. 2.1).

Nullah Aik (32°63 N-74°99 E and 32°45 N-74°69 E) and Nullah Palkhu (32°69 N-74°99 E and

32°37 N-74°02′E) originate at an altitude 530 m and 290 m, respectively, from Lesser Himalayas

in the Jammu Province, Kashmir. Nullah Aik and Nullah Palkhu cover a stretch of about 229.6

km (131.6 km and 98 km) before falling in the River Chenab, and drain approximately 1,875

km2 catchment areas (agricultural fields). The catchment area of both the Nullahs consist urban

areas of Sialkot city along with many towns viz, Ugoki, Simbrial, Bhopalwala, Begowala, Sodra

and Wazirabad city (part of Gujranwala district). Sialkot is situated along the mid-streams while

Wazirabad city is along down-streams of both these Nullahs (Fig. 2.1).

The study area has sub-tropical type of climate with extreme summer season (April-

September). The hottest months are usually May and June with maximum temperature of 48 °C,

sub-humid and harsh weather conditions. Summer season ends with the arrival of monsoon

rainfall in the end of July or start of August. Winter season starts from November and ends in

March; temperature range from 2 to 20 °C. Land of the study area is generally plain and fertile.

Average annual rainfall in the study area is about 1000 mm, of which maximum precipitation

(80%) occurs in the monsoon season. The average annual water discharge by Nullah Aik and

Palkhu is estimated as 315 Cs/second and 288 Cs/second, respectively (Qadir et al., 2008).

Population density estimated by the Population and Censes Organization (2011), of the

catchment area of both the Nullahs is about 903 persons/km2, which make it the populous area of

the country (SCN, 2013). Land in catchment area is used for agricultural purposes particularize,


Page 20

rice and wheat crops. However, fodder crops and vegetables are also cultivated extensively to

meet the local demand. Wastewater irrigation, use of agro-chemicals (pesticides, fertilizers) and

soil improving agents is a routine/common practice in the catchment area. Two obsolete

pesticide dumping stores (Simbrial and Wazirabad) are also located in the catchment area of

mid-streams and down-streams of Nullah Aik and Nullah Palkhu. After heavy rainfall or by

extensive irrigation, these chemicals make their way to agricultural fields and river tributaries. In

the catchment area the irrigation source is wastewater of Nullah Aik and Palkhu, used by

pumping (countless pumps have been recognized along both these Nullahs) or diversions of

wastewater tributaries into small distribution channels (common in mid-stream zone) (Plate 2.1

& 2.2).

2.1.1 Sampling strategy

The study area was divided into three zones; up-stream zone, including sites S8, S9, S10

and S11, midstream zone (S6, S7, S12 and S13) and down-stream zone (S1, S2, S3, S4, S5 and

S14). A total of fourteen sites (S1-S14) were sampled in the study area, from which S1 and S2

were located on the River Chenab (Fig.2.2). The zonation was thru on the basis of origin of these

streams (locally called [as] Nullahs). The upstream zone was defined as purely rural and

agricultural area. The midstream zone consists of urban/industrial area receiving urban and

industrial wastewater from the Sialkot city. The down-stream zone is located at down-stream of

Nullahs, which are passed from urban and peri-urban areas of Sialkot and Gujranwala districts

(Fig.2.3).

Within the fourteen sites that were marked for sampling of the environmental

compartments (water, sediment, soil and air) and cereal crops along the Nullah Aik and Palkhu,

River Chenab tributaries, six sites (two in each zone) were selected for the deployment of

polyurethane foam-passive air samplers (PUF-PAS). All samples; soil, sediment, water, air,

wheat and rice, were collected during the period from November, 2012 to June, 2013. Among

fourteen sampling sites, twelve sites were located along Aik and Palkhu Nullahs and two sites

were on the River Chenab.

The criteria for sites selection was based on the anthropogenic activities along the

catchment area of the study area, variation in habitat, presence or absence of solid and electronic

waste dumping sites and availability of food crops fields and their accessibility. Sites selection


Page 21

for soil, wheat and rice sampling were also based on Nullah Aik and Nullah Palkhu wastewater

irrigation system while air sampling sites were selected based on agricultural and industrial

activities in the study area.

2.2. Field sampling

2.2.1. Air sampling

Polyurethane foam-passive air samplers (PUF-PAS) were used in this study. Each PUF-

PAS consisted of pre cleaned and weighted PUF (thickness: 1.35 cm, diameter: 14 cm, density:

0.0213 gm cm-3

), was adjourned at the midpoint of two stainless steel domes (Fig. 2.2). The

design and development of PUF-PAS (Fig. 2.4) have been described in detail by Jaward et al.

(2005). Concentration of PCN was appropriated over the sampling duration and was converted to

estimate levels of air considering sampling rate of 3-4 m3 of air/day. Finally, standard value of

3.5 m3 per day for OCPs, PCBs, PCNs and PBDEs while 0.5 m

3 per day for DP was used for

previously reported calibration studies against active samplers (Shoeib and Harner, 2002; Ren et

al., 2008; Muenhor et al., 2010).

The samplers were deployed at six different locations (two in each sampling zone). The

PUF disks were pre-cleaned with DCM (dichloromethane) and acetone. Transportation blank

PUF disks were retained sealed during sampling trip and labeled properly with dates of the

sampling period. Field blank PUF disks were transported to the respective sampling site and

opened for about five minutes and closed tightly by sealing the glass jar lid with paraffin. Each

PUF-PAS were assembled and deployed at the sampling sites for a period of two months. The

PUFs were retrieved, sealed and transported to the State Keys Laboratory of Organic

Geochemistry, Guangzhou Institute of Geochemistry, Guangzhou (SKLG, GIG), China where

stored at -20 °C until further analysis.


Page 22

Table 2.1: Detail description of sampling sites along with the location and weather information

Locations Site

Codes Latitude Longitude Temperature

°C

Humidity

%

Survey

Condition Description of sampling sites

River Chenab

near Thaliwala S1 32.48995 74.12828 19 48 Partly

cloudy

Peri-urban and agricultural area located along the River

Chenab

Tahli da Kot S2 32.34679 73.80697 18 49.8 Partly cloudy

Peri-urban and agricultural area located along the River

Chenab

Pkaloki S3 32.4061 74.00532 18 37 Partly cloudy

Agricultural, peri-urban, partially industrial area located

near Wazirabad City

Wazirabad city S4 32.45512 74.14216 19 24 Sunny Urban, industrial, agricultural area of Wazirabad City

(one obsolete pesticide dumping site present in

Wazirabad city)

Sodra city S5 32.46355 74.235 21 33 Sunny Peri-urban, agricultural area situated along Nullah Palkhu near Simbrial City

Chitti Shaikhan

Sialkot S6 32.53001 74.48247 20 28 Sunny Urban, industrial, agricultural area situated along Nullah

Palkhu, Sialkot city

Sialk city S7 32.5268 74.51575 20 31 Sunny Urban, industrial, agricultural area situated along Nullah Palkhu, Sialkot city

Kaseery S8 32.56231 74.63331 18 37.6 Partly cloudy

Rural, agricultural area located along Nullah Palkhu

Sagr Pur S9 32.63069 74.64659 19 40 Partly cloudy

Rural, agricultural area located along Nullah Palkhu

Jhonji S10 32.50291 74.68338 19 41.7 Cloudy Rural, agricultural area located along Nullah Aik

Baba Faiz Shah S11 32.48863 74.59693 19 29 Sunny Rural, agricultural area located along Nullah Aik

Sialkot city S12 32.48735 74.55692 20 31 Sunny Urban, industrial, agricultural area located along Nullah Aik, Sialkot city

Bhuttr, Sialkot city S13 32.46279 74.4855 20 36 Sunny Urban, industrial, agricultural area located along Nullah Aik, Sialkot city

Koat Shah

Muhammad S14 32.43013 74.35017 20 27 Sunny

Peri-urban, agricultural area along Nullah Aik located

near Simbrial City (one obsolete pesticide dumping site

present in Simbrial city)


Page 23

Figure 2.1: Map showing location of the study area along with the population pressure


Page 24

Figure 2.2: The study area map, displaying the sampling strategy


Page 25

Figure 2.3: Map showing the allocated zones and sampling locations along with the possible pollution sources


Page 26

Figure 2.4: Schematic representation of passive air sampler

2.2.2. Surface soil sampling

A total of twenty eight composite surface soil samples were collected from fourteen

sampling sites (depth 0-20 cm) in the study area. Samples were collected from cereal crop fields

irrigated by the water from Nullahs. Two samples were collected from each site and ach sample

was a composite of five sub-samples, collected exactly from the field, from where cereal crops

were collected. Surface soil was thoroughly mixed and transported to the Environmental Biology

and Ecotoxicology Laboratory (EBEL), Department of Plant Sciences, QAU, Islamabad. Soil

samples were freeze dried, sieved via 2 mm sieve and transported to the SKLG, GIG, China,

where stored at -20 ᵒC until further analysis.


Page 27

2.2.3. Water sampling

Water samples were collected (n=28) from 14 selected sites of two tributaries of the river

Chenab during January-March 2013. Each sample was the composite (over 500 m stretch) of five

sub-samples, collected from a depth of about 2-3 m below the top surface of water in 5 L pre-

cleaned (washed with organic solvent) sampling jars. After collection, samples were placed in

ice containing cooler and transferred immediately to the EBEL, QAU, Pakistan. In laboratory

water samples were filtered with glass wool to remove debris and other small particles and

finally stored in -8 °C until further analysis.

2.2.4. Sediment sampling

Sediment samples were collected (n=28) from the bottom of streams of each site. Two

surface sediments were collected from each sampling site including one upstream and one

downstream sample from respective site. Each sample was composite of 5 subsamples collected

over a stretch of 500 m across both banks of streams and stored in a polythene bags (Fig. 2.2).

Samples were transported to the Environmental Biology and Ecotoxicology Laboratory, QAU,

where samples were freeze dried, sieved via 2 mm sieve, transported to SKLG, GIG, China, and

stored at -20 ᵒC until further analysis.

2.2.5. Wheat and rice sampling

Rice and wheat grain samples (n=28 for each cereal type) were collected from their fields

during harvesting seasons. Two samples were collected from each site over an area of 2x2 km

and each sample was the composite of 5 subsamples collected from different locations of

respective site (Fig. 2.2). Each composite sample was mixed and kept in polythene bags after

proper labeling. Samples were transported to the SKLG, GIG, China, where stored at -20 ᵒC until

analysis.

2.3. Experimental section

2.3.1. Extraction and cleanup procedure

All the soil, wheat, rice (20 g used for each sample) and PUF samples were Soxhlet-

extracted for 24 h with DCM. Water samples were extracted through separating funnel following

the liquid-liquid extraction technique. Before extraction water was filtered via Whatman 42


Page 28

filterpaper to remove the suspending particles or small debris. 1L of filtered water was mixed

with the 25-35 ml of DCM and shacked thoroughly for 2 minutes and stayed for 10 minutes to

get two layers (Li et al., 2007). A lower transparent layer of organic solvent containing

chlorinated pollutants was collected on anhydrous Na2SO4. A mixture of surrogate standards

[TCmX (2,4,5,6-tetrachloro-m-xylene) and PCB-209 (decachlorobiphenyl)] was added to every

sample prior to extraction (Zhang et al., 2008b). To remove the elemental sulfur, activated

copper granules were added into to the solvent in collection flask. The extracts were

concentrated through rotary evaporated and solvent phase was exchanged to hexane (hexane

obtained from Merck and Co., Inc.). Cleanup/purification was obtained through alumina/silica

column (an 8 mm i.d. glass column), packed from the bottom to top, with neutral alumina (3 cm,

3% deactivated), neutral silica gel (3 cm, 3% deactivated), 50% sulfuric acid silica (3 cm), and

anhydrous sodium sulfate (1cm). The column was eluted with 50 ml of DCM/hexane (1:1) (Li et

al., 2008). Column packing ingredients i.e. neutral alumina, neutral silica gel, and anhydrous

sodium sulfate were washed with DCM through Soxhlet-extraction assembly for 48 h, baked at

450 °C for 10-12 hours. Purified fraction of solvent was further subjected under gentle nitrogen

stream to concentrate upto 0.2 ml after adding dodecane (25 μl) as solvent keeper. A known

quantity internal standard (of PCB-54) was added was added, prior to GC-MS analysis (Xu et al.,

2014).

2.3.2. Chromatographic analysis

2.3.2.1. Organochlorines pesticides (OCPs)

OCPs including DDTs, HCB, HCHs, chlordane, mirex, heptachlor and endosulfan were

detected in all samples via GC-EI-MS. CP-Sil 8 CB. 50 m, 0.25 mm, 0.25 µm column was used

to detect OCPs by GC-EI-MS (Varian). Temperature of the injector was 250 °C. Initially,

temperature of the oven was set as 150 °C for 3 minutes and then temperature raised up to 290

°C at the rate of 4°C/minute and held for 10 minutes. Isomers of OCPs were identified with three

fragment ions in SIM mode (selective ion monitoring) with EIS (electron impact spectrometry).

The MSD source temperature was 230 °C and quadruple temperature was 150 °C (Li et al.,

2007).


Page 29

2.3.2.2. Polychlorinated biphenyls (PCB)

Thirty three PCB congeners, specifically PCB-8, -28, -37, -44, -49, -52, -60, -66, -70, -

74, -77, -82, -87, -99, -101, -105, -114, -118, -126, -128, -138, -153, -156, -158, -166, -169, -170,

-179, -180, -183, -187 and -189 were analyzed by GC-MS. Varian, CP-Sil 8 CB. 50 m, 0.25 mm,

0.25 µm column was used. The temperature of the injector was kept at 250 °C throughout. The

temperature program of the oven was as follows: 150 °C for 3 minutes and then temperature

raised up to 290 °C at the rate of 4°C/minute, isothermal hold for 10 minutes. The congeners of

PCB were identified on the basis of three fragment ions in SIM mode (selective ion monitoring)

with EIS (electron impact spectrometry). Temperature of MSD source and quadruple was 230 °C

and 150 °C, respectively.

2.3.2.3. Polychlorinated naphthalene (PCN)

PCN including: CN-14, -15, -16, -17/25, 19, -24, -23 (tri-CNs), CN-27/30, -32, -

33/34/37, -35, -38/40, -39, -28/43, -36/45, -46, -47 (tetra-CNs), CN-49, -50, -51, -54, -52/60, -53,

-56 -57, -58, -59, -61, -62, (penta-CNs), CN-63, -64/68, -65, -66/67, -69, -71/72 (hexa-CNs),

CN-73, -74 (hepta-CNs), CN-75 (octa-CN), were detected through Agilent 7890A GC-ECNI-MS

(gas chromatography electron capture negative-ion mass spectrometry) in selected ion

monitoring (SIM) mode. A DB5-MS (30 m × 0.25 mm i.d. × 0.25 μm film thickness) column

was used to separate the PCN compounds. The initial oven temperature was set at 80°C for 0.5

min, 15 °C/min to 160 °C, 3 °C/min to 240 °C, and 6 °C/min to 270 °C for 10 min. The MSD

source temperature was 230 °C and quadruple temperature was 150 °C (Xu et al., 2014). The

comparative contribution of each Halowax 1014 congener, has already been reported (Helm and

Bidleman, 2003). Halowax 1014 (a technical mixture of PCN) was used as quantification

standard.

2.3.2.4. Polybrominated diphenyl ethers (PBDEs) and Dechloran plus (DP)

GC-MS was used to determine 8 BDE congeners (BDE-28,-35, -47, -99, -100, -153, -

154, -183) and DPs. GC-MS (Agilent GC 7890 coupled with 5975 MSD) was equipped with the

DB5-MS capillary column (30 m * 0.25 mm i.d.; 0.25 µm film thickness). For MSD source and

quadruple temperature were all set to 150 °C.


Page 30

2.4. Quality control and quality assurance (QC/QA)

A quality control procedure was strictly followed for the entire analysis [sample] to

ensure the quality of results. Calibration standards were used daily for instrument calibration.

Analytical grade chemicals were used during the experimentation, purchased from MERCK,

Germany. Field, procedural and solvent blanks were analyzed according to the methodology,

used [adapted] for [original] the samples. Glassware was double washed with deionized distilled

water and baked at 450 °C for >6 hours. Agilent MSD Productivity Chemstation software was

used for data acquisition and processing. MDLs (method detection limits) were estimated as the

mean values of blanks plus three times standard deviation of blank readings. IDLs (instrumental

detection limits) were assimilated when the signal to noise ratio was equal to 3 and it ranged

between 0.01-0.09 ng sample-1

. MDLs (method detection limits) ranged between 0.02- 0.1 pg m-3

for air and 0.03-0.1 pg g-1

for water, sediment, soil, wheat and rice samples. Surrogate recoveries

in all samples for TCmX ranged between 52.8% and 77.3%, average recovery for PCB-30, PCB-

198 and PCB-209 was 84 ±9 %, 78±8% and 87±13% respectively and recovery for 13C-trans-

Chlordane ranged between 73-87%. In case of PBDEs and DP, MDL was calculated by USEPA

method 5055. MDLs for PBDEs ranged from 2 to 6 pg g-1

for water, sediment, soil, wheat and

rice samples and MDL for air samples ranged between 0.1-3.9 pg m-3

(Syed et al., 2013).

Average surrogate recoveries in all samples for TCmX ranged between 53-68% and average

recovery for PCB-209 was ranged between 77-81%. Reported concentration are blank, but not

by the surrogate recoveries. A standard of 5, 10, 20, 50, 100 and 200 μg L-1

was used to quantify

the calibration curves.

Standards were purchased from Dr. Ehrenstorpher GmbH, Germany.

2.5. Statistical analysis

2.5.1. General statistical analysis

Basic descriptive statistics was performed by using a statistical software SPSS (ver. 12)

and for proportion, percentage composition and graphical representation of contamination load in

the cereal crops and environmental compartments collected from allocated zones of the study

area, Microsoft excel 2010 (Microsoft Corporation 2007) was used.


Page 31

Arc-GIS software version 9.3 was used for the spatial distribution pattern of OCP, PCB,

PCN, PBDE and DP at sampling sites of the study area.

Analysis of variance (ANOVA) was performed by using Statistica version 5.5 (Stat Soft,

Inc. 1999) among rural, urban and peri-urban land use types to determine the difference of

persistent organic pollutant contamination load from each zone of the study ar

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