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BIOGEOCHEMICAL BEHAVIOUR OF HEAVY METALS IN SOIL-PLANT SYSTEM

By

Muhammad Shahid

Department of Environmental Sciences COMSATS Institute of Information Technology, Vehari

Pakistan

HIGHER EDUCATION COMMISSION

ISLAMABAD – PAKISTAN

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Muhammad Shahid, Dr.

Biogeochemical behavior of heavy metals in soil-plant system

1. Soil and Environmental Science

577.14 – dc23 2017

ISBN: 978-969-417-195-1

First Edition: 2017

Copies Printed: 500

Published By: Higher Education Commission - Pakistan

Disclaimer: The publisher has used its best efforts for this publication through a rigorous system of

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Copyrights @ Higher Education Commission

Islamabad

Lahore Karachi Peshawar Quetta

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DEDICATION

To ALLAH Almighty

Holy Prophet Muhammad (P.B.U.H)

My Parents & Teachers

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TABLE OF CONTENTS

LIST OF TABLES …………………………………………………………………………………………xi

LIST OF FIGURES ………………………………………………………………………………………xiii

LIST OF ABBREVIATIONS ……………………………………………………………………….…….xv

PREFACE ………………………………………………………………………………………………..xvii

FOREWORD ………………………………………………………………………………………….... xix

ACKNOWLEDGEMENT ……………………………………………………………………………......xxi

POLLUTION OF HEAVY METALS AND METALLOIDS............................................................. 1

1.1 METALS AND TYPES …………………………………………………………………………….... 2

1.2 HEAVY METALS AND METALLOIDS ……………………………………………………………. 4

1.3 HEAVY METAL SOIL CONTAMINATION ………………………………………………………… 5

1.4 HEAVY METALS OCCURENCE IN SOILS ………………………………………………………. 6

1.5 POTENTIAL HAZARDS OF HEAVY METAL CONTAMINATION ……………………………… 8

1.5.1 ENVIRONMENTAL PERSISTENCE …………………………………………………………. 8

1.5.2 POTENTIAL PHYTO-TOXICITY ……………………………………………………………… 8

1.5.3 POTENTIAL RISK OF METALS TO HUMAN HEALTH ……………………………………. 9

BIOGEOCHEMICAL BEHAVIOUR OF ARSENIC IN SOIL-PLANT SYSTEM …………………. 11

2.1 INTRODUCTION …………………………………………………………………………………… 11

2.2 GLOBAL USES OF ARSENIC ………………………………………………………………….... 13

2.3 ARSENIC LEVELS AND SOURCES IN SOILS ………………………………………………… 14

2.4 PHYTOAVAILABILITY OF ARSENIC IN SOILS ……………………………………………….. 15

2.5 EFFECT OF SOIL CHEMICAL PROPERTIES ON ARSENIC PHYTOAVAILABILITY .…… 15

2.5.1 SOIL PH AND ARSENIC PHYTOAVAILABILITY ……………………………………………. 15

2.5.2 SOIL ORGANIC MATTER AND ARSENIC PHYTOAVAILABILITY .………………………. 16

2.5.3 SOIL MICROBES AND ARSENIC PHYTOAVAILABILITY .………………………………… 17

2.6 SOIL-PLANT TRANSFER OF ARSENIC ………………………………………………………. 18

2.6.1 MOLECULAR UNDERSTANDING OF ARSENIC ABSORPTION BY PLANTS ……… 18

2.6.2 ARSENIC AND COMPLEMENTARY CATIONS .………………………………………….. 18

2.6.3 ARSENIC SEQUESTRATION INTO PLANT ROOTS ……………………………………. 19

2.6.4 ARSENIC TRANSLOCATION TO PLANT SHOOTS .…………………………………….. 19

2.6.5 ARSENIC ACCUMULATION IN EDIBLE PLANT PARTS ……………………………….. 20

2.7 TOXIC EFFECTS OF ARSENIC ON PLANTS …………………………………………….... 20

2.7.1 ARSENIC TOXICITY TO PLANT GROWTH ………………………………………………. 21

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2.7.2 ARSENIC GENOTOXICITY …………………………………………………………………. 21

2.7.3 ARSENIC-INDUCED OXIDATIVE STRESS ………………………………………………. 22

2.8 ARSENIC DETOXIFICATION IN PLANTS .……………………………………………………… 23

2.8.1 VACUOLAR COMPARTMENTALIZATION OF ARSENIC IN PLANTS ………………… 24

2.8.2 ARSENIC CHELATION BY PHYTOCHELATINS ……………………………………….... 25

2.8.3 ARSENIC CHELATION BY GLUTATHIONE .……………………………………………… 26

2.8.4 ANTIOXIDANT ENZYMES AND ARSENIC TOXICITY .………………………………….. 27

2.8.5 SALICYLIC ACID AND ARSENIC TOXICITY .…………………………………………….. 29

2.9 HORMETIC EFFECTS OF ARSENIC TOXICITY .……………………………………………… 29

2.10 CONCLUSIONS AND PERSPECTIVES ………………………………………………………. 30

BIOGEOCHEMICAL BEHAVIOUR OF LEAD IN SOIL-PLANT SYSTEM ……………………... 31

3.1 INTRODUCTION …………………………………………………………………………………… 31

3.2 GLOBAL USES OF LEAD .………………………………………………………………………… 32

3.3 LEVELS AND SOURCES OF LEAD IN SOILS ……………………………………………….... 33

3.4 PHYTOAVAILABILITY OF LEAD IN SOILS …………………………………………………….. 34

3.5 SOIL PROPERTIES AND LEAD PHYTOAVAILABILITY .……………………………………… 35

3.5.1 SOIL PH AND LEAD PHYTOAVAILABILITY …………………………………………….... 35

3.5.2 SOIL ORGANIC MATTER AND LEAD PHYTOAVAILABILITY .………………………… 37

3.5.3 SOIL MICROBIAL ACTIVITY AND LEAD PHYTOAVAILABILITY .……………………... 37

3.6 SOIL-PLANT TRANSFER OF LEAD .…………………………………………………………… 38

3.6.1 MOLECULAR UNDERSTANDING OF LEAD BIO-ABSORPTION …………………….. 38

3.6.2 LEAD SEQUESTRATION IN PLANT ROOTS ……………………………………………. 38

3.6.3 LEAD TRANSLOCATION FROM ROOTS TO SHOOTS .……………………………….. 39

3.7 TOXIC EFFECTS OF LEAD .…………………………………………………………………….. 40

3.7.1 LEAD TOXICITY TO PLANT GROWTH .………………………………………………….. 40

3.7.2 LEAD GENOTOXICITY .…………………………………………………………………….. 41

3.7.3 LEAD-INDUCED OXIDATIVE STRESS ..………………………………………………….. 42

3.8 LEAD DETOXIFICATION ..……………………………………………………………………….. 44

3.8.1 VACUOLAR COMPARTMENTALIZATION OF LEAD ..………………………………….. 44

3.8.2 LEAD CHELATION BY PHYTOCHELATINS ..……………………………………………. 44

3.8.3 LEAD CHELATION BY GLUTATHIONE ..…………………………………………………. 46

3.8.4 ANTIOXIDANT ENZYMES AND LEADTOXICITY ...……………………………………… 46

3.8.5 SALICYLIC ACID AND LEAD TOXICITY ..………………………………………………… 48

3.9 HORMETIC EFFECT OF LEAD TOXICITY ..…………………………………………………… 49

3.10 CONCLUSIONS ..………………………………………………………………………………… 50

BIOGEOCHEMICALBEHAVIOUR OF MERCURY IN SOIL-PLANT SYSTEM ………………… 51

4.1 INTRODUCTION ..…………………………………………………………………………………. 51

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4.2 GLOBAL USES OF MERCURY………………………………………………………………….. 52

4.3 MERCURY LEVELS AND SOURCES IN SOIL………………………………………………… 53

4.4 PHYTOAVAILABILITY OF MERCURY………………………………………………………….. 54

4.5 SOIL PROPERTIES AND HG BIO-AVAILABILITY…………………………………………….. 55

4.5.1 SOIL PH AND MERCURY PHYTOAVAILABILITY ..……………………………………... 55

4.5.2 SOIL ORGANIC MATTER AND MERCURY PHYTOAVAILABILITY …………………… 56

4.5.3 SOIL MICROBIAL ACTIVITY AND MERCURY BEHAVIOUR…………………………… 56

4.6 SOIL-PLANT TRANSFER OF MERCURY……………………………………………………… 57

4.6.1 MOLECULAR UNDERSTANDING OF MERCURY ABSORPTION BY PLANTS ..…… 57

4.6.2 COMPETITION BETWEEN MERCURY AND CATIONS FOR ABSORPTION ..……… 58

4.6.3 MERCURY SEQUESTRATION INTO PLANT ROOTS ………………………………….. 59

4.6.4 MERCURY TRANSLOCATION TO PLANT SHOOTS …………………………………… 59

4.6.5 MERCURY ACCUMULATION IN EDIBLE PLANT PARTS ……………………………… 60

4.7 EFFECTS OF MERCURY ON PLANTS ………………………………………………………… 60

4.7.1 MERCURY TOXICITY TO PLANT GROWTH .…………………………………………… 61

4.7.2 MERCURY GENOTOXICITY ………………………………………………………………. 62

4.7.3 MERCURY-INDUCED OXIDATIVE STRESS …………………………………………….. 63

4.8 MERCURY DETOXIFICATION IN PLANTS …………………………………………………… 65

4.8.1 VACUOLAR COMPARTMENTALIZATION OF MERCURY …………………………….. 65

4.8.2 MERCURY CHELATION BY PHYTOCHELATINS ………………………………………. 65

4.8.3 MERCURY CHELATION BY GLUTATHIONE …………………………………………….. 65

4.8.4 ANTIOXIDANT ENZYMES AND MERCURY TOXICITY ………………………………… 66

4.8.5 SALICYLIC ACID AND MERCURYTOXICITY ……………………………………………. 68

4.9 CONCLUSIONS AND PERSPECTIVES ..……………………………………………………… 68

BIOGEOCHEMICAL BEHAVIOUR OF COBALT IN SOIL-PLANT SYSTEM …………………. 71

5.1 INTRODUCTION ………………………………………………………………………………….. 71

5.2 GLOBAL USES OF COBALT ……………………………………………………………………. 72

5.3 COBALT LEVELS AND SOURCES IN SOILS ………………………………………………… 72

5.4 PHYTOAVAILABILITY OF COBALT IN SOILS ………………………………………………… 73

5.5 SOIL PROPERTIES ADN COBALT PHYTOAVAILABILITY …………………………………. 73

5.6 SOIL - PLANT TRANSFER OF COBALT ………………………………………………………. 74

5.6.1 MOLECULAR UNDERSTANDING OF COBALT ABSORPTION BY PLANTS ……….. 74

5.6.2 COMPETITION BETWEEN COBALT AND CATIONS FOR ABSORPTION ………….. 75

5.6.3 COBALT SEQUESTRATION INTO PLANT ROOTS …………………………………….. 75

5.6.4 COBALT TRANSLOCATION TO SHOOTS ……………………………………………….. 76

5.7 FOLIAR ABSORPTION OF COBALT …………………………………………………………… 76

5.8 TOXIC EFFECTS OF COBALT ON PLANTS ………………………………………………….. 76

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5.8.1 COBALT TOXICITY TO PLANT GROWTH ……………………………………………….. 76

5.8.2 COBALT GENOTOXICITY ………………………………………………………………….. 78

5.8.3 COBALT-INDUCED OXIDATIVE STRESS AND LIPID PEROXIDATION …………….. 79

5.9 COBALT DETOXIFICATION IN PLANTS ……………………………………………………… .80

5.9.1 VACUOLAR COMPARTMENTALIZATION OF COBALT ……………………………….. 80

5.9.2 COBALT CHELATION BY PHYTOCHELATINS ………………………………………….. 80

5.9.3 COBALT CHELATION BY GLUTATHIONE ………………………………………………. 81

5.9.4 ANTIOXIDANT ENZYMES AND COBALT TOXICITY …………………………………… 81

5.10 HORMETIC EFFECT OF COBALT TOXICITY ……………………………………………….. 82

5.11 CONCLUSIONS AND PERSPECTIVES ……………………………………………………… 83

BIOGEOCHEMICAL BEHAVIOUR OF NICKEL IN SOIL-PLANT SYSTEM …………………… 85

6.1 INTRODUCTION ………………………………………………………………………………….. 85

6.2 GLOBAL USES OF NICKEL ……………………………………………………………………… 86

6.3 NICKEL LEVELS AND SOURCES IN SOILS ………………………………………………….. 87

6.4 PHYTOAVAILABILITY OF NICKEL IN SOILS ………………………………………………… 88

6.5 SOIL PROPERTIES AND NI PHYTOAVAILABILITY …………………………………………. 88

6.5.1 SOIL PH AND NI PHYTOAVAILABILITY ………………………………………………….. 88

6.5.2 SOIL ORGANIC MATTER AND NI PHYTOAVAILABILITY ……………………………… 89

6.6 SOIL-PLANT TRANSFER OF NICKEL …………………………………………………………. 89

6.6.1 MOLECULAR UNDERSTANDING OF NI ABSORPTION BY PLANTS ……………….. 89

6.6.2 COMPETITION AMONG NI AND CATIONS FOR ABSORPTION ……………………… 90

6.6.3 NICKEL TRANSLOCATION FROM ROOT TO SHOOTS ……………………………….. 91

6.7 TOXIC EFFECTS OF NI ON PLANTS ………………………………………………………….. 91

6.7.1 NICKEL TOXICITY TO PLANT GROWTH ………………………………………………… 92

6.7.2 NICKEL GENOTOXICITY …………………………………………………………………… 92

6.7.3 NICKEL-INDUCED OXIDATIVE STRESS ………………………………………………… 93

6.8 NICKEL DETOXIFICATION IN PLANTS ……………………………………………………….. 93

6.8.1 VACUOLAR COMPARTMENTALIZATION OF NI ……………………………………….. 93

6.8.2 NICKEL CHELATION BY PHYTOCHELATINS …………………………………………… 95

6.8.3 NICKEL CHELATION BY GLUTATHIONE ………………………………………………… 95

6.8.4 NICKEL TOXICITY AND SALICYLIC ACID ………………………………………………. 95

6.8.5 ANTIOXIDANT ENZYMES AND NI TOXICITY …………………………………………… 96

6.9 HORMETIC EFFECT OF NITOXICITY …………………………………………………………. 97

6.10 CONCLUSIONS AND PERSPECTIVES ………………………………………………………. 98

BIOGEOCHEMICAL BEHAVIOUR OF ZINC IN SOIL-PLANT SYSTEM ………………………. 99

7.1 INTRODUCTION ………………………………………………………………………………….. 99

7.2 GLOBAL USES OF ZINC ……………………………………………………………………….. 100

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7.3 ZINC LEVELS AND SOURCES IN SOILS ……………………………………………………. 101

7.4 SOIL PROPERTIES AND ZINC PHYTOAVAILABILITY …………………………………….. 102

7.4.1 RHIZOSPHERE AND ZINC PHYTOAVAILABILITY ……………………………………. 103

7.4.2 MICROBIAL ACTIVITY AND ZINC BEHAVIOUR IN SOILS …………………………… 104

7.5 SOIL-PLANT TRANSFER OF ZINC …………………………………………………………… 104

7.5.1 MOLECULAR UNDERSTANDING OF ZINC ABSORPTION BY PLANTS ………….. 104

7.5.2 COMPETITION BETWEEN ZINC AND OTHER CATIONS FOR ABSORPTION …… 105

7.5.3 ZINC SEQUESTRATION INTO PLANT ROOTS ……………………………………….. 105

7.5.4 ZINC TRANSLOCATION INTO PLANT SHOOTS ……………………………………… 106

7.5.5 FOLIAR ABSORPTION OF ZINC ………………………………………………………… 106

7.6 ROLES OF ZINC IN PLANTS ………………………………………………………………….. 106

7.6.1 ROLE OF ZINC IN ENZYMES ……………………………………………………………. 107

A. ALCOHOL DEHYDROGENASE ………………………………………………………….. 107

B. CARBONIC ANHYDRASE ………………………………………………………………… 107

C. CUZN-SUPEROXIDE DISMUTASE ……………………………………………………… 108

D. OTHER ZN-CONTAINING ENZYMES …………………………………………………... 108

7.6.2 ZINC AND PROTEIN SYNTHESIS ………………………………………………………. 108

7.6.3 ZINC AND MEMBRANE STABILITY ……………………………………………………... 108

7.7 ZINC DEFICIENCY ……………………………………………………………………………… 109

7.8 ZINC TOXICITY ………………………………………………………………………………….. 110

7.8.1 ZINC TOXICITY TO PLANT GROWTH ………………………………………………….. 110

7.8.2 ZINC-INDUCED OXIDATIVE STRESS …………………………………………………... 110

7.9 ZINC DETOXIFICATION IN PLANTS ………………………………………………………….. 112

7.9.1 VACUOLAR COMPARTMENTALIZATION OF ZINC …………………………………… 112

7.9.2 ZINC CHELATION BY PHYTOCHELATINS …………………………………………….. 112

7.9.3 ZINC CHELATION BY GLUTATHIONE ………………………………………………….. 113

7.9.4 ANTIOXIDANTS ENZYMES AND ZINC TOXICITY …………………………………….. 114

7.10 CONCLUSIONS AND PERSPECTIVES …………………………………………………….. 116

REFERENCES ……………………………………………………………………………………….. 117

SUBJECT INDEX …………………………………………………………………………………….. 189

GLOSSARY ..………………………………………………………………………………………... 194

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LIST OF TABLES

TABLE 1.1: SOME BASIC CHARACTERISTICS OF HEAVY METALS AND METALLOIDS ............................... 6

TABLE 1.2: NATURAL AND ANTHROPOGENIC SOURCES OF SELECTED METALS AND METALLOIDS………7

TABLE 2.1: ARSENIC-INDUCED ENHANCED PRODUCTION OF ROS IN VARIOUS PLANT SPECIES GROWN

IN HYDROPONIC CULTURE ............................................................................................................. 24

TABLE 2.2: ARSENIC-INDUCED ACTIVATION OF ANTIOXIDANT ENZYMES IN DIFFERENT PLANT SPECIES

GROWN IN HYDROPONIC CULTURE ................................................................................................. 28

TABLE 3.1: LEAD CONCENTRATIONS IN DIFFERENT CONSTITUENTS OF EARTH'S CRUST .................... 34

TABLE 3.2: LEAD-INDUCED ENHANCED PRODUCTION OF ROS IN VARIOUS PLANT SPECIES GROWN IN

HYDROPONIC CONDITIONS ............................................................................................................. 43

TABLE 3.3: LEAD-INDUCED ACTIVATION OF ANTIOXIDANT ENZYMES IN DIFFERENT PLANT SPECIES

GROWN IN HYDROPONICS……………………………………………………………………..............45

TABLE 4.1: MERCURY CONTENTS IN DIFFERENT SOIL ORDERS AND ROCK TYPES.............................. 54

TABLE 4.2: MERCURY-INDUCED ENHANCED PRODUCTION OF ROS IN DIFFERENT PLANT SPECIES

GROWN IN HYDROPONICS .............................................................................................................. 64

TABLE 4.3: MERCURY-INDUCED ACTIVATION OF ANTIOXIDANT ENZYMES IN DIFFERENT PLANT SPECIES

GROWN IN HYDROPONICS .............................................................................................................. 67

TABLE 5.1: COBALT-INDUCED ENHANCED PRODUCTION OF ROS IN VARIOUS PLANT SPECIES GROWN IN

HYDROPONICS .............................................................................................................................. 79

TABLE 5.2: COBALT-INDUCED ACTIVATION OF ANTIOXIDANT ENZYMES IN DIFFERENT PLANT SPECIES

GROWN IN HYDROPONIC ................................................................................................................ 82

TABLE 6.1: NICKEL-INDUCED ENHANCED PRODUCTION OF ROS IN VARIOUS PLANT SPECIES GROWN IN

HYDROPONIC ................................................................................................................................ 94

TABLE 6.2: NICKEL-INDUCED ACTIVATION OF ANTIOXIDANT ENZYMES IN DIFFERENT PLANT SPECIES

GROWN IN HYDROPONIC ................................................................................................................ 97

TABLE 7.1: ZINC-INDUCED ENHANCED PRODUCTION OF ROS IN DIFFERENT PLANT SPECIES GROWN IN

HYDROPONIC .............................................................................................................................. 113

TABLE 7.2: ZINC-INDUCED ACTIVATION OF ANTIOXIDANT ENZYMES IN DIFFERENT PLANT SPECIES

GROWN IN HYDROPONIC .............................................................................................................. 115

ANNEXURE TABLE 1: HARMFUL EFFECTS OF ARSENIC ON PLANT GROWTH .................................... 179

ANNEXURE TABLE 2: HARMFUL EFFECTS OF LEAD ON PLANT GROWTH .......................................... 181

ANNEXURE TABLE 3: HARMFUL EFFECTS OF MERCURY ON PLANT GROWTH ................................... 183

ANNEXURE TABLE 4: HARMFUL EFFECTS OF COBALT ON PLANT GROWTH ...................................... 185

ANNEXURE TABLE 5: HARMFUL EFFECTS OF NICKEL ON PLANT GROWTH ....................................... 186

ANNEXURE TABLE 6: HARMFUL EFFECTS OF ZINC ON PLANT GROWTH........................................... 187

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LIST OF FIGURES

FIGURE 1.1: PERIODIC TABLE HIGHLIGHTING SELECTED HEAVY METAL(LOID)S (SHADED CELLS) ……...3

FIGURE 1.2: BIOGEOCHEMICAL BEHAVIOUR OF HEAVY METALS IN SOIL-PLANT SYSTEM........................9

FIGURE 2.1: ANNUAL WORLD REFINERY PRODUCTION OF ARSENIC (US-GS 2016). ......................... 12

FIGURE 2.2: BIOGEOCHEMICAL BEHAVIOUR OF ARSENIC IN SOIL-PLANT SYSTEM. ............................. 13

FIGURE 2.3: VACUOLAR COMPARTMENTATION OF ARSENIC IN PLANT CELLS. .................................... 23

FIGURE 3.1: ANNUAL WORLD REFINERY PRODUCTION OF LEAD (USGS 2016). ................................ 33

FIGURE 3.2: BIOGEOCHEMICAL BEHAVIOUR OF LEAD IN SOIL-PLANT SYSTEM .................................... 36

FIGURE 3.3: TOXIC EFFECTS OF LEAD ACCUMULATION IN PLANTS. ................................................... 40

FIGURE 3.4: LEAD-INDUCED OXIDATIVE STRESS IN PLANT CELLS ..................................................... 45

FIGURE 3.5: STRAIGHT AND INVERTED U-SHAPED HERMETIC CURVES. ............................................ 49

FIGURE 4.1: ANNUAL WORLD REFINERY PRODUCTION OF MERCURY (USGS 2016). ......................... 52

FIGURE 4.2: MERCURY ABSORPTION AND TRANSFORMATION IN PLANTS. ......................................... 58

FIGURE 5.1: ANNUAL WORLD REFINERY PRODUCTION OF COBALT (USGS 2016). ............................ 72

FIGURE 5.2: BIOGEOCHEMICAL BEHAVIOUR OF COBALT IN SOIL-PLANT SYSTEM. ............................... 77

FIGURE 6.1: ANNUAL WORLD REFINERY PRODUCTION OF NICKEL (US-GS 2016). ............................ 87

FIGURE 6.2: BIOGEOCHEMICAL BEHAVIOUR OF NICKEL IN SOIL-PLANT SYSTEM. ................................ 90

FIGURE 7.1 ANNUAL WORLD REFINERY PRODUCTION OF ZINC (USGS 2016). ................................ 100

FIGURE 7.2 . ENTRY OF ZINC INTO PLANT CELL WALLS AND ITS DETOXIFICATION MECHANISMS. ....... 111

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LIST OF ABBREVIATIONS

½O2 Singlet Oxygen

ABC transporters ATP-Binding Cassette Transporters

APX Ascorbate Peroxidase

As Arsenic

ASC Ascorbate

ATP Adenosine Triphosphate

ATSDR Agency for Toxic Substances and Disease Registry

CAT Catalase

CCA Chromated Copper Arsenate

Cd Cadmium

CDF Cation Diffusion Facilitators

Co Cobalt

DHAR Dehydroascorbate Reductase

DMAA Dimethyl Arsenic Acid

DMT Divalent Metal ion Transporter

DOM Dissolved Organic Matter

EEA European Environmental Agency

Eh Reduction Potential

EPA Environmental Protection Agency

FOREGS Forum of European Geological Surveys

GPX Guaiacol Peroxidise

GR Glutathione Reductase

GSH Glutathione or Reduced Glutathione

GSSG Oxidized Glutathione

H2O2 Hydrogen Peroxide

Hg Mercury

HO• Hydroxyl

IARC International Agency for Research on Cancer

JECFA Joint FAO/WHO Expert Committee Food Additives

LOX Lipoxygenase

MeHg Methylmercury

MDHAR Monodehydroascorbate Reductase

MMAA Mono Methyl Arsenic Acid

Mn Manganese

Mo Molybdenum

NADPH Nicotinamide adenine dinucleotide phosphate

Ni Nickel

NIP Nodulin-26-like Intrinsic Proteins

NRAMP Natural Resistance-Associated MacroPhage

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O2• − Superoxide Anion

OM Organic matter

P Phosphorous

Pb Lead

PC Phytochelatins

PCS Phytochelatin synthase

PGPR Plant Growth-Promoting Bacteria

POD Peroxidase

RAPD Random Amplified Polymorphic

RO• Alkoxyl

RO2• Peroxyl

ROOH Organic Hydroperoxide

ROS Reactive Oxygen Species

SA Salicylic Acid

Sb Antimony

SCE Sister Chromatid Exchanges

Se Selenium

SOD Superoxide Dismutase

SOM Soil Organic Matter

TBARS Thiobarbituric Acid Reactive Substances

TMA Trimethylarsine Oxide

USGS United States Geological Survey

ZIP ZRT, IRT-like Protein

Zn Zinc

Zr Zirconium

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PREFACE

hirteen years of extensive research work on biogeochemical behaviour of heavy metals in soil-plant system, and their potential ecotoxic effect in plants as well as associated human health risks is summarized in this book. This year’s long research journey started with my

work on biogeochemical behaviour of nickel under the visionary supervision of Prof. Dr. Abdul Ghafoor during my M.Sc. (Hons.) in Soil Science at Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Pakistan. This journey continued as I did my MPhil (2006-2007), PhD (2007-2010) and Post-PhD (2010-2011) research work from INP-ENSATS, Toulouse-France under world-renowned scientists: Prof. Dr. Camille Dumat and Prof. Dr. Eric Pinelli. My Ph.D. research work was about biogeochemical behaviour of heavy metals in soil-plant system, which was funded by HEC-Pakistan under “Overseas Scholarship Scheme”. I served as a lecturer for three years (2007-2010) at INP-ENSATS, Toulouse, France.

One book, nine book chapters and >52 impact factor articles in scientific literature regarding biogeochemical behaviour of heavy metals in soil-plant system with an accumulative impact factor >125 and citations >1250 precedes this book which I contributed in collaboration with my supervisors and other scientists from different countries. I have supervised (PI & Co-PI) > 25 MPhil students of Environmental Sciences which also broadened my exposure and experience in my research journey. I served as supervisory committee member of three PhDs and one Post-Doc researcher. Based on quality of research work and publications, my doctoral thesis was awarded Leopold Escande Award-2011 by INP-ENSAT France. I also received four “Research Productivity Awards” (2013-14, 2014-15, 2015-16 & 2016-17) by Pakistan Council for Science & Technology (PCST), and five “Research Productivity Awards” (2012, 2013, 2014, 2015 & 2016) by COMSATS Institute of Information Technology based on my research productivity that increased my morale and provided me enough motivation to move further in my extensive research journey.

This book is the collection of scientific data compiled on the basis of my thirteen years of research experience. The valuable information regarding biogeochemical behaviour of nickel, lead, arsenic, cobalt, mercury and zinc in soil-plant system on the same pattern makes this book a worth reading manuscript. Therefore, this book can be a useful window of information for the readers to compare the biogeochemical behaviour of heavy metals in soil-plant system.

Shahid

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FOREWORD

Our planet “Earth” is in danger and its morphology is getting worse and worse every day.

Environmental contamination by heavy metals through natural processes and anthropogenic activities is a prevalent and severe dilemma of society, and it is getting significant attention by researchers and regulatory authorities around the globe. Although, the origins of heavy metals contamination date back to ancient times, the dilemma became more profound after the rise of the industrial empires. This industrial revolution owes to the impact of modern technologies and enhanced metal production.

Numerous studies have validated this phenomenon that soil contamination by heavy metals results in the accumulation and uptake of these metals in crops that not only decrease crop growth and productivity but also affect animal and human health. This book is another valuable contribution to the scientific literature as it provides comprehensive knowledge regarding Biogeochemical Behaviour of Heavy Metals in soil-plant system. So, it is no less than a saviour because biogeochemical behaviour (bioavailability in soil, absorption, uptake and accumulation by plants, and toxicity and detoxification in plants) of heavy metals in soil-plant system is considered as a serious environmental concern and this book is providing a holistic knowledge about it.

Seven chapters in this book present the data available regarding biogeochemical behaviour of six heavy metals, i.e., arsenic (As), mercury (Hg), lead (Pb), cobalt (Co), nickel (Ni) and zinc (Zn) in soil-plant system in an easy and understandable manner. Heavy metals behaviour in soil-plant system (mobility, bioavailability, speciation, soil to plant transfer, toxicity and detoxification) differs greatly with respect to plants and metal type, and physico-chemical properties of soils. Six heavy metals selected to be discussed are the most toxic ones classified as human carcinogens according to the Agency for Toxic Substances and Disease Registry [ATSDR 2015a).

In this book, I have summarised data regarding: (i) bioavailability of selected metals in soil, (ii) uptake of metals by plants, (iii) factors affecting metals bioavailability in soil and uptake by plants, (iv) heavy metals compartmentation in different plant organs, (v) toxic effect of metals on plants, and (vi) detoxification mechanisms adopted by plants against the toxic effects induced by these metals.

Shahid

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ACKNOWLEDGEMENT

Without the grace and the power of Allah Almighty, this thirteen years long and arduous

journey would not have been successfully ended into this valuable addition of knowledge into scientific literature. This journey, though unconventional and sometimes disrupted, has always been driven by the light bestowed on our path by the Holy Prophet Muhammad (P.B.U.H.).

I am indebted to Dr. S.M. Junaid Zaidi, Rector CIIT and Prof. Khair-uz-Zaman, Director CIIT-Vehari Campus for providing favourable working environment that we enjoy while working at COMSATS Institute of Information Technology, Vehari Campus. I also thankful to the officials of ORIC-CIIT for their support during the entire period of book writing.

I feel enormously grateful and humbled by all of the amazing people who have guided, inspired and supported me throughout this publication. This book would not have been possible without the major contribution of Sana Khalid, Behzad Murtaza, Hafiz Faiq Siddique Gul Bakhat, Ghulam Abbas, Saliha Shamshad, Marina Rafiq, Sunaina Abbas, Zahida Zia, Faryal Naeem, Nabeel Khan Niazi, Muhammad Imtiaz Rashid, Ghulam Mustafa Shah, Rizwan Ashraf, Hafiz Mohkum Hammad, Muhammad Imran, Irshad Bibi, Muhammad Amjad and Natasha. Finding words comprehensive enough to express my gratitude to all these wonderful people are difficult indeed. I am grateful to all these scientists whose contributions and recommendations made this book a valuable and quality piece of work.

A special thanks goes to my family for their unwavering love, constant support and encouragement to realize my goals. They kept their faith in my abilities to complete this mission. A distinct love to my princes, Asna, who is the most beautiful gift and blessing of God to me in this world.

I would also like to acknowledge the invaluable support of Higher Education Commission (HEC), Pakistan for providing us opportunity to publish this book and financial support. The continuous support, guidance and involvement of HEC officials throughout this process made this project finalized.

Shahid