UNIVERSITI PUTRA

ASSESSMENT OF HEAVY METAL CONTAMINATION IN SOILS AND VEGETABLES IN VEGETABLE FARMS

EL IDRISSI ABOUJAAFAR SIDI MOHAMED

FP 2002 34

ASSESSMENT OF HEAVY METAL CONTAMINATION IN SOILS AND VEGETABLES IN CAMERON HIGHLANDS VEGETABLE FARMS

EL IDRISSI ABOUJAAFAR SIDI MOHAMED

MASTER OF AGRICULTURAL SCIENCE UNIVERSITI PUTRA MALAYSIA

2002 ASSESSMENT OF HEAVY METAL CONTAMINATION IN SOILS AND VEGETABLES IN CAMERON mGHLANDS VEGETABLE FARMS

By

EL IDRISSI ABOUJAAFAR SIDI MOHAMED

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfillment of the Requirement for the Degree of Master of Agricultural Science

October 2002 DEDICATION

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11 Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfillment of the requirements for the degree of Master Agricultural Science

ASSESSMENT OF HEAVY METAL CONTAMINATION IN SOILS AND VEGETABLES IN CAMERON HIGHLANDS VEGETABLE FARMS

By

EL IDRISSI ABOUJAAFAR SIDI MOHAMED October 2002

Chairman: Professor Dr. Shamshuddin Jusop Faculty: Agriculture

Vegetable cultivation is the most important agricultural activity in Cameron

Highlands; about 64% of the population are involved in vegetable cultivation, with a total area of 2 599 hectares. Due to the extensive land levelling and construction of terraces, the vegetables are essentially grown on the subsoil. The subsoil are mainly sandy clay or clay, with large amounts of organic matter being added usually in the form of chicken manure.

In a study of assessment of heavy metals in soils and vegetables of Cameron

Highlands, Peninsular Malaysia, 200 soil and 40 vegetable samples from various locations were analyzed for cation exchange capacity (CEC), texture, cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), chromium (Cr) and zinc (Zn), organic carbon COe), pH and available phosphorus (P). The results showed that there was no relationship between total Cd, Cr, Cu, Ni, Pb and Zn concentrations in the soils and in the vegetables.

Correlation studies of soil fertility parameters and total heavy metal concentration showed positive correlation between total P and Pb (r =0.492*) and Ni (r = 0.514*). This

1ll is indicative of addition of these metals as impurities in organic and inorganic fertilizers

Organic Cd showed a positive correlation (r = 0.538*) with soil carbon (OC), while Pb

showed a negative correlation (r = - 0.507*). This is indicative of addition of Cd as impurities in organic manures.

Copper was positively correlated with clay content (r = 0.678**), while Pb (r = -

0.484*) and Ni (r = -0.554*) were negatively correlated with AI. Pb was negatively

correlated with CEC (r = -0.502*). Anova analysis of total Zn, Cd, Cu, Cr, Ni and Pb with soil depth showed a very strong positive relationship. The concentration of Zn, Cd,

Cr and Cu are high only in the topsoil (0-20 em), but the concentration of these elements remain the same in the depths of 20-40 em and 40-60 em. This is indicative of the

contamination from agriculture activities. The difference in heavy metals from the

cultivated soils and the control (primary forest) provides further evidence of the

contamination by agriculture activities.

The concentrations of heavy metal in Cameron Highlands soils from different

vegetable farms were studied. and vegetable farms had very high

concentration of Zn (219.80 mglkg); in Brinchang it is above the background values

(Dutch Standard Guidelines). Also Brinchang and Tanah Rata farms had very high

concentration of eu (61.80 and 71.20 mglkg, respectively), which is above the

background level. Cd tends to be high in all Cameron Highlands farm soils.

The concentration of heavy metals in cabbage from Blue Valley had the highest

concentration of Zn (133.99 mglkg), while Tring Cap cabbage had the lowest

concentration (73.01 mglkg). cabbage had the highest concentration of

iv Pb (1.50 mglkg), while the lowest concentration (0.26 mglkg) occurs inthe Blue Valley cabbage. Bertam Valley cabbage had also the highest concentration of Cd (0.55 mg!kg), while the lowest concentration (0.18 mg/kg) was found in the Blue Valley cabbage.

Jalin Trisu cabbage had the highest concentration ofNi (10.26 mglkg), while the lowest concentration (4.78 mglkg) was in the Blue Valley cabbage. Finally, Taman

Sadia cabbage had the highest concentration of eu (92.66 mglkg), while the lowest concentration (5.01 mg/kg) was in the cabbage.

It can be considered that Cameron Highlands vegetables planted on contaminated soils are not harmful for human consumption.

v Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia Sebagai memenuhi syarat ijazah Master Sains Pertanian

PENILAIAN KONTAMINASI LOGAM BERAT DALAM TANAH DAN SAYUR­ SA YURAN DI LADANG SA YUR DI CAMERON HIGHLANDS

Oleh

EL IDRISSI ABOUJAAFAR SIDI MOHAMED

Oktober 2002

Pengerusi: Profesor Dr. Shamshuddin Jusop Fakulti: Pertanian

Pengeluaran sayur-sayuran merupakan aktiviti pertanian utama di Cameron

Hiaghlands. Lebih kurang 64% daripada pendudukanya tertibat, dengan keluasan kawasan sebanyak 2599lhektar. Oleh kerana proses meratakan tanah yang melampau dan pembinaran teres, sayur-sayuran sebenarnya ditanam di atas subtanah. Subtanah ini

kebanyakanya lempung berpasir dan lempung yang dibajakan dengan jumlah bahan

organik yang tingi dalam bentuk tahi ayam.

Kenpayaan pertukaran kation (KPK), tekstur, Cd, Cu, Ni, Pb, Cr, Zn, karbon

organik, pH dan P tersedia telah dianalisis dalam satu hajian untuk menilai logam berat

dalam tanah dan sayur di Cameron Highlands, semenanjung Malaysia. Sebanyak 200

contoh pilih dan 40 contoh sayur daripada beberapa lokasi telah dipili. Didapati tiada

vi kaitan diantara kepekatan Cd, Cr, Cu, Ni, Pb, dan Zn total di dalam tanah dan sayuran.

Kajian korelasi diantara parameter kesuburan dan kepekatan logam berat total

menunjukkan korelasi positif di antara P total dan Pb (r =0.492*) dan Ni (r :;:: 0.514*). lni menunjukkan penambahan logam berat tersebut sebagai bahan kotoran raeum fosfat nitro. Cadmium organik berkorelasi positif (r = 0.538*) dengan karbon organik, manakala Pb berkorelasi negatif (r = - 0.507*). lni juga menunjukkan pertambahan Cd sebagai bahan kotoran dalam baja organik.

Kuprum bereorelasi positif dengan kandungan lempung (r = 0.678**), manakala

Pb (r :;:: -0.484*) dan Ni (r = -0.554*) berkorelasi negatif dengan AI. Pb berkorelasi negatif dengan KPK (r = -0.502*). Analisis ANOVA Zn, Cd, Cu, Cr, Ni dan Pb dengan kedalaman tanah menunjukkan pertalian positif yang kuat. Kepekatan Zn, Cd, Cr dan Cu tinggi dalam tanah atas (0-20 em), tetapi kepekatan elemen ini pada kedalaman 20-40 dan 40-60 em tidak berubah. lni menunjukkan kontaminasi daripada aktiviti pertanian.

Perbezaan logam berat dalam tanah pertanian dengan eontoh kawalan (hutan primer) boleh di gunakan sebagai bukti tambahan.

Kepekatan logam berat dalam tanahCameron Highlands daripada ladang sayuran telah dikaji. Ladang sayur Brinehang dan Tanah Rata mengandungi kepakatan Zn yang sangat tingi (219.80 mg/kg); di Brinehang ianya melebehi nilai asas A (Dutch Standard

Guidelines). Di samping itu juga, ladang sayur Brinehang dan Tanah Rata mengandungi

Cu yang sangat tinggi (masing-masing bernilai 61.80 dan 71.20 mg/kg), berada di atas nilai asas. Cd di dapati agak tinggi dalam tanah sayuran di Cameron Highlands.

vii Kubis daripada ladang Blue Valley mengandungi Zn tertinggi (133.99 mglkg), manakala kubis daripada Tring Cap mengandungi Zn terendah (73.01 mg/kg). Kubis

daripada Bertam Valley mengandungi Pb tertinggi (1.50 mglkg) , manakala kubis

daripada Blue Valley mengandungi Ph terendah (0.26 mglkg). Kubis daripada Bertam

Valley mengandungi Cd yang tertinggi (0.55 mg/kg), manakala kuhis daripada Blue

Valley mengandungi Cd terendah (0.18 mg/kg). Kubis daripada Jalin Trisu

mengandungi Ni tertinggi (10.26 mglkg), manakala kubis daripada Blue Valley

mengandungi Ni terendah (4.78 mglkg). Akhir sekali, kubis daripada Taman Sadia

mengandungi Cu tertinggi (92.66 mglkg) , manakaIa kubis daripada Kea Farm

mengandungi eu terendah (5.01 mg/kg).

Adalah boleh dianggap bahawa sayur di Cameron Highlands yang ditanam di

atas tanah tercemar tidak merbahaya untuk dimakan

viii ACKNOWLEDGEMENTS

I wish to thank my great brother for the financial support, which made my study in Malaysia possible. Also, the completion of this thesis would have been impossible without the help of so many kind hearted individuals. To them, I am hugely indebted. I have no way of repaying such a debt except to express my sincerest gratitude.

I would like to thank Prof Dr J Shamshuddin, of the Department of Land

Management, Faculty of Agriculture, UPM, Malaysia for his keen interest, valuable

contribution and tireless guidance during the preparation of this thesis. His countless

patience, encouragement and generosity cannot be over emphasized.

I am also very grateful to Assoc. Prof Dr Mohd KhanifYusop, Dean, Faculty of

Agriculture, UPM, Malaysia for his support, guidance and friendship and Assoc. Prof Dr

Aminuddin Hussin for his support and guidance.

Finally I would like to thank my sister Khadija, my brothers, Ijaz, Youssef,

Fauzi, Othman and all my friends around the world and my colleagues and friends in the

department.

ix I certify that an Examination Committee met on 7Th October 2002 to conduct the final examination of El Idrissi Aboujaafar Sidi Mohamed on his Master of Agricultural Science thesis entitled .. Assessment of Heavy Metal Contamination in Soils and Vegetables in Cameron Highlands Vegetables Farms" in accordance with Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulation 1981. The Committee recommends that the candidate be awarded the relevant degree. Members of the Examination Committee are follows:

Zaharah Abdul Rahman,Ph.D. Professor, Faculty of Agriculture Universiti Putra Malaysia (Chairperson)

Shamshuddin Jusop, Ph.D. Professor, Faculty of Agriculture Universiti Putra Malaysia (Member)

Mohd KhanifYusop, Ph.D. Associate Professor, Faculty of Agriculture Universiti Putra Malaysia (Member)

Aminuddin Hussin, Ph.D. Associate Professor, Faculty of Agriculture Universiti Putra Malaysia (Member)

SHAMSHER MOHAMAD RAMADILI, Ph.D. Professor !Deputy Dean, School of Graduate Studies, Universiti Putra Malaysia

Date:

x This thesis submitted to the Senate of Universiti Putra Malaysia has been accepted as fulfillment of the requirements for the degree of Master of Agricultural Science. The members of the Supervisory Committee are as follows:

Shamshuddin Jusop, Ph.D. Professor, Faculty of Agriculture Universiti Putra Malaysia (Chairman)

Mohd Khanif Yusop, Ph.D. Associate Professor, Faculty of Agriculture Universiti Putra Malaysia (Member)

Aminuddin Hussin, Ph.D. Associate Professor, Faculty of Agriculture Universiti Putra Malaysia (Member)

AINI IDERIS, Ph.D. Professor /Dean, School of Graduate Studies, Universiti Putra Malaysia

Date: 1 3 FEB 2003

xi DECLARATION

I hereby declare that this thesis is based on my original work except for quotations and citations which, have been duly acknowledged. I also declare that it has not been previously or concurrentlysubmitted for any other degree at UPM or other institutions.

EI Idrissi Aboujaafar Sidi Mohamed EI Montassir

Date: � Itt. I � ,,0 2,.,

Xll TABLE OF CONTENTS

DEDICATION 11

ABSTRACT ill

ABSTRAK VI

ACKNO�EDGEMENTS IX APPROVAL SHEETS x

DECLARATION FORM Xl LIST OF TABLES XVI

LIST OF FIGURES XV11 LIST OF ABREVIATIONS xix

CHAPTER

1 INTRODUCTION 1.1 General introduction 1 1.2 Objectives 4 1.3 Hypothesis 4

2 LITERATURE REVIEW 2.1 Relationship between Heavy Metals and Rock Types 5 2.2 HeavyMetal Pollution As Related to Human Activity 6 2.3 The Relationship between Heavy Metals and Clay Content 7 2.4 The Effect of Phosphate Fertilizers on Heavy Metal Pollution 8 2.5 Relationship between Heavy Metals and Soil Fertility Parameters 10 2.6 Heavy Metals Contamination in Vegetables 11 2.7 Relationship betweenHeavy Metals and Plant Uptake 13 2.8 The Effects of Heavy Metals on Health 14 2.9 Contaminated Soils of Cameron Highlands 15 2.9.1 Vegetable Cultivation 17 2.9.2 Water Sources 18 2.9.3 Soil Toxicity 19 2.9.4 Fertilizer Practices 19 2.9.5 Pesticides 20 2.9.6 Insecticides 20 2.9.7 fungicides 21 2.9.8 Weedicides 21 2.10 Need for this Study 21 2.11 Dutch standards 22

3 MATERIALS AND METHODS 3.1 Surveyed Area and Sampling Sites 3.1.1 Location 24 3.1.2 Site Description 24

Xlll 3. 2 Sampling of the Rock, Soilsand Vegetables

3 . 2. 1 Rocks 27 3.2.2 Soil 27 3.2.3 Vegetables 27 3.3 Preparation of Samples 3.3.1 Rock 30 3.3.2 Soil 30 3.3.3 Vegetables 30

3.4 Analysis of Samples 3.4.1 Rock samples 31 3.4.2 Soil Samples 31

Texture Analysis 31 pH (H2O) 32 Cation Exchange Capacity (CEC) 32 Organic Carbon (OC) 32 AvaiIable Phosphorus 33 Exchangeable AI 33 DTPA Extractable Method 33 EDTA Extractable Method 34 0.1 N HCI Extractable Method 34 Total Analysis 35

3.4.3 Tissue Samples 36

3.5 Statistical Analysis 35

4 RESULTS AND DISCUSSION

4.1 Introduction 37 4.2 Soil Fertility and Heavy Metals 38 4.3 Soil contamination in relation to rock type 42 4.4 Distribution of Heavy Metals in Cameron Highlands Forest Soil 43 4.5 The Relationship between the Heavy Metals and the Soil Depth 46 4.6 The Heavy Metals in Cameron Highlands Soils as Compared to the Dutch Sandards 52 4.7 Relationship between Heavy Metals Concentration and Soil

Properties. . 54 4.8 The Concentration of Heavy Metals in Cameron Highlands Vegetables 56 4.9 The Concentration of Heavy Metals inCameron Highlands Cabbage 64 4.10 Relationship between the Total Heavy Metals and the Available Heavy Metals 67 4.11 Relationship between Heavy MetalsSoils and Vegetables 67

XlV 4.12 TheComparison of the Concentration of HeavyMetals in Various Vegetables 76 4.13 ThePermissible Level Concentration of Heavy Metals in the Vegetables 82 4.14 Degree of Pollution 4.14.1 Soil 82 4.14.2 Vegetables 83

5 CONCLUSIONS 86 6 REFERENCES 88

APPENDIX A

APPENDIXB

APPENDIXC

BIODATA

xv LIST OF TABLES

Table page

Dutch Standards for soil contamination assessment A. (total concentration 23 in soil: mglkg).

2 The pH, OC, CEC and clay contents of top soil (0-20) at the various farms 40

3 The P and heavy metals concentration in the topsoil 41

4 The mean value for Heavy metals concentration in the rock 42

5 Heavy metals concentration of the soils in the forests near the sampling Sites 45

6 Heavy metals concentration in the soils of cultivated farms in Cameron Highlands 51

7 The concentration of heavy metal from different locations of Cameron Highlands 54

8 The Correlation coefficient (r) between the heavy metals in the soil and soil attributes 56

9 Heavy metals concentrations in the cabbage from the different vegetable farms 65

10 Plant to soil heavy metal ratio 70

11 The concentration of heavy metals in vegetables in Cameron Highlands compared with the Australian food permissible 85

xvi LIST OF FIGURES

Figure Page

1 Map of Peninsular Malaysia showing the location of Cameron Highlands 25

2 A picture showing vegetables growing on the terrace cut from granite hill 26

3 A picture showing vegetables growing on Saprolite 26

4 Primary fo rest inCameron Highlands 29

5 A picture showing fo rest and where were samples were collected 29

6 The change of Zn, Pb and Cu with depth 48

7 The change of Cd, Cr andNi with depth 49

8 Mean, minimumand maximum Zn concentration inthe vegetables 59

9 Mean, minimumand maximum Pb concentration inthe vegetables 60

10 Mean, minimumand maximum Cd concentration inthe vegetables 61

11 Mean, minimumand maximumNi concentration inthe vegetables 62

12 Mean, minimum and maximumCu concentration in the vegetables 63

13 Distribution of vegetable fa rms in Cameron Highlands 66

14 Leafy vegetables andcabbage cultivation inthe steplands 66

15 The concentration of Zn in soil and vegetables 71

16 The concentration of Pb in soil and vegetables. 72

17 The concentration of Cd insoil and vegetables. 73

18 The concentration ofNi in soil and vegetables. 74

19 The concentration of Cu insoil and vegetables. 75

xvii 20 Concentration ofNi in cabbage, tomato andbee troot 78

21 Concentration ofPb in cabbage, tomatoand beetroot 79

22 Concentration of Zn incabbage, tomato and beetroot 80

23 Concentration of Cd incabbage, tomato and beetroot 81

XVlll LIST OF ABBREVIATIONS

ANOVA analysis of variance

Hel acid hydrochloric

HN03 acid nitric mg/kg milligram per kilogram

�gll microgram per liter

1 liter

ml milliliter

kg kilogram

g gram

cm centimeter

mm millimeter

dw dry weight

P phosphorus

K potassium

Ca calcium

Cu copper

Cr chromium

Cd cadmium

Ni nickel

Zn zinc

CEC cation exchange capacity

AAS atomic absorption spectrophotometer

ICP inductively coupled plasma

AI aluminum

DC organic carbon

XIX CHAPTER I

INTRODUCTION

1.1 General introduction

Cameron Highlands was discovered by Mr William Cameron in 1885.

Subsequently, it was revisited in 1908 by H.N.Ridley who studied the flora around

Ringlet and the Bertam Valley. In 1922 an expedition was organized to locate areas for tea and coffee cultivation (Sands, 1922). The soils collected by Sands (1922) were analyzed and studied. The soils were reported to be distinctly different from other Malaysian soils, but resembled the best tea soils of India and Java. The first real study of the soils of the Cameron Highlands was made by Dennet (1930) when he produced a sketch map showing the distribution of the soils according to their texture.

The variation in soils as a function of altitude was studied by Burnham

(1974). He concluded that weathering became less intense with an increase in altitude as shown by lower clay and higher silt and sand in the soils, and the appearance of saprolite with depths. He added that parallel changes in clay mineralogy give higher CEC and water dispersibility so that there are no Oxisols in

Malaysia above 1,200 meters (around 4,000 ft). Leaching is very strong at all elevations, particularly at the higher elevations but clay eluviations is not significant in the profiles studied. However, Burnham (1974) added that elevation of iron and aluminum isimportant in the soils of the cloud zone. Burnham (1974), however, did not attempt to explain these observations.

Cameron Highlands is situated in mountainous area with elevation exceeding

1000 m asl. The area experiences mild temperature, ranging from 14°C to 24°c throughout the year, making it very conducive to the growth of a wide range of su b­ tropical crops. Most of the Cameron Highlands area can be classified as steep lands,

with more than 66% of the land having gradients greater than 20°. Steep lands are

generally not recommended for agriculture, but the favorable cool climate has

encouraged the growth of several agricultural activities in the area.

There is an intensive form of agriculture being practiced in Cameron

Highlands especially for the cultivation of vegetables, flowers and tea. Most of the

vegetables are grown on terraces cut into granite hills. Often these terraces are on the

C-horizon or saprolite. Large inputs of chicken manures and chemical fertilizers are

added to sustain the vegetable cultivation.

Although agriculture takes only about 7 % of the area, it has caused a

significant amount of environmental pollution. The initial opening of forested areas

resulted in intensive soil erosion. Erosion continues to be a problem during the

cultivation of vegetables or other short-term crops. Soil loss exceeds 83 tonnes per

hectare every year in open cabbage farms (Wan Abdullah et ai., 2000). The erosion

under tea is low, while that in chrysanthemum farms under the rain shelter is less

than I tonne per hectare per year, which is about 80 times smaller than that in the

open vegetable farms (Wan Abdullah et al., 2000). High amounts of organic

2 fertilizers ranging from 49 to 84 tonnes per hectare per season are used in vegetable and flower farms, about 3.2% (43 kglha) of the applied N and 5.5 % (109 kglha) of the applied K were removed through runoff(Wan Abdullah et aI., 2000).

During peak. runoff periods, the concentration ofN0)- in runoff water reaches

25 mg/kg, exceeding the permissible limit (Wan Abdullah et ai., 2000). This is an indication that open vegetables farms in Cameron Highlands and the long-term addition of fertilizers either organic or inorganic such as phosphate rock. chicken dung and other kind of fertilizers may accumulate heavy metals in the soil.

Farm land in Cameron Highlands is increasingly being brought under plastic cover to keep rain out. It is estimated that there are about 777 ha under highland flower cultivation, of which almost the entire grown area is under rainshelter. A much smaller area under rainshelter is devoted to the growing of vegetables and ornamental plants (Wan Abdullah et ai., 2000). Given a choice, farmers will always prefer their land to be under rainshelter. Growing of crops under rainshelter offers many advantages. It avoids hazards associated with untimely rains and planting density is also higher as most rainshelters are built on flat and gently sloping platforms carved out of hillsides. Generally, cropping cycles are also faster. For chrysanthemum, each cropping cycle is about 3.5 months with 10-14 days break between seasons to allow for soil treatment and field preparation. The cropping cycle for some leafy vegetables can be as short as about a month. Rainshelter also offers a relatively more conducive working environment compared to open terraces (Wan

Abdullah et ai., 2000).

3 Intensive cropping cycle are accompanied by high inputs of fertilizers and other agrobiocides. Much of these inputs slowly accumulate over time in the soil.

Except for vegetable growing where crop rotation is practiced, flowerfarmers tend to grow the same type of flower on a continuous basis. This leads to a high accumulation of fertilizers in the soils given that natural leaching via rainfall and irrigation is minimal. This results in salt build up in the soil giving rise to high electrical conductivity. Salt accumulation in soils under plastic houses is a common and well documented occurrence (Chang and Liao, 1989).

1.2 Objectives

The objectives of this study were:

a. To determine the level of heavy metal concentration in

the agricultural soils commonly grownwith vegetables in

the Cameron Highlands;

b. To determineamong the heavy metals in thesoils,

thosewhich are available to be taken up by

the plants; and

c. To determinethe relationship between theheavy

metals in the soils and the vegetables

1.3 Hypothesis

The agricultural practices are the main factors that contribute to heavy metal

contamination in the soils and vegetables of Cameron Highlands.

4