**8. Chitosan-siRNA delivery system**

siRNA silencing technology is exploited in a wide range of biological studies, but has also become one of the most challenging therapeutic strategies. However, because of its poor delivery and susceptibility to nuclease degradation, siRNA-based approaches need a protective delivery system. A variety of polymer formulations have been proposed in the literature as potential carriers (De Fougerolles 2008; Gary et al., 2007; Zhang et al., 2007). Polymer molecular weight, change density, N/P ratio (ratio of protonatable polymer amine groups to nucleic acid phosphate groups) and ionic strength of the medium can affect electrostatic binding between siRNA and cationic polymers. Research over the years has revealed that chitosan is one of the desirable polymeric carriers of siRNA because of its natural biocompatibility, biodegradability, nontoxicity, and high nuclease resistance. The effects of different chitosan (114-kDa or more)-siRNA complexes on transfection activity have been observed previously (Katas et al., 2008; Katas & Alpar, 2006; Liu et al., 2007; Rojanarata et al., 2008). Higher MW and DDA are desirable characteristics for the formation of chitosan nanoparticles, as higher MW chitosan molecules are long and flexible while higher DDA enhances its electrostatic interaction with siRNAs, thus synergically reducing the size of complexes and increasing their stability (Liu et al., 2007). A high charge ratio also enhances the stability of complexes because the loosely bound excess chitosan on the outer surface of nanoparticles can promote binding and uptake across anionic cell surfaces and also provide subsequent protection against siRNA degradation within endosome compartments (Liu et al., 2007). The method of complexation also affects the gene-silencing

such as deoxycholic acid modification (Lee et al., 1998), or 5β-cholanic acid modification (Yoo et al., 2005), can attenuate the electrostatic attractions between cationic polymers and anionic DNA. It is actually a contradiction between the stability and dissociation ability of complexes. A temperature-sensitive modification of poly(N-isopropylacrylamide) (PNIPAAm) can control the dissociation of PNVLCS (N-isopropylacrylamide/vinyl laurate copolymer with chitosan) complexes with DNA by a temporary reduction in the culture

The cytoplasm, a mesh-like network of microfilaments and microtubules, will limit the diffusion of complexes or DNA about 500-1000-fold. Adenovirus particles naturally bind to dynein and are actively transported towards the nuclear pore complexes once they are inside the cytoplasm. Prior to entry into the nucleus, the viruses dissociate into smaller structures and use their attached transport factors such as importins or karyopherins which have nuclear localization signals (NLS) to recognize the nuclear pore complex (NPC) (Whittaker & Helenius, 1998). Justin Hanes et al. used a new method called multiple particles tracking (MPT) to quantify the intracellular transport of non-viral DNA nanocarriers. They found that PEI/DNA complexes can accumulate in the perinuclear area through a subdiffusive transport, which is a combination of diffusive transport and active transport. This discovery is a dispute to the common belief that non-viral vectors go through the cell cytoplasm in a slow random way. Further investigation showed that actively transported complexes of PEI/DNA are in endosomes undergoing motor protein-driven movement guided by microtubules or physically associated with the motor proteins themselves (Suh et al., 2003). As to chitosan and its derivatives, however, few studies have examined how they pass through the highly structured cytoplasm and eventually enter into

siRNA silencing technology is exploited in a wide range of biological studies, but has also become one of the most challenging therapeutic strategies. However, because of its poor delivery and susceptibility to nuclease degradation, siRNA-based approaches need a protective delivery system. A variety of polymer formulations have been proposed in the literature as potential carriers (De Fougerolles 2008; Gary et al., 2007; Zhang et al., 2007). Polymer molecular weight, change density, N/P ratio (ratio of protonatable polymer amine groups to nucleic acid phosphate groups) and ionic strength of the medium can affect electrostatic binding between siRNA and cationic polymers. Research over the years has revealed that chitosan is one of the desirable polymeric carriers of siRNA because of its natural biocompatibility, biodegradability, nontoxicity, and high nuclease resistance. The effects of different chitosan (114-kDa or more)-siRNA complexes on transfection activity have been observed previously (Katas et al., 2008; Katas & Alpar, 2006; Liu et al., 2007; Rojanarata et al., 2008). Higher MW and DDA are desirable characteristics for the formation of chitosan nanoparticles, as higher MW chitosan molecules are long and flexible while higher DDA enhances its electrostatic interaction with siRNAs, thus synergically reducing the size of complexes and increasing their stability (Liu et al., 2007). A high charge ratio also enhances the stability of complexes because the loosely bound excess chitosan on the outer surface of nanoparticles can promote binding and uptake across anionic cell surfaces and also provide subsequent protection against siRNA degradation within endosome compartments (Liu et al., 2007). The method of complexation also affects the gene-silencing

temperature to 20℃ (Sun et al., 2005)

**8. Chitosan-siRNA delivery system**

the nucleus.

activity of chitosan/siRNA complexes. Haliza Katas et al. studied the difference between simple complexation, ionic gelation (siRNA entrapment) and adsorption of siRNA onto the surface of preformed chitosan nanoparticles. Ionic gelation gave the strongest stability and the most efficient gene-silencing activity among the three methods tested. For the involvement of tripolyphosphate (TPP) ions during the complexation of ionic gelation, pH became one of the factors that mostly affected the gene-silencing activity. The decrease of pH resulted in a reduction in the charge number of TPP, which subsequently led to the need for more TPP ions for cross-linking of the chitosan by electrostatic forces (Katas & Alpar, 2006). Rojanarata et al. reported that chitosan-thiamine pyrophosphate (TPP)-mediated siRNA enhanced green fluorescent protein (EGFP) gene silencing efficiency depended on the molecular weight and weight ratio of chitosan and siRNA. The chitosan-TPP-siRNA complex with the lowest molecular weight of chitosan (20 kDa) at a weight ratio of 80 showed the strongest inhibition of gene expression (Rojanarata et al., 2008). A novel study of chitosan/siRNA nanoparticles with fluorescent quantum dots was taken to silence HER2/neu and achieved desirable silencing effects (Tahara et al., 2008; Tan et al., 2007). In the field of controlled release, chitosan coating PLGA nanospheres with a high loading efficiency of siRNAs were found to reduce the initial burst of nucleic acid release and to prolong release at later stages, without changing the release pattern (Tahara et al., 2008). Kenneth A. Howard found that the chitosan-based system had the ability for endosome escape through the proton sponge mechanism, because the endosomolytic agent chloroquine did not increase the effect of RNA interference (Howard et al., 2006). In terms of *in vivo* administration of chitosan/siRNAs complexes, only a few studies are available. Nasal administration to silence EGFP expression of the endothelial cells distributed in the bronchioles of transgenic EGFP mouse model has been successfully achieved without showing any adverse effects (Howard et al., 2006). Cross-linking of hyaluronan and chitosan has proven to have a higher efficiency of transfection in ocular tissue over unmodified chitosan (de la Fuente et al., 2008).


Preface

**Section 5 Advances in the Assessment of Heavy Metal Contamination -**

Chapter 25 **Geochemical Speciation and Risk Assessment of Heavy Metals**

Chapter 26 **The Effect of Industrial Heavy Metal Pollution on Microbial Abundance and Diversity in Soils — A Review 759**

Chapter 27 **Pollution of Pb in Soils Affected by Pyrite Tailings: Influence of**

**Fractionation and Bioavailability Assessment 799** Marija Romić, Lana Matijević, Helena Bakić and Davor Romić

**Polluted with Mercury: Occurrence, Transformations, Environmental Considerations and San Joaquin's Sierra**

I. Robles, J. Lakatos, P. Scharek, Z. Planck, G. Hernández, S. Solís and

**(Cu), Manganese (Mn), Lead (Pb), and Zinc (Zn) Contamination**

**in Agricultural' Soils and Wheat Crops Projects at Three**

Youssef F. Lawgali, Andy A. Meharg and Yousef M.T. Elgimati

**Land Application of Sewage Sludge: A Review with Data**

F. Martín, M. Simón, I. García, A. Romero and V. González

**Anthropogenic Modification of Two Sites in the Sudan**

Sunday Paul Bako, Augustine Uwanekwu Ezealor and Yahuza

Santosh Kumar Sarkar, Paulo J.C. Favas, Dibyendu Rakshit and K.K.

Chapter 24 **Heavy Metal Deposition in Soils and Plants Impacted by**

**Savanna of North Western Nigeria 697**

**in Soils and Sediments 723**

Anna Lenart-Boroń and Piotr Boroń

Chapter 28 **Copper Accumulation in Vineyard Soils: Distribution,**

Chapter 29 **Characterization and Remediation of Soils and Sediments**

Chapter 30 **Conducted and Investigate Arsenic (As), Cobalt (Co) Copper**

Chapter 31 **Risks of Heavy Metals Contamination of Soil-Pant System by**

Alysson Roberto Baizi e Silva and Fábio Camilotti

**Soil Properties 785**

**Gorda Case 827**

**Regions in Libya 851**

**from Brazil 873**

E. Bustos

**Case Studies 695**

Tanimu

**VIII** Contents

Satpathy

*"Continuing change is the dominant factor in society today. No sensible decision can be made with‐ out taking into account not only the world as it is, but the world as it will be."* Isaac Asimov.

The natural resources of the planet face enormous challenges in meeting food and energy demands of an increasing population, expected at 9 billion by 2050. Production challenges are exacerbated by unpredictable impacts on climate and natural ecosystems. Soil contami‐ nation and soil pollution constitute an essential issue to be addressed if we are to secure the life quality of present and future generations. Soil contamination is the presence of elevated concentrations of substances in the environment above the natural background level for the area and for the organism. Therefore, soil contamination is defined as the build-up of persis‐ tent toxic compounds in the natural soil environment, which have adverse effects on plant growth and animal health. More specifically, pollution is the introduction by man, directly or indirectly, of substances or energy into the environment resulting in deleterious effects to living resources and hazards to human health. The Environmental Protection Agency (EPA, USA) considers risk "to be the chance of harmful effects to human health or to ecological systems resulting from exposure to an environmental stressor". From historically contami‐ nated areas to recent environmental disasters, the quality of world soils is constantly jeopar‐ dized, with an immediate associated risk for all living organisms linked to the affected soil area. According to a recent report from the European Commission (EEA, 2013), approxi‐ mately three million sites in the EU have supported potential polluting activities, with 250,000 sites needing urgent remediation. The most frequent contaminants are heavy metals and mineral oil and the main causes of pollution are past and present industrial and com‐ mercial activities, agricultural chemicals, and the improper disposal and treatment of waste, but these categories vary widely worldwide. The Cooperative Research Centre for Contami‐ nation Assessment and Remediation reported in 2013 that Australia has 160,000 potentially contaminated sites, less than 1 per cent remediated, and most of the sites being in urban areas. According to data discussed at the 13th International Conference on Environmental Science and Technology (Athens, 2013), the number of contaminated sites exceeds 500,000 in the USA, 30,000 in Canada and 500,000 in Japan, while there are no official available data for several other areas such as Eastern Europe, Africa and South America and for countries such as China and India.

The protection of soil as the irreplaceable resource that sustains life in the planet requires integrated efforts from researchers and policy makers to develop sound risk assessment pro‐ cedures and policies as well as feasible soil management and remediation strategies. To date, the relevance of soil contamination in environmental research and policy remains con‐ siderably belittled. Despite the substantial body of published research currently available,

circa 3.5 million records returned from the web of science for "soil" search (650,000 records for "soil pollution" search), official guidelines and risk assessment procedures are frequent‐ ly obsolete. Moreover, the advance of legislation concerning soil protection from the poten‐ tial impact of human activities fails to meet the urgent need of developing sustainable land management practices. Overall, an increased effort to assess soil contamination and develop remediation and quality preservation strategies has become essential for the present and fu‐ ture of world soils.

*Environmental risk assessment of soil contamination* is a book designed by InTech - Open Access Publisher in collaboration with recognized international authors, unifying biological, chemi‐ cal and agronomic approaches to research on soil contamination and pollution.

This book is intended to provide a wide depiction of current research in soil contamination and risk assessment, encompassing broad reviews and case studies on soil pollution by heavy metals and organic pollutants. Moreover, the book introduces several innovative ap‐ proaches for soil remediation and risk assessment, including recent advances in phytoreme‐ diation. Therefore, this volume will be a valuable reading to a global audience of scientists, researchers, environmental educators, policy makers, technicians, managers, students and the general public.

The first section comprises nine chapters corresponding to broad studies on soil contamina‐ tion and pollution, including a wide diversity of environmental scenarios and general revi‐ sions of soil pollution assessment and remediation strategies. Section 2 introduces seven chapters dedicated to advanced methodological approaches for risk assessment and soil re‐ mediation, including several up to date chemical and biological techniques. Section 3 specif‐ ically addresses progresses in phytoremediation, which is traditionally considered a top strategy for soil reclamation. A collection of 11 case studies on soil contamination with or‐ ganic pollutants (section 4) and heavy metals (section 5) provides a worldwide depiction of soil contamination and pollution, highlighting the variability of contaminated sites and as‐ sessment approaches across the world.

The 31 chapters of this book can be read independently, but like different soil quality indica‐ tors they mutually benefit and enrich each other, providing a valuable composition that de‐ picts current status of research in soil contamination and advances on risk assessment from a multidisciplinary approach.

For their excellent work, special thanks to the technical editors and sincere appreciation to Ms Iva Lipović, Deputy Head of Book Publishing Department, who coordinated the publica‐ tion process of this volume and assisted me and the authors in completing our tasks smooth‐ ly and in a timely manner.

> **Dr. Maria C. Hernández-Soriano** The University of Queensland Australia

**Risk Assessment: Soil Contamination Scenarios and Strategies**

circa 3.5 million records returned from the web of science for "soil" search (650,000 records for "soil pollution" search), official guidelines and risk assessment procedures are frequent‐ ly obsolete. Moreover, the advance of legislation concerning soil protection from the poten‐ tial impact of human activities fails to meet the urgent need of developing sustainable land management practices. Overall, an increased effort to assess soil contamination and develop remediation and quality preservation strategies has become essential for the present and fu‐

*Environmental risk assessment of soil contamination* is a book designed by InTech - Open Access Publisher in collaboration with recognized international authors, unifying biological, chemi‐

This book is intended to provide a wide depiction of current research in soil contamination and risk assessment, encompassing broad reviews and case studies on soil pollution by heavy metals and organic pollutants. Moreover, the book introduces several innovative ap‐ proaches for soil remediation and risk assessment, including recent advances in phytoreme‐ diation. Therefore, this volume will be a valuable reading to a global audience of scientists, researchers, environmental educators, policy makers, technicians, managers, students and

The first section comprises nine chapters corresponding to broad studies on soil contamina‐ tion and pollution, including a wide diversity of environmental scenarios and general revi‐ sions of soil pollution assessment and remediation strategies. Section 2 introduces seven chapters dedicated to advanced methodological approaches for risk assessment and soil re‐ mediation, including several up to date chemical and biological techniques. Section 3 specif‐ ically addresses progresses in phytoremediation, which is traditionally considered a top strategy for soil reclamation. A collection of 11 case studies on soil contamination with or‐ ganic pollutants (section 4) and heavy metals (section 5) provides a worldwide depiction of soil contamination and pollution, highlighting the variability of contaminated sites and as‐

The 31 chapters of this book can be read independently, but like different soil quality indica‐ tors they mutually benefit and enrich each other, providing a valuable composition that de‐ picts current status of research in soil contamination and advances on risk assessment from

For their excellent work, special thanks to the technical editors and sincere appreciation to Ms Iva Lipović, Deputy Head of Book Publishing Department, who coordinated the publica‐ tion process of this volume and assisted me and the authors in completing our tasks smooth‐

> **Dr. Maria C. Hernández-Soriano** The University of Queensland

> > Australia

cal and agronomic approaches to research on soil contamination and pollution.

ture of world soils.

X Preface

the general public.

sessment approaches across the world.

a multidisciplinary approach.

ly and in a timely manner.


**1. Introduction**

Economic growth based on use of non renewable energy constitutes a serious problem because of, especially, negative environmental externalities. Growth of energy consumption and gas emissions are the principal negative impacts of these modes of development. However, the sustainable development requires modes of development which demand few of energy and produce few of pollutant gas. Literature has interested of this problematic in an aggregate or disaggregate contexts. The first is concerning the relationship between economic growth, domestic energy consumption and gas emissions. The second is corresponding to the same relationship but per economic sector. Industry and transport sectors are more studied because of their important link with economic and environmental spheres. They have an important contribution in economic growth but they are responsible of several environmental externalities.

The transport is one of the major activities which consume more energy and produce gas pollutants. Majority of freight and passengers is transported by road mode which is considered an important source of fossil fuels consumption and CO2 emissions. In order to make transport sector more sustainable, some strategies should be elaborated to reduce its energy consumption and gas emissions. In other terms, governments should apply a set of instruments, such as economic, fiscal, regulatory and technological instruments, to control driving factors of transport-related energy consumption and gas emissions.

Before any strategy, it's necessary to evaluate the sustainability degree of transport sector. Sustainable transport literature give us several indicators through them it's possible to measure energy demand and gas pollutants production associated to transport activity. Examples include transport intensity, transport energy intensity, transport energy emission

© 2012 Mraihi, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

intensity, vehicle intensity and vehicle energy intensity. Other indicators, such as modal mix (road, rail, air and water shares), energy mix for every mode (gasoline, diesel, liquefied petroleum gas (LPG), electricity or other fuel types, such as bio-carburant ), rate of motorization, transport energy consumption share and annual growth of Vehicle Park are also used to diagnostic sustainability from transport sector. Determine the driving factors of transport-related energy consumption and pollutants gas emission growth is a one of main phases. It helps to choice the optimal strategy which corresponds to every responsible factor. With all types of intensities which are evoked, economic, demographic, urban and technological factors are taken as the main factors which can influence energy consumption and so gas emissions of transport sector. Moreover, examples of influencing factors include also average travelling distance, vehicle types share (personal cars, bus, heavy and light trucks), average vehicle age, driving condition, urbanization, urbanized kilometers and national road network.

Transport Intensity and Energy Efficiency: Analysis of Policy Implications of Coupling and Decoupling 273

of transport service (*tkm* or *pkm*). Amelioration of energy efficiency from transport sector implies reduction of energy intensity and so saving energy consumption for the sector.

Transport energy intensity has studied in several contexts. Examples include studies which interest to the relationship between economic growth and transport activity and transport energy consumption. This analyze is defined in two approaches. Firstly, the economic approach which aims to study the causality relationship between them and to analyse the expenditure in energy consumption. Secondly, the ecologic approach which aims to study the correlation between them in order to determine the coupling phenomena between them and to measure and analyse energy consumption and gas emissions. Moreover, examples include studies which decomposing the intensities in order to determine the influencing

More existing studies have focused on the causality and cointegration relationship between transport energy consumption, transport activity and some main factors. Their main objective is to determine the time tendencies of their trends, the sense of their causality, the degree of their cointegration and then the coupling problem (Meersman et Van De Voorde, 1999; Kulshreshtha et al*.*, 1999; Stead, 2001; Banister and Stead, 2003; Léonardi et

Recently, Akinboade, Ziramba and Kumo (2008) have used the co-integration techniques in order to analyze the long-run relationship among the variables which explicating the aggregate gasoline demand function over the period 1978-2005 in South Africa. The results confirm the existence of a co-integrating relationship. The estimation of the price and income elasticities of gasoline demand serves to develop appropriate energy policy. The estimated elasticities show that gasoline demand in South Africa is price and income inelastic. The important policy implication is the unreliability of the public transport system in South Africa. Yaobin (2009) explains cointegration relationship between transport energy consumption growth, population growth, economic growth and urbanization process for china over the period 1978 -2008. The results show a unidirectional Granger causality running from urbanization to energy consumption both in the long and short run. Lu, Lewis and Lin (2009) have estimated the development trends of the number of motor vehicles, vehicular energy consumption and CO2 emissions in Taiwan during 2007-2025. They have adopted simulation of different economic growth scenarios in order to explore the influence

Pongthanaisawan and Sorapipatana (2010) have analyzed the relationship between motorcycle and car ownerships and level of economic development for the case of Thailand. They study the impacts of this relationship on fuel consumption and greenhouse gas emissions. Using semi-parametric techniques, the authors have shown that economic development affects the ownership of private vehicles which and so fuel consumption and gas emissions. The important conclusion of their study is that the amelioration of public transport system leads to reducing the traffic mobility of private vehicles, promotion of the vehicle efficiency and so reducing fuel consumption and gas emissions. Yan and Crookes (2010) have forecasted the future trends of energy demand of road vehicle and emissions

factors of the transport-related energy consumption growth.

Baumgartner, 2004; Tanczos et Torok, 2007).

of economic growth on energy consumption.

More existing methods has presented by sustainable transport literature to examine the relationship between economic growth, transport activity and environmental impacts and to determine the driving factors. We distinguish three principal approaches: first, causality approach that based on time series methods, Kuznets Environmental Curve model and third, decomposing analysis method.

The aim of this chapter is to analyze the sustainability of transport activity especially through the energy efficiency indicator and different associated influencing factors. To this end, the rest of the chapter is structured as followed: section 2 presents an overview of works which have focused on transport energy efficiency. Section 3 describes methodologies applied to study energy consumption from transport sector with more interesting to decomposing analysis. Section 4 presents the driving factors and policy options to ameliorate transport energy efficiency. Section 5 concludes.

### **2. Transport energy saving: literature review**

Transport activity is strongly related to economic activities. Traffics realized permit to link markets of production and consumption through the satisfaction of persons and freight transport demand. However, transport services supply is often associated to many problems that affect economy, society and environment. Negative environmental externalities appear especially if economic activity and transport services are more coupled. In this context, *transport intensity* is often used to measure transport demand and to analyze negative consequences of the coupling relationship between economic growth and transport activity. It's defined as the ratio of gross mass movement to Gross Domestic Production (GDP). It can be measured separately for the passenger services (passenger kilometres, *pkm*) and freight (ton kilometres, *tkm*). Close relationship between the growth in transport and economic growth implied an increase of transport intensity and so an increase of transport-related energy consumption and gas emissions. Transport-related energy consumption is currently measured in the literature through *energy intensity* which calculated by the ratio of transport energy consumption to transport services supply. It indicates the demand of energy per unit of transport service (*tkm* or *pkm*). Amelioration of energy efficiency from transport sector implies reduction of energy intensity and so saving energy consumption for the sector.

272 Energy Efficiency – The Innovative Ways for Smart Energy, the Future Towards Modern Utilities

national road network.

third, decomposing analysis method.

ameliorate transport energy efficiency. Section 5 concludes.

**2. Transport energy saving: literature review**

intensity, vehicle intensity and vehicle energy intensity. Other indicators, such as modal mix (road, rail, air and water shares), energy mix for every mode (gasoline, diesel, liquefied petroleum gas (LPG), electricity or other fuel types, such as bio-carburant ), rate of motorization, transport energy consumption share and annual growth of Vehicle Park are also used to diagnostic sustainability from transport sector. Determine the driving factors of transport-related energy consumption and pollutants gas emission growth is a one of main phases. It helps to choice the optimal strategy which corresponds to every responsible factor. With all types of intensities which are evoked, economic, demographic, urban and technological factors are taken as the main factors which can influence energy consumption and so gas emissions of transport sector. Moreover, examples of influencing factors include also average travelling distance, vehicle types share (personal cars, bus, heavy and light trucks), average vehicle age, driving condition, urbanization, urbanized kilometers and

More existing methods has presented by sustainable transport literature to examine the relationship between economic growth, transport activity and environmental impacts and to determine the driving factors. We distinguish three principal approaches: first, causality approach that based on time series methods, Kuznets Environmental Curve model and

The aim of this chapter is to analyze the sustainability of transport activity especially through the energy efficiency indicator and different associated influencing factors. To this end, the rest of the chapter is structured as followed: section 2 presents an overview of works which have focused on transport energy efficiency. Section 3 describes methodologies applied to study energy consumption from transport sector with more interesting to decomposing analysis. Section 4 presents the driving factors and policy options to

Transport activity is strongly related to economic activities. Traffics realized permit to link markets of production and consumption through the satisfaction of persons and freight transport demand. However, transport services supply is often associated to many problems that affect economy, society and environment. Negative environmental externalities appear especially if economic activity and transport services are more coupled. In this context, *transport intensity* is often used to measure transport demand and to analyze negative consequences of the coupling relationship between economic growth and transport activity. It's defined as the ratio of gross mass movement to Gross Domestic Production (GDP). It can be measured separately for the passenger services (passenger kilometres, *pkm*) and freight (ton kilometres, *tkm*). Close relationship between the growth in transport and economic growth implied an increase of transport intensity and so an increase of transport-related energy consumption and gas emissions. Transport-related energy consumption is currently measured in the literature through *energy intensity* which calculated by the ratio of transport energy consumption to transport services supply. It indicates the demand of energy per unit Transport energy intensity has studied in several contexts. Examples include studies which interest to the relationship between economic growth and transport activity and transport energy consumption. This analyze is defined in two approaches. Firstly, the economic approach which aims to study the causality relationship between them and to analyse the expenditure in energy consumption. Secondly, the ecologic approach which aims to study the correlation between them in order to determine the coupling phenomena between them and to measure and analyse energy consumption and gas emissions. Moreover, examples include studies which decomposing the intensities in order to determine the influencing factors of the transport-related energy consumption growth.

More existing studies have focused on the causality and cointegration relationship between transport energy consumption, transport activity and some main factors. Their main objective is to determine the time tendencies of their trends, the sense of their causality, the degree of their cointegration and then the coupling problem (Meersman et Van De Voorde, 1999; Kulshreshtha et al*.*, 1999; Stead, 2001; Banister and Stead, 2003; Léonardi et Baumgartner, 2004; Tanczos et Torok, 2007).

Recently, Akinboade, Ziramba and Kumo (2008) have used the co-integration techniques in order to analyze the long-run relationship among the variables which explicating the aggregate gasoline demand function over the period 1978-2005 in South Africa. The results confirm the existence of a co-integrating relationship. The estimation of the price and income elasticities of gasoline demand serves to develop appropriate energy policy. The estimated elasticities show that gasoline demand in South Africa is price and income inelastic. The important policy implication is the unreliability of the public transport system in South Africa. Yaobin (2009) explains cointegration relationship between transport energy consumption growth, population growth, economic growth and urbanization process for china over the period 1978 -2008. The results show a unidirectional Granger causality running from urbanization to energy consumption both in the long and short run. Lu, Lewis and Lin (2009) have estimated the development trends of the number of motor vehicles, vehicular energy consumption and CO2 emissions in Taiwan during 2007-2025. They have adopted simulation of different economic growth scenarios in order to explore the influence of economic growth on energy consumption.

Pongthanaisawan and Sorapipatana (2010) have analyzed the relationship between motorcycle and car ownerships and level of economic development for the case of Thailand. They study the impacts of this relationship on fuel consumption and greenhouse gas emissions. Using semi-parametric techniques, the authors have shown that economic development affects the ownership of private vehicles which and so fuel consumption and gas emissions. The important conclusion of their study is that the amelioration of public transport system leads to reducing the traffic mobility of private vehicles, promotion of the vehicle efficiency and so reducing fuel consumption and gas emissions. Yan and Crookes (2010) have forecasted the future trends of energy demand of road vehicle and emissions

under various strategies for reducing the impacts of china's road vehicles on energy resources and environment. These strategies have concerned on the fuel economy regulation, alternative fuels and vehicles, public and non-motorized transport and economic incentives. Rudra (2010) explores the causality relationship between transport infrastructure, energy consumption and economic growth in India over the period 1970-2007. He finds a unidirectional causality from transport infrastructure to energy consumption. This results mains that energy and transportation policies must be recognized. Marshall *et al*. (2011) explores the causal relationship between residential location and vehicle miles of travel, energy consumption and CO2 emissions in Chicago metropolitan area over the period 2007 - 2008. Reinhard *et al.* (2011) concluded that urban energy planning and urbanization management are strongly linked and must be coordinated to lead to sustainable energy development.

Transport Intensity and Energy Efficiency: Analysis of Policy Implications of Coupling and Decoupling 275

(2007) have studied the relationship between road transport, energy consumption and CO2 emissions for the case of Autriche. Sorrell *et al*. (2009) have found for the case of England during the period 1989-2004 that increasing of vehicle transportation capacity and reducing of vehicle average energy consumption have ameliorated the energy efficiency. Niovi *et al.* (2010) estimates the effect of the spatial structure of the economy and the degree of spatial concentration of activities on fuel demand by using decomposition analysis. The results

**3. Methodologies used for study of transport energy efficiency**

**3.1. Causality and cointegration relationship between transport energy**

An open question for relationship between transport activity, economic growth and environmental effects is the correlation between their trends. Negative environmental effect will be increasing when correlation between economic growth and transport is largely important. Exam of this correlation is important in so far as it provides a several instruments to elaborate an efficient transport policy. In literature, a large majority of studies have interested to determine separately correlation between first, transport activity and economic growth (coupling problem) and secondly transport activity and energy consumption and gas emission. In this chapter we propose a demarche which treats simultaneously both the tow problems. We attempt to include in our analysis dimension of sustainable transport for

In this context, a large number of studies have interested to the problem of coupling. An important number of institutional reports had elaborated like REDEFINE (1999) and SPRITE (2000) in Europe. Otherwise, several scientific studies have been elaborated in two directions. First, studies which estimate relationships between transport of passengers or goods and economic growth using previous traffic models (Meersman and Van De Voodre (1999) for the case of Belgium and Klushershtha and al. (1999) for India). Second, studies which have interested to aggregated indicators in order to estimate the coupling (Baum (2000) and Baum and Kurte (2002) have used the intensity of road transport to measure

In order to study the relationship between transport energy consumption, transport activity and economic growth, we should test the stationary of the series. To this end tests which are common use are Augmented Dickey-Fuller (ADF) tests (Dickey and Fuller, 1979) and Phillips-Perron (PP) tests (Phillips and Perron, 1988). The objective is to know if the series are stationary in levels or in some order of differentiation. If the integration of the two series is of the same order, we should test whether the two series are cointegrated over the same period. Analyze of

The Trace and maximum eigenvalue test provide us the information concerning the presence or nor of the cointegration. Consequently, we can estimate a vector error correction model (VECM) that incorporates variables and variation levels for information on the speed

cointegration between the series is often realized through method of Johansen (1988).

coupling for the case of Germany and Stead (2001) for the case of Europe).

show that urban density increases fuel consumption.

which actual policies transport have been taken.

**consumption, transport activity and economic growth**

In order to study transport-related energy consumption, majority of works have used the decomposition method. It's one of the most effective applied tools used to investigate the factors influencing energy consumption and its environmental impacts. The intensity decomposition method dates back to studies undertaken in the 1980s. It has known an expansion with works interesting to evaluation of aggregate energy consumption caused especially by the preceding energy crisis. It had evoked especially in the industrial context (Howarth *et al.,* 1991, Parck 1992). However, in the 1990s and 2000s this technique has been generalized to be used and applied to other sectors such as transport sector. The main objective of this method is to identifying factors that influence directly or indirectly energy consumption. One of the important decomposition of energy efficiency is which had proposed by Kaya (1989) in the context of energy economy. Kolbs and Waker (1995) have used decomposition method to find determinants of energy consumption and greenhouse gas emissions1.

For the case of transport, several studies have been interested to decomposing energy consumption in transport sector in order to show the contribution of traffic in pollution. Schipper, Scholl and Price (1997) have decomposed energy intensity on three factors; transport activity (tone kilometre), structure of transport (types of modals) and intensity (energy used per unit of transport). They have concluded that best energy efficiency cannot compensate increasing of transport and modal share of road transport. Kveiborg and Fosgerau (2004) have decomposed the energy intensity of road transport for Denmark along the period 1981-1997. They have found that energy efficiency has been ameliorated by reducing of industrial production share and travelling distance through implantation of logistic platforms. Steer Davies Gleave (2003) have concluded, for the case of Germany, France, Spain, Italy and England during the period 1970-2000, that reducing of the road transport share has ameliorated the energy efficiency for the countries group. Steenhof *et al*. (2006) have used decomposition of energy intensity in order to examine the determinants of GES caused by freight transport in Canada. They have concluded that technical progress is inadequate solution if share of freight road transport increase for USA. Tanczos and Torok

<sup>1</sup> Liu and Ang (2007) have exposed a large majority of studies which used the method of intensity decomposition.

(2007) have studied the relationship between road transport, energy consumption and CO2 emissions for the case of Autriche. Sorrell *et al*. (2009) have found for the case of England during the period 1989-2004 that increasing of vehicle transportation capacity and reducing of vehicle average energy consumption have ameliorated the energy efficiency. Niovi *et al.* (2010) estimates the effect of the spatial structure of the economy and the degree of spatial concentration of activities on fuel demand by using decomposition analysis. The results show that urban density increases fuel consumption.