Crude oil is an important mineral resource vital to everyday life. Modern trend toward increasing dependence on the use of petroleum hydrocarbons for energy needs has resulted in severe pressure on the energy resource as well as increased accidental discharges of oil and its products into the environment. This occurs frequently during operations such as extraction, transportation, storage, refining and distribution notwithstanding technology-driven precautions. It would be reasonable to state that oil contamination is one of the most serious forms of water and land pollution as it endangers public health, imperils drinking water, devastates natural resources, and disrupts the economy.
Get Help With Your Essay
If you need assistance with writing your essay, our professional essay writing service is here to help!
Nigeria is one of the largest crude oil producing countries in the world and depends almost entirely (over 90%) on it for her revenue. The Niger Delta region in Nigeria contains the bulk of Nigeria’s proven oil and gas reserves. The region is ridden with environmental problems, ranging from devastation of land and water (crippling income generation through farming and fishing), through death of thousands of domestic animals, disastrous fire out-breaks, various illnesses to deaths. This is as a result of oil spillage which has become a daily experience in the region. There exist some prevention and mitigation measures associated with oil and gas exploration activities but these measures are not implemented in Nigeria. Owing perhaps to poor enforcement of the standards by regulatory bodies, corruption, high cost of procuring and maintaining some of the mitigation equipments, ignorance, lack of vision, or carelessness. These have led, to political unrest, with the people of the area feeling exploited and calling for reparations. Contamination of soil by is a widespread environmental problem that often requires clean-up of the contaminated site. Though many techniques have been undertaken to address oil contamination of land in the Niger Delta region, these either have negative effects or result to incomplete clean-up of the hydrocarbon contaminated soil. Although disposal or open dump burning may be simple and easily adaptable, these techniques have undesirable health and safety hazards from e.g. air pollution. Bioremediation is an alternative technology which is likely to be capable of achieving permanent remediation.
Nature has developed microorganisms that can degrade hydrocarbons to avoid their accumulation to a point of being detrimental to life. To achieve rapid bioremediation, nutrients and aeration are applied to the soil and the indigenous microorganism is often augmented to obtain enhanced bioremediation. The design of an efficient bioremediation system requires a set of careful studies of the local conditions of the site to be remediated.
Despite several indications of the environmental degradation and health effects caused by oil contamination of land in the Niger Delta region, little attention has been paid to investigating the effectiveness of the use of bioremediation in this region. Undertaking an evaluation of a selection of case studies could provide better insight whether bioremediation is the appropriate solution to oil contamination problems in the region.
Various application of bioremediation on oil contaminated soil has been reported with encouraging results but its effectiveness has not been fully employed in the region.
1.2 Aim and Objectives
The primary aim of this study is firstly to consider oil contamination of land as a global problem, assess the causes and effects of oil contamination of land both across the world and in Nigeria and secondly to evaluate whether bioremediation could be an effective treatment technique of land contaminated by oil with particular reference to the Niger Delta of Nigeria. In order to achieve this, the following will be addressed;
(a) The extent and causes of oil contamination
(b) The effect of oil contamination
(c) Oil contamination in Nigeria
(d) Remediation methods
(e) Case studies and/or questionnaire
1.3 Overview of oil contamination of land
Pollution of the land by oil has become a matter of widespread concern, attracting attention of politicians, environmentalists and scientists. There is growing public concern as a wide variety of toxic organic chemicals are being introduced accidentally or deliberately into the environment. Petroleum hydrocarbons are one common example of these chemicals, which enter the environment frequently and in large volumes through numerous routes. These routes include seepage from natural deposits, human activities in exploration, production, transportation and storage of petroleum. Such human activities inevitably involve the risk of accidental spills that can only be minimized but not eliminated completely. Deonarine and Basdeo (2001) explained that leaks from wellheads, leaks from pipelines, and overflows at gathering stations and deposition of oily mud are also other routes through which hydrocarbon enter the environment. Oil spills are now becoming a frequent and major source of water and land contamination across the globe especially in the Niger Delta region of Nigeria.
1.4 Justification of the Study
In time past, land contamination was usually perceived in terms of relatively rare incidents, with poorly known but possibly catastrophic impact on human health and the environment. According to Nathanail and Bardos (2004) numerous incidents drew media attention and these include Love canal in New York; Times Beach Missouri in United States and Minamata, Japan disaster. They further explained that today land contamination is no longer perceived in terms of few severe incidents rather as extensive infrastructural problems of varying intensity and significance that is inherited from past and present industrial and waste disposal activities.
Nowadays across the globe, land contamination is gaining a higher official recognition and is been recognised as a serious challenge to present and future generation. Recently a lot of policies for sustainable development and contaminated land management have been introduced and so many countries especially in developed countries have implemented these policies. Despite this trend, the Nigeria Government and oil multinational companies operating in that country are yet to implement such policies. They agree with sustainable development and good environmental management but these are only seen as a “paper exercise”. There is no adequate implementation of sustainable development and environmental management in Nigeria.
Moreover, oil spill incidence still occurs and no adequate management is given to the spilled site. There are no known instances in Nigeria whereby an oil polluted site had been fully remediated and restored by any of the oil companies. Most polluted sites are neglected to the mercy of slow process of natural recovery that takes several years to accomplish. Even in terrestrial environments where remediation is conventionally cheaper and easy, in the Nigerian situation, it is a luxury that is ‘impossible’. For example, most sites in Ogoniland where incident oil spill incident occurred since 1970 remains unclean till date 2009. Besides deliberate negligence, corporate corruption and penchant to cut-corners hinder remediation programmes in the Nigerian oil industry. Remediation contracts are often awarded to contractors who simply transport topsoil from elsewhere to mask contaminated spill sites. These sites are often reported as begin remediated
Although many people and organisations especially non-governmental organisation (NGO) have writing about oil pollution in Nigeria and its negative effects, but solution to the pollution have been limited.
1.5 Structure of the Report
Chapter one began with an introduction and justification of the study. It brought problems, Aims and objectives and conceptual framework of the work.
The second chapter carries out a review of the existing on oil contamination of land with emphasis on the meaning, causes, effects, issues across the world and Nigeria, technology and oil spillage as a major cause of the oil contamination. Also this chapter review oil contamination in the Niger Delta of Nigeria.
Chapter three looks at the methodology, nature and sources of data collection as well as the technique for data analysis.
The Chapter four looks at the proposed solution to oil contamination.
Chapter five focuses on case studies and Discussion of findings of the study. (develop best practice guide for Nigeria)
Chapter six looks at the conclusions and recommendations
CHAPTER TWO
2.0 LITERATURE REVIEW
2.1 Introduction
Oil contamination is a major environmental problem which is caused as result of oil operations. Activities of oil companies constitute environmental problems; with substantial implications for economic development and human health. As a result of its impacts some individuals live as aliens in their own communities, where they are unable to actualize their interest or aspirations. This chapter provides a review of the menace of oil contamination.
2.2 The problem – Oil contamination of land.
The demand for energy is increasing globally as a result of rising population, increased industrialisation and prosperity. This has resulted on severe pressure on available energy resources. Energy has a major impact on every aspects of socio-economic life as it plays a vital role in the economic, social and political development of any nation. As a result, the demand for energy is increasing worldwide, along with this, pollution is on the increase. Many parts of the world have as a consequence, suffered significant contamination. Khan et al (2004) pointed out that these oil contaminants enter the environment directly as a result of oil waste (sludge), spills during exploration, production and transportation, leakage from storage sites, or from industrial facilities. Oil spillage and oily waste deposits represent the majority of hydrocarbon contamination of our planet. Al-Saleh and Obuekwe (2005) asserted that accidental and deliberate oil spills have been and still continue to be a significant source of environmental pollution. Contamination of soil arising from spills is one of the most limiting factors to soil fertility and hence crop productivity as well as animal activity. Also the runoff from oil spill impacted site usually degrade the quality of the fresh water source which serves the domestic rural water supply needs of the host communities. Molina-Barahona et al (2004) corroborated that oil spills caused great damages to the ecology and economy of rural regions as well as nations. Therefore these polluted areas constitute a big potential risk to human health, environment, subsoil infrastructure, flora and fauna as well as groundwater.
2.3 Causes of oil contamination
Crude oil is extracted world-wide at a very high rate to meets the bulk of the world’s energy requirements. At the same time, crude oil constitutes a potential hazard if discharged into the environment. Such discharge happens despite the fact that the distribution and storage network for crude oil is closely and well monitored.
Oil development activities involve several polluting processes. The extent of these processes depends mainly on the environmental practices and technology used by oil companies. Apart from oil spills that mainly cause oil contamination of land, there are other different operations in the petroleum industry that cause contamination. These include drilling operation, leakage from wellhead and pipeline and over-flows at gathering stations.
Fisher and Sublette (2005) stated that these causes of oil contamination are as a result of overflows, intentional dumping , illegal activity, aging facilities, equipment failure, operator’s error, construction defect, accidental damage, transport accident, defeat/bypassing protective system, ineffective quality control, over pressuring, natural phenomenon, blow out of oil well, sabotage and corrosion.
During drilling, each well that is drilled produces drilling wastes, including formation water and drilling muds. Miguel and Anna-Karin (2004) pointed out that these wastes are frequently deposited into open pits, from which they are either directly discharged into the environment or leached out as the pits degrade or overflow from rainwater. Extraction of oil is also accompanied by seepage and spills. Offshore drilling routinely creates low level spills, and sometimes causes a “blowout,” a massive gush of petroleum. Most oil-wells are situated in deserts and oceans, which is where the majority of the world’s documented blow-outs have occurred. Storage facilities and pipelines can typically be destroyed by e.g.; either natural disasters like hurricanes, or accidents during construction or due to acts of sabotage or ageing of the facilities all resulting in release of large amounts of oil.
The table below shows incident oil spill causes and number of incidents between 2000 and 2008.
Table 1: Incident oil spill causes 2000-2008
2007
Incidents Causes
No of incidents
2000
2001
2002
2003
2004
2005
2006
2007
2008
Equipment failure
8,383
8,429
8,341
9,132
10,078
9,958
10,209,
10,849
8,578
Operator error
3,459
2,885
2,305
2,889
2,997
2,684
2,908
2,885
3,022
Transport accidents
609
713
563
631
1,050
1,152
1,103
1,361
1,387
Dumping
1,523
1,494
1,265
960
806
757
863
1,004
935
Natural phenomenon
472
716
497
711
685
575
804
708
726
Sabotage
6,428
7,204
7457
6,531
3,907
3,865
3858
3860
3,942
Accidental spillage(aging facilities, construction defect, blow out of oil well, etc)
10,552
11,800
10,266
10,314
10,078
9,958
10,209
10,849
10,578
Source: (National response center statistics U.S 2008)
It is observed from the table above that equipment failure and accidental spillage are the two main causes and these account for over 50% of oil spillage cause. Accidentals spillage could be as a result of traffic accident, aging facilities and blow-out of oil well.
In addition to the above table, European Environmental Agency report that tanker accidents account for about 10-15 per cent of all oil that spill into the ocean world-wide every year. Fingas and Charles (2001) argued that oil spills accounts for a highest number and volume of oil contamination. Mokhalalati et al (2000) demonstrated that observations from many oil spill incidents around the world have shown that both land and aquatic environment suffer oil exposure and these environments are particularly difficult to protect and also clean- up once a spill has occurred.
2.4 Effects of oil contamination
The oil and gas sector is one of the most lucrative sectors in business but reducing its negative impacts is one of the most pressing issues today. As an example, one barrel of crude oil can make one million barrels of water undrinkable and make hectares of land and water bodies useless. It has also destroyed crops, damage the quality and productivity of soil use for farming and as well damage fisheries. This exacerbates hunger and poverty in affected communities. In addition the residents often experience an increase of conflict with their neighbourhood.
Miraglia, A.R (2002) observed that Chenega Bay, Niger Delta, Ecuador indigenous communities etc have been fighting due to oil compensation. This has resulted in killing of people, destroying of houses, property, etc.
Khan,M.I and Islam,R.M (2003) asserted that practically all activities of hydrocarbon operations are accompanied by undesirable discharges of liquid, solid and gaseous wastes which have enormous devastating impacts . When oil reaches and penetrates into the soil and deep sea, the effects will be apparent for long period of time, thus the oil that reaches quickly will be more toxic. The effect depends on the following factors such as; size of the spill, the spread of the oil slick, the toxicity and persistence of the oil and the sensitivity of the environmental region affected.
Find Out How UKEssays.com Can Help You!
Our academic experts are ready and waiting to assist with any writing project you may have. From simple essay plans, through to full dissertations, you can guarantee we have a service perfectly matched to your needs.
View our academic writing services
However oil contamination has caused a range of pervasive impacts on the environment, human health, economy and society. Ecological effects may include physical and chemical changes in habitats, changes in growth or behaviour and increased mortality of organisms and species. Wildlife can be impacted by direct physical contact with the oil, e.g., filterfeeding shellfish and bird eggs can be smothered by oil and the feathers of birds or the fur of seals lose their insulating properties when coated with oil, leading to the danger of death from cold. Also if oil is ingested, it can damage the digestive system of the animals. Its vapours have the potential to damage the nervous system of animals, as well as their lungs and liver.
The oil impedes proper soil aeration as oil film on the soil surface acts as a physical barrier between air and the soil and this affects soil fertility which consequently has great negative impact on food productivity. Oil contamination affects certain soil parameters such as the mineral and organic matter content, the cation exchange capacity, redox properties and pH value. As crude oil creates anaerobic condition in the soil, coupled to water logging and acidic metabolites, Onwurah et al (2007) stated that the result is high accumulation of aluminum and manganese ions, which are toxic to plant growth.
The smearing root plants with oily substances may cause the plants to wilt and die off due to blockage of stomata inhibiting photosynthesis, transpiration, respiration and reduces permeability of cell membranes. Due to the toxic nature of oil, Pezeshki et al (2000) asserted that petroleum-based products have adverse impact on yields of various plant species and in high doses they can depress germination of plants and cause necrosis of seedlings.
A substantial high rate of illness as well as psychological and physical symptoms is usually reported in areas affected by spill oil and on increase on the days when oil exposure was at its highest. Rodrigue-Trigo et al (2007) stated that these illnesses include; respiratory tract irritation, vertigo, headache, sore eyes, sore throat and exacerbation of asthma. They further stated that anxiety and depression rate is usually on high increase in the exposed region.
Oil contamination has shown to have great influence on the engineering properties and behaviour of a soil. Puri, K.V (2000) corroborated that it has resulted in decrease in shear strength of a clayey soil, angle of internal friction of sand based on total stress condition decrease with the presence of oil in the pore spaces and compression characteristics of sand are significantly influenced. Khamehchiyan et al (2007) asserted that it has resulted in decrease in the value of the constrained modulus with increase in the degree of oil saturation. Oil contamination induces a reduction in permeability and strength of soil samples. Generally oil contamination has drastically reduced the bearing capacity of the soil.
2.5 Worldwide issues: Oil spill across the world
In the last decade, a lot of oil contamination across the world has been experienced as a result of oil spill incident which account for highest cause of oil contamination. Meniconi et al (2002) pointed out that, characterizing the spilled oil, monitoring the affected ecosystem, determining the fate of the oil in the environment and subsequently assessing the environmental damage caused have been a pressing issue. The spill case studies described below encompass crude and fuel oil release on coastal ecosystems and land. We know that oil spill on sea can spread and dispersed to land by wind, tide, wave action and rainfall. Any oil spill on sea also affects the land. Some of the oil spill case studies in Nigeria and major spills across the world are highlighted below;
The Torrey canyon supertanker disaster (1967)
This is the first major oil spill to awaken the international community to the dangers of oil transport. On 18th March, 1967 the Torrey Canyon carrying 117000 tons of Kuwait crude oil ran aground on the Pollard’s Rock in the Seven Stones reef between the Scilly Isles and Land’s End, England. Approximately119, 000 tonnes of Kuwait oil leaked from the ship and spread along the sea between England and France, killing most of the marine life it touched along the whole of the south coast of Britain and the Normandy shores of France.
Sands, P. (2003).
The Torrey Canyon oil spill proved for the first time the immense environmental damage that could result from an accident involving a large oil tanker as well as revealed the problems inherent in the international system for assessing liability and compensation for oil spill damage. Jacobsson (2007) stated that this spill triggered the International Compensation Convention.
Exxon Valdez (1989)
In March 1989, the tanker Exxon Valdez hit a reef in Prince William sound, Alaska and spilled about 37,000 tonnes of oil, the worst spill in US history. The spill subsequently affected a variety of shores, mainly rock and cobble, to varying degrees over an estimated 1,800km in Prince William Sound. The spilled oil impacted a wide range of intertidal organisms and as a result thousands of marine animals and seabirds were killed. (Peterson 2001)
Braer (1993)
The oil tanker Braer ran aground at Garth’s Ness on the Southern Shetland Isles Coast on 5th January, 1993 spilling approximately 84,700 tonnes of crude oil. The spilt oil was dispersed naturally in the wave action against the North Sea. The BRAER spill was unusual in that a significant amount of oil was blown on to land adjacent to the wreck site. Seabird casualties were also moderately low. Considering the size of the spill, the environmental impacts were surprisingly limited . (Gregory – 2007).
Erika Incident
The Maltese tanker ERIKA, carrying some 31,000 tonnes of heavy fuel oil, broke in two in a severe storm in the Bay of Biscay on 11th December, 1999, off the coast of France. About 20,000 tonnes of oil were spilled. The main environmental impact of the spill was on sea birds and 65,000 oiled birds were collected from beaches, of which about 50,000 were dead. This incident led to rapid moves to accelerate the phasing out of all single hull oil tankers. (Le Moigne, and Laubier, 2004).
Prestige (2002)
In September 2002, oil tanker prestige sunk of the Galician north west of Spain spilling about 30,000 tonnes of oil. The spilled oil affected the entire coastline particularly the exposed rocky shores and sandy beaches which caused the largest ecological catastrophe in the history of Spain (de la Huz et al, 2005). Bernabeu et al (2006) observed that the spill had a huge economic impact as it affected the fishing and marine cultivation on which the Costa da Morte (Galicia, N.W. Spain) depends economically.
Tasman Spirit (2003)
The oil tanker Tasman spirit grounded in the channel of the port of Karachi, on 27th July, 2003 carrying a cargo of 67,535 tonnes of light crude. Approximately 30,000 tonnes of oil spilled when the Tasman Spirit broke down. Strong winds and rough seas spread the light crude along 10 kilometres (seven miles) of the highly populated residential and recreational coastline. As a result of the spill incident, people living around the area have experienced health problems. The coastal environment in which the Tasman Spirit spill occurred was a rich and diverse tropical ecosystem which was negatively affected by the spill. (Janjua et al 2006)
Gulf war 1991
The Gulf War in Kuwait 1991 resulted in one of the largest man made environmental disasters, and almost certainly the greatest acute contamination of land and water with oil, in history as the result of oil spills. Kostreba (1999) described that during the Gulf war an estimated 67 million tonnes of crude oil was spilt and burnt on land. The oil spills were as a result of deliberate damage done by Iraqi forces during their invasion of Kuwait. Crude oil was deliberately dumped into the gulfs and oil production, storage, and refining facilities were destroyed. The oil leaking from the well heads, storage tanks, and pipelines formed huge oil lakes as deep as 2 meters. Many of the oil wells were also set on fire and this resulted in the aerial deposition of partially combusted oil particles and associated non-combusted products of the oil fires, which also polluted large areas.
The resulting oil pollution affected mainly Kuwait and Saudi Arabia. Hans-Jorg Barth (2001) pointed out that over 700 km of coastline from southern Kuwait to Abu Ali Island were smothered with oil and tar, erasing most of the local plant and animal communities.
Lebanon (2006)
During hostilities in Lebanon in 2006, Isreali planes struck the Jiyyeh power plant about 25 kilometres south of Beirut. The hit storage tanks leaked 20,000 to 30,000 tonnes of oil into Eastern Mediterranean Sea. The oil slick covered 170km of coastline and was threatening Turkey and Cyprus. This is the worst environmental problem in the history of the country. The oil spill damaged land and marine ecosystems, destroyed fishermen’s livelihoods and rendered coastal areas lifeless. To worst the issue, no clean-up started until after three weeks due to security situation in Lebanon. (Friends of the Earth 2007).
Ogbodo oil spill
On 24th June, 2001 the community of Ogbodo in Rivers State, Nigeria, heard a loud explosion which was the bursting of a Shell Petroleum pipeline which traverses the village lands and waterways. Crude oil began to spill out into the environment. Rains and swiftly flowing water rapidly distributed the crude oil into the waterways surrounding the community. At least about 26,500 barrels of oil were spilt. The impact of the spill and the fire on local livelihoods was extensive and the devastating impact of the oil spill was exacerbated and prolonged because of failure to contain the spill swiftly.
(www.waado.org).
Oshire-2 oil spill
According to Osuji and Opiah, (2007) on the 24th July, 2003, an oil spillage occurred in Ogba/Egbema/Ndoni Local Government Area of Rivers State in Niger Delta region of Nigeria. The oil spill was as a result of leakage of one of the above-ground pipelines that criss-cross the Oshire-2 oil field. About 3,000 barrels of crude oil was allegedly spilled as a result a suspected sabotage.
Oil spill in Ogoniland
Ogoniland is the site of huge Shell facilities that have devastated the local environment. On June 6, 2001, Shell oil pipeline, which passes through the Baraale community, ruptured and started spilling crude oil into nearby forests, farmlands and houses. Many houses were flooded with crude oil. Disaster struck on 1st October, 2001, when the leaking oil caught fire. Residents of the community were about going to bed that night when a large fire started following a loud explosion. (Olukoya 2002). Also on 1 Sep 2003Crude oil from a ruptured oil pipeline caught fire, destroying farmland and polluting streams in the Ogoni area.
This Day (2006) reported that oil spill from one of the Shell company’s oil wellheads has devastated another Ogoni community. The spill is as a result of leak which occurred at Bomu Well-2, a dormant well in Ogoni land belonging to Shell Petroleum Development Company of Nigeria limited.
Oil spill incidence in Nigeria has become everyday news and its occurrence is too numerous that it can’t all be highlighted in this study. Federal ministry of Environment on 2006 reported that quantity of oil spilled over 50 years is equivalent to 50 Exxon Valdez spills. This makes the Nigeria delta one of the 5 most oil polluted environments in the world.
2.6 Oil spill in Nigeria
2.6.1 Oil exploration in Nigeria
In 1956, Royal Dutch Shell discovered crude oil at Oloibiri, a village in the Niger Delta, and the first commercial production started in 1958. Nwilo and Badejo (2005a) stated that 50 years later, 606 oil fields exist in the Niger Delta, of which 360 are on-shore and 246 off-shore. Nigeria is now the largest oil producer in Africa and the sixth largest in the world, averaging 2.7 million barrels per day (bbl/d) in 2006. Nigeria’s economy is heavily dependent on earnings from the oil sector, which provides 20% of GDP, 95% of foreign exchange earnings, and about 65% of budgetary revenues (Central intelligence Agency (CIA) World Fact Book, 2005).
Current oil exploration and production activities in Nigeria is concentrated in the Niger Delta region, a huge fertile wetland which covers a land mass of over 70,000 km2, and cuts across 800 oil producing communities. Oguejiofor (2008) demonstrated that the region has huge oil and gas reserve and accounts for 90 per cent of national exports and 70 per cent of Government revenue, mainly from oil and gas exported is from the region. Geological record and research shows that the region (both onshore and offshore areas) is particularly conducive for the formation and accumulation of oil and gas. Today, the oil industries are highly visible in the Niger Delta and have control over a large area in the region. The area is crisscrossed by thousands of kilometres of pipeline, punctuated by wells and flow stations. Much of the oil infrastructure is located close to the homes, farms and water sources of communities.
2.6.2 Overview of the damage in the Niger delta
Oil and gas activities and enormous oil installations deployed in the Niger Delta explains her vulnerability to oil spill. The social and environmental costs of oil contamination have been extensive. These include destruction of wildlife and biodiversity, loss of fertile soil, pollution of air and drinking water, degradation of farmland and damage to aquatic ecosystems, all of which have caused serious health problems for the inhabitants of areas surrounding oil production. Oil spills in the Niger Delta have destroy vegetation, mangrove forests, food/cash crops, fishing ground/marine life, reduces nutrient value of the soil, induces land fragmentation, and sets communities on fire. For example a spill at Osima creek in Agbakabiriyai, near Nembe on February 28th 1998, led to eight days of fire, which razed down the entire community. This resulted to the destruction of about 400 houses, and the displacement of about 130,000 inhabitants. Also a spill that occurred on 7th December, 2008 in Ikarama community terribly caught fire on 1st of March 2009. The fire caused more damage to the environment (www.eration.org/index.php?). Given these challenges, land as an economic power resource base becomes critical for the Niger Delta region.
Without fertile soil and good water, indigenous communities in the region lose their mode of survival and are faced with the crisis of food shortages. Due to oil spillage, many water ways, land and marine systems in the region have been badly polluted and residents have been badly affected by enviro
Cite This Work
To export a reference to this article please select a referencing style below:
