Construction of tunnels, either to pave the way for vehicles, pedestrians, and/or water, requires civil engineers to consider the impacts that such an endeavour has on the environment. A tunnel is a duct that goes through or under the earth surface or another structure purposely to offer passage for rains, people, and cars amongst others.
The research goes down to unearth the impacts of construction of tunnels together with the current and future impacts of complete channels on the environment. Various investors who use tunnels, for example, environmental, electrical, mechanical, and civil engineers have been working hard to prevent environmental problem.
Several methods and procedures have been put in place to prevent environmental pollution (FHWA 2011: Rabier 2012: Sugarloaf Pipeline Alliance 2003). Various Acts have been made by congress to prevent pollution in tunnels. For instance, in 1980, Comprehensive Environmental Response Compensation and Liability Act (CERCLA) was enacted to provide funds to clean waste sites.
The study’s endeavour to analyse the various environmental conditions in tunnels will include various channels in various countries across the globe and various systems and methods that they adopt to prevent environmental pollution. The major areas of attention for this research are noise and air pollution, ground water pollution, use of resources, energy, and materials.
In most cases, pollution from tunnels results from various materials that end up leaving a lot of waste behind. This study will also be useful to engineers and other construction related undertakings. The research also analyses literature materials and references that have been carried out from the past concerning the subject under scrutiny by students (researchers) (Schuman, Olson, & Etheridge 1985).
Review of literature on various methods and efforts put forward to prevent the environment from tunnels will confirm whether there have been many efforts to curb environmental pollution from tunnels in various countries across the globe such as the Unites States’ Environmental Protection Agency (EPA).
However, the research will also confirm that efforts to reduce tunnel environmental pollution have achieved little or no success at all. This foundation makes clear the basis of various systems and methods of air pollution, noise pollution, visibility reduction, and ground water pollution. The research also discusses the theoretical framework behind various methods of protection of the environmental pollution from the tunnels.
It adopts various tools such as questionnaires to collect data from respondents from diverse tunnels. After gathering data, the survey analyses the results and reports them in the form of tables and graphs, which are then analysed and discussed in relation to the research problems.
The research finally concludes by a review of the analysis of the findings before making recommendations for various alterations and initiatives that are aimed at eliminating environmental pollution from tunnels.
While erection of tunnels is a rare undertaking that reduces congestion of vehicles and people besides easing the flow of liquids such as oil, industry wastes, and water, it is worth noting to consider and address the impact that the development and construction processes pose on the environment.
Lyakhova, Lukashenko, Larionova, and Tur (2012, p. 107) argue that environmental pollution that emanate from the tunnels may be in the form of ground water contamination during tunnel construction and after, noise pollution, air pollution, and construction pollution that will in turn affect the environment and community.
The EPA has been in place primarily to protect the environment in the United States from undertaking such as tunnel erection. It is applied in cases where the intensity of the use of the environment by tunnel constructors exceeds the ability of the environment to sustain it. The main negative impacts of tunnels on the environment are pollution and use of resources.
On the usage of resources, construction and the use of tunnels require a variety of natural resources for growth and sustenance. The main natural resources that are important in construction, development, and maintenance are water and land, which can easily be threatened by the impacts of use of tunnels.
When erection and use of tunnels are done without any control, a number of areas that occur naturally in many parts of the world can be destroyed. Too much pressure on land results in negative effects, for example increased level of soil erosion, pollution, loss of natural types of habitats, increased waste discharges to the sea, destruction of forests though fires, and increased strain especially on species that live underground.
This extends the pressure to water resources, which in turn makes the local populations compete for the use of significant resources (Lyakhova, Lukashenko, Larionova, & Tur 2012, p. 107). As a negative impact on the environment, pollution emanating from construction of tunnels can tamper with air, aesthetics, and water.
Lyakhova, Lukashenko, Larionova, and Tur (2012, p. 107) argue that, during construction and use of tunnels, the major source of pollution of water originates from oil and industrial wastes that are released or worse still pumped directly to water bodies like ocean, lakes, or even rivers.
It can also come from oil spills from vehicles and trains that provide transport in the tunnels as well as agrochemicals that are used in the maintenance of various sites for vehicles and train stops.
According to Giovanni et al. (2012, p. 171), management of the environment in the tunnels for example spraying of flowers and or even applying inorganic fertilizers and agrochemicals such as DDT on flowers, trees, and other parts of the flora that are essential for tunnel management results in soil pollution in the tunnels.
Mancilla and Mendoza (2012, p. 449) argue that the main sources of air pollution especially in tunnels emanate from the means of transport that is adopted by people, animals and even the objects that are part of tunnels. Most of them use cars that use fossil fuels. Cowie et al. (2012, 2918) point out the fact that, during combustion, these fossil fuels release pollutant gases into the air.
This kind of pollution is referred to as smog, which is a smoky mixture of carbon monoxide and organic compounds that result from incomplete combustion of fossil fuels such as coal, sulphur, and carbon dioxide. This emission is a health hazard to both human beings and animals.
Bari and Naser (2010, p. 70) reveal how the tunnels have also harboured photochemical smog that results from combustion from vehicles for example cars, lorries, and trains that use the tunnels. These vehicles emit nitrogen oxide and hydrocarbons that come from incomplete combustion of fuels.
When nitrogen is emitted into the atmosphere, the presence of sunbeams enables “nitrogen oxides and hydrocarbons to combine with oxygen to form the ozone” (Giovanni et al. 2012, p. 169). According to Giovanni et al. (2012, p. 169), the ozone is a harmful chemical to human beings and vegetation. It irritates the lungs and destroys plants. In addition, hydrocarbons are oxidised to form pungent haze.
As smog lives for a long period, it mixes with oxygen forming organic and sulphuric substances that condense in the atmosphere to form acid rains. When acid rains fall into forests and oceans, they cause the death of plants and aquatic animals. Eventually, lakes and water bodies that are contaminated end up becoming lifeless.
Construction of more tunnels continues to add harmful substances to the atmosphere hence damaging the environment, human health, and quality of life.
Mancilla and Mendoza (2012, p. 449) confirm that people become sick for instance by developing breathing difficulties while others suffer from cancer. Compounds such as Clorofluorocarbons (CFCs) that are used in refrigerators and air conditioners result in dangerous diseases such as cancer.
According to Giovanni et al. (2012, p. 169), by extension, human life is endangered when air pollutants from tunnels destroy the environment in which human beings, animals, and plants inhabit. Because of the CFCs) in the air, people become sick and even develop cancer. Since most of the tunnels are constructed underground, it becomes difficult to eliminate the aerosols from the tunnels.
Mancilla and Mendoza (2012, p. 449) point out to the fact that regions that have been hardly hit by the problem of air pollution and acid rains include the United States of America, Europe, and Canada. The countries have built tunnels that assist in the transportation of people, industrial raw materials, and products.
According to Mancilla and Mendoza (2012, p. 449), evidence of the impact of air pollution from tunnels can be clearly seen in the erosion of fabricated items and objects including the decomposition of historical statues and facades in Athens. Corrosion of buildings in London is another evidence of the effects of acid rains that results from air pollution. In Rome, many buildings have also weathered because of acid rains.
Presence of air pollutants in the environment because of emission of gases from the tunnels into the atmosphere also results in global warming. Cowie et al. g2012, 2918) argues that global warming has resulted in the increase of temperatures in the world following the build up of various atmospheric gases for example carbon dioxide and nitrogen.
Confirming the argument, Bari and Naser (2010, 70) posit that the use of fossils fuels in vehicles and trains that use tunnels results to the increase in temperatures on earth. From another perspective, Cowie et al. (2012, 2918) point out how there cannot be an escape of gases from the face of the earth with the greenhouse effect.
In fact, a scientific projection indicates an equivalent of 2.5 to 10.4 Fahrenheit degrees from the current level of 1.4 to 5.8 degree Celsius. Global warming will tamper with climatic conditions and patterns, distribution of animals, and increase in sea levels across the world.
Construction and maintenance of tunnels also results in noise pollution. As people and animals travel to various parts of the world, they use a variety of means of transport. People who live or work in busy national tunnels experience noise pollution. Trains and vehicles that move through these tunnels emit a loud noise into the air. This noise becomes even louder especially by the intensification of the effect of the tunnel.
Bari and Naser (2010, p. 70) reveal that there is also noise pollution when tunnel management areas get into construction of various facilities that are used in the process of construction.
Such causes include the use of earth moving machines to make gold pitches, use of lorries to deliver building materials, and even the use of heavy machines that facilitate the construction process. This aesthetic form of pollution is mainly in mountainous and coastal areas where tunnels are constructed while at the same time being ignorant of the aesthetic concerns.
Ground water pollution because of construction and use of channels is also evident. For example, in the United States of America, 37 percent of all lakes in the country and approximately 36 percent of rivers are currently polluted. In fact, this pollution has made rivers and lakes difficult to swim in and even to rear aquatic animals such as fish. CERCLA was meant to eliminate such wastes to restore the environment.
In some cases, channels dispose untreated substances into the water bodies, which on the other hand threaten human health. Water that leaks from the tunnels results in runoffs that carry various substances such as fertilisers, harmful chemicals such as Dichlorodiphanyltrichloroethane (DDT) phosphates, and other agrochemicals into water bodies.
When these fertilisers get into water bodies, they combine with phosphates that pave a way for the growth of algae grows. These algae decays and reduces oxygen in water bodies thus resulting in the chocking of organisms that live in water.
Dead algae are harmful to aquatic life for example Pfiesteria piscicida, which is a type of algae that led to the death of many fishes in various water bodies in Delaware Bay and the Gulf of Mexico in the 1990s.
Hazardous wastes are released from the tunnels. Such wastes include liquid, solid, and gaseous materials. These hazardous wastes may have high quantities of CFCs that result from various construction activities that are carried out in the tunnels.
These materials, which may include toxic substances, radioactive substances, industrial wastes, medical wastes, and solvents are harmful to people and the environment. In fact, about 400 million metric tons of hazardous wastes are developed every year. In the United States of America, about 250 million metric tons to 70 % hazardous materials result from chemical industries. It is also hazardous to transport the waste.
These materials are dangerous to human health since exposure to hazardous wastes can result in the death of thousands of people and animals. The wastes can also cause water, soil, air, and environmental contamination that last for years.
Exposure to these materials can also result in cancer, defective births, disorders of the nervous system, and to a certain extent death. A good example is the use of DDT, which has been recalled due to its harmful health effects.
The main theory behind pollution in channels is the miasma theory. Miasma is regarded as one of the most poisonous gases that are made up of decomposed materials. Miasmata are materials whose vapour causes sickness in human health. This theory posits that diseases are caused by pollution.
Since there is a link between environmental pollution and construction, maintenance and use of channels, the theory is adaptable to the situation. According to the miasma theory, diseases that attack animals and humankind are caused by environmental factors. Such environmental factors include contaminated air, polluted water, and dirty environmental conditions.
The miasma theory explains that diseases that are caused by contamination of air, water, and the environment are not transferrable from one person to the other. However, this theory explains that different individuals can acquire the disease causing pathogens directly from contaminated air, water, and the environment. The misasmatic theory has been popular across the world.
During the 1850s, this theory was used to explain the reasons why cholera spread speedily in the cities of London and in the city of Paris. According to the theory, it was possible to eliminate cholera from people and the two cities through cleaning of the environment and air.
Through the provision of a clean environment, people could get out of cholera. Pollution in the channels has been a major problem to administrators. Air, ground water, and noise pollution are evident in tunnels.
The other theory adopted in this research is the germ theory. Louis Pauster advanced this theory between 1860 and 1864. He realised that germs cause diseases. The germ theory is founded on the premise that various microorganisms that are found in contaminated air, water, and the environment cause diseases that affect human beings and animals.
Pollution that results from tunnels can lead into the multiplication of microbes that are likely to cause diseases to human beings and animals. Such disease-causing pathogens bring infections and hence diseases.
For example, the germ that causes cholera, dysentery, typhoid, and many other diseases multiplies in dirty environments. This case can only indicate that the presence of pollutants in tunnels is a major predisposing factor that threatens the life of users of the channels and even others that share a similar environment.
Research Techniques and Equipments
This part of research deals with research methodology that will be employed in conducting the study. It therefore covers the research locale, research design, target population, sample selection, research instruments, piloting, reliability of research instruments, validity of the research instruments, data collection procedures, data analysis, and reporting.
The locale of the study will be conducted in various channels in the United States of America. The choice of location will be based on how accessible the channels are to the researcher based on Singleton’s (1993) argument that the ideal setting for any study should be easily accessible to the researcher. Another basis for the choice of location is that no similar study has been carried out in the country.
The researcher is also concerned about the improvement of pollution prevention performance in the country. It is therefore in the researcher’s interest to investigate the possible factors that influence the performance of various pollution prevention measures to offer remedies to the same.
On research design, the study will adopt a descriptive survey design to investigate pollutants in tunnels and the corresponding influence of past prevention measures. The design involves collecting data from a given population to determine the status of the population concerning one or more variables.
Gay (1992) notes that this type of research design attempts to describe things such as behaviour and attitude of people towards the immediate and future outcome of tunnel construction processes. Therefore, the design is best suited for this study. The rationale behind the choice of the design is that it studies individuals or objects as whole units and not in parts.
The design also investigates a particular tunnel construction phenomenon in depth with a view of understanding it more broadly. Descriptive survey designs are used in the preliminary and explorative studies that allow researchers to gather, summarise, present, and interpret information for clarification. It is thus clear that the objectives of this research can only be achieved using descriptive survey design.
The target groups for this research are the various employees, management, and travellers who use tunnels in the United States. A sample that is fully representative of attitude and views of people that use tunnels shall be selected. This study will also adopt a certain sampling procedure. Sampling is a technique used by researchers to gather information. It involves selecting individuals or objects from a population or a group for study.
The selected group must contain elements that are representative of the characteristics found in the entire group. According to Gay (1992), if a sample is well selected, the research findings based on this sample can be generalised to the whole group population. It is thus fundamental to select a small but adequately representative sample since it will save considerable efforts, time, and finances.
Stratified random sampling will be used to select 50 employees, 20 managers, 10 engineers, and 50 travellers. The main research instruments to be used in this study will be questionnaires. In this case, three sets of questionnaires will be prepared for the target groups. These questions will target the employees, the management, and the engineers.
The questionnaires will have both open- ended and closed-ended questions. According to Kombo (2006), the closed form of questionnaires is easy to administer and fill in enabling the researcher to cover a relatively wide range of information in a short period.
They also state that anonymity of the respondents elicits more and candid responses. The researcher will also use interview schedules for the administrators upon booking an appointment with them.
A pilot study will be conducted to test the research instruments for example the questionnaire. The researcher will pre-test the questionnaire with one tunnel in the country, which will not be included in the final sample. The purpose of the pilot study will be to enable the researcher improve on the reliability and validity of the instruments, as well as familiarise with its administration.
The research will also test the validity of the research instruments. Mugenda and Mugenda (1999) define validity as the accuracy and meaningfulness of inferences that are based on the research results. This argument implies that the validity is the degree to which the results obtained from the analysis of the data represents the phenomena under study.
Validity is the degree to which an apparatus quantifies what it is required to evaluate. The authors also suggest that validity of an instrument is improved through an expert judgment. Therefore, the researcher will seek assistance from the supervisor to improve the content and instruments validity. The research will also test the reliability of the research instruments.
Reliability of research instruments is its level of internal consistency or suitability over time. A reliable instrument is therefore one that constantly produces the expected results when used more than once to collect data from two samples that are randomly drawn from the same population. The reliability of a standard test is usually expressed as a correlation that measures the strength of association between variables.
Such coefficients vary between 0.00 and 1.00, with the former showing that there is no reliability whereas the latter shows perfect reliability, which is very difficult to achieve in practice. Reliability coefficient shows the extent to which an instrument is free of error variance. The researcher therefore intends to test the research instruments to assess their reliability.
To achieve this goal, test-retest method will be used whereby one tunnel will be selected. The questionnaire will be given to the respondents to fill for a later scoring. After one week, the same questionnaire will be given to the same group for scoring. The researcher will accept the instruments as reliable at a correlation coefficient of 0.7.
Table 1.0 Rating of the presence of various pollutants in the tunnels in Belgium
|Rating of type of pollution in tunnel||Managers (out of 20)||Travellers (out of 50)||Employees (out of 50)||Engineers (out of 20)|
|Ground water pollution||10||20||10||5|
From the table above, we can deduce that the ratings of various stakeholders in the tunnels are closely related. The air pollution inside tunnels in Belgium was an issue to 80 percent of the managers, 90 percent of travellers, 96 percent by employees, and 50 percent of engineers.
The ratings differed with the amount of time that these stakeholders remain in the tunnels. Employees who are likely to remain in the tunnels for a longer period are likely to be the most affected respondents by the poor air quality.
On the other hand, various stakeholders also rated noise pollution differently. Various respondents cited it as a course of worry in the tunnels. From graph 1.0, it is clear that 60 percent of managers, 60 percent of travellers, 20 percent of employees, and 10 engineers cited noise pollution as a course to worry in tunnels.
It is worth noting the difference of 50 percent between managers and engineers. Ground water pollution was also a cause of worry for various stakeholders. For example, we can deduce from the table above how 50 percent of managers, 60 percent of travellers, 20 percent of employees, and 15% of engineers cited underground pollution from tunnels.
Environmental pollution through hazardous materials was also an important facet for to various stakeholders.
Graph 1.0 Rating of the presence of various pollutants in Belgium tunnels
From graph 1.0 above, it is clear that 50 percent of managers, 60 percent of travellers, 24 percent of employees, and 3 percent of managers were worried about environmental pollution.
Table 3.0 Noise pollution level in tunnels in Egypt at various points (in decibels)
|Station in Egypt||Noise level in decibels|
Table 3.0 above indicates that noise pollution in tunnels is normally above the acceptable levels. From graph 2.0, at all points where data on noise pollution was colleced, the ratings exceeded that of the acepted level. The graph indicates that in Egypt, noise pollution in tunels is very high relative to the normal background levels. At Gamaah location, the amount of noise was indicated as 70.
At Behoos, the noise level was at 75 decibels, 78 decibels at point Dukki, 72 percent at point Dokki, 74 decibels at Opera, 79 decibels at Sadaat, 72 decibels M.Naguib, and 70 decibels at Mubarak. This finding is also clear in the graph 2.0 below.
All the noise ratings that were collected from various points of the tunnels in Egypt indicated that the noise level was above the acceptable level. The graph below indicates that noise pollution was at its peak at Sadaat in Egypt with 79 decibels.
Noise pollution level was at the lowest at point Gamaah and Mubarak. The other points such as Benhoos were also at the peak with 78 decibels, which were way ahead of what is acceptable. The average noise level in the tunnels is far ahead of the acceptable intensity. We can therefore deduce that the high percentage of noise in tunnels will result in advance effects on both human beings and animals that use the tunnels.
Table 3.0 Comparison of tunnel air quality in terms of organic hydrocarbons and background air quality before pollution
|Compounds and hydrocarbons concentration pg/m3||Tunnel||Background|
Source: (Daisey, Cheney, & Lioy 1986)
From table 3.0 above, one can confirm the various air pollutants that increase with an increase in the use and construction of tunnels. Methane is the most prominent gas in the tunnels. From graph 3.0, methane had an indication of 1021 in the channels. This figure was only 54 metres cubed below that of the background environment, which is 1075. The second most prominent gas in the environment is Toluene.
This gas had an indication of 58 compared to the background presence of 4.2. This was a big range of difference. The big difference in volume indicates an emission of high quantities of this gas by vehicles and trains that use tunnels. Cowie et al. (2012, p. 2918) point out that Docane (a poisonous hydrocarbon) is emitted in high quantities in the tunnels.
The research found 29-metre cubed Docane gas in the tunnels. Compared to the background environment, there was a remarkable difference of 28.9. The research indicates that, although the amount of Docane in the air is low, use of tunnels by vehicles and trains increases its volume in the air.
Graph 3.0 Analysis of various organic compounds and hydrocarbons comparison of air quality in tunnels and backgrounds
Graph 3.0 above also indicates that Butane is also emitted in high quantities. According to the graph, Butane was indicated by 24 cubic metres in the tunnels and 4.1m3 in the background environment. The indication is that the use of tunnels highly increases the volume of Butane in the environment. According to Giovanni et al. (2012, p. 169), as a hydrocarbon, Butane may have advance effects on human beings, plants, and animals.
In conclusion, this research was set out to investigate pollution in channels and the reason behind the failure of various prevention efforts. The research found out that, with the increase in the number of tunnels in the world, there has been a corresponding increase in underground water pollution, air pollution, environmental pollution, and noise pollution.
Efforts by managers, engineers, and environmentalists to prevent pollution in tunnels have become futile. Mancilla and Mendoza (2012, p. 449) argue that air pollution has been the leading pollutant in the tunnels resulting from gases that are released into the air by vehicles and trains that use the tunnels. Gases such as Carbon, Butane, Toluene, and Nitrogen among others have side effects such as respiratory diseases.
Lyakhova, Lukashenko, Larionova, and Tur (2012, p. 107) argue that underground water pollution is also evident in tunnels as various wastes result from the use for water in the channels. The wastes are also released into water bodies. The research also indicates that noise pollution is evident in tunnels. Noise results from activities that take place in channels, for example from construction, vehicles, and trains.
Bari and Naser (2010, p. 70) confirm how noise in the tunnels exceeds the acceptable amount of decibels hence resulting in hearing problems. Environmental pollution was also evident in the tunnels following the resulting solid wastes from various construction activities.
The research recommends further research to be done on the remedies to air pollution especially on precipitation materials that are associated with tunnel erection. The research also advises that the governments of the world should put laws that control pollution especially in countries with pronounced use of tunnels. Noise pollution should also be reduced using low-noise vehicles and trains.
Vehicles and trains using the tunnels should also be fitted with silencers. The research recommends that organisations that are charged with the responsibility of maintaining environmental health should also be empowered to prosecute organisations and individuals who pollute the environment in the process of construction of tunnels.
Governments of the world should enact Acts that clearly spell out the levels of air pollution, underground water pollution, and noise pollution that are acceptable, or prohibited. The responsible organisations also have to engage the public through civic education.
Civic education will enable citizens to understand the implications of pollution in tunnels together with how to prevent it to achieve the desired environmental objectives (Spence 1983).
The research also recommends that governments also put in place various mechanisms to inspect and to regulate pollution in tunnels besides confirming to the tunnel contractors that they are not condemning their works but rather advocating for the contractors’ responsibility to curb, minimise, or handle properly any pollutants that arise in the course of their construction of the tunnels.
Such an effort will only translate to the good health of all people including the key construction stakeholders.
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