This thesis examines the socio-cultural and demographic factors influencing sanitation conditions in Ghana, identifies the presence of Escherichia coli in household drinking water samples and investigates prevalence of diarrhoea among infants. It is based on questionnaire interviews of 120 household heads and 77 caretakers of young children below the age of 5years, direct observation of clues of household sanitation practice as well as analyses of household water samples in six surrounding communities in Bogoso. Data collected was analysed using SPSS and the Pearson Product Moment Correlation Value(R) technique. The findings revealed that the sanitation condition of households improved with high educational attainment and ageing household heads. On the contrary, sanitation deteriorated with overcrowding in the household. Furthermore, in houses where the religion of the head of household was Traditional, sanitation was superior to those of a Christian head and this household also had better sanitary conditions than that with a Moslem head of household. Water quality analysis, indicated that 27 samples out of the 30 representing 90% tested negative for E. Coli bacteria whilst 17(56.7%) samples had acceptable levels of total Escherichia coli. Finally, it was found out that diarrhoea among infants were highly prevalent since 47 (61.04%) out of the 77 child minders admitted their wards had a bout with infant diarrhoea. Massive infrastructural development, supported by behavioural change education focussing on proper usage of sanitary facilities is urgently needed in these communities to reduce the incidence of public health diseases. Intensive health education could also prove vital and such programs must target young heads of household, households with large family size and households whose heads are Christians and Moslems.
BACKGROUND TO THE STUDY
Efforts to assuage poverty cannot be complete if access to good water and sanitation systems are not part. In 2000, 189 nations adopted the United Nations Millennium Declaration, and from that, the Millennium Development Goals were made. Goal 4, which aims at reducing child mortality by two thirds for children under five, is the focus of this study. Clean water and sanitation considerably lessen water- linked diseases which kill thousands of children every day (United Nations, 2006). According to the World Health Organization (2004), 1.1 billion people lacked access to an enhanced water supply in 2002, and 2.3 billion people got poorly from diseases caused by unhygienic water. Each year 1.8 million people pass away from diarrhoea diseases, and 90% of these deaths are of children under five years (WHO, 2004).
Ghana Water and Sewerage Corporation (GWSC) had traditionally been the major stakeholder in the provision of safe water and sanitation facilities. Since the 1960’s the GWSC has focussed chiefly on urban areas at the peril of rural areas and thus, rural communities in the Wassa West District are no exception. According to the Ghana 2003 Core Welfare Indicators Questionnaire (CWIQ II) Survey Report (GSS, 2005), roughly 78% of all households in the Tamale Metropolis, 97 percent in Accra, 86% in Kumasi and 94% in Sekondi-Takoradi own pipe-borne water. Once more, the report show that a few households do not own any toilet facilities and depend on the bush for their toilet needs, that is 2.1%, 7.3%, and 5% for Accra, Kumasi, and Sekondi-Takoradi correspondingly. Access to safe sanitation, improved water and improved waste disposal systems is more of an urban than rural occurrence. In the rural poor households, only 9.2% have safe sanitation, 21.1% use improved waste disposal method and 63.0% have access to improved water. The major diseases prevalent in Ghana are malaria, yellow fever, schistosomiasis (bilharzias), typhoid and diarrhea. Diarrhea is of precise concern since it has been recognized as the second most universal disease treated at clinics and one of the major contributors to infant mortality (UNICEF, 2004). The infant mortality rate currently stands at about 55 deaths per 1,000 live births (CIA, 2006).
The Wassa West District of Ghana has seen an improvement in water and sanitation facilities during the last decade. Most of the development projects in the district are sponsored by the mining companies, individuals and some non-governmental organisations (NGO’s). Between 2002 and 2008, Goldfields Tarkwa Mine constructed 118 new hand dug wells (77 of which were fitted with hand pumps) and refurbished 48 wells in poor condition. Also, a total of 44 modern style public water closets, were constructed in their catchment areas. The company also donated 19 large refuse collection containers to the District Assembly and built 6 new nurses quarters. The Tarkwa Mine has so far spent 10.5million US dollars of which 26% went into health, water and sanitation projects, 24% into agricultural development, 31% into formal education and the remaining went into other projects like roads and community centre construction ( GGL, 2008). Golden Star Resources (consist of Bogoso/Prestea Mine and Wassa Mine at Damang) also established the community development department in 2005 and has since invested 800 thousand US dollars. Their projects include 22 Acqua-Privy toilets, 10 hand dug wells (all fitted with hand pumps) and supplied potable water to villages with their tanker trucks (BGL, 2007). Other development partners complimenting the efforts of the central government include NGO’s WACAM, Care International and Friends of the Nation (FON). WACAM is an environmentally based NGO which monitors water pollution by large scale mining companies. They have sponsored about 10 hand dug wells for villages in the district. Care International sponsors hygiene and reproductive health programmes in schools and on radio. They have also donated a couple of motor bicycles to public health workers in the district who travel to villages.
The aims of all these projects were to improve hygiene and sanitation so as to reduce disease transmission. Despite efforts by the development partners, water supply and sanitation related diseases are highly prevalent in the district. Data obtained from the Public and Environmental Health Department of the Ministry of Health (M.O.H., 2008) showed that the top ten most prevalent diseases in the district include malaria, acute respiratory infections, skin diseases and diarrhoea. The others are acute eye infection, rheumatism, dental carries, hypertension, pregnancy related complications and home/occupational accidents. A lot more illnesses occur but on a lower scale and these include intestinal worms, coughs and typhoid fever. A complete data on the top ten diseases prevalent in the district is attached as Appendix D but below is a selection of the illnesses that directly result from bad water and sanitation practices.
The number of malaria cases decreased from 350 in 2006 to 300 cases per 1000 population in 2008. Despite the decrease, the values involved are still quite high. The incidence of diarrhoea among infants and acute respiratory infection remained 30 and 60 cases per 1,000 populations respectively. This can be attributed to several reasons, including population boom, lack of uninterrupted services and inadequate functioning facilities. In fact, according to the World Health Organization (WHO, 2004), an estimated 90% of all incidence of diarrhoea among infants can be blamed on inadequate sanitation and unclean water. For example, in a study of 11 countries in Sub-Saharan Africa, only between 35-80% of water systems were operational in the rural areas (Sutton, 2004). Another survey in South Africa recognized that over 70% of the boreholes in the Eastern Cape were not working (Mackintosh and Colvin, 2003). Further examples of sanitation systems in bad condition have also been acknowledged in rural Ghana, where nearly 40% of latrines put up due to the support of a sanitation program were uncompleted or not used (Rodgers et al., 2007). The author had a personal communication with the District Environmental Officer and he estimated that, approximately there are 224 public toilets, 560 hand dug wells, 1,255 public standpipes and 3 well managed waste disposal sites in the district. According to the 2006 projection, the population of the district is expected to reach 295,753 by the end of the year 2009 (WWDA, 2006).
Development partners in the past have concentrated their efforts on facilities provision only. They have not looked well at the possible causes of the persistence of disease transmission despite the effort they are making. Relationships between household’s socio cultural demographic factors and people’s behaviour with respect to the practice of hygiene could prove an essential lead to the solution of the problem. The fact is, merely providing a water closet does not guarantee that it could be adopted by the people and used well to reduce disease transmission. Epidemiological investigations have revealed that even in dearth supply of latrines, diarrhoeal morbidity can be reduced with the implementation of improved hygiene behaviours (IRC, 2001: Morgan, 1990). Access to waste disposal systems, their regular, consistent and hygienic use and adoption of other hygienic behavioural practices that block the transmission of diseases are the most important factors. In quite a lot of studies from different countries, the advancement of personal and domestic hygiene accounted for a decline in diarrhoeal morbidity (Henry and Rahim, 1990). The World Bank, (2003) identifies the demographic characteristics of the household including education of members, occupation, size and composition as influencing the willingness of the household to use an improved water supply and sanitation system. Education, especially for females results in well spaced child birth, greater ability of parents to give better health care which in turn contribute to reduced mortality rates among children under 5years (Grant, 1995). In a study into water resource scarcity in coastal Ghana, Hunter (2004) identified a valid association between household size, the presence of young children and the gender of the household head. It was noted that, female heads were less likely to collect water in larger households. Furthermore, increasing number of young children present increased the odds of female head/spouse being the household water collector. Cultural issues play active part in hygiene and sanitation behaviour especially among members of rural communities. For example, women are hardly seen urinating in public due to a perceived shame in the act but men can be left alone if found doing it. Also, the act of defecation publicly is generally unacceptable except when infants and young children are involved. The reason is that the faeces from young people are allegedly free from pathogens and less offensive (Drangert, 2004). Ismail’s (1999) work on nutritional assessment in Africa, detected that peoples demographic features, socioeconomic and access to basic social services such as food, water and electricity correlate significantly to their health and nutrition status. Specifically, factors such as age, gender, township status and ethnicity, which are basic to demography, can play a role in the quality of life especially of the elderly.
This research assessed people’s practice of personal hygiene in Bogoso and surrounding villages. It also identified the common bacteria present in household stored water sources. Furthermore, the research identified the relationships between some socio-cultural demographic factors of households and the sanitation practice of its members.
THE PROBLEM STATEMENT
The Wassa West District in the Western Region is home to six large scale mining companies and hundreds of small scale and illegal mining units. Towns and villages in the district have been affected by mining, forestry and agricultural activities for over 120 years (BGL EIS, 2005). Because of this development, the local environment has been subjected to varying degrees of degradation. For example, water quality analysis carried out in 1989 by the former Canadian Bogoso Resources (CBR) showed that water samples had Total coliform bacteria in excess of 16 colonies per 100ml (BGL EIS,2005). Most of the water and sanitation programs executed in the district exerted little positive impact and thus, diarrhoeal diseases are still very high in the towns and villages (See Appendix D on page 80).
However, in order to solve any problem it is important to appreciate the issues that contribute to it; after all, identifying the problem in itself is said to be a solution in disguise. Numerous health impact research have evidently recognized that the upgrading of water supply and sanitation alone is generally required but not adequate to attain broad health effects if personal and domestic hygiene are not given equivalent prominence (Scherlenlieb, 2003). The troubles of scarce water and safe sanitation provisions in developing countries have previously been dealt with by researchers for quite some time. However, until recent times they were mostly considered as technical and/or economic problems. Even rural water and sanitation issues are repeatedly dealt with from an entirely engineering point of view, with only a simple reference to social or demographic aspects.
Therefore, relatively not much is proven how the socio-cultural demographic influences impinge on hygiene behaviour which in turn influences the transmission of diseases. The relationship between household socio cultural factors and the sanitation conditions of households in the Wassa West District especially the Bogoso Rural Council area has not been systematically documented or there is inadequate research that investigates such relationship.
THE RESEARCH QUESTIONS
The following research questions were posed to help address the objectives;
- Why are the several sanitation intervention projects failing to achieve desired results?
- Why is the prevalence of malaria and diarrhea diseases so high in the district?
- What types of common bacteria are prevalent in the stored drinking water of households?
The main aim of this research was to investigate people’s awareness and practice of personal hygiene, access to quality water and sanitation and the possible causes of diarrhoeal diseases and suggest ways to reduce the incidence of diseases in the community. The specific objectives were;
- To assess the quality of stored household drinking water
- To establish the extent to which sanitation behaviour is affected by household socio-cultural demographic factors like age and education level of the head.
- To investigate the occurrence of diarrhoea among young children (0-59 months old) in the households.
- To identify and recommend good intervention methods to eliminate or reduce the outbreak of diseases and improve sanitation.
In addition to the above objectives, the following hypotheses were tested;
- Occurrence of infant diarrhoea in the household is independent on the educational attainment of child caretakers.
- There is no relationship between households’ background factors and the sanitation conditions of the household.
In this chapter, various literature related to the subject matter of study are reviewed. Areas covered are sanitation, hygiene, water quality and diarrhoeal diseases. Theories and models the study contributed to include USAID’s Sanitation Improvement Framework, the “F diagram” by Wagner and Lanois and the theory of Social learning.
Until recently, policies of many countries have focused on access to latrines by households as a principal indicator of sanitation coverage, although of late there has been a change and an expansion in understanding the term sanitation. Sanitation can best be defined as the way of collecting and disposing of excreta and community liquid waste in a germ-free way so as not to risk the health of persons or the community as a whole (WEDC, 1998).
Ideally, sanitation should end in the seclusion or destruction of pathogenic material and, hence, a breach in the transmission pathway. The transmission pathways are well known and are potted and simplified in the “F diagram” (Wagner and Lanois 1958) shown below by figure 3.1. The more paths that can be blocked, the more useful a health and sanitation intervention program will be.
It may be mentioned that the health impact indicators of sanitation programmes are not easy to define and measure, particularly in the short run. Therefore, it seems more reasonable to look at sanitation as a package of services and actions which taken together can have some bearing on the health of a person and health status in a community.
According to IRC (2001:0), issues that need to be addressed when assessing sanitation would include:
- How complete the sanitation programme is in addressing major risks for transmitting sanitation-related diseases;
- Whether the sanitation programme adopted a demand driven approach, through greater people’s participation, or supply driven approach, through heavy subsidy;
- Whether it allows adjustment to people’s varying needs and payment;
- If the programme leads to measurably improved practices by the majority of men and women, boys and girls;
- If it is environmentally friendly. That is; if it does not increase or create new environmental hazards (IRC, 2001)
Sanitation is a key determinant of both fairness in society and society’s ability to maintain itself. If the sanitation challenges described above cannot be met, we will not be able to provide for the needs of the present generation without hindering that of future generations. Thus, sanitation approaches must be resource minded, not waste minded.
Hygiene is the discipline of health and its safeguarding (Dorland, 1997). Health is the capacity to function efficiently within one’s surroundings. Our health as individuals depends on the healthfulness of our environment. A healthful environment, devoid of risky substances allows the individual to attain complete physical, emotional and social potential. Hygiene is articulated in the efforts of an individual to safeguard, sustain and enhance health status (Anderson and Langton, 1961).
Measures of hygiene are vital in the fight against diarrhoeal diseases, the major fatal disease of the young in developing countries (Hamburg, 1987). The most successful interventions against diarrhoeal diseases are those that break off the transmission of contagious agents at home. Personal and domestic hygiene can be enhanced with such trouble-free actions like ordinary use of water in adequate quantity for hand washing, bathing, laundering and cleaning of cooking and eating utensils; regular washing and change of clothes; eating healthy and clean foods and appropriate disposal of solid and liquid waste.
Diarrheal Dise ases
Diarrhoea can be defined in absolute or relative terms based on either the rate of recurrence of bowel movements or the constancy (or looseness) of stools (Kendall, 1996). Absolute diarrhoea is having more bowel movements than normal. Relative diarrhoea is defined based on the consistency of stool. Thus, an individual who develops looser stools than usual has diarrhoea even though the stools may be within the range of normal with respect to consistency.
According to the United States Centre for Disease Control and Prevention (CDC, 2006), with diarrhoea, stools typically are looser whether or not the frequency of bowel movements is increased. This looseness of stool which can vary all the way from slightly soft to watery is caused by increased water in the stool. Increased amounts of water in stool can occur if the stomach and/or small intestine produce too much fluid, the distal small intestine and colon do not soak up enough water, or the undigested, liquid food passes too quickly through the small intestine and colon for them to take out enough water. Of course, more than one of these anomalous processes may occur at the same time. For example, some viruses, bacteria and parasites cause increased discharge of fluid, either by invading and inflaming the lining of the small intestine (inflammation stimulates the lining to secrete fluid) or by producing toxins (chemicals) that also fire up the lining to secrete fluid but without causing inflammation. Swelling of the small intestine and/or colon from bacteria or from ileitis/colitis can increase the haste with which food passes through the intestines, reducing the time that is available for absorbing water. Conditions of the colon such as collagenous colitis can also impede the capacity of the colon to soak up water.
Escherichia coli O157:H7 is probably the most dreaded bacteria today among parents of young children. The name of the bacteria refers to the chemical compounds found on the bacterium’s surface. Cattle are the main sources of E. coli O157:H7, but these bacteria also can be found in other domestic and wild mammals. E. coli O157:H7 became a household word in 1993 when it was recognized as the cause of four deaths and more than 600 cases of bloody diarrhoea among children under 5years in North-western United States (US EPA, 1996). The Northwest epidemic was traced to undercooked hamburgers served in a fast food restaurant. Other sources of outbreaks have included raw milk, unpasteurized apple juice, raw sprouts, raw spinach, and contaminated water. Most strains of E. coli bacteria are not dangerous however, this particular strain attaches itself to the intestinal wall and then releases a toxin that causes severe abdominal cramps, bloody diarrhoea and vomiting that lasts a week or longer. In small children and the elderly, the disease can advance to kidney failure. The good news is that E. coli O157:H7 is easily destroyed by cooking to 160F throughout.
Reducing diarrhoea morbidity with USAID’s Framework
To attain noteworthy improvement in reducing the number of deaths attributed to diarrhoea, its fundamental causes must be addressed. It is approximated that 90% of all cases of diarrhoea can be attributed to three major causes: insufficient sanitation, inadequate hygiene, and contaminated water (WHO 1997). According to USAID, for further progress to be made in the fight against diarrhoea, the concentration will need to include prevention, especially in child health programs. The first method, case management of diarrhoea, has been tremendously successful in recent years in reducing child mortality. The primary process of achieving effect has been through the initiation and operation of oral rehydration therapy; i.e. the dispensation of oral rehydration solution and sustained feeding (both solid and fluid, including breast milk).
In addition, health experts have emphasized the need for caretakers to become aware of the danger signs early in children under their care and to obtain suitable, appropriate care to avoid severe dehydration and death. The second approach, increasing host resistance to diarrhoea, has also had some victory with the enhancement of a child’s nutritional status and vaccination against measles, a familiar cause of diarrhoea. The third element is prevention through hygiene improvement. Although the health care system has dealt comprehensively with the symptoms of diarrhoea, it has done insufficiently to bring down the overall incidence of the disease. Despite a drop in deaths owing to diarrhoea, morbidity or the health burden due to diarrhoea has not decreased, because health experts are treating the symptoms but not addressing the causes. Thus, diarrhoea’s drain on the health system, its effects on household finances and education, and its additional burden on mothers has not been mitigated. Programs in several countries have confirmed that interventions can and do reduce diarrhoea morbidity. A critical constituent of successful prevention efforts is an effective monitoring and appraisal strategy.
In order to reduce transmission of faecal-oral diseases at the household level, for example, an expert group of epidemiologist and water supply and sanitation specialist concluded that three interventions would be crucial. These are:
- Safer disposal of human excreta, particularly of babies and people with diarrhoea.
- Hand washing after defecation and handling babies’ faeces and before feeding, eating and preparing food, and;
- Maintaining drinking water free from faecal contamination in the home and at the source (WHO, 1993).
Studies on hand washing, as reported in Boot and Cairncross (1993), confirm that it is not only the act of hand washing, but also how well hands are washed that make a difference. To prevent diarrhoea, its causes must first be fully tacit. According to the USAID’s hygiene improvement framework, a thorough approach to diarrhoea at the national level must tackle the three key elements of any triumphant program to fight disease. These are; contact with the necessary hardware or technologies, encouragement of healthy behaviours, and assistance for long-term sustainability. The concept is explained by figure 3.3 below;
The first part, water supply systems, addresses mutually the issue of water quality and water quantity, which reduces the risk of contamination of food and drink. Similarly, ensuring access to water supply systems can greatly ease the time women spend collecting water, allowing more time to care for young children and more time for income generating activities. The third element, household technologies and materials, refers to the increased accessibility to such hygiene supplies as soap (or local substitutes), chlorine, filters, water storage containers that have restricted necks and are covered, and potties for small children. The second element of the hardware component, toilet facilities, involves providing facilities to dispose off human excreta in ways that safeguard the environment and public health, characteristically in the form of numerous kinds of latrines, septic tanks, and water-borne toilets. Sanitation reporting is important because faecal contamination can spread from one household to another, especially in closely populated areas.
WATER QUALITY STANDARDS AND GUIDELINES
Water quality is defined in terms of the chemical, physical, and biological constituents in water. The word “standards” is used to refer to legally enforceable threshold values for the water parameters analyzed, while “guidelines” refer to threshold values that are recommended and do not have any regulatory status. This study employs the world health organization (WHO) and the Ghana standards board (GSB) “standards” and “guidelines” in determining the quality of water.
Water Quality Requirements for Drinking Water – Ghana Standards
The Ghana Standards for drinking water (GS 175-Part 1:1998) indicate the required physical, chemical, microbial and radiological properties of drinking water. The standards are adapted from the World Health Organizations Guidelines for Drinking Water Quality, Second Edition, Volume 1, 1993, but also incorporate national standards that are specific to the country’s environment.
The Ghana Standards set the maximum turbidity of drinking water at 5 NTU. Other physical requirements pertain to temperature, odour, taste and colour. Temperature, odour and taste are generally not to be “objectionable”, while the maximum threshold values for colour are given quantitatively as True Colour Units (TCU) or Hazen units. The Ghana Standards specify 5 TCU or 5 Hazen units for colour after filtration. The requirements for pH values set by the Ghana Standards for drinking water is 6.5 to 8.5 (GS 175-Part1:1998).
The Ghana Standards specify that E.coli or thermotolerant bacteria and total coliform bacteria should not be detected in a 100ml sample of drinking water (0 CFU/100ml). The Ghana Standards also specify that drinking water should be free of human enteroviruses.
WHO Drinking Water Guidelines
Although no health-based guideline is given by WHO (2006) for turbidity in drinking water, it is recommended that the median turbidity should ideally be below 0.1 NTU for effective disinfection.
Like the Ghana Standards, no E.coli or thermotolerant bacteria should be detected in a 100 ml sample of drinking water.
Water Related Diseases
Every year, water-related diseases claim the lives of 3.4 million people, the greater part of whom are children (Dufour et. al, 2003). Water-related diseases can be grouped into four categories ( Bradley, 1977) based on the path of transmission:
- waterborne diseases,
- water-washed diseases,
- water-based diseases,
- insect vector-related diseases.
Waterborne diseases are caused by the ingestion of water contaminated by human or animal faeces or urine containing pathogenic bacteria or viruses. These include cholera, typhoid, amoebic and bacillary dysentery and other diarrhoeal diseases. Water washed diseases are caused by poor personal hygiene and skin or eye contact with contaminated water. These include scabies, trachoma and flea, lice and tick-borne diseases. Water-based diseases are caused by parasites found in intermediate organisms living in contaminated water. These include dracunculiasis, schistosomiasis and other helminths. Water related diseases are caused by insect vectors, especially mosquitoes that breed in water. They include dengue, filariasis, malaria, onchocerciasis, trypanosomiasis and yellow fever.
The Theory of Social Learning
Learning is any relatively permanent change in behaviour that can be attributed to experience (Coon, 1989). According to the social learning theory, behavioural processes are directly acquired by the continually dynamic interplay between the individual and its social environment (Mc Connell, 1982). For example, children learn what to do at home by observing what happens when their siblings talk back to their parents or throw rubbish into the household compound.
The learning process occurs through reinforcement and punishment. Reinforcement refers to any event that increases chances that a response will occur again (Coon, 1989). Reinforcement and punishment can be learned through education where the person can read about what happens to people as a result of actions they make. The elementary unit of society is the household and this can be defined as a residential group of persons who live under the same roof and eat out of the same pot (Friedman, 1992). Social learning is necessary for the household in acquiring the skills pertinent to the maintenance of health promoting behaviour. Most of our daily activities are learned in the household. Individuals begin to learn behaviour patterns from childhood by observing especially the parents and later on their siblings.
The environment is understood as comprising the whole set of natural or biophysical and man-made or socio-cultural systems, in which man and other organisms live, work or interact (Ocran, 1999). The environment is human life’s supporting system from which food, air and shelter are derived to sustain human life. Humans interact with the physical and man-made environment and this interaction creates a complex, finely balanced set of structures and processes, which evolve over the history of a people. These structures and processes determine the culture of the society, their social behaviour, beliefs and superstition about health and diseases. Social relationships seem to protect individuals against behavioural disorders and they facilitate health promoting behaviour (Barlow and Durand, 1995; Ho
Cite This Work
To export a reference to this article please select a referencing stye below:
Related ServicesView all
Related ContentAll Tags
Content relating to: "Health and Safety"
Health and Safety is a set of regulations, policies, procedures, and guidelines that aim to prevent any accidents or injuries from occurring. Health and Safety procedures are essential to ensuring a safe, efficient working environment.
Health and Safety Case Study: KunShan Explosion and Cancer at Samsung
Table of Contents Assignment Title: Section 1: Literature Review 1.1 Definition of Employment relation: 1.2 The importance of Employment relation: 1.3 Health and safety Section 2: Case Study 2.1 KunS...
ESTIMATION OF EMISSIONS NEAR ROAD CONSTRUCTION PROJECTS AND THEIR IMPACTS ON WORKERS HEALTH
ABSTRACT Highway maintenance workers spend most of their work time in traffic and are constantly exposed to traffic-related emissions produced from various sources that have severe impacts on their h...
DMCA / Removal Request
If you are the original writer of this dissertation and no longer wish to have your work published on the UKDiss.com website then please: