Natural resource and waste management in Tanzania

Tanzania, officially known as the United Republic of Tanzania, is a mid-sized country in southeastern Africa bordering the Indian Ocean. It is home to a population of about 43.1 million people. Since gaining its independence from the United Kingdom in 1961, Tanzania has been continuously developing in terms of its economy and modern industry. However, the country’s economic success has been limited. Environmental obstacles, such as the mismanagement of natural resources and industrial waste, have been contributing factors and results of the relatively low economic status of the country. Tanzania’s annual output still falls below the average world GDP. In 2010, the GDP for Tanzania was US $23.3 billion and the GDP per capita was US $1,515. Comparatively, the GDP for the United States was $15.1 trillion and the GDP per capita was approximately $47,153. Eighty percent of the workers accounting for this annual output in Tanzania work in agriculture, while the remaining 20% work in industry, commerce, and government organizations. Such a heavy reliance on agriculture has placed a huge amount of strain on an already limited supply of viable land.

Land use and degradation

Land in Tanzania is a valuable resource. Since most of the country is dry and arid, the wetlands surrounding Lake Victoria are the most fertile and consequently, in high demand for farming. These areas have been thoroughly evaluated to determine their potential and abundance of natural resources. The results have shown that these wetlands are indeed very productive ecosystems, rich in nutrients and capable of sustaining crop growth. However, the natural resources of the wetlands are being exhausted due to a lack of regulation over the use of the land. Long term sustainable practices have not been implemented to preserve the limited area available. Consequently, the parts of Tanzania around the wetlands are densely inhabited while much of the rest of the country is sparsely populated. The nutrient rich land is overused, overgrazed, and will slowly be depleted of its natural resources.

Land degradation is one of the leading environmental problems resulting from a mostly agricultural nation. Tanzania among other states in southern Africa is being adversely affected by DONKEY

inappropriate farming methods and overgrazing. Most of the eastern region of Africa, of which Tanzania is a significant part, gets less than 600 mm of rainfall each year. Regions with an average rainfall of 500–1000 mm are classified as semiarid climates. Achieving a high level of crop production with such a limited amount of rainfall is not wholly practical, leading many pastoral farmers to focus on raising livestock.

There are many economic benefits for raising livestock in developing countries. Typically, the monetary value for raising cattle and other associated animals is higher than the income potential from producing crops. Additionally, less manual labor is involved. However, there is a danger in becoming too reliant on livestock over crop production. Producing crops such as wheat, beans, and grains generates more food for large populations than does raising livestock. These vegetative food sources can be made to feed a much larger group of people than slaughtering individual animals. Not only that, but crops are also necessary to feed livestock which further limits the food supply. It has been projected that there will be a great food shortage in sub-Saharan Africa in the coming years resulting from decreased crop production. Solutions are being proposed to solve the problem, but they do not come without problems of their own. Suggestions for increased integration of crop and livestock production have been put forth in an attempt to maintain a balance between the two methods. However, increasing integration of these two products will lead to an overall intensification in agriculture, advancing the already permeating problem of land degradation and diminution of resources.

A different, possibly viable, solution has also been proposed: sustainable agriculture. The concept of sustainable agriculture is one that is not fully understood throughout the world and has many definitions. These can range from the idea of producing strictly organic crops to instituting fertilizing practices which better the environment rather than deplete it. However, the overarching concept of this new farming method implies shifting modern conventional agriculture away from focusing so much on generating capital. The desire for economic success is important, yet the heavy use of pesticides and chemical fertilizers in raising crops and livestock is not eco-friendly. However, there are several concerns raised with this approach. First, some farmers argue that as the world population continues to increase, sustainable agriculture will not be able to support the necessary amount of food production. Conventional farming’s heavy reliance on chemicals is believed to produce a much higher overall output than alternative farming methods. On the opposing side, supporters of agricultural sustainability argue that sustainable yields have the potential to exceed those of conventional agriculture. The crops produced would be less exposed to chemical toxins and better able to feed the human population.

Land degradation and effects on human health

While the increasing trend of exhausted land use has been shown to cause various environmental problems, physical human health issues can result as well. Research has shown that many parts of the world affected by land degradation and human interference are experiencing much higher rates of infectious disease. As land degradation increases across the globe, the status of human health is affected by the changing ecological systems that play host to various pathogens. Furthermore, human susceptibility toward infections often increases alongside changes to the environment. By incorporating sustainable living practices into daily life, many forerunners of biological disease can be avoided, thus preventing instances of epidemics or premature death. Current research has not been able to outline definitive cause and effect relationships between land degradation and the microbiology of pathogens, but well known examples of associations between the two are widely known. These include the contraction of tetanus from spores found in soil and water-related diseases caused by agricultural runoff contaminants. Further experimentation and observations must be conducted in Tanzania to establish concrete evidence for this theory. However, it is reasonable to predict some type of connection between the country’s widespread land degradation and an increased predilection for disease.

Management of toxic chemicals

Another growing problem in Tanzania is the stems from the mismanagement of chemical resources. An increasing number of studies have been done on the levels of toxic substances in the soil, water systems, and atmosphere of the region. In several instances, these results detected high levels of contamination. For instance, one of Tanzania’s main exports is gold, the mining of which requires excess amounts of mercury. It has been estimated that approximately 1.32 kg of mercury is lost to the environment for every 1 kg of gold mined. However, the actual values are likely higher. The unregulated use of mercury in the mines has led to high quantities of the element being released into the atmosphere, exposing the miners to harmful toxins. In one case study, 150 miners, 103 fishermen and their families, and 19 civilians from Mwanza City in Tanzania were tested for mercury exposure. Using a mercury detector test, each subject’s hair was examined to detect traces of the chemical. Fourteen of the subjects had extremely high readings, the highest being 953 ppm. On average, the mercury level found in these 14 subjects was 48.3 ppm per person. Keeping this information in context, the value considered critical for Minamata disease is 50 ppm. The expected exposure level for a typical person is about 10 ppm. The remaining 258 participants had levels at roughly 10 ppm suggesting no increase in mercury exposure.

The reasoning behind choosing miners as test subjects is clear. The gold mines release an enormous amount of mercury on a daily basis. Approximately 60% of the total generated mercury is released in a gaseous form and exposes the miners via inhalation or absorption through the skin. Fishermen, their families, and residents of Mwanza City were also test subjects to exhibit the far-reaching effects of the remaining 40% of the mercury released from the mines. Efficient waste systems are not in place to safely dispose of the toxin, so much of it is directly released into rivers, streams, and lakes or absorbed by sediment in the surrounding area. From there, it is taken up by fish and other aquatic animals which are then caught by fishermen and consumed by the Tanzanian people. Thus, the effects of chemical contamination, particularly of mercury, extend far beyond immediate hazardous exposure.

In addition to testing for mercury contamination, studies have been conducted in Tanzania to test for levels of pesticides in the environment. In one example, tests were completed at a former site of pesticide storage as well as various farms and sugar cane plantations where levels of agricultural pesticide use were known to be high. Results showed that areas with high agricultural use of pesticides did have notable pesticide residue, but it was not near the critical level. The bodies of water accompanying the farms and plantations tested positive for both DDT and HCH (two common insecticides). However, pesticides are widely used in the agricultural practices of Tanzania. They provide a feasible method to increase crop yield which is important for economic success regardless of environmental impact. While the agricultural areas did not show intense pollution, the former pesticide storage site contained residue levels that were considerably greater. Approximately 40% of the site’s surrounding soil was saturated with pesticides. Though the results did not necessitate any urgent clean-up of agricultural sites and associated water systems, the prevalence of DDT and HCH must continue to be monitored to prevent future health concerns.

While evidence from the previous case study does not indicate hazardous agricultural practices, a second study was conducted testing the toxicity of soil used in the farming of maize. This research focused on determining levels of the potentially toxic elements (PTEs) arsenic, lead, chromium, and nickel. Samples were taken from 40 farms throughout the country and toxic levels of these elements were found in several samples from different farms. The likely causes of this increase in toxins are increased use of pesticides, mining, and improper waste disposal. Although very small quantities of PTEs are found in soil naturally, the increased levels found in Tanzania are the result of human actions. Intensive use of pesticides increases the prevalence of toxic chemicals as evidenced by previous case studies. However, this experiment drew conclusive evidence that agricultural practices do contribute to toxins in the soil – contradictory to previous evidence. Excessive mining also releases PTEs from rocks and into surrounding sediment and water systems. Finally, the improper disposal of chemical waste further increases PTE concentration. Crops that are high in lead and nickel are seen as unfit for human consumption. Therefore, after analyzing the results, researchers recommended that humans neither consume nor feed their animals the maize that was found to be high in PTEs. Not only were the crops contaminated, but the soil was as well. These tests indicated levels of PTEs above the recommended limits in the tissues of the maize grown as well as the soil. While it is true that PTEs pollute crops, they also inhibit the soil from taking up nutrients which further reduces the overall yield. The high concentrations of these chemicals pose a potential health risk among the Tanzanian people.

Water management and sanitation

In addition to soil contamination and general land degradation, Tanzania has a long history of water mismanagement. Inherently, water management is a complex process in that it involves the authority of many people from different sectors of governing bodies. See Water supply and sanitation in Tanzania for more information on Tanzanian water management practices and sanitation.

Management of solid waste

Waste management, like natural and chemical resource management, is continuously evolving in developing countries including Tanzania. The country's profile in Waste Atlas Platform shows that currently (2012) 16.9 million tonnes of MSW or 365 kg/cap/year are produced. The current practice of solid waste disposal is to simply remove it from cities and other metropolitan areas and dump it in rural or deserted areas to be forgotten. Solid waste is defined as any solid, discarded material generated by municipal, industrial, or agricultural practices. Over the past 30 years, urban areas such as Dar es Salaam have grown both in terms of population and physical size. However, there have been minimal efforts made to establish sustainable waste management procedures to accompany the long term increase. By default, metropolitan areas produce a significant portion of the total solid waste of the country due to the large concentration of industry in such regions. In Dar es Salaam, the largest city in Tanzania, residents generate approximately 0.31 kg of waste per capita. In comparison, residents of squatter areas – rural regions between cities – produce only 0.17 kg per capita on average. However, the current practice of removing waste from cities disproportionately places the burden on the rural communities. Urban residents are not encouraged to reduce the amount of waste they create because they are not directly affected by its existence.

Although there are not many immediate health risks correlated with dumping solid wastes such as paper and plastic, there are potential hazards associated the improper disposal of medical and other toxic waste from hospitals. While Tanzania has made efforts to further develop its urban centers by allowing private hospitals, there has been a lack of infrastructure generated to accommodate the growing amounts of bio-hazardous waste. The rapid industrialization of the country is outgrowing any current infrastructure in place to ensure the health and safety of its citizens. Combining a lack of appropriate waste storage, protective equipment, and removal services can lead to a plethora of health threats. Currently, the more dangerous medical wastes are simply mixed with municipal solid waste and dumped at the disposal sites discussed above. However, Tanzania is undergoing changes in making a comprehensive, functioning waste disposal system a pre-requisite for the development of new hospitals.

Resolving the issues and planning for the future

Though there are many problems plaguing Tanzania, there are also a large number of activist groups pursuing solutions. It is especially crucial for developing nations to develop sound infrastructure in order to progress toward complete development. The most pressing problem in Tanzania is the lack of sustainable disposal practices for waste. More specifically, Tanzania is under to pressure to either significantly reduce the amount of waste generated or develop a sustainable plan for disposing of the waste without environmental repercussions. Ideally, the final solution will involve both. Recycling programs are being investigated in order to reduce the total amount of waste and generate jobs for Tanzanian citizens.

Additionally, progressive research is being conducted on converting solid waste into usable energy. Since waste is continually being generated, inventing a method for converting such waste into a usable resource would supply essentially limitless energy. Furthermore, if the program is successful, overall waste will be reduced and an efficient method of disposal will be in place. In fact, researchers in the field have predicted that waste could be reduced by 50-60% with the success of such a program. An organization called the Taka Gas Project has been researching methods for converting solid waste into biogas to be used for generating electrical energy. The biogas will be created using anaerobic digestion of organic materials (most of the waste is organic).

An additional area of ongoing study is converting waste into plant nutrients by way of composting. In this way, not only will waste be reduced, but there is the added benefit of reducing the amount of chemical fertilizers necessary to grow crops. As a result, chemical toxicity of soil will also be reduced. Thus one program has the potential to address many of the waste management issues prevalent in Tanzania today.

Bibliography

• Collins, A.E. 2001 Health Ecology, Land Degradation and Development. Land Degradation & Development 12: 237-250.
• Dahlberg, Annika. 1994 Contesting Views and Changing Paradigms: The Land Degradation Debate in Southern Africa. Uppsala: Reprocentralen HSC.
• Ellis, Jim and Kathleen A. Galvin. 1994 Climate Patterns and Land Use Practices in the Dry Zones of Africa. BioScience 44(5): 340-349.
• Harada, Masazumi, et al. 1999 Monitoring of mercury pollution in Tanzania: relation between head hair mercury and health. Science of The Total Environment 227(2-3): 249-256.
• Hongo, H and M. Masikini. 2003 Impact of immigrant pastoral herds to fringing wetlands of lake Victoria in Magu district Mwanza region, Tanzania. Physics and Chemistry of the Earth, Parts A/B/C 28(20-27): 1001-1007.
• Kaseva, M.E. and S.K. Gupta. 1999 Recycling — an environmentally friendly and income generating activity towards sustainable solid waste management. Case study — Dar es Salaam City, Tanzania. Resources, Conservation and Recycling 17(4): 299-309.
• Kishimba, M.A., L. Henry, H. Mwevura, A.J Mmochi, M. Mihale, and H. Hellar. 2004 The status of pesticide pollution in Tanzania. Talanta 64(1): 48-53.
• Marwa, Ernest M.M., Andrew A. Meharg, and Clive M. Rice. 2011 Risk assessment of potentially toxic elements in agricultural soils and maize tissues from selected districts in Tanzania. Science of The Total Environment 416: 180-186.
• Mato, R.R.A.M and G.R. Kassenga. 1998 A study on problems of management of medical solid wastes in Dar es Salaam and their remedial measures. Resources, Conservation, and Recycling 21(1): 1-16.
• Mbuligwe, Stephen E. and Gabriel R. Kassenga. 2004 Feasibility and strategies for anaerobic digestion of solid waste for energy production in Dar es Salaam city, Tanzania. Resources, Conservation and Recycling 42(2): 183-203.
• Schaller, Neill. 2003 The concept of agricultural sustainability. Agriculture, Ecosystems & Environment 46(1-4): 89-97.
• Stein, C., H. Ernstson, and J. Barron. 2011 A social network approach to analyzing water governance: The case of the Mkindo catchment, Tanzania.
• Yhdego, Michael. 1999 Urban solid waste management in Tanzania Issues, concepts and challenges. Resources, Conservation and Recycling 14(1): 1-10.
• U.S. Department of State: Background Note: Tanzania. http://www.state.gov/r/pa/ei/bgn/2843.htm.