indoor air pollution project
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UNIVERSITY OF NAIROBICOLLEGE OF BIOLOGICAL AND PHYSICAL SCIENCESDEPARTMENT OF CHEMISTRYINDOOR AIR POLLUTION: ANALYSIS OF EMISSIONS FROM VARIOUS COOKING STOVESBy:David NgangaI20/I542/2011A RESEARCH PROJECT SUBMITTED IN PARTIAL FULFILLMENT OF THE BACHELOR OF SCIENCE DEGREE IN (CHEMISTRY) OF THE UNIVERSITY OF NAIROBIDECLARATIONDeclaration by student
I hereby declare that this project is my original work to the best of my knowledge and has not been submitted to any other University for any award or academic purpose.
. David NgangaSupervisors Approval
I hereby confirm that this project has been written and submitted with my (our) approval as the supervisor(s) and therefore approve it for submission to the University.
Prof. Kithinji .P. Jacob: .Dr. Damaris N. Mbui: .
Department of Chemistry, University of Nairobi
DEDICATIONI dedicate this project:To my Grandmother, Salome, who believed in me and everything I did and supported me all through to the completion of my education.To my Parents and siblings, who have stood by me and accorded me the love and support that has always been my beacon of hope.To all who made the completion of this project a success.A big Thank you
ACKNOWLEDGEMENTI would first like to acknowledge Mr. Hesborn Nyangena and Justus Muoki for their support and training on the Water Boiling test Protocol that made carrying out the tests required for this study a success.I would also like to extend my heartfelt gratitude to fellow undergraduate students John Julius Mutua, Mercy Barasa, Dennis Sulwey, Violet Awuor, Michael Mwangi and the class of 2015 for their co-operation and assistance in all stages of carrying out this research.Last, but not least, I would like to extend my gratitude to the Department of Chemistry: the Chairman and all the lecturers for their important role they have played in my education.Above all, my greatest appreciation goes out to my supervisors Prof. J.P.Kithinji and Dr. Damaris.N.Mbui for their expertise, guidance and supervision together with providing resources, without which this research would not have reached its successful completion.
TABLE OF CONTENTDEDICATION3ACKNOWLEDGEMENT4TABLE OF CONTENT5ABSTRACT6CHAPTER 181.0.INTRODUCTION8CHAPTER 2172.0. LITERATURE REVIEW172.3. ILLNESS CAUSED BY IAP262.3.1. CHRONIC OBSTRUCTIVE PULMONARY DISEASE262.3.2. LUNG CANCER262.3.3. PNEUMONIA26CHAPTER 3273.0. METHODOLOGY273.1. APPARATUS AND REAGENTS273.2. TEST PROCEDURE28CHAPTER 4334.0. RESULT AND DISCUSSION33CHAPTER 5405.0. CONCLUSION AND RECOMMENDATIONS405.1. CONCLUSION405.2. RECOMMENDATIONS415.3. RELEVANCE OF FINDINGS41References43
List of Abbreviationsppm: Parts per millionCO: Carbon monoxideWHO: World Health OrganizationPM: Particulate matterCO2: Carbon dioxideMg/m^3: Milligrams per meter cubedg/litre: Grams per Litreg: grammesg/min: Grams per Minutemin: MinutesKPT: Kitchen Performance TestCCT: Controlled Cooking Test
ABSTRACTIndoor air pollution (IAP) from biomass cook stoves seriously affects human health worldwide. Most of the biomass stoves in use are traditional cook stoves, which produce toxic emissions and are inefficient. This has prompted the introduction of improved stoves which enable families to meet their household cooking and heating requirements without the risks posed by traditional stoves. The purpose of this study was to investigate the stove performance (in terms of IAP levels and efficiency) of an improved wood stove (here referred to as stove A) and an improved charcoal (here referred to as stove B) and compare with the traditional three stone and the Kenyan metallic Jiko. The efficiency of the stoves were tested using the water-boiling test (WBT), while particulate matter, CO and CO2 were monitored using data loggers, which work on the principle of light scattering. Results were entered in the WBT data calculation sheet to obtain the parameters critical in evaluating the stoves performance.Results indicated a 50% and 72% decrease in CO emissions in Stove A compared to the three stone fire wood stove and Kenyan metallic jiko respectively. A 60% and 34 % decrease in CO in charcoal stove B compared to metallic charcoal jiko and three stone firewood stove respectively was noted. Both traditional stoves fell below WHO limit of 30ppm over an hour of CO exposure.CO2 decreased by 20% and 6% with stoves A and B respectively compared to three stone and metallic jiko. Charcoal Stove B and Three-stone firewood stoves were above the 600ppm WHO limit. There was an 80% decrease in PM2.5 in stove B, compared to metallic jiko and 17% decrease in stove A compared to three stone firewood stove. All stoves except B exceeded 0.2mg/m3 limit set by WHO for PM2.5 when using biomass fuel. There was a 63% and 185.7% increase in level of efficiency in charcoal stove B compared to the Metallic Jiko and three stone stoves respectively. A 64% increase and 8% decrease in thermal efficiency in stove A compared to three stone stove and Kenyan metallic jiko respectively were noted. A 73% and 23% decrease in specific fuel consumption was noted in firewood stoves A and charcoal stove B compared to the metallic and three stone firewood stove respectively. Objectives of the study were met.CHAPTER 11.0. INTRODUCTIONIndoor air pollution is the presence of physical, chemical and biological contaminants in air that are not normally present in outdoor air of a high quality system (Ezzati M, 2000). Indoor air pollution is a concern in the developed countries, where energy efficiency improvements sometimes make houses relatively airtight, reducing ventilation and raising pollutant levels. Indoor air problems can be subtle and do not always produce easily recognized impacts on health. Different conditions are responsible for indoor air pollution in the rural areas and the urban areas. In the developing countries, the rural areas face the greatest threat from indoor pollution, where some 95% of the population continues to rely on biomass for cooking and heating. Concentration of IAP in households that burn traditional fuels are alarming (Clough, 2012). The use of biomass as a source of fuel in a confined environment results to increased level of exposure. Women and children are the groups most vulnerable as they spend more time indoors and are exposed to the smoke (Ezzati M, 2000). In 2009, the World Bank designated indoor air pollution in the developing countries as one of the four most critical global environmental problems (WHO, 2010). According to the study, daily averages of IAP often exceed the current limits set by W.H.O. Although many hundreds of separate chemical agents have been identified in the smoke from biofuels, the four most serious pollutants are particulates, carbon monoxide, polycyclic organic matter, and formaldehyde. Although there has been no large-scale statistically represented survey on the levels of emissions on stoves, hundreds of small-scale studies show that use of biomass, as a source of fuel is the biggest contributor to indoor air pollution in the world (Ezzati M, 2000). The problem has prompted the introduction of improved stoves in developing countries to shift the focus from the traditional three stone to metallic charcoal stoves. This helps in improving the stove efficiency and reducing the level of emissions from such stoves.1.1 COOK STOVES IN USE IN KENYACook stoves are classified based on the nature of fuel used as well as the different modifications that they have undergone. Based on the classification of fuel used, there are two types of stoves: Wood-based fuels and Charcoal-based fuel. If the classification is based on the modifications, there are two types of stoves: Improved stoves and traditional stoves as will be seen below.1.1.1. THREE STONE COOKSTOVESThe traditional method of cooking is on a three stone cooking stove. It is the cheapest to produce and set-up. It requires only three stones of the same height on which a cooking pot can be balanced over a fire.
Fig 1.1 Picture showing a three stone stove in useCourtesy of Google imagesThe method however, has a number of problems: Smoke is vented into the home instead of outdoors thus causing health problems. According to the World Health Organization, "Every year, indoor air pollution is responsible for the death of 1.6 million people- that is one death every 20 seconds (WHO, 2014)." There is a lot of fuel wastage, as heat is allowed to escape into the open air. This requires more labor on the part of the user in gathering fuel and may result to increased deforestation if wood fuel is used. It can only serve one cooking pot at a time The use of the open fire increases the risk of burns and scalds. Especially when the stove is used indoors, cramped conditions make adults and particularly children susceptible to falling or stepping into the fire and receiving burns. Additionally, accidental spills of boiling water may result in scalding, and blowing on the fire to supply oxygen may discharge burning embers and cause eye injuries.1.1.2. TRADITIONAL METAL COOKSTOVESThe traditional metal jiko (figure 1.2 below) is a charcoal stove of Kenyan origin mostly used in the rural areas. The stove has the following specifications: A. Stove Body-Metal Cylinder B. Metal or Wood insulated Handle C. Feet for Elevation and Stability D. Damper/Fuel Access Port Door E. Fuel Feed/Ash Removal F. Grate G. Pot Adjustment-Simmer Position
Fig 1.2 showing the a Kenyan traditional metal JikoIt is of Kenyan origin and most preferred among the rural folks when the type of fuel is charcoal. It is cheap compared to other charcoal stoves. It however has some disadvantages compared to other improved versions such as the Kenya Ceramic Jiko and Eco-zoom Charcoal stoves. Low thermal efficiency High emissions High burn rate High risk of burns and scalds due to conductive parts1.1.3. IMPROVED COOKSTOVESCook stoves are term improved if they are more