The undersigned certify that they have read and hereby recommend for acceptance by the Open University of Tanzania (OUT) a dissertation titled “Determination of Heavy Metal Concentration in Bottom Ash in the Medical Waste Incinerators: The Case Study of Dar es Salaam City”, in partial fulfilment of the requirements for the degree of Master of Science in Environmental Studies (Health) of the Open University of Tanzania.
Dr. Josephat Saria
Prof. Samwel V. Manyele
This dissertation is a copy right material protected under the Berne Convention, the Copyright Act 1999 and other international and national enactments in that behalf on intellectual property. It may not be reproduced by any means in full or in part, except for short extracts in fair dealings, for research or private study, critical scholarly review or discourse with an acknowledgement, without the written permission of the Open University of Tanzania.
I, Honest E. Anicetus, do hereby declare that this dissertation is my own original work and that it has not been presented and will not be presented to any other University for a similar or any other degree award.
This study is dedicated to my wife Grace Tairo and my Daughters Irene and Clara who strugled taking cover of various responsibilities and family ties to ensure welfare of our families during the period of my studies. God bless them all.
This work is the output of the study supported by a number of people and organizations. First and foremost may I take this opportunity to thank GOD for enabling me persue with success this MES – Health program. Secondly my appreciation goes to my Employer, the Permanent Secretary of the Ministry of Health and Social Welfare for allowing me enrol for the course and also for the financial support owed to me. Thirdly much appreciation goes to my supervisors Dr Josephat Saria of the Faculty of Science, Technology and Environmental Studies, Open University of Tanzania and Prof. Samwel Manyele who is the Chief Government Chemist of the Government Chemist Laboratory Agency (GCLA). The guidance and the constructive criticisms they provided for the whole period of this study are greatly appreciated. They made themselves available for assistance throughout the study.
Many thanks go to the Hospital Directors for Mwananyamala, Amana-Ilala, Muhimbili Orthopaedic Institute (MOI), Buguruni Anglican Hospital, and Magomeni Health Centre for allowing me to conduct this study in their respective health facilities. Special thanks are due to the appointed Officers and other staffs from the aforementioned health facilities for facilitating the collection of samples for this study. Specifically, I recognize the assistance of Sifa Mgaya, Ali Mussa, Grace Ngugo, Dr. Simon David and Deus Mugisha.
The results of this study would not have been possible without the hard and consistent work of the Incinerator operators namely Juma Salum and Elikana Manyibu from MOI, Kahabu Kalamba and Yudas Mwaluana from Magomeni Health Centre, David Azael from Buguruni Anglican Hospital and J. Mhina from Amana Hospital.
I acknowledge with thanks the support and spirit of cooperation provided by the Open University of Tanzania Lecturers and other staffs. In particular, I am grateful to the support from Prof. Mbogo, Director for Post Graduate Studies, Dr. J. Saria Coordinator of the Programme, Dr. Yohana Lawi, Director of Examination Syndicate, Prof. Kigadye, Prof. Muhoma, Dr. Fweja, Dr. Mhache and Dr. Rukatambura.
Special thanks go to the management of the GCLA for allowing me to carry out the analysis of the collected samples in their laboratory. In particular, my appreciation goes to Prof. Samwel Manyele, Chief Government Chemist, G. Mtega, Director for Forensic Services, and James Ludanha Senior Chemist. More appreciations goes to Dr. T. Kassile for his assistance of the SAS software in the maintenance and analysis of the collected data.
My Special gratitude goes to my Wife Grace A.Tairo, my Daughters Irene and Clara for the sacrifices, support and encouragement their rendered to me throughout this MES-Health program. Without their support would have affected this big achievement.
The use of medical waste incinerators appears to be rapidly expanding in developing countries including Tanzania. Nuisance arising from medical waste has received much attention but relatively less consideration has been given to bottom ash. This study focused on determination of heavy metal concentration in bottom ash in medical waste incinerators found in different medical hospitals in Temeke, Ilala and Kinondoni Municipalities, Dar es Salaam. Samples of bottom ash were collected and analyzed at the Government Chemist Laboratory Agency. Statistical analysis of the data was done in the SAS software. The results show that, three types of incinerators namely high tech pyloritic, low cost pyloritic and single chamber are used in the study areas. Meanwhile, the findings show that the mean concentration value for Hg, Cd and As was below detectable limits while highest mean concentration of Fe was (9484.806 mg kg-1), Pb was (67.413 mg kg-1), Cu was (28.873 mg kg-1), Cr was (743.750 mg kg-1), and that of Ni was (596.906 mg kg-1). The amount of Cr, Zn, and Ni were above MPL (above 1,100, 150 and 100 mg/Kg respectively) for some hospitals. However, the levels of Cu and Pb obtained in all tested bottom ash were within maximum permissible levels (MPL) to be discharged to the environment. The excess Cd, Cr, Zn and Ni when leaching may contaminate the environment and results into public health risks The study recommends designing of engineered treatment methods for safe disposal of medical waste incinerator bottom ash to reduce contamination of surface and ground water, and soil in general.