Arsenic Contamination Study of Drinking Water in Nepal by Patricia M. Halsey B.S. Agricultural and Biological Engineering Cornell University, 1996 SUBMITTED TO THE DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ENGINEERING IN CIVIL AND ENVIRONMENTAL ENGINEERING at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2000  2000 Patricia M. Halsey. All rights reserved. The author hearby grants to M.I.T. permission to reproduce and distribute publicly paper and electronic copies of this thesis document in whole or in part. Signature of the Author___________________________________________________________ Patricia M. Halsey Department of Civil and Environmental Engineering May 5, 2000 Certified by____________________________________________________________________ Susan Murcott Lecturer Thesis Supervisor Accepted by___________________________________________________________________ Daniele Veneziano Chairman, Departmental Committee on Graduate Studies Arsenic Contamination Study of Drinking Water in Nepal by Patricia M. Halsey Submitted to the Department of Civil and Environmental Engineering on May 5, 2000 In Partial Fulfillment of the Requirements for the Degree of Master of Engineering in Civil and Environmental Engineering ABSTRACT A study of arsenic contamination of drinking water in Nepal was conducted. Samples were collected in Nepal in January 2000 from tube wells, hand dug wells, natural springs, municipal systems and surface water bodies. Samples were analyzed in Nepal using EM Quant test strips and Affiniti Concentration kits. Samples were also preserved and brought back to the U.S. for analysis using Graphite Furnace Atomic Absorption Spectrometry. Combined results from these tests indicate that no arsenic contamination was found above the World Health Organization (WHO) maximum contaminant level of 10ppb in the Kathmandu Valley. However, 18% of samples taken from the Terai region of Nepal were above the WHO limit. Detectable levels of arsenic were found in tube wells ranging from approximately 30 to 300 feet deep. Forty-eight percent of samples taken from wells aged 9 to 12 years had detectable levels of arsenic. This study concludes that, although not as extensive as in neighboring West Bengal, India and Bangladesh, arsenic contamination does exist in the Terai region of Nepal. A comparison of analytical methods indicates that field kits provide a general indication of high levels of arsenic, but should be used in conjunction with more accurate methods if detailed results are required. Further testing is recommended in the Terai region of Nepal. A detailed study of the geology of the Terai region and potential anthropogenic sources is recommended to further characterize the area. Thesis Supervisor: Susan Murcott Title: Lecturer Acknowledgements I would like to thank my advisor, Ms. Susan Murcott, for her support throughout this project. Her undying enthusiasm and vision culminated in the amazing experience of this project. I would also like to thank Dr. Eric Adams and the Department of Civil and Environmental Engineering for making this project and the entire school year so rewarding. Thanks to the Nepal Water Project team, including Andy Bittner, Amer Khayyat, Kim Luu, Benoit Maag, Junko Sagara, and Andrea Wolfe, for making the trip to Nepal and execution of this project an unforgettable experience. You all have unique and important gifts to offer the world, and I wish you all the luck in making your mark. Special thanks go to several members of the Nepal community whose help made our stay most enjoyable. In particular, I would like to thank Mr. Ram Mani Sharma of the DWSS for his help in sample collection and keeping us safe in Parsa District. I would also like to thank Mangala Karanjit for making all of our arrangements, including our stay in Patan, possible. I would like to thank Professor Harry Hemond for the use of his laboratory and GFAAS unit. This thesis would not have been completed without the guidance of several graduate students at the Ralph M. Parsons Laboratory at MIT. Nicole Keon, Dave Senn and Chris Swartz were a great help in teaching me about arsenic and GFAAS. Finally, I would like to thank my family and friends for their unrelenting support throughout this year. I would like to dedicate this thesis to my loving parents, Ron and Mary Ann Halsey, whose love and encouragement have made me who I am today. To my siblings, Kathy, Brett and Kristin, thanks for cheering me on and making me laugh. I would like to express a final note of thanks to Jon. Your support and love have made this year amazing and I owe all of this to you. Oh yeah, and thanks for the fruit. 3 Arsenic Contamination Study of Drinking Water in Nepal Table of Contents Table of Contents CHAPTER 1 - INTRODUCTION............................................................................................10 1.1 Nepal Water Project...........................................................................................................10 1.1.1 Project Motivation........................................................................................................10 1.1.2 Project Purpose............................................................................................................11 1.2 Arsenic Contamination Study............................................................................................12 1.2.1 Study Motivation...........................................................................................................13 1.2.2 Study Purpose...............................................................................................................13 CHAPTER 2 - BACKGROUND..............................................................................................15 2.1 Arsenic in the Environment................................................................................................15 2.1.1 General Chemistry.......................................................................................................15 2.1.2 Common Sources..........................................................................................................17 2.2 Arsenic Contamination in Other Countries........................................................................19 2.2.1 Crisis in Bangladesh....................................................................................................20 2.2.2 Crisis in India...............................................................................................................23 2.2.3 Contamination in the United States..............................................................................24 2.3 Overview of Hydrology and Geology of Nepal.................................................................25 2.3.1 Geography and Geology..............................................................................................25 2.3.2 Typical Water Sources..................................................................................................27 CHAPTER 3 - HEALTH EFFECTS.......................................................................................32 3.1 Toxicology of Arsenic Compounds...................................................................................32 3.1.1 Arsine............................................................................................................................32 3.1.2 Inorganic Arsenic.........................................................................................................33 3.2 Exposure Limits and Health Guidelines.............................................................................34 3.3 Symptoms of Arsenic Poisoning........................................................................................35 3.3.1 Acute Health Effects.....................................................................................................35 3.3.2 Chronic Health Effects.................................................................................................35 3.4 Health Problems in Nepal...................................................................................................36 4 Arsenic Contamination Study of Drinking Water in Nepal Table of Contents CHAPTER 4 - ANALYTICAL METHODS...........................................................................38 4.1 Possible Test Methods........................................................................................................38 4.2 EM Quant Test Strips......................................................................................................46 4.2.1 Theoretical Principles..................................................................................................46 4.2.2 Description of Procedure Used....................................................................................47 4.3 Affiniti Concentration Kits.................................................................................................50 4.3.1 Theoretical Principles..................................................................................................50 4.3.2 Description of Procedure Used....................................................................................52 4.4 Graphite Furnace Atomic Absorption Spectrometry..........................................................54 4.4.1 Theoretical Principles..................................................................................................54 4.4.2 Description of Procedure Used....................................................................................55 4.5 NIPSOM Field Test Kits....................................................................................................57 4.5.1 Theoretical Principles..................................................................................................57 4.5.2 Description of Procedure Used....................................................................................58 CHAPTER 5 - RESULTS.........................................................................................................59 5.1 Analytical Results Obtained by the Author........................................................................60 5.1.1 EM Quant Test Kit Results........................................................................................60 5.1.2 Affiniti Concentration Kit Results................................................................................61 5.1.3 Graphite Furnace Atomic Absorption Spectrometry Results.......................................63 5.2 Analytical Results Obtained by DWSS..............................................................................64 5.3 Discussion of Results.........................................................................................................66 5.4 Comparison of Analytical Methods...................................................................................69 CHAPTER 6 - CONCLUSIONS AND RECOMMENDATIONS.........................................71 6.1 Study Conclusions..............................................................................................................71 6.2 Recommendations..............................................................................................................72 REFERENCES............................................................................................................................73 APPENDIX A - TRIP REPORT...............................................................................................77 APPENDIX B – DATA TABLES AND CALIBRATION CURVES.....................................80 5 Arsenic Contamination Study of Drinking Water in Nepal Table of Contents APPENDIX C - LIST OF ACRONYMS................................................................................123 6 Arsenic Contamination Study of Drinking Water in Nepal List of Tables List of Tables Table 3-1: Incidence Rates for Male Adults in Various Countries...............................................37 Table 4-1: Possible Analytical Methods for Measurement of Arsenic in Potable Water.............40 Table 4-2: Possible Chemical Interferences for EM Quant Test Kits.......................................44 Table 4-3: Procedure for using EM Quant Test Strips..............................................................49 Table 4-4: Procedure for Using Stage II Affiniti Concentration Kits...........................................52 Table 4-5: Procedure for Regeneration of Used Affiniti Concentration Kits...............................54 Table 4-6: Procedure for GFAAS Testing....................................................................................56 Table 5-1: EM Quant Test Kit Results......................................................................................60 Table 5-2: Affiniti Concentration Kit Results..............................................................................62 Table 5-3: Graphite Furnace Atomic Absorption Results............................................................63 Table 5-4: Summary of Results of DWSS Arsenic Sampling Program.......................................65 Table B-1: Sample Descriptions...................................................................................................81 Table B-2: Test Results for EM Quant Test Strips and Affiniti Concentration Kits.................94 Table B-3: GFAAS Results..........................................................................................................98 7 Arsenic Contamination Study of Drinking Water in Nepal List of Figures List of Figures Figure 2-1: Eh – pH Diagram for Arsenic at 25oC and One Atmosphere....................................16 Figure 2-2: Predominance Charts for Arsenite and Arsenate at Varying pH...............................17 Figure 2-3: Chemical Forms of Arsenic and Their Transformations in Soils..............................18 Figure 2-4: A Simplified, Comprehensive Cycle Transfer of Arsenic.........................................19 Figure 2-5: Map of Bangladesh....................................................................................................21 Figure 2-6: Map of Arsenic Contamination in Bangladesh..........................................................22 Figure 2-7: Arsenic Contamination in West Bengal.....................................................................24 Figure 2-8: Map of Nepal.............................................................................................................26 Figure 2-9: Typical Hand Pump Tube Well.................................................................................28 Figure 2-10: Typical Hand Dug Well...........................................................................................29 Figure 2-11: Traditional Public Water Spout in Patan Durbar Square.........................................30 Figure 2-12: Traditional Natural Spring Water Source................................................................31 Figure 3-1: Conversion of Arsenite to Water Soluble DMAA.....................................................33 Figure 4-1: Experimental Set-up for EM Quant Test Strips......................................................48 Figure 4-2: Picture of EM Quant Test Strip Kit........................................................................49 Figure 4-3: Picture of Affiniti Concentration Kit Resins..............................................................51 Figure 4-4: Experimental Set-up for Affiniti Concentration Kits.................................................53 Figure 5-1: Locations of Sampling Areas.....................................................................................59 Figure 5-2: Em Quant Test Strip Results...................................................................................61 Figure 5-3: Affiniti Concentration Kit Results.............................................................................62 Figure 5-4: GFAAS Results..........................................................................................................64 Figure 5-5: NIPSOM Test Results Obtained by DWSS...............................................................65 Figure 5-6: Sampling Locations in the Kathmandu Valley..........................................................67 Figure 5-7: Sample Frequency by Well Depth.............................................................................68 Figure 5-8: Sample Frequency by Well Age................................................................................69 Figure B-1: Calibration Curve for Sample Group 1...................................................................104 Figure B-2: Calibration Curve for Sample Group 2...................................................................105 Figure B-3: Calibration Curve for Sample Group 3...................................................................106 Figure B-4: Calibration Curve for Sample Group 4...................................................................107 8 Arsenic Contamination Study of Drinking Water in Nepal List of Figures Figure B-5: Calibration Curve for Sample Group 5...................................................................108 Figure B-6: Calibration Curve for Sample Group 6...................................................................109 Figure B-7: Calibration Curve for Sample Group 7...................................................................110 Figure B-8: Calibration Curve for Sample Group 8...................................................................111 Figure B-9: Calibration Curve for Sample Group 9...................................................................112 Figure B-10: Calibration Curve for Sample Group 10...............................................................113 Figure B-11: Calibration Curve for Sample Group 11...............................................................114 Figure B-12: Calibration Curve for Sample Group 12...............................................................115 Figure B-13: Calibration Curve for Sample Group 13...............................................................116 Figure B-14: Calibration Curve for Sample Group 14...............................................................117 Figure B-15: Calibration Curve for Sample Group 15...............................................................118 Figure B-16: Calibration Curve for Sample Group 16...............................................................119 Figure B-17: Calibration Curve for Sample Group 17...............................................................120 Figure B-19: Calibration Curve for Sample Group 19...............................................................122 9 Arsenic Contamination Study of Drinking Water in Nepal Introduction Chapter 1 - Introduction 1.1 Nepal Water Project The Nepal Water Project is a collective effort by seven Master of Engineering students at the Massachusetts Institute of Technology (MIT) to document and analyze several water quality and household water treatment issues in the country of Nepal. The study has been completed as part of the degree requirements for the Master of Engineering program, and each student has completed an individual thesis and collaborated to produce a group report. The advisor for the project is Susan Murcott, and Nepalese hosts and partners in this effort include the Royal Government of Nepal Department of Water Supply and Sewerage (DWSS), the Business and Professional Women’s Federation of Nepal, the Nepal Water Supply Corporation (NWSC) and the local chapter of the United Nations Childrens Fund (UNICEF-Nepal). The project advisor, Susan Murcott, initiated the Nepal Water Project. Ms. Murcott was involved in a Women and Water Conference held in Kathmandu, Nepal in 1998. During this conference, the water quality issues plaguing the country became evident and real to her. This sparked the beginning of the Master of Engineering program project in Nepal. The project involved a myriad of research topics all relating to water quality issues, and included a three- week field trip to the country. This thesis is one of the products of the study efforts, and is submitted as a portion of the overall goal of the project. 1.1.1 Project Motivation Nepal is a developing country bordered by India to the south, east and west and China to the north. More than half of the Nepalese population lives below the international poverty line, making it the seventh poorest nation in the world. The average yearly income for a Nepalese person is only $210, and many rural communities live within a subsistence economy.1 Like many other countries with limited economic means, serious health and sanitation concerns in Nepal stem from over-population of areas with limited available natural resources. 1 U.S. Agency for International Development, 2000. 10