Centre for International Health The impact on respiratory ailments through reduction of Indoor Air Pollution by smokeless metal stove and solar lighting: Results of a study in rural Nepal Jason Mann This thesis is presented as part of the requirements for the award of the Degree of Masters of International Health at Curtin University of Technology. November 2009 Jason Mann, stud. No. 13194556 Page 1 Jason Mann, stud. No. 13194556 Page 2 Acknowledgements I would like to thank Alex Zahnd (RIDS-Nepal) for his tireless commitment to the Humla people, providing me with local insight, initial and ongoing contact with the Holistic Community Development project. Also, thank you to Kimber Haddix (ISIS foundation) for allowing me to use the data she compiled as part of her ongoing research. Thank you to Mohammed Ali for academic guidance and BK Tan for her continued support. Jason Mann, stud. No. 13194556 Page 3 Abstract Indoor air pollution (IAP) is a known cause of respiratory disease which has a major impact on the world‟s burden of disease, particularly evident in developing countries. The major contributor to their polluted home environment is attributed to the indoor use of solid fuels for cooking, heating and light. Objectives: (1) To determine whether the Smokeless Metal Stove (SMS) and solar lighting affect the prevalence of respiratory ailments in the Humla district, Nepal. (2) To explore the impact of the SMS and solar lighting on the reported prevalence of respiratory symptoms by comparing the statistical impact between groups with relation to age and gender. (3) To explore the influences confounding factors such as smoking and seasonality have upon the reported prevalence of respiratory symptoms. Design: Analysis of secondary data collected as part of an ongoing evaluation for the Holistic Community Development (HCD) programme developed and implemented by the non- government organisation (NGO) RIDS-Nepal who introduced SMS and solar lighting in its project area in Humla district. The evaluation used an open cohort design comparing the prevalence rates of respiratory ailments (between 2004-07) before and at least one year after the introduction of the interventions. Participants: 404 households (2469 individuals) were initially surveyed who were using the traditional open fire; 265 of these households (1601 individuals) were re-surveyed following the implementation of the SMS and solar lighting. The study sample was made up of those who wanted to participate in the HCD programme in the project area. Intervention: As part of the HCD programme all households surveyed received a SMS and solar lighting with ongoing support. Results: The installation of the SMS and solar lighting was associated with a distinct reduction in the prevalence of respiratory ailments. Compared to households following the intervention the relative risk of respiratory symptoms among those with a traditional open fire was 1.53 (95% confidence interval 1.2 to 1.96, p = 0.0006). While the very young and old together accounted for 70% of all people with respiratory symptoms and had no significant Jason Mann, stud. No. 13194556 Page 4 change following the intervention, the people between the ages of 5 to 49 years with a traditional open fire had a relative risk of respiratory symptoms of 2.9 (95% confidence interval 1.7 to 4.9, p = <0.0001). Males benefited over females, tobacco smoking increased from before to after the intervention and winter had a higher prevalence of respiratory symptoms than summer. Conclusion: In Humla, the prevalence rates of respiratory ailments decreased markedly after the implementation of the SMS and solar lighting. Jason Mann, stud. No. 13194556 Page 5 Table of Contents Declaration 2 Acknowledgements 3 Abstract 4 1.0 Introduction 9 2.0 Background/Review of Literature 11 2.1 Indoor Air Pollution 11 2.11 Airborne Particulate Matter 12 2.12 Carbon Monoxide 13 2.2 The Study Population 15 2.3 Interventions 17 3.0 Methodology 20 3.1 Study Design 20 3.2 Setting 21 3.21 Relevant dates 21 3.22 Data collection 21 3.3 Participants 22 3.31 Sampling 22 3.4 Variables 23 3.5 Data sources/measurement 23 3.6 Bias 24 3.7 Study size 25 3.8 Quantitative variables 25 3.9 Statistical Methods 26 4.0 Results 27 4.1 Participants 27 4.11 Seasonality 29 4.12 Tobacco smoking 29 Jason Mann, stud. No. 13194556 Page 6 4.2 Descriptive Data 31 4.3 Outcome Data 31 4.4 Main Results 32 4.5 Effect of mediating factors 34 4.51 Age groups 34 4.52 Seasonality 36 4.6 Sensitivity Analyses 37 5.0 Discussion 39 5.1 Significance of main study findings 39 5.11 Reduction in prevalence of respiratory symptoms 39 5.12 Age and sex 41 5.13 Tobacco smoking and season 41 5.2 Limitations 42 5.21 Season 42 5.22 Smoking 42 5.23 Immunity 43 5.24 Secondary data 44 5.25 Other potential confounding factors 45 6.0 Conclusion 47 References 49 Appendices 54 Appendix 1 Interventions for reducing exposure to indoor air pollution 54 Appendix 2 Graphs showing comparisons of PM and CO between SMS and open fire cooking 55 Appendix 3 Baseline questionnaire 58 Appendix 4 Follow-up questionnaire 65 Appendix 5 Guidelines for the nurse 72 Appendix 6 ISIS research guidelines 73 Jason Mann, stud. No. 13194556 Page 7 List of Tables Table 1: Respiratory Symptoms....Season/Phase 1 (All data) 29 Table 2: Respiratory Symptoms....Season/Phase 2 (All data) 29 Table 3: Smoking rates between phase 1 and 2 divided by season (All data) 30 Table 4: Smoking rates between phase 1 and 2 (Controlled data) 30 Table 5: Demographic stats of Humla region from survey (All data) 31 Table 6: Respiratory Symptoms over time (Controlled data) 32 Table 7: Respiratory Symptoms....Phase 1 and 2/sex (Controlled data) 33 Table 8: Respiratory Symptoms....Age group/phase 1 and 2/sex/season (Controlled data) 35 Table 9: Households with Eye disease....Phase 1 and 2/season (All data) 37 Table 10: Differences in prevalence (%) rates between phase 1 and 2 with regard to Respiratory Symptoms 38 List of Figures Figure 1: Method of exclusion to provide data for respiratory symptoms analysis 28 Figure 2: Respiratory Symptoms: Prevalence rates (Confidence Interval 95%) (Controlled data) 34 Jason Mann, stud. No. 13194556 Page 8 1.0 Introduction Indoor air pollution (IAP) and the resulting respiratory diseases have a major impact on the world‟s burden of disease, measured in both death and disability-adjusted life years (DALYs). The effect is felt most in developing countries where access to safe living environments is difficult to attain for various reasons. The major contributor to people‟s polluted home environment is attributed to the use of solid fuels for cooking, heating and light. While seemingly insignificant in a modern industrial society, access to simple technology has the ability to radically change this risk factor. Adoption of new knowledge into traditional societies however, is a long and complex process, wrought with unforseen difficulties by those trying to assist in their development. Rural Integrated Development Service (RIDS-Nepal), an NGO based in Nepal and their major contributor, the ISIS foundation, have assisted in the development and implementation of the Holistic Community Development (HCD) Program called „Family of 4‟. This project is aimed at improving the health and wellbeing of the people in the remote Humla district of Nepal. Through community involvement they have developed local and culturally appropriate technology to deal with various focus areas. Specific to this study, the smokeless metal stove (SMS) has been created with local needs and cooking practices in mind in association with the implementation of solar lighting and a supportive infrastructure. These technologies combined dramatically reduce the levels of IAP, particularly particulate matter and carbon monoxide. This study aims to briefly outline the risks associated with IAP in the Humla region while providing the base for the more specific analysis of the respiratory effects associated with the implementation of these technologies. Jason Mann, stud. No. 13194556 Page 9 Aim To assess, through secondary data analysis, the respiratory health benefits of the Smokeless Metal Stove (SMS) and solar lighting in the remote Humla region of Nepal. Objectives 1) To determine the impact of an improved SMS and solar lighting on the reported prevalence of respiratory symptoms in comparison with the traditional open fire. 2) To explore the statistical impact of the intervention in relation to age and gender by using the reported prevalence of respiratory symptoms as a means by which to compare differences between groups. 3) To explore the influences of confounding factors, for example smoking and season on the reported prevalence of respiratory symptoms with relation to the intervention of the SMS and solar lighting. Test hypothesis Null hypothesis: The reduction in IAP from the implementation of the SMS and solar lighting will not change the prevalence of respiratory symptoms. Alternative hypothesis: The implementation of SMS and solar lighting with subsequent reduction in IAP will decrease the prevalence of respiratory symptoms. Jason Mann, stud. No. 13194556 Page 10