Profile:
Gabriel is a leading exposure scientist driving action at the nexus of climate change, air pollution, health, and sustainable development in rapidly urbanising cities. With over a decade of experience, his work confronts the climate crisis by advancing long-term, context-specific strategies that safeguard population and planetary health.
Gabriel’s work is grounded in mixed-methods, participatory, and transdisciplinary approaches, enabling the co-creation of evidence-informed solutions tailored to the realities of fast-growing urban environments. His approach is deeply collaborative, engaging stakeholders across academia, policy, business, and communities to co-design strategies that are both scientifically robust and socially grounded. Gabriel is also passionate about promoting citizen science and locally relevant interventions.
Currently, Gabriel works with collaborators across Africa, the UK, Europe, Asia, and the U.S., building bridges between research and policy, and fostering training and engagement that reflect lived realities. His work strengthens research-policy ecosystems and promotes coordinated action across sectors.
Above all, Gabriel navigates the complex worlds of science, policy, and society with urgency, empathy, and strategic foresight, driving transformative change in urban health and sustainability.
Biography
Gabriel’s current research interests focus on the interconnectivity between environmental health and disease with a view to helping foster healthier and safer communities. Gabriel has a wider ambition to raise public awareness of air pollution exposure and engage stakeholders across African cities to address the air pollution problem using evidence informed policies and programmes. Gabriel is also interested in increasing capacity and integrate air pollution data in healthcare, policy and practice and increasing air pollution, climate change and health awareness. His approach is centred on collaborative participatory involvement of actors within and outside academia (community, commercial and policy) into the co-production and co-design of context specific interventions to address non-communicable disease risk by focusing on air pollution in rapidly urbanising settings.
Career
- 2024 to present: The King's Global Sustainability Fellow in Air Quality and NCDs (Senior Research Associate)
- 2020 to 2023: The Prince of Wales Global Sustainability Fellow in Air Quality and NCDs (Research Associate)
- 2019 to 2020: Founder, African Centre for Clean Air
- 2015 to 2019: Postgraduate researcher, University of Aberdeen, Respiratory Group
- 2013 to 2018: Operations Director, Green Heat Uganda
- 2011 to 2013: Master’s student, Northeast Normal University
- 2010 to 2011: Quality Assurance Specialist, Nile Breweries Limited
Qualifications
- PhD Medical Sciences, University of Aberdeen
- Pan African Thoracic Society Methods in Epidemiology Clinical and Research Operations Research (PATS MECOR Level 2), Liverpool School of Tropical Medicine
- M.Sc. Organic Chemistry, Northeast Normal University
- BSc Food Processing Technology; Kyambogo University
Other affiliations
- 2021 to date: Honorary Visiting Fellow, MRC Epidemiology Unit, University of Cambridge
- 2021 to date: Bye Fellow, Murray Edwards College, University of Cambridge
- 2021 to date: Visiting Research Fellow, AirQo, Makerere University
- Air Quality Faculty: Pan African Thoracic Society Methods in Epidemiology Clinical and Research Operations Research (PATS MECOR)
- Biomass Reduction and Environmental Air Towards Health Effects (BREATHE) -Africa Partnership
Funding and awards
- Applying transdisciplinary and youth-driven citizen science to address air pollution and create healthy climate resilient cities (Co-I) 2024
- Exploring the potential health impacts of electrifying of two-wheelers in Kampala, Uganda (PI) 2023
- Air Quality and Non-communicable Diseases Fellowship Extension (PI) 2023
- The National Research Council (NERC) Impact Grant: Discipline Hoping (DH) for Environmental Solutions Application (PI) 2021
- Air Quality and Non-communicable Diseases Fellowship (PI) 2020
- Systems of Cities: Urban Mobility in Kampala and its Surrounding Areas (PI)
- Understanding Household Fuel Transitions: The Case of Namuwongo (Kampala). 2020. Collaboration study between ACCA, ACTogether, EASE Women’s enterprise and University of Birmingham (PI)
- PATS MECOR Small grant. 2019. Determining the level of exposure to ambient air pollution among urban traffic-junction officers in Kampala, Uganda
- BREATHE Small Awards 2018: Effect of cooking behaviour on exposure to household air pollution from different cooking fuels (PI)
- Biomass Reduction and Environmental Air Towards Health Effects in Africa – BREATHE Partnership. MRC, UK. (Postgraduate Researcher)
- UN Capital Development Fund (UNCDF) Clean Start.
- Value addition in milk production using renewable energy. United States Africa Development Fund (Co-PI).
Publications
Book chapters
Chapter 3: "The Impact of Gendered Roles in the Briquette Production and Supply Chain: Lessons Learned from Green Heat Ltd, Uganda" by Okello, G., Tumwesige, V., Angura, R. et al in Njenga, M., and Mendum, R., eds. 2018. Recovering Bioenergy in Sub-Saharan Africa: Gender Dimensions, Lessons and Challenges. Colombo, Sri Lanka: International Water Management Institute.
Reports
Okello, G. and Tatah, L. (2025). Exploring the potential health impacts of electrifying two-wheelers in Kampala, Uganda. Cambridge: Cambridge Institute for Sustainability Leadership.
United Nations Environment Programme, Climate & Clean Air Coalition, African Union (2022). Integrated Assessment of Air Pollution and Climate Change for Sustainable Development in Africa - Summary for Decision Makers.
Gabriel Okello and Dr Jake Reynolds (2022). Pathways to e-mobility transitions in Uganda: Policy brief on transition to electric mobility. University of Cambridge Institute for Sustainability Leadership.
Gabriel Okello, Fredrick Mugisha, Irene Namaganda and William Avis. 2020. Understanding Household Fuel Transitions: The Case of Namuwongo (Kampala). A Systems Approach to Air Pollution – East Africa (ASAP-East Africa) project.
Gabriel Okello and William Avis (University of Birmingham). Systems of Cities: Urban Mobility in Kampala and its Surrounding Areas. (Under final review).
Peer reviewed journals
Okello et al. 2024. Association between Ambient Air Pollution and Respiratory Health in Kampala, Uganda: Implications for Policy and Practice. https://doi.org/10.1016/j.uclim.2024.102128
Alaran, J. A., O'Sullivan, N., Tatah, L., Sserunjogi, R., Okello. 2024. Air pollution (PM2.5) and its meteorology predictors in Kampala and Jinja cities, in Uganda. https://pubs.rsc.org/en/Content/ArticleLanding/2024/EA/D4EA00074A
Appiah-Dwomoh, C., Tettey, P., Akyeampong, E., Prince Amegbor, P., Okello, G., et al. (2024). Smoke exposure, hemoglobin levels and the prevalence of anemia: a cross-sectional study in urban informal settlement in Southern Ghana. BMC Public Health 24, 854 (2024). https://doi.org/10.1186/s12889-024-18304-4
Mead, M.I., Okello, G., Mbandi, A.M. et al. Spotlight on air pollution in Africa. Nat. Geosci. 16, 930–931 (2023). https://doi.org/10.1038/s41561-023-01311-2
Okello, G., Nantanda, R., Awokola, B., Thondoo, M., Okure, D., Tatah, L., Bainomugisha, E., & Oni, T. (2023). Air quality management strategies in Africa: A scoping review of the content, context, co-benefits and unintended consequences. Environment International, 171, 107709. https://doi.org/10.1016/j.envint.2022.107709
Awokola, B., Okello, G., Johnson, O. et al (2022). Longitudinal Ambient PM2.5 Measurement at Fifteen Locations in Eight Sub-Saharan African Countries Using Low-Cost Sensors. Atmosphere 13, no. 10: 1593. https://www.mdpi.com/2073-4433/13/10/1593
Semple, S., Dobson, R., O’Donnell, R., Zainal Abidin, E., Tigova, O., Okello, G., & Fernández, E. (2022). Smoke-free spaces: A decade of progress, a need for more? Tobacco Control, 31(2), 250. https://doi.org/10.1136/tobaccocontrol-2021-056556
Woolley, K. E., Thomas, G. N., Kirenga, B., Okello, G., Kabera, T., Lao, X.-Q., Pope, F. D., Greenfield, S. M., Price, M. J., & Bartington, S. E. (2022). Association of household cooking location behaviour with acute respiratory infections among children aged under five years; a cross sectional analysis of 30 Sub-Saharan African Demographic and Health Surveys. Atmospheric Environment, 276, 119055. https://doi.org/10.1016/j.atmosenv.2022.119055
Singh, A., Dobbie, F., Kinnunen, T.I., Okello, G., Semple, S., Okyere, P.B., Logo, D.D., Lartey, K.F., McNeil, A., Britton, J., Bauld, L., & Owusu-Dabo, E.. (2021). Adherence to smoke-free policies in Ghana: Findings from a cross-sectional survey of hospitality venue owners and staff. Tobacco Prevention & Cessation, 7(January), 4. https://doi.org/10.18332/tpc/131058
Awokola, B.I., Okello, G., Mortimer, K.J., Jewell, C.P., Erhart, A., & Semple, S. (2020). Measuring Air Quality for Advocacy in Africa (MA3): Feasibility and Practicality of Longitudinal Ambient PM(2.5) Measurement Using Low-Cost Sensors. International Journal of Environmental Research and Public Health, 17(19). https://doi.org/10.3390/ijerph17197243
Okello, G., Mortimer, K., Lawin, H. & Semple, S. 2020. Quantifying exposure to respiratory hazards in sub-Saharan Africa: a simple guide to some practical issues to help plan your study. AJRM 14, no 2. https://dspace.stir.ac.uk/retrieve/2bbc117e-239a-45a5-9acf-8b5e99796869/...
Singh, A., Okello, G., Semple, S., Dobbie, F., Kinnunen, T.I., Lartey, K.F., Logo, D.D., Bauld, L., Ankrah, S.T., McNeill, A. & Owusu-Dabo, E. 2020. Exposure to secondhand smoke in hospitality settings in Ghana: Evidence of changes since implementation of smoke- free legislation. Tob. Induc. Dis. 2020;18(May):44
Okello G., Mortimer, K., Lawin, H., and Semple, S.. 2019. Quantifying exposure to respiratory hazards in sub-Saharan Africa: a simple guide to some practical issues to help plan your study. AJRM. Vol 14 No 2
Okello, G., Devereux, G. and Semple, S. 2018, "Women and girls in resource poor countries experience much greater exposure to household air pollutants than men: Results from Uganda and Ethiopia", Environment International, vol. 119, pp. 429-437
Gravely S, Nyamurungi KN, Kabwama SN, Okello G, Robertson L et al. 2018. Knowledge, opinions and compliance related to the 100% smoke-free law in hospitality venues in Kampala, Uganda: cross-sectional results from the KOMPLY Project. BMJ Open 2018;8:e017601. doi:10.1136/ bmjopen-2017-017601
Tumwesige, V., Okello, G., Semple, S., Smith, J. 2017. Impact of partial fuel switch on household air pollutants in sub-Sahara Africa. Environmental Pollution 231 (1)1021-1029.
Okello, G. 2017. Assessing Personal Exposure to Biomass fuel smoke in sub-Saharan Africa using GPS and Time-Activity Diaries data. Global Positioning System in Health Research Network. Issue Number: 11. https://www.gps-hrn.org/pages/admin/imageUploader/CMS_Photos/welcomeSide/docs/16.pdf
Online articles
Okello, G. (2021) Could electric motorcycles (e-bodas) reduce air pollution in Kampala and other rapidly growing African cities? UrbanBetter.
Okello, G. and Thondoo, M. (2023) Air pollution is a hidden pandemic in Africa - tips on how to reduce your exposure and help combat it. The Conversation.
Okello, G. (2022). Effective collaboration is a crucial pathway to tackling air pollution, climate change. NewVision.
Okello, G. (2024). Addressing organic waste management in Uganda through multi-stakeholder participatory approaches: Inception meeting and Mapping Brief. https://africancentreforcleanair.org/sowu/
Okello, G. (2024). Kiteezi landfill collapse exposes critical need for waste management reform. https://www.cisl.cam.ac.uk/news/blog/kiteezi-landfill-collapse-exposes-critical-need-waste-management-reform
Online outputs
RE:TV Terra Carta film showcasing sustainability conversation pivots and how policy, business, and finance leaders can accelerate transition to a sustainable economy that delivers for people, nature and climate. Available at: https://www.youtube.com/watch?v=xp2E6GqfTaw
RE:TV documentary film, entitled ‘Recirculating plastic’. 2021. This documentary film showcases innovation around plastic recycling and creating of green jobs (decent work). Available at: https://www.re-tv.org/rebalance/recirculating-plastic
Webinar for Air Quality, Urban Mobility and Governance in Kampala: an urbanising African city context. 2021. Available at: https://www.youtube.com/watch?v=rupQhYSK6Tc&t=144s
2023: BBC radio Cambridgeshire – Effects of air pollution on health, importance of monitoring air pollution, and actiond that can be taken to address air pollution. https://lnkd.in/g3AqAGzJ (scroll to around 2hrs and 8mins).
2023: Vehicle, industry emissions are the main causes of poor air quality. https://www.youtube.com/watch?v=F_jZh49k4y8
