Unveiling the Crucial Role of Emissions Inventories from Solid Waste Burning in Air Quality Management across Diverse LMICs; A Case of Nairobi City

Air pollution poses a significant environmental risk in low- and middle-income countries (LMICs), characterized by diverse pollution sources and complex atmospheric processes. Specifically, the city of Nairobi grapples with air quality challenges, generating approximately 2800 tons of solid waste daily, with 75% undergoing collection and the remaining 700 tons (3.9KG/person/year) being openly burnt. Our study underscores the crucial role of bottom-up emissions inventories, particularly those associated with solid waste burning, in quantifying emissions and guiding evidence-based air quality management strategies within the context of data-scarce LMICs. Leveraging the Solid Waste Emission Estimation Tool (SWEET), our estimations encompass Methane (CH4), Black Carbon (BC), Particulate Matter (PM), oxides of Nitrogen (NOX), and other pollutants from municipal solid waste sources. Our baseline scenario, established for the year 2022, is compared with successive five-year alternative scenarios. Preliminary findings indicate alarming emissions, with around 5.2 million metric tons of PM10, 3,400 metric tons of SOx, and 300 million metric tons of Black Carbon annually from open burning under the business-as-usual scenario. Notably, implementing emission reduction strategies, such as the closure of official dumping site, exhibits promising outcomes. Projected reductions include up to 15% in Methane emissions by 2031 (Scenario1) and a substantial 75% reduction by 2033 (Scenario2). Furthermore, SOx, CO2, and PM emissions are anticipated to decrease by over 90% under these scenarios. Strategically reducing waste burning activities, coupled with measures like cutting the garbage truck fleet by 50%, could yield drastic emission reductions. Our findings emphasize the potential for impactful emissions reduction benefits in addressing open waste burning, an often overlooked source contributing significantly to air pollution in rapidly developing cities like Nairobi. The discussion highlights the importance of a bottom-up approach in developing emissions inventories to comprehend the impact of waste burning on overall city emissions reduction goals and incorporating Gender dynamics.