Investigating Air Quality in Palapye, Botswana using GEOS-Chem and Low-Cost Sensors

Title: Investigating Air Quality in Palapye, Botswana using GEOS-Chem and Low-Cost

Sensors

Janica Gordon1 , Kelsey R. Bilsback2 Marc N. Fiddler3 , Vaios Moschos4 , Gizaw Mengistu Tsidu5, Jeffrey R. Pierce6, Solomon Bililign1,4

1Applied Sciences and Technology Program, North Carolina A&T State University, Greensboro, NC, USA

2PSE Healthy Energy, Oakland, CA, USA

3Department of Chemistry North Carolina A&T State University, Greensboro, NC, USA

4Department of Physics North Carolina A&T State University, Greensboro, NC, USA

5Department of Earth and Environmental Sciences Botswana International University of Science and

Technology, Palpaye, Botswana

6Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA

Exposure to ambient fine particulate matter (PM2.5) pollution is listed among the leading environmental risk factors of premature death in Sub-Saharan Africa. However, continuous ground-based monitors are particularly sparse in Africa which drives the need for such monitors and or sensors to monitor changes in air quality. Under this study, two field campaigns were conducted in Botswana at Botswana International University of Science and Technology (BIUST) located in Palapye, Botswana. The first campaign occurred during June and July of 2018 and 2022. Wildland fires can be spotted burning in the region each year starting around April. But they tend to grow larger and more intense starting in August, fueled by dried out vegetation and fanned by strong winds. Over half of the population in Africa still relies on residential combustion of solid fuels such as wood, coal, dung, crop waste, and charcoal for household heating and cooking. When such fuels are combusted, high levels of PM2.5 are emitted where a large fraction of PM2.5 is composed of black carbon (BC) and organic matter. To complete this task, numerous simulations using GEOS-Chem were conducted to identify the top source contributors of PM2.5 and BC in this region during June and July of 2018 and 2022. For field measurements, BC data was collected by micro-aethalometer and hourly observations of PM2.5 [ug/m3] from Plantower time-resolved PM2.5 concentrations. The overall goal for this study is to compare the relative contributions of anthropogenic activity to ambient PM2.5 and BC over Botswana from GEOS-Chem and field measurements estimates.