Emission Flux and Dispersion Analysis of Particulate Matter (PM10) from Mining and Industrial Areas in Rusizi District-Rwanda.

Industrial and mining operations are classified as the primary sources of particulate matter (PM₁₀) that pose substantial health and environmental risks, with much attention when situated in or near residential areas. The absence of a standardized approach for quantifying air pollutant fluxes in mining areas has been identified as a research gap, particularly given the increasing rate of mining extraction, especially in developing countries. This study used the AERMOD air pollutants dispersion model to analyze PM₁₀ dispersion from the CIMERWA Cement Plant and adjacent mining sites in Rusizi District, Rwanda, throughout 2022. We developed methods to quantify PM₁₀ horizontal and vertical fluxes and their emission rates within the framework of dispersion analysis. Results indicate high concentrations of PM₁₀ in the vicinity of mining areas, with daily, hourly, monthly, and annual maximum mean ground-level concentrations of 158.86 µg m⁻³, 92.87 µg m⁻³, 46.15 µg m⁻³, and 27.65 µg m⁻³, respectively. Wind erosion, with a daily horizontal speed of 0.66 m s⁻¹ and shear speed of 0.03 m s⁻¹, contributes to a daily mean horizontal flux of 8.50 µg m⁻² s⁻¹ and vertical flux of 0.4 µg m⁻² s⁻¹ of PM₁₀. Dispersion maps analysis highlights residents' exposure to significant levels of PM₁₀ depicted with 28 discrete receptors in all directions. The circulation of polluted windy air masses substantially impacts regional air quality. The findings offer evidence-based recommendations for strategic mitigation measures targeted at residents, policymakers, stakeholders, and urban planners to address air quality issues arising from industrial mining activities. [ABSTRACT FROM AUTHOR]