Evaluation of the Downwind Dispersion of Gaseous Emissions from Cement Milling and Grinding Facilities in Athi River, Machakos County, Kenya

Cement manufacturing results in the release of gaseous emissions, which cause air pollution. Air pollution affects human health. In this study, two cement grinding and milling facilities in Athi River, Machakos County, in Kenya, were selected to determine the downwind dispersion of flue gases (CO, CO2, SO2 and NOx) emitted into the environment using AERMOD software. Cement Factory 1 (CF1) contained one sampling point (Stack 1) and Cement Factory 2 (CF2) contained two points (Stacks 2a and 2b). The sampling procedures were based on the Environmental Protection Agency (EPA) standard methods. Unlike CO2, the modelling results showed that the maximum peak concentrations of CO, SO2 and NOx were below the permissible limits under the EMCA 2014 and WHO Air Quality Guidelines 2021. The 8-hour and 1-hour mean maximum concentration was 8.809±1.570 mg/m3 and 32.715±4.362 mg/m3, respectively. Both stack 2a and 2b recorded negligible concentrations of CO, SO2 and NOx.