Estimating Plume Emission Rate and Dispersion Pattern from a Cement Plant at Yandev, Central Nigeria

Cement production at Yandev, Nigeria commenced in 1980 without an environmental impact assessment to ascertain the extent of damage production activities would bring to bear on the physical conditions of the host environment. This study was carried out to provide baseline data on the rate and pattern of plume rise from the factory. Field survey was employed for primary data collation, while secondary data (climatic and factory data) were acquired from NIMET Makurdi Office and Dangote Cement Plc. Plume rate was estimated using the Gaussian (Mathematical) Model; Kriging, using Arc GIS, was adopted for modelling the pattern of plume dispersion. ANOVA and HSD's Tukey test were applied for statistical analysis of the plume coefficients. The results indicate that plume dispersion is generally high with highest values recorded for the atmospheric stability classes A and B, while the least values are recorded for the atmospheric stability classes F and E. The variograms derived from the Kriging (spatial correlational analysis) reveal that the pattern of plume dispersion is outwardly radial and omni-directional. With the exception of 3 stability sub-classes (DH, EH and FH) out of a total of 12, the 24-hour average of particulate matters (PM10 and PM2.5) within the study area is outrageously higher (highest value at 21392.3) than the average safety limit of 150 μg/m 3 - 230 μg/m 3 prescribed by the 2006 WHO guidelines. This indicates the presence of respirable and non-respirable pollutants that create poor ambient air quality. The study concludes that the environmental compliance status of Dangote Cement Plc, Yandev towards attaining sustainability for the host communities and physical environment is far from meeting the target requirement as spelt by the Millennium Development Goals No. 7. The study recommends ameliorative measures including periodic environmental audits; and adoption of technologies that would reduce the rate of plume emission.