Estimation and Prediction of AtmosphericPollutants Coming from Vehicles: Case ofYaounde City from 2005 to 2035

摘要

Aims: The aim of the present work is to estimate and to predict the pollutant concentrations coming from vehicles in Yaounde city. Study Design: A sample of vehicles was selected and experimental measurements of pollutants were made using a combustion analyser.Place and Duration of Study: October 2012 to June 2013 in the University of Yaounde I, National Advanced School of Engineering, and the Energizing and Water and Environment Laboratory, Yaounde, Cameroon.Methodology: We used, for this study, the statistical data, from the National institute of Statistics, concerning the importation of vehicles in Cameroon estimated at 312,259 in 2005. The measurements of pollutant concentrations in gas, coming from a sample of 218 vehicles, were made using a combustion analyser. Using the statistical data obtained, the correlation of the evolution of importation of vehicles in Cameroon was established following the case of Yaounde city. The evolution of the number of vehicles, the measurements of pollutant concentrations and the quantities of fuel consumed were used to estimate the pollutant concentrations, during the emergence prediction year 2035 in Yaounde city, representing a population of 1.82 million inhabitants. Analysed atmospheric pollutants, for motor vehicle exhausts, were carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxide (NOx) and hydrocarbon (HC).Results: Until 2005, the estimate of the pollutant concentrations coming from vehicles in Yaounde city showed that the average quantities emitted every year were 82.26×106 kg of CO2, 1.16×106 kg of CO, 2.35×106 kg of HC and 9.18×106 kg of NOx. According to the provision alem ergence in the year 2035, the quantities of the four pollutants would attain the following values: 472×106 kg of CO2, 6.65×106 kg of CO, 13.51×106 kg of HC and 52.72×106 kg of NOx.Conclusion: The results obtained from this work are a useful tool to monitor the air pollution levels caused by urban transport.