Abstract

This study assessed the risks of air pollution in the city of Dakar. The objective is to evaluate the concentration levels of the pollutants measured in different sites of the Air Quality Management Center (CQA) of Dakar. The study took place between January and August 2013 and is divided into three phases or measurement campaigns. The first step consisted of continuous and real-time measurements of the different types of pollutants using automatic analysers that are specific to them in different zones, defined according to the kind of pollution (Urban, Traffic-related, or Industrial). In the second phase, the pollutants were transmitted under controlled conditions to the CGQA laboratory by varying the levels of concentrations reached for each of the pollutants studied. In the third phase, the analysis should be compared to the regulatory threshold values for health protection, which are NS-05-062 and WHO. The results showed that there is excellent seasonal variability in the concentrations of some pollutants studied, especially the suspended particles (PM10 and PM2.5). The analysis of variance revealed that the first two measurement campaigns (January-June) were the most affected by these pollutants, this is explained by a high concentration of dust in the air emanating from the North, mainly from the Sahara, which has a significant effect on recorded concentration peaks, but also due to weather phenomena during this study period. The quality of the air is appreciated through a global index for the city of Dakar. The evolution of this index shows a medium to poor air quality during the dry season (January-June) and good air quality at the heart of the rainy season (July-August).

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